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Text Truncated. Only the first 1MB is shown below. Download the file for the complete contents. 4DOS (r) 4OS2 (tm) 4DOS for Windows NT Reference Manual Developed By Rex Conn and Tom Rawson Documentation By Hardin Brothers, Tom Rawson, and Rex Conn Published By JP Software Inc. P.O. Box 1470 East Arlington, MA 02174 U.S.A. (617) 646-3975 fax (617) 646-0904 ACKNOWLEDGMENTS We couldn't produce products like 4DOS, 4OS2, and 4DOS/NT without the dedication and quality work of many people. Our thanks to: JP Software Staff: Mike Bessy, Bobby Kelley, Ellen Stone, Marcella Turner, Misty White. Online Support: Brian Miller and Tess Heder of Channel 1 BBS; Don Watkins of CompuServe's IBMNET. Beta Test Support: David Moskowitz and the sysops of CompuServe's CONSULT forum. Beta Testers: We can't list all of our beta testers here! A special thanks to all of you who helped make 4DOS, 4OS2, and 4DOS/NT elegant, reliable, and friendly. The following tools are used in creating and maintaining 4DOS, 4OS2, and 4DOS/NT: Compilers: Microsoft C, Microsoft Macro Assembler, IBM C-Set/2, Borland Turbo Pascal Libraries: Spontaneous Assembly (Base Two Development), Turbo Professional (Turbo Power Software) Editors: Edix (Emerging Technology), Brief (Solution Systems) Debuggers: Periscope (The Periscope Company), Soft- ICE (Nu-Mega Technologies) Version Control: PVCS (Sage Software) Documentation: Microsoft Word for Windows with Adobe Type Manager Program and Documentation Copyright c 1988 - 1994, JP Software Inc., All Rights Reserved. 4DOS is a registered trademark and 4OS2, JP Software, and the JP Software logo and product logos are trademarks of JP Software Inc. Other product and company names are trademarks of their respective owners. 10-94 CONTENTS ------------------------------------------------------------------- CONTENTS Introduction...............................................1 How to Use This Manual.................................2 Registration and Upgrade Information...................6 Technical Support......................................7 Chapter 1 / General Concepts..............................10 Operating Systems and Command Processors..............10 Primary and Secondary Shells......................12 Files and Directories.................................13 Drives and Volumes................................14 File Systems......................................14 Directories and Subdirectories....................15 File Names........................................16 File Attributes...................................18 Internal and External Commands........................19 Executable Files and File Searches....................20 The Environment.......................................21 ASCII and Key Codes...................................22 The Keyboard..........................................23 Video.................................................24 ANSI Drivers..........................................25 Chapter 2 / Conventions...................................26 Colors and Color Names................................26 Blinking Text and Bright Background Colors........28 Color-Coded Directories...............................30 Keys and Key Names....................................31 Chapter 3 / Using 4DOS, 4OS2, and 4DOS/NT.................34 At the Command Line...................................34 Command-Line Editing..............................35 Command History and Recall........................36 Local and Global Command History..................39 Command History Window............................40 Filename Completion...............................41 Filename Completion Window........................42 Directory Changes and CDPATH......................43 Directory History Window..........................45 Local and Global Directory History................45 Automatic Directory Changes.......................47 Multiple Commands.................................47 Temporarily Disabling Aliases.....................48 Command Line Help.................................48 Command-Line Length Limits........................50 Page and File Prompts................................ 50 Critical Errors.......................................51 Input and Output......................................52 ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / i CONTENTS ------------------------------------------------------------------- Redirection.......................................52 Piping............................................55 Keystack..........................................57 File Selection........................................58 Extended Parent Directory Names...................59 Wildcards.........................................59 Date, Time, and Size Ranges.......................62 Multiple Filenames................................66 Include Lists.....................................67 Executable Extensions.............................68 Advanced Features.....................................71 Conditional Commands..............................71 Command Grouping..................................71 Escape Character..................................73 4DOS, 4OS2, and 4DOS/NT Compatibility.................74 Chapter 4 / Aliases and Batch Files.......................77 Aliases...............................................77 Batch Files...........................................80 .BAT, .CMD, and .BTM Files........................80 Echoing...........................................81 Batch File Parameters.............................81 Batch File Commands...............................83 Interrupting a Batch File.........................85 Automatic Batch Files.............................85 Detecting 4DOS, 4OS2, or 4DOS/NT..................86 Using Aliases in Batch Files......................87 Debugging Batch Files.............................89 Batch File String Processing......................91 Batch File Compression............................93 REXX Support......................................95 EXTPROC Support...................................96 Using the Environment.................................96 Configuration Variables...........................98 Internal Variables...............................100 Variable Functions...............................108 Command Parsing......................................121 Argument Quoting.................................123 Chapter 5 / Configuration................................126 Using the .INI File..................................126 .INI File Directives.................................127 Types of Directives..............................130 Initialization Directives........................131 Configuration Directives.........................136 Color Directives.................................141 Key Mapping Directives...........................143 Advanced Directives..............................148 Examples.........................................151 ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / ii CONTENTS ------------------------------------------------------------------- Chapter 6 / Command Reference Guide......................153 Command Categories...................................154 How to Use the Command Descriptions..................155 ?....................................................159 ACTIVATE.............................................160 ALIAS................................................161 ATTRIB...............................................173 BEEP.................................................176 BREAK................................................177 CALL.................................................179 CANCEL...............................................180 CD / CHDIR...........................................181 CDD..................................................183 CHCP.................................................184 CLS..................................................185 COLOR................................................186 COPY.................................................187 CTTY.................................................194 DATE.................................................195 DEL / ERASE..........................................196 DELAY................................................200 DESCRIBE.............................................201 DETACH...............................................203 DIR..................................................204 DIRS.................................................214 DO...................................................215 DPATH................................................218 DRAWBOX..............................................219 DRAWHLINE............................................221 DRAWVLINE............................................222 ECHO.................................................223 ECHOS................................................225 ENDLOCAL.............................................226 ESET.................................................227 EXCEPT...............................................229 EXIT.................................................231 FOR..................................................237 FREE.................................................242 GLOBAL...............................................243 GOSUB................................................245 GOTO.................................................246 HELP.................................................248 HISTORY..............................................249 IF...................................................251 IFF..................................................257 INKEY................................................259 INPUT................................................262 KEYBD................................................264 KEYS.................................................265 KEYSTACK.............................................266 ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / iii CONTENTS ------------------------------------------------------------------- LH / LOADHIGH........................................269 LIST.................................................272 LOADBTM..............................................276 LOG..................................................277 MD / MKDIR...........................................279 MEMORY...............................................280 MOVE.................................................282 MSGBOX...............................................287 ON...................................................288 PATH.................................................290 PAUSE................................................293 POPD.................................................294 PROMPT...............................................295 PUSHD................................................299 QUIT.................................................301 RD / RMDIR...........................................302 REBOOT...............................................303 REM..................................................305 REN / RENAME.........................................306 RETURN...............................................309 SCREEN...............................................310 SCRPUT...............................................312 SELECT...............................................313 SET..................................................319 SETDOS...............................................322 SETLOCAL.............................................329 SHIFT................................................330 START................................................331 SWAPPING.............................................339 TEE..................................................340 TEXT.................................................342 TIME.................................................343 TIMER................................................344 TITLE................................................346 TRUENAME.............................................347 TYPE.................................................348 UNALIAS..............................................350 UNSET................................................351 VER..................................................352 VERIFY...............................................353 VOL..................................................354 VSCRPUT..............................................355 WINDOW...............................................357 Y....................................................358 Appendix A / Error Messages..............................359 Appendix B / ASCII and Key Codes.........................371 Keys and Key Codes...................................375 ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / iv CONTENTS ------------------------------------------------------------------- Glossary.................................................381 Index....................................................393 Quick Reference..........................................407 Internal Variables...................................407 Variable Functions...................................408 .INI File Directives.................................409 ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / v CONTENTS ------------------------------------------------------------------- CONTACTING JP SOFTWARE You can contact JP Software at any of the following addresses. Our normal business hours are 9:00 AM to 5:00 PM weekdays, eastern US time. For more information about contacting us for technical support, see page 7. By mail: JP Software Inc. P.O. Box 1470 East Arlington, MA 02174 USA By telephone / fax: Voice: (617) 646-3975 Fax: (617) 646-0904 Order Line: (800) 368-8777 (orders only, USA only) Electronically: CompuServe: Customer Service 75020,244 Technical Support, GO JPSOFT or GO PCVENB (section 10), User ID 75300,1215 Internet: Customer Service 75020.244@compuserve.com Technical Support 75300.1215@compuserve.com BBS Support: Via Channel 1 BBS, Boston, 617-354-5776 at 2,400 - 14,400 baud, no parity, 8 data bits, 1 stop bit ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / vi INTRODUCTION ------------------------------------------------------------------- INTRODUCTION Welcome to our Reference Manual. We have designed this manual to accompany three of our products: 4DOS, 4OS2, and 4DOS for Windows NT. Technically, each of these programs is a command interpreter or "shell." That means that they respond to the commands you type at the C:\> or [C:\] prompt. Each is designed to replace the default command interpreter that was supplied with your operating system: 4DOS replaces COMMAND.COM from DOS 4OS2 replaces CMD.EXE from OS/2 4DOS/NT replaces CMD.EXE from Windows NT 4DOS can also be used as the command interpreter for DOS sessions running under OS/2, and under Windows 3.0 and above. Each of our products is highly compatible with the command interpreter that it replaces. That means that you don't have to change your computing habits or unlearn anything to use any of these products. Each also adds many new features and commands to its operating environment. They make the operating system friendlier, easier to use, and much more powerful and versatile, without requiring you to learn a new program, a new set of commands, or a new style of work. Each product is shipped with this manual plus a smaller Introduction and Installation Guide. Please start with the smaller manual. It will tell you how to get started with the product you purchased and also contains some other information that applies specifically to that product. Once you have installed 4DOS, 4OS2, or 4DOS for Windows NT, you can learn its features at your own pace. Relax, enjoy the power of your new program, and browse through both manuals occasionally. Press the F1 key whenever you need help. The program will soon become an essential part of your computer, and you'll wonder how you ever got along without it. If you are a new user and want to take your new program for a spin without performing a complete installation, see the Guided Tour pamphlet included with your copy of 4DOS, 4OS2, or 4DOS/NT. We are constantly working to improve these programs. If you have suggestions for features or commands that you think we ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 1 INTRODUCTION ------------------------------------------------------------------- should include in the next version, or any other way we could improve our product, please let us know. Many of the improvements in this version were suggested by our users, and while we can't promise to include every suggested feature, we really do appreciate and pay attention to your comments. How to Use This Manual This manual covers three separate products: 4DOS, 4OS2, and 4DOS for Windows NT. We have combined reference information for the products in one manual because 4DOS, 4OS2, and 4DOS for Windows NT offer almost exactly the same features and commands, so individual manuals would be almost identical. Many of our customers use more than one of these products; they find that a single manual helps them understand the similarities and differences of the three products. In addition, printing a single manual reduces our costs and lets us bring you the most powerful command interpreters available for the lowest possible price. Most of this manual describes commands and features which are available in all three products. When we need to discuss the features or behavior of a single product, we mention it specifically in the text. When an entire paragraph or section applies to a specific product, we use marginal text to identify that product: 4DOS marks sections that apply only to 4DOS. 4OS2 marks sections that apply only to 4OS2. 4NT marks sections that apply only to 4DOS for Windows NT. For brevity, we often refer to this product as "4DOS/NT", or by the actual program name, "4NT", in this manual. Occasionally, a feature will be marked with two of these marginal notations when it applies to two different products. We have designed this manual to serve as a gentle introduction to our products for novice users and as a reference manual for advanced users. You will likely find some parts of the manual too simple or too technical for your tastes. Unless you are convinced that one of those sections holds just the information you need for a specific task, feel free to skip to the next part of the manual that is more to your liking. You can use almost every feature of our products without having to worry about other features or commands. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 2 INTRODUCTION ------------------------------------------------------------------- As you read the manual, you will occasionally see an exclamation point [!] next to a paragraph. The exclamation point means that that paragraph contains a caution or warning you should observe when using the feature it discusses. You will also see the symbol ## next to certain paragraphs. This indicates an in-depth discussion or a more advanced topic which you can skip if you wish to stick with the basics. Come back to this topic later for more details, or if you're having trouble with the particular issue it discusses. If you see the ## next to a section heading, it means the entire section contains such information. You may find the information in such marked sections useful even if you're relatively new to computers or to our products. However, you can also skip the marked section and still understand and use the basic topic of the larger section you're reading. This manual is divided into six chapters and two appendices, plus a glossary and index. Here's a brief overview of what you'll find in each: Chapter 1 / General Concepts This chapter is an introduction to several terms and concepts that we use throughout the manual. If you're a novice, you might want to browse through the entire chapter. If you're a power user and all of the topics in this chapter seem simple, then go on to the next chapter. If you think you need to brush up a bit on the basics of a couple of terms and ideas, you'll probably find them here. Chapter 2 / Conventions and Restrictions This chapter contains information about three conventions that are used throughout 4DOS, 4OS2, and 4DOS/NT: colors and color names, color-coded directories, and keys and key names. You'll find many references in the manual to the information in this chapter. You may choose to read through this chapter to see what is available, or refer to the topics here when you come to a cross reference later in the manual. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 3 INTRODUCTION ------------------------------------------------------------------- Chapter 3 / Using 4DOS, 4OS2, and 4DOS/NT This chapter is for everyone. It contains a description of 4DOS, 4OS2, and 4DOS/NT features, and lots of examples to help you learn to use each one. Even if you are a novice user and want to ignore some of these features until later, skim through this chapter to get an idea of what is available and where to find the information that you will eventually want. Our products offer both features which are not related to specific commands, and a complete set of over 80 internal commands. This chapter has complete reference information on most of the non-command features. Reference information on commands is in Chapter 6. Chapter 4 / Aliases and Batch Files This chapter introduces two of the most powerful features in 4DOS, 4OS2, and 4DOS/NT: Aliases and Batch Files. You can use both to automate much of your computing work. Even if you are a novice user, you should skim through this chapter to see what is available. This chapter also contains information about using environment variables, and the internal variables and variable functions that make aliases and batch files extremely powerful and flexible. Chapter 5 / Configuration This chapter is for advanced users who want to be sure that 4DOS, 4OS2, or 4DOS/NT is running at top efficiency on their systems. It includes detailed information on setting up your command processor and on changing its configuration. Chapter 6 / Command Reference Each of our products offers over 80 internal commands. This chapter explains the purpose of each command and tells you how to use it. It has examples that will help you learn each command and the technical details you will need to get the command to behave exactly as you wish. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 4 INTRODUCTION ------------------------------------------------------------------- Appendices We've included some helpful tables here, as well as information for those who like to know technical details. There are two appendices. Appendix A lists all error messages. Look here if you need an explanation of an error message, or if you aren't sure if the message came from 4DOS, 4OS2, or 4DOS/NT. Appendix B lists codes for the ASCII character set (your computer's internal method for representing letters, digits, and other characters) and for the keys on your keyboard. These codes can be useful with certain commands. Glossary If you need help with any of the terminology in this manual, look here. Index If you can't find the information you need, this should help you find it. Quick Reference This quick index will give you the page number for detailed information on each internal variable, variable funtion, and .INI file directive. Additional Files Files distributed with 4DOS, 4OS2, and 4DOS/NT cover important additional information beyond what's included in this manual. README.DOC contains general notes, highlights of the latest release, and brief installation instructions for those upgrading from a downloaded copy of 4DOS, 4OS2, or 4DOS/NT. MANMOD.DOC covers changes or corrections in the manual, if any, and UPDATxxx.DOC contains detailed information for users with older versions on what has changed in the latest release ("xxx" is the version number). For 4DOS users we also include APPNOTES.DOC, which contains application notes for a ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 5 INTRODUCTION ------------------------------------------------------------------- variety of other software packages to help you use those packages with 4DOS. Registration and Upgrade Information If you purchased 4DOS, 4OS2, or 4DOS/NT from a software dealer, your copy came with a registration card. Please fill out this card and return it promptly to JP Software. It ensures that we have a record of your registration so that we can give you ongoing technical support and notices of upgrades. If you purchased 4DOS, 4OS2, or 4DOS/NT directly from JP Software, you are already registered and no registration card is necessary. Once you are a registered user, you will receive: * A subscription to The Prompt Solution, JP Software's customer newsletter. The Prompt Solution includes tips for using 4DOS, 4OS2, and 4DOS/NT; notification of upgrades; and information about other products from JP Software. * Technical support via electronic mail, fax, mail, or telephone. * A downloadable upgrade to the next version of 4DOS; see below for details. 4DOS, 4OS2, and 4DOS/NT are upgraded regularly through maintenance releases, designed to fix minor problems or improve compatibility, and major upgrades which contain enhancements and additional features. Maintenance releases are identified by a change in the hundredths digit of the version number, for example from 5.0 to 5.01 or 5.02. Major upgrades are identified by a change in the tenths digit or "ones" digit, for example from 5.0 to 5.1 or 6.0. Major upgrades can be purchased from JP Software or your dealer for a modest charge. For most users the first major upgrade released after your initial purchase is available at no charge if you download it from one of our support areas (see below). You can also download maintenance releases from one of the support areas, or order them on disk at a nominal cost. As a registered user, you will automatically be notified when a major upgrade is released. We don't send out notices when maintenance releases become available, because you don't usually need them unless you're having a problem. If you call ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 6 INTRODUCTION ------------------------------------------------------------------- with a problem that's been addressed in a maintenance release, we'll mail you a copy on disk or assist you in downloading it. As a registered user, you can download maintenance releases and your first major upgrade from the JP Software support area on CompuServe (GO PCVENB, library 10), or Channel 1 (see below). If you are familiar with the Internet, you can also obtain JP Software files via anonymous ftp from the 4DOS directory on simtel20 or any of its mirrors. The file names used for updates vary from time to time depending on the extent of the changes made, but typically will look like 4DOS5*.ZIP, 4OS22*.ZIP, etc. The "*" refers to one or more characters further identifying the file. .ZIP files are "archives" which contain many other files within them. The files stored inside the .ZIP file are compressed for more efficient downloads. To decompress the .ZIP file and gain access to the actual 4DOS, 4OS2, or 4DOS/NT files you will need the PKUNZIP program or an equivalent. Such programs are available from the same source as the .ZIP files themselves. Check the directory listings and file descriptions on the service you are using to identify the files you need. Downloads are also available from many other local bulletin boards and online services. Lists of download locations, including bulletin boards outside the USA, are published from time to time in The Prompt Solution and are included in the SUPPORT.BBS file that comes with each product. We offer BBS support through Channel 1 in Boston, one of the largest and best-run bulletin boards in the US. Channel 1 is an independent bulletin board and is not owned or operated by JP Software. To access Channel 1 set your modem to any speed from 2,400 to 14,400 baud, no parity, 8 data bits, and 1 stop bit, and dial 617-354-5776. Join conference 5 for 4DOS downloads. You can leave support messages and download files at no charge, but if you want to use any of Channel 1's other excellent services you may need to purchase a membership to have sufficient online time. Technical Support Technical support is available via public electronic support conferences, private electronic mail, telephone, fax, and mail. When you contact us for support please give us your serial number so that we can verify your status as a customer, keep track of your inquiry, and contact you if necessary. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 7 INTRODUCTION ------------------------------------------------------------------- Often the best way to contact us for support is in one of the following public electronic support conferences. The numbers in parentheses indicate the usual delay, in business days, to receive a reply to a message. CompuServe / ZiffNet: Primary support is via the JP Software section of the CompuServe PCVENB forum (GO JPSOFT or GO PCVENB, section 10, "JP Software") (1 day). Bulletin Boards: Primary support is via the Channel 1 BBS, Boston, MA (1 - 3 days; see above for access details). Messages may be left in any of the 4DOS conferences; check the online list for exact conference numbers. Support is also available from many local BBSes via the 4DOS conferences on the RIME, ILink, SmartNet, and FidoNet BBS Networks (3-5 days). To contact JP Software for support by mail, telephone, fax, or electronic mail, see our addresses and phone numbers on page vi of this manual. If you call for support and no technical support representative is available, we will do our best to return your call within 24 hours (weekends and holidays excluded). If your problem is urgent and requires a faster response, please let us know and we will try to accommodate you. If you contact us by telephone and don't receive a reply within 24 hours, please try again. We may have tried to return your call and been unable to reach you. Before contacting us for support, please check the manuals and other documentation for answers to your question. If you can't find what you need, try the Index. If you're having trouble getting 4DOS, 4OS2, or 4DOS/NT to run properly, either alone or with your particular hardware or software, see the Introduction and Installation Guide, and (for 4DOS) the APPNOTES.DOC file on your disk. Also look through the README.DOC and UPDATxxx.DOC files, as they may contain updates to this manual or other important information ("xxx" is the version number). If you do need to contact us for support, it helps if you can give us some basic information: * What exactly did you do? A concise description of what steps you must take to make the problem appear is much more useful than a long analysis of what might be happening. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 8 INTRODUCTION ------------------------------------------------------------------- * What went wrong? At what point did the failure occur? If you saw an error message or other important or unusual information on the screen, what exactly did it say? * Briefly, what techniques did you use to try to resolve the problem? What results did you get? * What computer and operating system are you using? * Are you running a network, or using a particular operating environment (such as DESQview or Windows)? * What are the contents of any startup files you use (such as CONFIG.SYS, AUTOEXEC.BAT, 4START, 4EXIT, and the .INI file), any batch files they call, and any alias or environment variable files they load? * Can you repeat the problem or does it occur randomly? If it's random, does it seem related to the programs you're using when the problem occurs? ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 9 CHAPTER 1 / GENERAL CONCEPTS ------------------------------------------------------------------- CHAPTER 1 / GENERAL CONCEPTS You can start using 4DOS, 4OS2, or 4DOS/NT as soon as you finish installing it, because each of our products is compatible with the traditional commands you're used to. But most users find that the more they know about their computer systems, the more power they get from our products. And, the more experience they gain, the more they want to know about their computer system as a whole. This section of the manual explains some fundamental concepts about your computer, operating system, and 4DOS, 4OS2, and 4DOS/NT. It should help you understand the terms and concepts in the pages that follow. If you find some of the concepts overwhelming, just remember that they are here when you need them. If you find this material too simple, skim over the topics and then go on to the next section. Each topic in this chapter is independent, so if you read it straight through you won't necessarily find a natural "flow" from one topic to another. If you come across terms or concepts in this chapter that you are unsure about, refer to the Glossary on page 381 or the Index. Operating Systems and Command Processors This section explains briefly what an operating system is, what a command processor is, and how the command processor works under DOS, OS/2, and Windows NT. An operating system is nothing more than a collection of software. However, unlike application software, which performs a specific, user-oriented task (such as creating and printing documents, or performing calculations on rows and columns of numbers), operating system software is designed to perform some special functions. The operating system typically: * Starts the computer system. The operating system is the first software loaded when you turn on the computer. * Provides services to other software. These include basic file access, assignment of your computer's memory for use by different programs, and the control of hardware devices like the keyboard, display, printer, and serial ports. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 10 CHAPTER 1 / GENERAL CONCEPTS ------------------------------------------------------------------- * Ensures that programs don't interfere with each other while they are running. * Provides a way for you to start programs to do your work. * Includes utilities to control and manage your system, for example to organize disks and files, display status information, or adjust your system for international conventions. More complex operating systems may include many more functions, such as built-in network connections, the ability to switch rapidly between many tasks, support for high-quality sound output, and so on. Our products run under the DOS, OS/2, and Windows NT operating systems. Each of these operating systems includes a command processor: a program that accepts your instructions and carries them out. The basic operation of a command processor is very simple: It prompts you for a command, you type in the command, the command processor executes it, and the cycle repeats. This sometimes called a "command line" interface, because commands are typically executed line by line. Under DOS, the command-line interface is the only way to tell the operating system what you want it to do. OS/2 and Windows NT each include a graphical user interface that is intended to replace the command line as the primary method for providing instructions to the operating system. However, most OS/2 and Windows NT users find that the command line is required for some tasks, and much more efficient for many others. They therefore use both the graphical interface and the command line, depending on the task at hand. The command processor shipped with DOS is called COMMAND.COM. The command processors shipped with OS/2 and Windows NT are both called CMD.EXE. When you install 4DOS, 4DOS.COM replaces COMMAND.COM as your command processor. 4OS2 replaces the OS/2 version of CMD.EXE with 4OS2.EXE, and 4DOS/NT replaces the Windows NT version of CMD.EXE with 4NT.EXE. All of these command processors are normal programs that know how to translate your commands into actions. 4DOS, 4OS2, and 4DOS/NT are simply much more powerful command processors than those supplied with each operating system. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 11 CHAPTER 1 / GENERAL CONCEPTS ------------------------------------------------------------------- 4DOS Under DOS, the command processor is started automatically at the end of the boot process. If you don't want to use COMMAND.COM as your command processor, you use the SHELL statement in CONFIG.SYS to specify a different command processor. 4OS2 Under OS/2, the command processor is started whenever you select the appropriate object on your OS/2 desktop. If you don't want to use CMD.EXE as your command processor, you use the SET OS2_SHELL statement in CONFIG.SYS to specify a different command processor. Because OS/2 includes the ability to run DOS programs, it also includes a copy of COMMAND.COM as its default DOS command processor. You can change to a different DOS command processor with the SHELL statement in the OS/2 CONFIG.SYS file. 4NT Under Windows NT, there is no CONFIG.SYS file, and no special way to specify a default command processor. Instead, you simply create a desktop object for any command processor you want to use. Primary and Secondary Shells Technically, the command processor is a shell: a program that understands your commands and makes the correct calls to the underlying operating system to perform various tasks, including running programs. 4DOS Under DOS, the command processor that runs when the computer boots up, or when an OS/2 DOS session starts, is called the primary shell. Any command processor that is started as a "child" to a primary shell is a secondary shell. Typically, secondary shells are started by application programs with a "shell to the command prompt" feature, and by multitasking environments like Windows or DESQView. A secondary shell has most of the same features as a primary shell. There are a few differences between primary and secondary shells under DOS. Generally, less memory is available when a secondary shell is running, because at least part of the program that started it is still in memory waiting to spring back to life when you exit. And normally only the primary shell automatically executes the instructions in your AUTOEXEC.BAT file. Under DOS you can leave a secondary shell with the EXIT command, but there is normally no way to exit from the primary ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 12 CHAPTER 1 / GENERAL CONCEPTS ------------------------------------------------------------------- shell, because DOS requires a shell present to operate. However, if you are running 4DOS in a DOS session under OS/2 version 2.0 or later you can use EXIT in the primary DOS shell to close the session and return to the OS/2 desktop. 4OS2, Under OS/2 and Windows NT, each 4OS2 or 4DOS/NT session that 4NT is started from the desktop is a primary shell. Secondary shells are started by applications with a "shell to the command prompt" feature, and are also used for a special kind of communication between programs called a pipe (see page 55). Under 4OS2 and 4DOS/NT, you can exit from both primary and secondary shells. When you exit from a primary shell, the command processor session is closed and you are returned to the desktop. You may also see the term shell used to describe programs which assist you in managing your files (for example XTree or Lotus Magellan for DOS, or Norton Commander for OS/2). This is a different and less precise meaning of "shell" than the one used above and elsewhere in this manual. Such programs are also sometimes called "visual shells" because they use a menu or graphical interface to receive commands. Unlike 4DOS, 4OS2, and 4DOS/NT, these programs are not command processors, and cannot replace COMMAND.COM or CMD.EXE. Each time 4DOS, 4OS2, or 4DOS/NT starts as either a primary or secondary shell, it looks for and executes one or more "automatic" batch files. These files are explained on page . 85 Files and Directories You may have dozens, hundreds, or thousands of files stored on your computer's disks. Your operating system is responsible for managing all of these files. In order to do so, it uses a unique name to locate each file in much the same way that the post office assigns a unique address to every residence. The unique name of any file is composed of a drive letter, a directory path, and a filename. Each of these parts of the file's name is case insensitive; you can mix upper and lower case letters in any way you wish. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 13 CHAPTER 1 / GENERAL CONCEPTS ------------------------------------------------------------------- Drives and Volumes A drive letter designates which drive contains the file. In a file's full name, the drive letter is followed by a colon. Drive letters A: and B: are normally reserved for the floppy disk drives. (Systems with a single drive use both A: and B: for that drive. The operating system asks you to swap diskettes as necessary to turn that single physical drive into two separate logical disk drives.) Normally, drive C: is the first (or only) hard disk drive. Later versions of DOS, some DOS-based utility programs, and both OS/2 and Windows NT can divide a large hard disk into multiple logical drives or volumes that are usually called C:, D:, E:, etc. Also, the DOS and Windows NT utility SUBST lets you use drive letters as a substitute for directory names. Many network systems (LANs) use a similar feature to give drive letters to sections of the network file server drives. Some computers also have "RAM disks" (sometimes called "virtual disks"), which are areas of memory set aside by software (a "RAM disk driver") for use as fast but temporary storage. RAM disks are also assigned drive letters, typically using letters beyond that used by the last hard disk in the system, but before any network drives. For example, on a system with a large hard disk you might have A: and B: as floppy drives, C:, D:, and E: as parts of the hard disk, F: as a RAM disk, and G: and H: as network drives. File Systems Each disk volume is organized according to a file system. The file system determines how files are named and how they are organized on the disk. The DOS file system uses a File Allocation Table or FAT to keep track of each file, and therefore it is often called a FAT file system. Both OS/2 and Windows NT also include support for the traditional FAT file system. OS/2 also supports the High Performance File System or HPFS. Windows NT can work with HPFS disk volumes plus volumes formatted with its own file system, which is called NTFS. The file system type (FAT, HPFS, or NTFS) is determined when a hard disk volume is formatted and applies to the entire volume. For example, you might have a 200 MB hard disk divided into four 50 MB volumes, with the first three volumes (C:, D:, and E:) formatted for the FAT file system, and the fourth formatted for HPFS or NTFS. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 14 CHAPTER 1 / GENERAL CONCEPTS ------------------------------------------------------------------- When you are using DOS, only files on FAT volumes are visible and available. HPFS and NTFS volumes are completely inaccessible. If you boot your system under OS/2, you can access FAT and HPFS volumes, both from OS/2 itself and from DOS sessions running under OS/2 (DOS sessions can only access files with FAT-compatible names; see page 17 for details). If you boot under Windows NT, you can access FAT, HPFS, and NTFS volumes. 4NT Files on an NTFS volume have both a "long" and a "short" or FAT- compatible file name. You can view the short file name with the DIR /X command. If you use 4DOS/NT to COPY or MOVE files from an NTFS volume to a FAT volume, the files will saved with their short, FAT-compatible names. Beginning with version 3.5, Windows NT supports the use of long filenames even on FAT drives; see page 18 for additional details. 4OS2 Finally, OS/2 also supports installable file systems, which are installed with the IFS= directive in the OS/2 CONFIG.SYS file. The CD-ROM file system supplied with OS/2 2.x is an example of an installable file system, and many OS/2 networks are also implemented as installable file systems. Directories and Subdirectories A file system is a method of organizing all of the files on an entire disk or hard disk volume. Directories are used to divide the files on a disk into logical groups that are easy to work with. Their purpose is similar to the use of file drawers to contain groups of hanging folders, hanging folders to contain smaller manila folders, and so on. Every drive has a root or base directory, and many have one or more subdirectories. Subdirectories can also have subdirectories, extending in a branching tree structure from the root directory. The collection of all directories on a drive is often called the directory tree, and a portion of the tree is sometimes called a subtree. The terms directory and subdirectory are typically used interchangeably to mean a single subdirectory within this tree structure. Subdirectory names follow the same naming rules as files in each operating system (see below). However, under DOS it is best to use a name of 8 characters or less, without an extension, when naming subdirectories, because some application programs do not properly handle subdirectory names that have an extension. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 15 CHAPTER 1 / GENERAL CONCEPTS ------------------------------------------------------------------- The drive and subdirectory portion of a file's name are collectively called the file's path. For example, the file name C:\DIR1\DIR2\MYFILE.DAT says to look for the file MYFILE.DAT in the subdirectory DIR2 which is part of the subdirectory DIR1 which is on drive C. The path for MYFILE.DAT is C:\DIR1\DIR2. The backslashes between subdirectory names are required. The total length of a file's path may not exceed 64 characters in DOS, and on FAT volumes under OS/2 and Windows NT. (This limit excludes the file name and extension, but includes the drive letter and colon). On HPFS and NTFS volumes, the path and file name must each be 255 characters or less in length, and in addition the total length of the path and file name together cannot exceed 260 characters. The operating system and command processor remember both a current or default drive for your system as a whole, and a current or default directory for every drive in your system. Whenever a program tries to create or access a file without specifying the file's path, the operating system uses the current drive (if no other drive is specified) and the current directory (if no other directory path is specified). The root directory is named using the drive letter and a single backslash. For example, D:\ refers to the root directory of drive D:. Using a drive letter with no directory name at all refers to the current directory on the specified drive. For example, E:4DOS.DOC refers to the file 4DOS.DOC in the current directory on drive E:. There are also two special subdirectory names that are useful in many situations: a single period [.] by itself means "the current default directory." Two periods together [..] means "the directory which contains the current default directory" (often referred to as the parent directory). These special names can be used wherever a full directory name can be used. 4DOS, 4OS2, and 4DOS/NT allow you to use additional periods to specify directories further "up" the tree (see page 59). File Names Finally, each file has a filename. Under the FAT file system, the filename consists of a base name of 1 to 8 characters plus an optional extension composed of a period plus 1 to 3 more characters. You can use alphabetic and numeric characters plus the punctuation marks ! # $ % & ' ( ) - @ ^ _ ` { } and ~ in both the base name and the extension. Because the exclamation point [!], percent sign [%], caret [^], at sign [@], parentheses [()], and back-quote [`] also have other ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 16 CHAPTER 1 / GENERAL CONCEPTS ------------------------------------------------------------------- meanings to 4DOS, 4OS2, and 4DOS/NT, it is best to avoid using them in filenames. The HPFS file system, which can be used under OS/2 and Windows NT, allows file names with a maximum of 255 characters, including spaces and other characters that are not allowed in a FAT system file name, but excluding some punctuation characters which are allowed in FAT file names. See your operating system documentation for details on the characters allowed. If you use HPFS filenames which contain semicolons [;], see page 62 for details on avoiding problems with interpretation of the semicolon under 4OS2 and 4DOS/NT. The NTFS file system which can be used under Windows NT also allows file names with a maximum of 255 characters. HPFS and NTFS filenames, and all filenames under Windows NT 3.5 and above, are stored and displayed exactly as you entered them, and are not automatically shifted to upper or lower case. For example, you could create a file called MYFILE, myfile, or MyFile, and each name would be stored in the directory just as you entered it. However, case is ignored when looking for filenames, so you cannot have two files whose names differ only in case (i.e., the three names given above would all refer to the same file). This behavior is sometimes described as "case- retentive but not case-sensitive" because the case information is retained, but does not affect access to the files. Files stored on HPFS and NTFS volumes often have "FAT- compatible" names: names which contain only those characters legal on a FAT volume, and which meet the 8-character name / 3-character extension limits. Programs which cannot handle the long names supported by HPFS and NTFS (for example, DOS programs running under OS/2) generally can access files with FAT-compatible names. 4DOS 4DOS is compatible with FAT volumes. When running in a DOS session under OS/2, 4DOS can also access files on HPFS volumes and installable file system volumes (see below), provided the files have FAT-compatible names. Files on such volumes which do not have FAT-compatible names will be invisible to 4DOS. If an HPFS or NTFS-compatible file name includes spaces or other characters that would not be allowed in a FAT name, you must place double quotes around the entire name. For example, suppose you have a file named LET3 on a FAT volume, and you want to copy it to the LETTERS directory on drive F:, an HPFS partition, and give it the name Letter To Sara. To do so, use either of these commands in 4OS2 or 4DOS/NT: ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 17 CHAPTER 1 / GENERAL CONCEPTS ------------------------------------------------------------------- [c:\wp] copy let3 f:\LETTERS\"Letter To Sara" [c:\wp] copy let3 "f:\LETTERS\Letter To Sara" HPFS and NTFS do not explicitly define an "extension" for file names which are not FAT-compatible. However, the convention used by 4OS2 and 4DOS/NT (and by CMD.EXE) is to treat all characters after the last period in the file name as the extension. For example, the file name "Letter to Sara" has no extension, whereas the name "Letter.to.Sara" has the extension Sara. 4NT Beginning with version 3.5, Windows NT supports the use of long filenames even on FAT drives. 4DOS/NT will take this difference into account automatically under Windows NT 3.5 and above. For example, COPY will retain long filenames if possible when copying files to a FAT drive, and DIR will use the HPFS / NTFS display format which accommodates long filenames on all drives by default. As a result of this change in Windows NT, for compatibility 4DOS/NT assumes that all file and directory names retain their case under Windows NT 3.5 and above, even on FAT drives (normally this assumption is made only for HPFS and NTFS drives; see page 17 above for details). File Attributes Each file also has attributes which define characteristics of the file which may be useful to the operating system, to you, or to an application program. Attributes can be set with the ATTRIB command (see page 173) and viewed with the ATTRIB and DIR commands. Every time a program modifies a file, the operating system sets the Archive attribute, which signals that the file has been modified since it was last backed up. This can be used by 4DOS, 4OS2, or 4DOS/NT to determine which files to COPY, and by backup programs to determine which files to back up. When the Read-only attribute is set, the file can't be changed or erased; this can be used to protect important files from damage. The Hidden and System attributes prevent the file from appearing in normal directory listings. The DIR command (see page 204) has options which allow you to select filenames to view based on their attributes, to view the attributes themselves, and to view information about normally "invisible" hidden and system files. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 18 CHAPTER 1 / GENERAL CONCEPTS ------------------------------------------------------------------- When a file is created, and every time it is modified, the operating system records the system time and date in a time stamp in the file's directory entry. Several 4DOS, 4OS2, and 4DOS/NT commands and variable functions, and many backup and utility programs, use this time stamp to determine the relative ages of files. Internal and External Commands Whenever you type something at the command line and press the Enter key, you have given a command to the command processor, which must figure out how to execute your command. If you understand the general process that 4DOS, 4OS2, and 4DOS/NT use, you will be able to make the best use of them and their commands. The command processor begins by dividing the line you typed into a command name and a command tail. The command name is the first word in the command; the tail is everything that follows the command name. For example, in this command line: dir *.txt /2/p/v the command name is "dir", and the command tail is " *.txt /2/p/v." If the command name is not an alias (see page 77), the command processor tries to find the name in its list of internal commands. An internal command is one that the command processor can perform itself, without running another program. DIR and COPY are examples of internal commands. If the command name is not found in the command processor's list of internal commands, it assumes that it must find and execute an external command. This means that the command processor must load and run a separate program, either an executable program or a batch file. DOS, OS/2, and Windows NT are shipped with a number of external utility programs (such as FORMAT and DISKCOPY), and any program or application you install on your system becomes a new external command. The advantage of internal commands is that they run almost instantly. When you give an internal command, the command processor interprets the command line and carries out the necessary activities without having to look for, load, and run another program. The advantage of external commands is that they can be large, varied, and complex without taking space inside the system ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 19 CHAPTER 1 / GENERAL CONCEPTS ------------------------------------------------------------------- command processor. External commands can also be renamed or replaced easily. If you want to rename the external DOS command XCOPY to MYCOPY, for example, all you need to do is find the file called XCOPY.EXE on your DOS disk or directory and change its name to MYCOPY.EXE. If you want to replace XCOPY with a more efficient program, you can do so. 4DOS, 4OS2, and 4DOS/NT add this flexibility to internal commands. You can rename or replace any internal command by using an alias (see pages 77 and 161), and you can enable or disable internal commands whenever you wish (see SETDOS /I on page 324). Executable Files and File Searches Once the command processor knows that it is supposed to run an external command, it tries to find an executable file (one with a .COM or .EXE extension) whose name matches the command name. It runs the executable file if it finds one. (See the previous section for more information on external commands.) If the command processor cannot find an external program to run, it next looks for a batch file (a file with one or more commands in it) whose name matches the command name. 4DOS recognizes a file as a batch file if its extension is .BAT or .BTM. 4OS2 recognizes .CMD, .BTM, and .BAT as batch file extensions. It will run .CMD and .BTM files itself, and will start a DOS session to run .BAT files. 4DOS/NT can run batch files with a .BAT, .CMD, or .BTM extension. If the command processor finds such a file, it then reads each line in the file as a new command. If the search for a batch file fails, the command processor checks to see if the command name matches the name of a file with an extension that you have defined as executable. If a match is found, the command processor runs the program you specified when you defined the executable extension. (Executable extensions are used to associate file extensions with the specific program that processes a particular type of file; see page 68 for details). 4DOS, 4OS2, and 4DOS/NT first search for an executable program, a batch file, and a file with an executable extension in the current directory. If the command name doesn't match a .COM, .EXE, .BTM, .BAT or .CMD file or an executable extension in the current directory, the command processor repeats its search in every directory in your search path. The search path is a list of directories that the command processor (and some applications) search for executable files. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 20 CHAPTER 1 / GENERAL CONCEPTS ------------------------------------------------------------------- For example, if you wanted the command processor to search the root directory of the C: drive, the \DOS subdirectory on the C: drive, and the \UTIL directory on the D: drive for executable files, your search path would look like this: PATH=C:\;C:\DOS;C:\UTIL Notice that the directory names in the search path are separated by semicolons. You can create or view the search path with the PATH command (see page 290). You can use the ESET command (see page 227) to edit the path. Many programs also use the search path to find their own files. The search path is stored in the environment with the name PATH. Remember, the command processor always looks for an executable file or a file with an executable extension first in the current subdirectory, and then in each directory in the search path. (You can change the search order so the current directory is not searched first; see the PATH command for details.) If you include an extension as part of the command name, the command processor only searches for a file with that extension. For example, if you enter the command WP, 4DOS, 4OS2, or 4DOS/NT will search for any executable file whose base name is WP. However, if you enter WP.EXE as the command name, the command processor will search the current directory and each directory in your search path for WP.EXE, but will not look for files with other extensions. If the command processor cannot find an executable file, batch program, or a file with an executable extension in the current directory or any directory in the search path, it looks for an alias called UNKNOWN_CMD (see ALIAS on page 161 for details). If you have defined an alias with that name, it is executed. Otherwise, the command processor displays an "Unknown command" error message and waits for your next instruction. The Environment The command processor allows you to keep a list of information in memory. This list is called the environment. Every program receives a copy of the environment when it begins, and many programs use some of its information to configure themselves or to find files. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 21 CHAPTER 1 / GENERAL CONCEPTS ------------------------------------------------------------------- The environment is arranged as a series of variables and their related values. Each variable is a name stored in upper case. The name is followed by an equal sign [=] and some text. You can view the environment by typing SET, and add new entries or edit existing entries with the SET and ESET commands. You can erase entries in the environment with both the UNSET and SET commands. A typical environment entry looks like this: LIB=c:\lib In this example, the name of the variable is "LIB" and its value is "c:\lib". The text string or value can include any characters except nulls (ASCII 0). The format and meaning of each entry in the environment is up to the program that uses the particular variable. Environment variables can contain just about anything, and can be used for any purpose the author of a program desires. The "purpose" of the environment as a whole is simply to hold small amounts of text which programs can then access according to their own rules. Most environment variables are used by single programs for their own information; a few have well-defined meanings and are used by many different programs. 4DOS, 4OS2, and 4DOS/NT use several environment variables to control their own behavior. They also provide a wide range of facilities for manipulating and managing the environment. See "Using the Environment" beginning on page 96 for details about these special variables, the size of the environment, and other environment-related features. ASCII and Key Codes Internally, computers use numbers for everything. To represent the text that you type, a computer must translate each letter to and from a number. For all PC-compatible computers, the code used for this translation is called ASCII (American Standard Code for Information Interchange). ASCII codes are used both for the characters you type and for the characters that are displayed on the screen. The original ASCII code has 128 values for upper and lower case letters, numerals, punctuation marks, and control codes (control codes correspond to pressing the Ctrl key plus another character). Some control codes are represented on the keyboard with such keys as Tab, Enter, Backspace, and Esc. IBM, in its original PC, defined an additional 128 extended ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 22 CHAPTER 1 / GENERAL CONCEPTS ------------------------------------------------------------------- ASCII codes for math symbols, international characters, the line characters used to draw boxes, and some miscellaneous symbols. You can enter extended ASCII codes on the keyboard by holding down the Alt key while you type the code number on the numeric key pad. The symbol that the computer displays for each ASCII and extended ASCII code, and the code generated by each key on the keyboard, depends in part on the country and language support that your computer is configured to use. Through the use of code pages in DOS and OS/2, and the Registry in Windows NT, your computer can be configured for use in most countries. See your operating system documentation for more information about country and language support. Do not confuse extended ASCII with extended key codes. The latter include special codes that the computer generates when you press a function key, cursor key, or Alt plus a letter (see below). Those keys do not have any representation in either the ASCII or extended ASCII code systems. Another set of key codes, called scan codes, is discussed in the section on the keyboard below. Appendix B on page 371 has a complete list of ASCII, extended ASCII, and extended key codes. The Keyboard When you press a single key or a key combination on the keyboard, the computer translates your keystroke into two numbers. For all alphabetic, numeric, and punctuation keys, the Tab, Enter, Backspace, Esc keys and Ctrl plus an alphabetic key, these numbers are an ASCII code plus a scan code. The ASCII code represents the key's meaning; the scan code identifies which specific key was pressed. For example, many keyboards have two plus [+] keys, one above the equal sign and one on the numeric keypad. Both generate the same ASCII code, but they generate different scan codes. Keys which are not represented by ASCII codes are translated to an ASCII 0 plus an extended key code. These keys include the function keys, the cursor keys, and Alt plus a key. The extended key code for a key is generally the same as the scan code for that key. Some keys, like the Alt, Ctrl, and Shift by themselves or in combination with each other, plus Print Screen, SysReq, Scroll Lock, Pause, Break, Num Lock, and Caps Lock, do not have any code representations at all. The computer performs special ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 23 CHAPTER 1 / GENERAL CONCEPTS ------------------------------------------------------------------- actions automatically when you press these keys (for example, it switches your keyboard into Caps Lock mode when you press the Caps Lock key), and does not report the keystrokes to whatever program is running unless the program has been written specially to accept them. Appendix B has a complete list of ASCII and scan codes for the keys on most keyboards. Video 4DOS, 4OS2, and 4DOS/NT are "character-based" programs, which means they work in text mode on your computer. In text mode, the screen or window used by the program displays text in a single, fixed-pitch font (a font where every character is the same width), but cannot mix fonts or display graphics. All three command processors can run graphics programs which change your screen to graphics mode, but the screen must be returned to text mode whenever the command processor is active. In the early days of the IBM PC, text mode was a single, simple video operating environment. Today, advanced video boards and video software have created a wide range of text modes. The original IBM PC monochrome and CGA color video cards can display 80 columns and 25 rows of text. Newer, advanced video systems normally run in this 80 x 25 display mode but can also display more columns and rows. For example, EGA video cards can display 43 rows of text and VGA video cards can display 50 rows. With special driver programs, a VGA can display 60 rows or more and up to 132 columns of text. Each of these different screen configurations is a different text mode. In addition to running in a variety of text modes, 4DOS, 4OS2, and 4DOS/NT can run in "normal" full-screen mode or in a window inside a graphical environment such as the Windows or Windows NT desktop, or the OS/2 Workplace Shell. When they run in such a window, they are still operating in text mode. The underlying graphical environment translates their text commands into the appropriate graphics for your video display. 4DOS, 4OS2, and 4DOS/NT support whatever number of rows and columns of text you decide to use. They don't have commands to switch from one screen size to another - you will need to use the software that came with your computer or video board to do that - but they can read and work with the number of rows and columns on your screen. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 24 CHAPTER 1 / GENERAL CONCEPTS ------------------------------------------------------------------- ANSI Drivers 4DOS Every version of DOS includes a program called ANSI.SYS. This program lets you use text colors other than drab white on black, redefine keys, and control screen output. Commercial ANSI drivers are available as replacements for ANSI.SYS. The commercial programs usually include many new features, boost screen display speed dramatically, and support text displays that have more than 80 columns and 25 lines. In most cases, 4DOS automatically determines whether you have an ANSI driver installed (if the automatic determination does not work on your system you can set the ANSI state manually). If you do have an ANSI driver installed, 4DOS will use the driver to clear the screen and set screen colors. 4OS2 OS/2 includes ANSI support for character mode sessions. 4OS2 enables this feature when it starts, and assumes that it remains enabled. You can turn off ANSI support with OS/2's external ANSI command (ANSI.EXE). If you do, however, 4OS2 will not notice the change and will display unusual characters or ignore colors in your CLS and COLOR commands. 4NT There is no provision for ANSI support in Windows NT, and 4DOS/NT always assumes that no ANSI driver is present. Several 4DOS, 4OS2, and 4DOS/NT commands provide replacements for traditional ANSI commands. For example, there are commands to set the screen colors and display text in specific colors. These commands are easier to understand and use than the traditional ANSI control sequences. Some of these commands manipulate screen colors directly. Others use an ANSI driver if one is installed (under 4DOS) or expected (under 4OS2), but save you the work of figuring out complex ANSI control sequences. Any special interaction between 4DOS or 4OS2 and the ANSI driver is described in the documentation for each command. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 25 CHAPTER 2 / CONVENTIONS ------------------------------------------------------------------- CHAPTER 2 / CONVENTIONS This chapter contains information about three conventions that are used throughout 4DOS, 4OS2, and 4DOS/NT: colors and color names, color-coded directories, and keys and key names. These topics are combined here in a central reference spot so that they will be easy to find when you need to refer to them. You will find cross references to this chapter in several other parts of this manual. Colors and Color Names You can use color names in several of the directives in the .INI file and in many commands. The general form of a color name is: [BRIght] [BLInk] fg ON [BRIght] bg [BORder bc] where fg is the foreground or text color, bg is the background color, and bc is the border color. The available colors are: Black Blue Green Red Magenta Cyan Yellow White Color names and the words BRIght, BLInk, and BORder may be shortened to the first 3 letters. BORder is valid only in 4DOS and 4OS2. You can also specify colors by number instead of by name. The numbers are most useful in potentially long INI file directives like ColorDir. The following numbers are recognized: 0 - Black 8 - Gray (bright black) 1 - Blue 9 - Bright blue 2 - Green 10 - Bright green 3 - Cyan 11 - Bright cyan 4 - Red 12 - Bright red 5 - Magenta 13 - Bright magenta 6 - Yellow 14 - Bright yellow 7 - White 15 - Bright white Use one number to substitute for the [BRIght] fg portion of the color name, and a second to substitute for the [BRIght] bg portion. For example, instead of bright cyan on blue you could use 11 on 1 to save space in a ColorDir specification. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 26 CHAPTER 2 / CONVENTIONS ------------------------------------------------------------------- There are several subtleties that complicate the use of colors and color names. In order to understand them, you will need to read through the restrictions described below. You may also want to review the Video section in the previous chapter (see page 24). These restrictions are due to the design of your PC video hardware, BIOS, and video drivers, and are not inherent in 4DOS, 4OS2, or 4DOS/NT. Some of the restrictions are complex, so feel free to skip over those that do not apply to color combinations you use. Some restrictions depend on the display "mode." 4DOS, 4OS2, and 4DOS/NT can run in either normal display mode, when the command processor is using the full screen and has more direct control over the video hardware; or in windowed display mode, when the command processor appears in a window as part of a graphical display under Windows 3.x, OS/2, or Windows NT. Monochrome Video Adapters If you have a monochrome video adapter, you cannot display any colors except white and black in either normal or bright intensity. If you have a color video adapter, you can use any of the standard colors listed above (provided you meet the other restrictions below). Color Errors A standard color specification allows sixteen foreground and eight background colors (sixteen if bright backgrounds are enabled, see below). However, most video adapters and monitors do not provide true renditions of certain colors. For example, most users see normal "yellow" as brown, and bright yellow as yellow; many also see normal red as red, and "bright red" as pink. Color errors are often much worse when running in windowed mode (see above), because the graphical environment that created the window may not map the text-mode colors the way you expect. These problems are inherent in the monitor, video adapter, and driver software. They cannot be corrected using 4DOS, 4OS2, or 4DOS/NT color specifications. Border Colors In order to use border colors, you must have a color video adapter (monochrome adapters do not support border colors). 4NT 4DOS/NT does not support border colors, and will ignore the BORder keyword. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 27 CHAPTER 2 / CONVENTIONS ------------------------------------------------------------------- 4DOS, 4DOS and 4OS2 can only accept border colors in the CLS and COLOR 4OS2 commands, and in the StdColors directive in the .INI file. Border colors will be ignored, or will cause an error, if they are used elsewhere. Border colors do not work in windowed mode, and will be ignored if used in a windowed session under Windows or OS/2. Blinking Text and Bright Background Colors The interactions between blinking characters, bright backgrounds, and your display mode can be complex. You will need to understand them if you use either attribute in your color specifications. Bright background colors are only available if you have an EGA- or VGA-compatible display adapter. If you have a monochrome or CGA adapter, you can use blinking displays and ignore the interactions described below. The effects of blinking and bright background color specifications depend partly on whether you are in normal or windowed display mode. Normal Display Mode In normal, full-screen display mode your video hardware can be configured via software commands to display either blinking text, or text with a bright background, but not both. This is due to the design of PC video hardware, and is not a software restriction. The memory on your video adapter includes a "flag" for each character on the screen. The flag controls blinking text and bright background colors. If the flag is off, the character is displayed with a normal background and does not blink. If the flag is "on," the character either blinks or is displayed with a bright background, depending on which way your video adapter is currently configured. 4DOS, In normal display mode, the configuration of your video 4OS2 adapter can be controlled by 4DOS and 4OS2 with the BrightBG directive in the 4DOS.INI file (see page 141) or the SETDOS /B command (page 323). If you set BrightBG = No or use the SETDOS /B0 command, 4DOS and 4OS2 will configure the video adapter for blinking text, and characters with the blink / bright background flag set will blink. If you set BrightBG = ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 28 CHAPTER 2 / CONVENTIONS ------------------------------------------------------------------- Yes or use SETDOS /B1, 4DOS and 4OS2 will configure the video adapter for bright background colors, and the characters will be displayed with a bright background instead. 4NT BrightBG and SETDOS /B are not available under 4DOS/NT, because Windows NT always enables bright backgrounds and disables blinking text. Because there is only one flag for each character to specify both blinking text and bright background color, it doesn't matter which attribute you use when you specify the color. Whether you specify blinking text or a bright background, you will see the same thing on your screen. For example, these two COLOR commands will always produce the same results: color blink white on blue color white on bright blue If bright backgrounds are enabled, both commands will produce white text on a bright blue background. If blinking text is enabled, both commands will produce blinking white text on a blue background. If you don't use BrightBG or SETDOS /B, 4DOS and 4OS2 will not attempt to configure your video hardware. Most video adapters default to blinking text in normal mode, but this can be changed by application programs. If you use BrightBG or SETDOS /B, 4DOS and 4OS2 will configure the hardware each time they display the prompt. The method used to adjust the video hardware may not be compatible with all video cards. If you see screen "flashes" at each prompt when you use BrightBG or SETDOS /B, discontinue using both commands. This problem is very rare and is not likely to occur on standard EGA and VGA systems. Windowed Mode In windowed mode, the command processor cannot control your hardware to select blinking or bright backgrounds. Instead, Windows, OS/2, and Windows NT all display bright background colors, regardless of the BrightBG or SETDOS /B setting. They do not provide a way to display blinking characters in windowed mode. As an example, the two commands given above would both display white text on a bright blue background when run in windowed mode. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 29 CHAPTER 2 / CONVENTIONS ------------------------------------------------------------------- Switching Modes Windows and OS/2 allow you to switch any DOS session between full-screen and windowed mode; Windows NT allows you to switch modes for any console (non-graphical) session. For example, when running 4DOS in a DOS session under Windows, you can switch modes by pressing Alt-Enter. Switching modes will usually alter color rendition, as you switch between direct interaction with the video board (in full-screen mode) and the color mapping provided by your graphical environment (in windowed mode). In addition, switching modes may alter the display of blinking text and bright background characters. 4DOS Under 4DOS, if BrightBG is set to Yes, bright background colors will be preserved when you switch modes. However, if BrightBG is set to No, the display will shift from blinking text in the full-screen mode to bright background colors behind that text in the windowed mode. This effect can be disturbing; you may need to take it into account if you write batch files or aliases which may be used in either mode. 4OS2 You cannot switch modes for OS/2 sessions, so 4OS2 is not directly affected by mode switching. However, if you write batch files or aliases which run in both modes, you may need to take into account that OS/2 defaults to displaying blinking text in full-screen mode and bright backgrounds in windowed mode. Color-Coded Directories The DIR and SELECT commands can display each file name in a different color, depending on the file's extension. To choose the DIR and SELECT display colors, you must either use the SET command to create an environment variable called COLORDIR, or use the ColorDir directive in your .INI file. If you do not use the COLORDIR variable or the ColorDir directive, DIR will use the default screen colors and SELECT will use the default screen colors or those set with the SelectColors directive. If you use both the COLORDIR variable and the ColorDir directive, the environment variable will override the settings in your .INI file. You may find it useful to use the COLORDIR variable for experimenting, then to set permanent directory colors with the ColorDir directive. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 30 CHAPTER 2 / CONVENTIONS ------------------------------------------------------------------- The format for both the COLORDIR environment variable and the ColorDir directive in the .INI file is: ext ... :ColorName; ... where "ext" is a file extension (which may include wildcards) or one of the following file types: DIRS Directories RDONLY Read-only files HIDDEN Hidden files SYSTEM System files ARCHIVE Files modified since the last backup and "ColorName" is any valid color name (see page 26 for information on color names). Unlike most color specifications, the background portion of the color name may be left out for directory colors. If you don't specify a background color, DIR and SELECT will use the current screen background color. For example, to display the .COM and .EXE files in red on the current background, the .C and .ASM files in bright cyan on the current background, and the read-only files in blinking green on white (this should be entered on one line): c:\> set colordir=com exe:red; c asm:bright cyan; rdonly:blink green on white Extended wildcards (for example "BA[KXC]" for .BAK, .BAX, and .BAC files) can be used in directory color specifications. See page 59 for more information on extended wildcards. 4DOS ## 4DOS normally writes text directly to the screen when displaying color-coded directories. If you have an unusual display adapter which does not support direct video output, see the OutputBIOS directive on page 150. Keys and Key Names Key names are used to define keystroke aliases, in several of the .INI file directives, and with the 4DOS KEYSTACK command. The format of a key name is the same in all three uses: [Prefix-]Keyname The key prefix can be left out, or it can be any one of the following: ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 31 CHAPTER 2 / CONVENTIONS ------------------------------------------------------------------- Alt followed by A - Z, 0 - 9, F1 - F12, or Bksp Ctrl followed by A - Z, F1 - F12, Tab, Bksp, Enter, Left, Right, Home, End, PgUp, PgDn, Ins, or Del Shift followed by F1 - F12 or Tab. The possible key names are: A - Z Enter PgDn 0 - 9 Up Home F1 - F12 Down End Esc Left Ins Bksp Right Del Tab PgUp All key names must be spelled as shown. Alphabetic keys can be specified in upper-case or lower-case. You cannot specify a punctuation key. The prefix and key name must be separated by a dash [-]. For example: Alt-F10 This is okay Alt F10 The space will cause an error If you prefer, you can use a numeric value instead of a key name. Use the ASCII code for an ASCII, extended ASCII, or control character. Use the scan code preceded by an at sign [@] for extended key codes like F1 or the cursor keys. For example, use 13 for Enter, or @59 for F1. In general, you will find it easier to use the names described above rather than key numbers. See Appendix B (page 371) for an explanation and list of ASCII and key codes. Some keys are intercepted by your operating system or BIOS and are not passed on to 4DOS, 4OS2, or 4DOS/NT. For example, under DOS Ctrl-S pauses screen output temporarily, and on some systems Ctrl-P toggles Print Echo mode (where text displayed on the screen is automatically echoed to the printer). Keys which are intercepted by the operating system or BIOS generally cannot be assigned to aliases or with key mapping directives, because the command processor never receives these keystrokes and therefore cannot act on them. You also may not be able to use certain keys if your keyboard is not 100% IBM-compatible, your keyboard driver does not support them, or, under DOS, if you have an ANSI driver which does not support them. For example, on some systems the F11 and F12 keys are not recognized; others may not support unusual combinations like Ctrl-Tab. These problems are rare; when they do occur, they are usually due to the operating ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 32 CHAPTER 2 / CONVENTIONS ------------------------------------------------------------------- system and/or your ANSI driver, and not to any problem with 4DOS, 4OS2, or 4DOS/NT. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 33 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT 4DOS, 4OS2, and 4DOS/NT are both a collection of commands and a set of features which make your computer easier to use. The commands are explained in the Command Reference section which begins on page 153. This chapter explains each of the features that are not directly related to individual commands. Most of the features described in this section are easy to use, but a few are more technical in nature. Such features are marked with a ## next to the feature name or the paragraph which describes the feature's operation. As you read through this section, we urge you to experiment with the features that catch your interest and pass over any which seem too complicated. Come back to this section as you gain expertise, and you will probably discover that the more complex features will seem easy and very useful. You don't need to learn any more than you want, and even if you are a computer novice, you'll find some features that will interest you immediately. If you come across terms or concepts in this chapter that you are unsure about, refer to Chapter 1 / General Concepts, the Glossary on page , or the Index. 381 At the Command Line 4DOS displays a c:\> prompt when it is waiting for you to enter a command. 4OS2 and 4DOS/NT display the similar [c:\] prompt. (In each case, the actual text depends on the current drive and directory as well as your PROMPT settings.) This is called the command line and the prompt is asking you to enter a command, an alias or batch file name, or the instructions necessary to begin an application program. This section of the manual explains the features that will help you while you are typing in commands, and how keystrokes are interpreted when you enter them at the command line. The keystrokes discussed here are the ones normally used by 4DOS, 4OS2, and 4DOS/NT. If you prefer using different keystrokes to perform these functions, you can assign new ones with keystroke directives in the .INI file (see page 126). ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 34 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- Command-Line Editing The command line works like a single-line word processor, allowing you to edit any part of the command at any time before you press Enter to execute it, or Esc to erase it. The command line extends to a maximum of 255 characters under 4DOS and 1023 characters under 4OS2 and 4DOS/NT. You can use the following editing keys when you are typing a command (the words Ctrl and Shift mean to press the Ctrl or Shift key together with the other key named): Cursor Movement: Left arrow Move the cursor left one character. Right arrow Move the cursor right one character. Ctrl-Left arrow Move the cursor left one word. Ctrl-Right arrow Move the cursor right one word. Home Move the cursor to the beginning of the line. End Move the cursor to the end of the line. Insert and Delete: Ins Toggle between insert and overtype mode. Del Delete the character at the cursor. Backspace Delete the character to the left of the cursor. Ctrl-L Delete the word or partial word to the left of the cursor. Ctrl-R or Ctrl-Bksp Delete the word or partial word to the right of the cursor. Ctrl-Home Delete from the beginning of the line to the cursor. Ctrl-End Delete from the cursor to the end of the line. Esc Delete the entire line. Ctrl-C Cancel the command. or Ctrl-Break Enter Execute the command line. 4OS2, ## 4OS2 and 4DOS/NT will prompt for additional command-line 4NT text when you include the escape character as the very last character of a typed command line. The default escape character in both programs is the caret [^]. For example, [c:\] echo The quick brown fox jumped over the lazy^ ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 35 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- More? sleeping dog. > alphabet ## Sometimes you may want to enter one of the above keystrokes on the command line instead of performing the key's usual action. For example, suppose you have a program that requires a Ctrl-R character on its command line. Normally you couldn't type this keystroke at the prompt, because it would be interpreted as a "Delete word right" command. To get around this problem, use the special keystroke Alt-255. You enter Alt-255 by holding down the Alt key while you type 255 on the numeric keypad, then releasing the Alt key (you must use the number keys on the numeric pad; the row of keys at the top of your keyboard won't work). This forces the command processor to interpret the next keystroke literally and places it on the command line, ignoring any special meaning it would normally have as a command-line editing or history keystroke. You can use Alt-255 to suppress the normal meaning of command-line editing keystrokes even if they have been reassigned with key mapping directives in the .INI file (see page 126), and Alt-255 itself can be reassigned with the CommandEscape directive. If you want your input at the command line to be in a different color from the command processor's prompts or output, you can use the InputColors directive in your .INI file. You must have an ANSI driver installed to use InputColors under 4DOS. See page 142 for more details on InputColors. Most of the command-line editing capabilities are also available when a 4DOS, 4OS2, or 4DOS/NT command prompts you for a line of input. For example, you can use the command- line editing keys when DESCRIBE (page 201) prompts for a file description, when INPUT (page 262) prompts for input from an alias or batch file, or when LIST (page 272) prompts you for a search string. Command History and Recall Each time you execute a command, the entire command line is saved in a command history list. You can display the saved commands, search the list, modify commands, and rerun commands. The simplest use of the command history list is to repeat a command exactly. For example, you might enter the command c:\> dir b:*.wks;*.doc ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 36 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- to see some of the files on drive B. You might move some new files to drive B and then want to repeat the DIR command. Just press the Up Arrow key repeatedly to scan back through the history list. When the DIR command appears, press Enter to execute it again. After you have found a command, you can edit it before pressing Enter. You will appreciate this feature when you have to execute a series of commands that differ only slightly from each other. The history list is "circular". If you move to the last command in the list and then press the down arrow one more time, you'll see the first command in the list. Similarly, if you move to the first command in the list and then press the up arrow one more time, you'll see the last command in the list. You can search the command history list to find a previous command quickly using command completion. Just enter the first few characters of the command you want to find and press Up Arrow. You only need to enter enough characters to identify the command that you want to find. For example, to find the DIR command, enter DI and then press Up Arrow. If you press the Up Arrow key a second time, you will see the previous command that matches. The system will beep if there are no matching commands. The search process stops as soon as you type one of the editing keys, whether or not the line is changed. At that point, the line you're viewing becomes the new line to match if you press Up Arrow again. You can specify the size of the command history list with the History directive in the .INI file (see page 133). When the list is full, the oldest commands are discarded to make room for new ones. You can also use the HistMin directive in the .INI file to enable or disable history saves and to specify the shortest command line that will be saved (see page 139). You can prevent any command line from being saved in the history by beginning it with an at sign [@]. When you execute a command from the history, that command remains in the history list in its original position. The command is not copied to the end of the list (unless you modify it). If you want each command to be copied to the end of the list when it is re-executed, set HistCopy to Yes in your .INI file (see page 139). ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 37 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- Command History Keys: Up Arrow Recall the previous (or most recent) command, or the most recent command that matches a partial command line. Down Arrow Recall the next (or oldest) command, or the oldest command that matches a partial command line. F3 Fill in the rest of the command line from the previous command, beginning at the current cursor position. Ctrl-D Delete the currently displayed history list entry, erase the command line, and display the previous matching history list entry. Ctrl-E Display the last entry in the history list. Ctrl-K Save the current command line in the history list without executing it, and then clear the command line. Ctrl-Enter Copy the current command line to the end of the history list even it has not been altered. @ As the first character in a line: Do not save the current line in the history list when it is executed, or store it in the CMDLINE environment variable (see CMDLINE on page 99 for further details). Use F3 when your new command is different from your old one by just a character or two at the beginning. For example, suppose you want to execute a DIR on several file names then use DEL to delete those same files. After the DIR is complete type DEL and press F3; the rest of the command line will be completed for you. Check that it's correct, and then press Enter to delete the files. F3 also retrieves the entire previous command (like up-arrow) if nothing has been typed on the line. Use Ctrl-E to "get your bearings" by returning to the end of the list if you've scrolled around so much that you aren't sure where you are any more. Use Ctrl-K to save some work when you've typed a long command and then realize that you weren't quite ready. For example, if you forget to change directories and notice it after a command is typed or mostly typed, but before you press Enter, just press Ctrl-K to save the command without executing it. Use the CD or CDD command to change to the right directory, ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 38 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- press up-arrow twice to retrieve the command you saved, make any final changes to it, and press Enter to execute it. Use Ctrl-Enter to organize the history list for repetitive tasks. Instead of searching through the command history for the next command in a sequence, you can place all of the necessary commands next to each other and make them easier to repeat. Local and Global Command History The command history can be stored in either a "local" or "global" list. With a local history list, any changes made to the history will only affect the current copy of the command processor. They will not be visible in other shells, or other sessions. A local history list is the default under 4DOS. With a global history list, all copies of the command processor will share the same command history, and any changes made to the history in one copy will affect all other copies. Global lists are the default for 4OS2 and 4DOS/NT. You can control the type of history list with the LocalHistory directive in the .INI file (see page 134), and with the /L and /LH options of the START command (see page 331). There is no fixed rule for deciding whether to use a local or global history list. Depending on your work style, you may find it most convenient to use one type, or a mixture of types in different sessions or shells. We recommend that you start with the default approach for your command processor, then modify it if you find a situation where the default is not convenient. 4DOS If you select a global history list for 4DOS running under DOS, you can share the history among all copies of 4DOS. However, if you run 4DOS under OS/2, global lists will apply within each DOS session, but will not allow you to share the history between different DOS sessions. 4OS2, ## If you select a global history list for 4OS2 or 4DOS/NT, you 4NT can share the history among all copies of the command processor running in any session. When you close all 4OS2 or 4DOS/NT sessions, the memory for the global history list is released, and a new, empty history list is created the next time you start 4OS2 or 4DOS/NT. If you want the history list to be retained in memory even when no command processor ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 39 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- session is running, you need to load the SHRALIAS program, which performs this service for the global history and alias lists. SHRALIAS is described in more detail under the ALIAS command (see page 170). Whenever you start a secondary shell (see page 12) which uses a local history list, it inherits a copy of the command history from the previous shell. However, any changes to the history made in the secondary shell will affect only that shell. If you want changes made in a secondary shell to affect the previous shell, use a global history list in both shells. Command History Window You can also view the command history in a scrollable command history window, and select the command to modify or re-execute from those displayed in the window. To activate the command history window press PgUp or PgDn at the command line. A window will appear in the upper right corner of the screen, with the command you most recently executed marked with a highlight. (If you just finished re-executing a command from the history, then the next command in sequence will be highlighted.) You can scroll the command history window up and down one line at a time with Up Arrow and Down Arrow, and one page (screen) at a time with PgUp and PgDn. The display is not circular as it is at the prompt; it has a fixed beginning and end. Left Arrow and Right Arrow will pan the text in the history to the left or right. Home or Ctrl-PgUp will go to the beginning of the history, and End or Ctrl-PgDn will go to the end. The Ctrl-D (delete from history) key works within the history window as it does at the command line. Once you have selected a command in the history window, press Enter to execute it immediately, or Ctrl-Enter to move the line to the prompt for editing (you cannot edit the line directly in the history window). You can bring up a "filtered" history window by typing some characters on the command line, then pressing PgUp or PgDn. Only those commands matching the typed characters will be displayed in the window. You can control the position and size of the history window with directives in the .INI file (see page 139). You can also change the keys used in the window with key mapping directives in the .INI file (see page 146). ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 40 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- Command History Window: PgUp or PgDn (from the command line) Open the command history window. Up Arrow Scroll the display up one line. Down Arrow Scroll the display down one line. Left Arrow Scroll the display left 4 columns. Right Arrow Scroll the display right 4 columns. PgUp (inside the window) Scroll the display up one page. PgDn (inside the window) Scroll the display down one page. Ctrl-PgUp or Home Go to the beginning of the history list. Ctrl-PgDn or End Go to the end of the history list. Ctrl-D Delete the selected line from the history list. Enter Execute the selected line. Ctrl-Enter Move the selected line to the command line for editing. Filename Completion Filename completion can help you by filling in a complete file name on the command line when you only remember part of the name. For example, suppose you want to copy a file. You know that its name begins AU but you can't remember the rest of the name. Type: c:\> copy au and then press the Tab key or F9 key. 4DOS, 4OS2, or 4DOS/NT will search the current directory for filenames that begin AU and insert the first one onto the command line in place of the AU that you typed. If this is the file that you want, simply complete the command. If the command processor didn't find the file that you were looking for, press Tab or F9 again to substitute the next filename that begins with AU. When there are no more filenames that match your pattern, the system will beep each time you press Tab or F9. If you go past the filename that you want, press Shift-Tab or F8 to back up and return to the previous matching filename. After you back up to the first filename, the system will beep each time you press Shift-Tab or F8. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 41 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- If you want to enter more than one matching filename on the same command line, press F10 when each desired name appears. This will keep that name and place the next matching filename after it on the command line. You can then use Tab (or F9) and Shift-Tab (or F8) to move through the remaining matching files. The pattern you use for matching may contain any valid filename characters, as well as wildcard characters and extended wildcards (see page 59). For example, you can copy the first matching .TXT file by typing c:\> copy *.txt and then pressing Tab. If you don't specify part of a filename before pressing Tab, the matching pattern will be *.*. If you type a filename without an extension, the command processor will add *.* to the name. It will also place a "*" after a partial extension. If you are typing a group of file names in an include list (see page 67), the part of the include list at the cursor will be used as the pattern to match. When filename completion is used at the start of the command line, it will only match directories, executable files (see page 20), and files with executable extensions, since these are the only file names that it makes sense to use at the start of a command. If a directory is found, a "\" will be appended to it to enable an automatic directory change (see page 47). Filename Completion Keys: F8 or Shift-Tab Get the previous matching filename. F9 or Tab Get the next matching filename. F10 Keep the current matching filename and display the next matching name immediately after the current one. Filename Completion Window You can also view filenames in a scrollable filename completion window and select the file you want to work with. To activate the window, press F7 or Ctrl-Tab at the command line. You will see a window in the upper-right corner of the screen, with the names of files that match any partial filename you have entered on the command line. If you haven't yet entered a file name, the window will contain the name of ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 42 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- all files in the current directory. (Ctrl-Tab will work only if your keyboard and BIOS or keyboard driver support it. If it does not work on your system, use F7 instead.) You can scroll the filename completion window up and down one line at a time with Up Arrow and Down Arrow, and one page (screen) at a time with PgUp and PgDn. Home or Ctrl-PgUp will go to the beginning of the list of file names; End or Ctrl- PgDn will go to the end. You can scroll the window left and right 4 spaces at a time with the Left Arrow or Right Arrow. Once you have selected the filename you want, press Enter to insert it into the command line. Filename Completion Window: F7 or Ctrl-Tab (from the command line) Open the filename completion window. Up Arrow Scroll the display up one line. Down Arrow Scroll the display down one line. Left Arrow Scroll the display left 4 columns. Right Arrow Scroll the display right 4 columns. PgUp Scroll the display up one page. PgDn Scroll the display down one page. Ctrl-PgUp or Home Go to the beginning of the filename list. Ctrl-PgDn or End Go to the end of the filename list. Enter Insert the selected filename into the command line. Directory Changes and CDPATH The operating system and command processor remember both a current or default drive for your system as a whole, and a current or default directory for every drive in your system. The current directory on the current drive is sometimes called the current working directory. You can change the current drive by simply typing the new drive letter plus a colon at the prompt. You can change the current working directory with the CD command (see page 181), the CDD command (page 183), the PUSHD and POPD commands (pages 47 and 299), and with automatic directory changes (page 294). The CD command can change the default directory on any drive, but it cannot change the current working directory from one drive to another. The other methods of changing the current working directory can change both the current drive and the current directory in a single command. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 43 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- Whenever you change the current working directory, 4DOS, 4OS2, or 4DOS/NT saves the original directory in up to three places. First, the directory is saved as the previous working directory. You can change to the previous working directory with the CD - and CDD - commands (see pages 181 and 183). You can use either of these commands repeatedly to switch back and forth between two directories. The original directory is also saved in the directory history (see the next topic below). You can use this list to change to a recent directory with the cursor keys instead of typing a directory name. Finally, the PUSHD command records the old directory in the directory stack. You can view the contents of this stack with the DIRS command and return to the directory on the top of the stack with the POPD command. If CD, CDD, PUSHD, or an automatic directory change can't locate the specified directory to change to, they will look for the CDPATH environment variable. The command will append the specified directory name to each directory in CDPATH and attempt to change to that drive and directory, until the first match or the end of the CDPATH argument. This allows you to use CDPATH as a quick way to find commonly used subdirectories which have unique names. For example, if you are currently in the directory C:\WP\LETTERS\JANUARY and you'd like to change to D:\SOFTWARE\UTIL, you could enter the command: c:\wp\letters\january> cdd d:\software\util However, if the D:\SOFTWARE directory is listed in your CDPATH variable, and is the first directory in the list with a UTIL subdirectory, you can simply enter the command c:\wp\letters\january> cdd util to change to D:\SOFTWARE\UTIL. You can create CDPATH with the SET command. The format of the CDPATH is similar to that of PATH: a list of directories separated by semicolons [;]. For example, if you want the directory change commands to search the C:\DATA directory, the D:\SOFTWARE directory, and the root directory of drive E:\ for the subdirectories that you name, you should create CDPATH with this command: c:\> set cdpath=c:\data;d:\software;e:\ ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 44 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- Directory History Window Every time you change to a new directory or drive, the current directory is recorded in an internal directory history list. You can set the size of the list with the DirHistory directive in the .INI file (see page 132). As new entries are added, old entries are deleted from the list. Directory changes are recorded whether you make them from the command line with the CD, CDD, PUSHD, or POPD commands, with an automatic directory change, or by typing a new drive letter followed by a colon. Directories are recorded whether you change from one to another at the command line, from within a batch file, or from within an alias. In order to conserve space, each directory name is recorded just once in the directory history, even if you move into and out of that directory several times. You can view the directory history from a scrollable directory history window and change to any drive and directory on the list. To activate the directory history window, press Ctrl- PgUp or Ctrl-PgDn at the command line. You can then select a new directory with the Enter key. Directory History Window: Ctrl-PgUp (from the command line) Open the or Ctrl-PgDn directory history window. Up Arrow Scroll the display up one line. Down Arrow Scroll the display down one line. Left Arrow Scroll the display left 4 columns. Right Arrow Scroll the display right 4 columns. PgUp Scroll the display up one page. PgDn Scroll the display down one page. Ctrl-PgUp or Home Go to the beginning of the directory list. Ctrl-PgDn or End Go to the end of the directory list. Ctrl-D Delete the selected line from the directory list. Enter Change to the selected drive and directory. Ctrl-Enter Move the selected line to the command line for editing. Local and Global Directory History The directory history can be stored in either a "local" or "global" list. With a local directory history list, any changes made to the list will only affect the current copy of the command ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 45 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- processor. They will not be visible in other shells, or other sessions. A local directory history list is the default under 4DOS. With a global list, all copies of the command processor will share the same directory history, and any changes made to the list in one copy will affect all other copies. Global lists are the default for 4OS2 and 4DOS/NT. You can control the type of directory history list with the LocalDirHistory directive in the .INI file (see page 134), and with the /L and /LD options of the START command (see page 331). You can control where a global directory history list is stored with the UMBDirHistory directive in the .INI file (see page 135). There is no fixed rule for deciding whether to use a local or global directory history list. Depending on your work style, you may find it most convenient to use one type, or a mixture of types in different sessions or shells. We recommend that you start with the default approach for your command processor, then modify it if you find a situation where the default is not convenient. 4DOS If you select a global directory history list for 4DOS running under DOS, you can share the list among all copies of 4DOS. However, if you run 4DOS under OS/2, global lists will apply within each DOS session, but will not allow you to share the history between different DOS sessions. 4OS2, ## If you select a global directory list for 4OS2 or 4DOS/NT, you 4NT can share the list among all copies of the command processor running in any session. When you close all 4OS2 or 4DOS/NT sessions, the memory for the global directory history list is released, and a new, empty list is created the next time you start 4OS2 or 4DOS/NT. If you want the list to be retained in memory even when no command processor session is running, you need to load the SHRALIAS program, which performs this service for the global command history, directory history, and alias lists. SHRALIAS is described in more detail under the ALIAS command (see page 170). Whenever you start a secondary shell (see page 12) which uses a local directory history list, it inherits a copy of the directory history from the previous shell. However, any changes to the list made in the secondary shell will affect only that shell. If you want changes made in a secondary shell to affect the previous shell, use a global directory history list in both shells. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 46 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- Automatic Directory Changes The automatic directory change feature gives you a quick method for changing directories. You can use an automatic directory change in place of the CD or CDD command. To do so, simply type the name of the directory you want to change to at the prompt, with a backslash [\] at the end. For example: c:\> 4dos\ c:\4dos> This feature can make directory changes very simple when it's combined with the CDPATH environment variable (see page 44). CDPATH is a list of directories for the CD and CDD commands to search if the directory you name does not exist below the current directory. Automatic directory changes use CDPATH as well. For example, suppose CDPATH is set to C:\;D:\;E:\, and the directory WIN exists on drive E:. You can change to this directory with a single word on the command line: c:\4dos> win\ e:\win> In executing the command shown above, the command processor first looks for a WIN subdirectory of the current directory, i.e., C:\4DOS\WIN. If no such directory exists it looks for a WIN subdirectory in every directory in the CDPATH list, and changes to the first one it finds. Internally, automatic directory changes use the CDD command, so the text before the backslash can include a drive letter, a full path, or a partial path. Commands like "....\" can be used to move up the directory tree quickly (see page 59). Automatic directory changes save the current directory, so it can be recalled with a "CDD -" or "CD -" command. For more information on directory changes see page 181, CD on page 44, and CDD on page 183. Multiple Commands At times, you probably know the next two or three commands that you want to execute. Instead of waiting for each one to finish before you type the next, you can type them all on the same command line, separated by a caret [^] in 4DOS, or an ampersand [&] in 4OS2 or 4DOS/NT. For example, if you know you want to copy all of your .TXT files to drive A: and then run CHKDSK to be sure that drive A's file structure is in good shape, in 4DOS you could enter the following command: ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 47 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- c:\> copy *.txt a: ^ chkdsk a: You may put as many commands on the command line as you wish, as long as the total length of the command line does not exceed 255 characters in 4DOS or 1023 characters in 4OS2 and 4DOS/NT. You can use multiple commands in batch files (see page 80) and alias definitions (see page 77) as well as from the command line. If you don't like using the default command separator, you can pick another character using the SETDOS /C command (see page 323) or the CommandSep directive in the .INI file (see page 137). If you plan to share aliases or batch files between 4DOS, 4OS2, and 4DOS/NT, see page 74 for details about choosing compatible command separators for two or more products. Temporarily Disabling Aliases Aliases can be used to create shorthand names for commonly used commands, or to define default options for existing commands (for more information see pages 161 and 77). At times, you may want to temporarily disable an alias that you have defined. You may have an alias that changes the defaults of a particular command, for example, and want to run the unmodified version of the command. To do so, precede the command name with an asterisk [*]. For example, if you have an alias for DIR which displays directories in 2-column paged mode by default, you can use the following command to display a directory in the normal single-column, non-paged mode: c:\> *dir You can also disable aliases temporarily with the SETDOS /X command (see page 327). Command Line Help All of our products include complete online help. You can start the help system by typing HELP or HELP plus a command name at the prompt, or by pressing the F1 key at any time at the command line. 4DOS In 4DOS,a special program (4HELP.EXE) displays the online help. If you press F1, the 4DOS help system will display the ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 48 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- list of all help topics just as if you had entered the HELP command. 4OS2, In 4OS2 and 4DOS/NT, the online help uses the operating 4NT system's built-in help facility. If you press F1, the table of contents will be displayed and you can select the desired help topic using the standard help "navigation" keys for your system. If you have already typed part or all of a command on the line, the help system will provide "context-sensitive" help by using the first word on the line as a help topic. If it's a valid topic, you will see help for that topic automatically; if not, you will see the list of all help topics (in 4DOS) or the table of contents (in 4OS2 and 4DOS/NT), and you can then pick the topic you want. For example, if you press F1 after entering each of the command lines shown below you will get the display indicated: c:\> Topic list / table of contents c:\> copy *.* a: Help on COPY c:\> c:\util\map Topic list / table of contents If you type the name of any internal command at the prompt, followed by a slash and a question mark [/?] like this: copy /? then you will see help for the command in a "quick-reference" style. Output from a /? display may be redirected with > or >> (see page 52). The /? option may not work correctly if you have redefined how the command operates with an alias. In this case you may need to add an asterisk to the beginning of the command to disable alias processing: alias copy copy /r *copy /? /? will only access the help system when you use it with an internal command. If you use it with an external command name, the external command will be executed and will interpret the /? parameter according to its own rules. Some external commands, including some DOS and OS/2 external utility programs, do display help when run with a /? parameter, but this a characteristic of these commands and does not depend on the command processor. Many other external commands do not have this feature. Please see the Introduction and Installation Guide that was supplied with your version of 4DOS, 4OS2, or 4DOS/NT for a ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 49 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- more thorough explanation of the online Help available with the program you use. ## Command-Line Length Limits Under 4DOS, when you first enter a command at the prompt or in an alias or batch file, it can be up to 255 characters long. The 4OS2 and 4DOS/NT command lines can hold 1,023 characters. As the command processor scans the command line and substitutes the contents of aliases and environment variables for their names, the line usually gets longer. This expanded line is stored in an internal buffer which allows each individual command to grow to 255 characters during the expansion process (1,023 characters in 4OS2 and 4DOS/NT). In addition, if you have multiple commands on a single line, during expansion the entire line can grow to as much as 511 characters in 4DOS, or 2,047 characters in 4OS2 and 4DOS/NT. If your use of aliases or environment variables causes the command line to exceed either of these limits as it is expanded, you will see an error message and the remainder of the line will not be executed. Page and File Prompts Several 4DOS, 4OS2, and 4DOS/NT commands can generate prompts, which wait for you to press a key to view a new page or to perform a file activity. When 4DOS, 4OS2, or 4DOS/NT is displaying information in page mode, for example with a DIR /P or SET /P command, it displays the message Press Esc to Quit or any other key to continue... At this prompt, you can press Esc, Ctrl-C, or Ctrl-Break if you want to quit the command. You can press almost any other key to continue with the command and see the next page of information. During file processing, if you have activated prompting with a command like DEL /P, you will see this prompt before processing every file: Y/N/R ? You can answer this prompt by pressing "Y" for "Yes, process this file;" "N" for "No, do not process this file;" or "R" ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 50 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- for "process the Remainder of the files without further prompting." You can also press Ctrl-C or Ctrl-Break at this prompt to cancel the remainder of the command. If you press Ctrl-C or Ctrl-Break while a batch file is running, you will see a "Cancel batch job" prompt. For information on responses to this prompt see page 85. Critical Errors DOS, OS/2, and Windows NT all watch for physical errors during input and output operations. Physical errors are those due to hardware problems, such as trying to read a floppy disk while the drive door is open. These errors are called critical errors because the operating system, command processor, or application program cannot proceed until the error is resolved. When a critical error occurs, you will see a message asking you to choose one of four error handling options. The message comes from the command processor or the operating system, and will vary slightly depending on your operating system and (under OS/2 and Windows NT) whether you are in full-screen or windowed mode. You can respond with a single character (under DOS), or a mouse click or menu selection (under OS/2 or Windows NT). However, the options and their meanings are similar in all cases: Retry Retry the operation. Choose this option if you have corrected the problem. Ignore Ignore the error and continue. Use caution when choosing this option. Ignoring critical errors, especially on the hard disk, can cause errors in your applications or damage data on the disk. Fail Tell the program that the operation failed. This option returns an error code to the command processor or to the application program that was running when the error occurred. 4DOS, 4OS2, and 4DOS/NT generally stop the current command when an operation fails. This option is not available for all errors; if you don't see it, use Abort instead. Under DOS, you can force a Fail response to all critical errors with the CritFail directive in 4DOS.INI (see page 148). ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 51 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- Abort Abort the program. Choose this option to stop the program that was running when the error occurred. Choosing Abort after an error in 4DOS, 4DOS/NT, or the 16-bit version of 4OS2 will abort the command, but not the command processor itself. Choosing Abort after an error in the 32- bit version of 4OS2 will abort both the command and the command processor. To avoid this, use Fail rather than Abort if possible. Input and Output Internal commands and many external programs get their input from the computer's standard input device and send their output to the standard output device. Some programs also send special messages to the standard error device. Normally, the keyboard is used for standard input and the video screen for both standard output and standard error, but you can temporarily change these assignments for special tasks. For example, suppose you want a printed list of the files in a directory. If you change the standard output to the printer and issue a DIR command, the task is easy. DIR prints to standard output, and you have redirected standard output to the printer, so the DIR command prints filenames instead of displaying them on the screen. You can just as easily send the output of DIR (or any other command) to a file or a serial port. We offer three methods of manipulating input and output: Redirection, Piping, and (under 4DOS) the Keystack. All three are explained in this section. Redirection and piping affect the standard input, standard output, and standard error devices. They do not work with application programs which read the keyboard hardware directly, or which write directly to the screen. Redirection Redirection assigns standard input, standard output, and standard error to a device like the printer or serial port, or to a file. (You must use some discretion when you use redirection with a device; there is no way to get input from the printer, for example.) Redirection always applies to a specific command, and lasts only for the duration of that command. When the command is ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 52 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- finished, the assignments for standard input, standard output, and standard error revert to whatever they were before the command. In the descriptions below, filename means either the name of a file or of an appropriate device (PRN, LPT1, LPT2, or LPT3 for printers; COM1 to COM4 for serial ports; CON for the keyboard and screen; etc.). To use redirection, place the redirection symbol and filename at the end of the command line, after the command name and any parameters. For example, to redirect the output of the DIR command to a file called DIRLIST, you could use a command line like this: c:\> dir /b *.dat > dirlist You can use both input and output redirection for the same command, if both are appropriate: c:\> sort < dirlist > dirlist.srt If you redirect the output of a single internal command like DIR, the redirection ends automatically when that command is done. If you start a batch file with redirection, all of the batch file's output is redirected, and redirection ends when the batch file is done. Similarly, if you use redirection at the end of a command group (see page 71), all of the output from the command group is redirected, and redirection ends when the command group is done. Here are the redirection options supported by 4DOS, 4OS2, and 4DOS/NT: To get input from a file or device instead of from the keyboard: < filename To redirect standard output to a file or device: > filename To redirect standard output and standard error to a file or device: >& filename To redirect standard error only to a file or device: ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 53 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- >&> filename If you want to append output to the end of an existing file, rather than creating a new file, replace the first ">" in the last three commands above with ">>" (use >>, >>&, and >>&>). ## When output is directed to a file with >, >&, or >&>, if the file already exists, it will be overwritten. You can protect existing files by using the SETDOS /N1 command (see page 325) or the NoClobber directive in the .INI file (see page 140). ## When output is appended to a file with >>, >>&, or >>&>, the file will be created if it doesn't already exist. Setting NoClobber will also prevent the creation of a new file. ## You can temporarily override the current setting of NoClobber by using an exclamation mark [!] after the redirection symbol. For example, to redirect the output of DIR to the file DIROUT, and allow overwriting of any existing file despite the NoClobber setting: c:\> dir >! dirout ## Redirection is fully nestable. For example, you can invoke a batch file and redirect all of its output to a file or device. Output redirection on a command within the batch file will take effect for that command only; when the command is completed, output will revert to the redirected output file or device in use for the batch file as a whole. ## You can use redirection if you need to create a zero-byte file. To do so, enter >filename as a command, with no actual command before the > character. 4DOS ## For another method of changing the standard input and output devices see CTTY on page 194. 4OS2, In addition to the extended 4DOS redirection options, 4OS2 and 4NT 4DOS/NT also support the OS/2 and Windows NT CMD.EXE syntax n>file and n>&m where [n] and [m] are digits between 0 and 9. You may not put any spaces between the n and the >, or between the >, &, and m in the second form. The digits represent file handles; OS/2 and Windows NT interpret "0" as standard input, "1" as ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 54 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- standard output, and "2" as standard error. Handles 3 to 9 will probably not be useful unless you have an application which uses those handles for a specific, documented purpose, or have opened a file with the %@FILEOPEN variable function (see page 114) and the file handle is between 3 and 9. The n>file syntax redirects output from handle n to a file. You can use this form to redirect two handles to different places. For example: [c:\] dir > outfile 2> errfile sends normal output to a file called OUTFILE and any error messages to a file called ERRFILE. The n>&m syntax redirects handle n to the same location as the previously assigned handle m. For example, to send standard error to the same file as standard output, you could use this command: [c:\] dir > outfile 2>&1 Notice that you can perform the same operations by using 4OS2 or 4DOS/NT's enhanced redirection features. The two examples above could be written as [c:\] dir > outfile >&> errfile and [c:\] dir >&outfile Piping You can also create a "pipe," which means sending the standard output of one command to the standard input of another command. To send the standard output of command1 to the standard input of command2: command1 | command2 To send the standard output and standard error of command1 to the standard input of command2: command1 |& command2 For example, to take the output of the SET command (which displays a list of your environment variables and their ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 55 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- values) and pipe it to the SORT utility to generate a sorted list, you would use the command: c:\> set | sort To do the same thing and then pipe the sorted list to the internal LIST command for full-screen viewing (see page 272): c:\> set | sort | list /s ## The TEE and Y commands (see pages 340 and 358) are "pipe fittings" which add more flexibility to pipes. ## Like redirection, pipes are fully nestable. For example, you can invoke a batch file and send all of its output to another command with a pipe. A pipe on a command within the batch file will take effect for that command only; when the command is completed, output will revert to the pipe in use for the batch file as a whole. You may also have 2 or more pipes operating simultaneously if, for example, you have the pipes running in different windows in a multitasking system. 4DOS ## 4DOS creates one or two temporary files to hold the output of pipes. The files are given unique names. By default, these files are stored in the root directory of the boot drive, but you can override this with either the TEMP4DOS or TEMP environment variable (see page 100). 4OS2, ## 4OS2 and 4DOS/NT implement pipes by starting a new process for 4NT the receiving program instead of using temporary files. The sending and receiving programs run simultaneously; the sending program writes to the pipe and the receiving program reads from the pipe. When the receiving program finishes reading and processing the piped data, it is ended automatically. If you are used to using pipes under 4DOS, you normally will not see any difference with a 4OS2 or 4DOS/NT pipe except perhaps less disk activity. But you may not get the results you expect if you use a pipe command like: [c:\] echo test | input %%var 4DOS In 4DOS, this pipe will create an environment variable called VAR and set its value as "test." You will be able to see the new variable by typing SET at the prompt. 4OS2, In 4OS2 and 4DOS/NT, VAR will be set in the environment that 4NT belongs to the receiving program. But that environment will be discarded when the pipe has been emptied and the process ends. You will never see VAR in the environment even though ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 56 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- the command processor and the operating system are both operating correctly. The same cautions apply to the "pipe-fitting" commands, TEE and Y. When you use pipes with 4OS2 or 4DOS/NT, make sure you think about any possible consequences that can occur from using a separate process to run the receiving program. 4DOS Keystack The 4DOS Keystack overcomes two weaknesses of input redirection: many programs ignore standard input and read the keyboard directly, and input redirection doesn't end until the program or command terminates. You can't, for example, use redirection to send the opening commands to a program and then type the rest of the commands yourself. But the Keystack lets you do exactly that. The 4DOS Keystack sends keystrokes to an application program. Once the Keystack is empty, the program will receive the rest of its input from the keyboard. The Keystack is useful when you want a program to take certain actions automatically when it starts. It is most often used in batch files and aliases. The Keystack is invoked with the KEYSTACK command (see page 266). It depends on a small resident program called KSTACK.COM, which may be installed from your AUTOEXEC.BAT file (see page 86). If you don't have KSTACK.COM installed, the KEYSTACK command will display an error message. If you are using a multitasking system such as DESQview or Windows, see your 4DOS Introduction and Installation Guide for information on loading KSTACK within a window. To place the letters, digits, and punctuation marks you would normally type for your program into the keystack, enclose them in double quotes: c:\> keystack "myfile" Many other keys can be entered into the Keystack using their names. This example puts the F1 key followed by the Enter key in the keystack: c:\> keystack F1 Enter See page 31 for details on how key names are entered. See the KEYSTACK command on page 266 for information on using numeric key values along with or instead of key names, and other details about using the Keystack. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 57 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- The following command creates an alias (see page 161) that will run a dBASE report called TIMEREP (it should be entered on one line): c:\> alias drpt `keystack "use times index times" Enter "report form timerep to print" Enter "quit" Enter ^ dbase` This command creates an alias called DRPT which puts the following characters on the keystack: the characters "use times index times" the Enter key's code the characters "report form timerep to print" the Enter key's code the characters "quit" and one more Enter key The alias then runs the program dBASE which receives those characters just as if you had typed them. When you use the Keystack, remember that you must put the keystrokes into the Keystack before you run the program that will receive them. The Keystack will hold the keystrokes until the program asks for them. File Selection Most internal commands (like COPY, DIR, etc.) work on a file or a group of files. Besides typing the exact name of the file you want to work with, you can use several shorthand forms for naming or selecting files: Extended Parent Directory Names; Wildcards; Date, Time, and Size Ranges; Multiple Filenames; Include Lists; and Executable Extensions. These six features are explained in this section. These features apply to 4DOS, 4OS2, and 4DOS/NT commands only, and generally can not be used to pass file names to external programs. For example, the file name ...\FILE.DAT uses an extended parent directory name ("..."). It can be used in an internal command like COPY or MOVE. However, your editor probably was not designed to support this extension to traditional directory names, and is likely to give an error message if you try to pass it such a name. Remember throughout this section that, if you are using DOS, or the FAT file system under OS/2 or Windows NT, a filename is a base name of 1 to 8 characters, optionally followed by an extension which is a period [.] and 1 to 3 more characters. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 58 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- On an HPFS or NTFS drive, file names can contain up to 255 characters, including spaces. If an HPFS or NTFS filename includes spaces, you must place it in quotation marks on the command line. (See page 13 for additional details on filename formats and restrictions.) Extended Parent Directory Names 4DOS, 4OS2, and 4DOS/NT allow you to extend the traditional DOS ".." syntax for naming the parent directory, by adding additional [.] characters. Each additional [.] represents an additional directory level above the current directory. For example, .\FILE.DAT refers to a file in the current directory, ..\FILE.DAT refers to a file one level up (in the parent directory), and ...\FILE.DAT refers to a file two levels up (in the parent of the parent directory). If you are in the C:\DATA\FINANCE\JANUARY directory and want to copy the file LETTERS.DAT from the directory C:\DATA to drive A: C:\DATA\FINANCE\JANUARY>copy ...\LETTERS.DAT A: Wildcards Wildcards let you specify a file or group of files by typing a partial filename. The appropriate directory is scanned to find all of the files that match the partial name you have specified. Most internal commands accept filenames with wildcards anywhere that a full filename can be used. There are two wildcard characters, the asterisk [*] and the question mark [?], plus a special method of specifying a range of permissible characters. An asterisk [*] in a filename means "any zero or more characters in this position." For example, this command will display a list of all files in the current directory: c:\> dir *.* If you want to see all of the files with a .TXT extension, you could type this: c:\> dir *.txt If you know that the file you are looking for has a base name that begins with ST and an extension that begins with .D, you ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 59 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- can find it this way. Filenames such as STATE.DAT, STEVEN.DOC, and ST.D will all be displayed: c:\> dir st*.d* With 4DOS, 4OS2, or 4DOS/NT, you can also use the asterisk to match filenames with specific letters somewhere inside the name. The following example will display any file with a .TXT extension that has the letters AM together anywhere inside its base name. It will, for example, display AMPLE.TXT, STAMP.TXT, CLAM.TXT, and AM.TXT: c:\> dir *am*.txt A question mark [?] matches any single filename character. You can put the question mark anywhere in a filename and use as many question marks as you need. The following example will display files with names like LETTER.DOC and LATTER.DAT, and LITTER.DU: c:\> dir l?tter.d?? The use of an asterisk wildcard before other characters, and of the character ranges discussed below, are enhancements to the standard wildcard syntax, and are not likely to work properly with software other than 4DOS, 4OS2, and 4DOS/NT. ## "Extra" question marks in your wildcard specification are ignored if the file name is shorter than the wildcard specification. For example, if you have files called LETTER.DOC, LETTER1.DOC, and LETTERA.DOC, this command will display all three names: c:\> dir letter?.doc The file LETTER.DOC is included in the display because the "extra" question mark at the end of "LETTER?" is ignored when matching the shorter name LETTER. ## In some cases, the question mark wildcard may be too general. You can also specify what characters you want to accept (or exclude) in a particular position in the filename by using square brackets. Inside the brackets, you can put the individual acceptable characters or ranges of characters. For example, if you wanted to match LETTER0.DOC through LETTER9.DOC, you could use this command: c:\> dir letter[0-9].doc ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 60 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- You could find all files that have a vowel as the second letter in their name this way. This example also demonstrates how to mix the wildcard characters: c:\> dir ?[aeiouy]*.* You can exclude a group of characters or a range of characters by using an exclamation mark [!] as the first character inside the brackets. This example displays all filenames that are at least 2 characters long except those which have a vowel as the second letter in their names: c:\> dir ?[!aeiouy]*.* The next example, which selects files such as AIP, BIP, and TIP but not NIP, demonstrates how you can use multiple ranges inside the brackets. It will accept a file that begins with an A, B, C, D, T, U, or V: c:\> dir [a-dt-v]ip ## You may use a question mark character inside the brackets, but its meaning is slightly different than a normal (unbracketed) question mark wildcard. A normal question mark wildcard matches any character, but will be ignored when matching a name shorter than the wildcard specification, as described above. A question mark inside brackets will match any character, but will not be discarded when matching shorter filenames. For example: c:\> dir letter[?].doc will display LETTER1.DOC and LETTERA.DOC, but not LETTER.DOC. ## A pair of brackets with no characters between them [], or an exclamation point and question mark together [!?],will match only if there is no character in that position. For example, [c:\] dir letter[].doc will not display LETTER1.DOC or LETTERA.DOC, but will display LETTER.DOC. This is most useful for commands like [c:\] dir /I"[]" *.btm which will display a list of all .BTM files which don't have a description. ## You can repeat any of the wildcard characters in any combination you desire within a single file name. For ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 61 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- example, the following command lists all files which have an A, B, or C as the third character, followed by zero or more additional characters, followed by a D, E, or F, followed optionally by some additional characters, and with an extension beginning with P or Q. You probably won't need to do anything this complex, but we've included it to show you the flexibility of extended wildcards: c:\> dir ??[abc]*[def]*.[pq]* 4OS2, ## You can also use the square bracket wildcard syntax to work 4NT around a conflict between HPFS and NTFS filenames containing semicolons [;], and the use of a semicolon to indicate an include list (see page 67). For example, if you have a file on an HPFS drive named C:\DATA\LETTER1;V2 and you enter this command: [c:\] del \data\letter1;v2 you will not get the results you expect. Instead of deleting the named file, 4OS2 or 4DOS/NT will attempt to delete LETTER1 and then V2, because the semicolon indicates an include list. However if you use square brackets around the semicolon it will be interpreted as a filename character, and not as an include list separator. For example, this command would delete C:\DATA\LETTER1;V2: [c:\] del \data\letter1[;]v2 Date, Time, and Size Ranges Most internal commands which accept wild cards also allow date, time, and size ranges to further define the files that you wish to work with. 4DOS, 4OS2, and 4DOS/NT will examine the files' timestamps (which record when the file was last modified), and the files' sizes, to determine which files meet the range criteria that you specify. A range begins with the switch character (usually a slash [/]), followed by a left square bracket ("[") and a character that specifies the range type: "s" for a size range, "d" for a date range, or "t" for a time range. The "s", "d", or "t" is followed by a start value, and an optional comma and end value. The range ends with a right square bracket ("]"). ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 62 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- Size Ranges Size ranges simply select files whose size is between the limits given. For example, /[s10000,20000] selects files between 10,000 and 20,000 bytes long. Either or both values in a size range can end with "k" to indicate thousands of bytes, "K" to indicate kilobytes (1,024 bytes), "m" to indicate millions of bytes, or "M" to indicate megabytes (1,048,576 bytes). For example, the range above could be rewritten as /[s10k,20k]. All ranges are inclusive. Both examples above will match files that are exactly 10,000 bytes and 20,000 bytes long, as well as all sizes in between. The second argument of a size range is optional. If you use a single argument, like /[s10k], you will select files of that size or larger. You can also precede the second argument with a plus sign [+]; when you do, it is added to the first value to determine the largest file size to include in the search. For example, /[s10k,+1k] select files from 10,000 through 11,000 bytes in size. Some further examples of size ranges: Specification Selects Files /[s0,0] of length zero (empty) /[s1M] 1 megabyte or more in length /[s10k,+200] between 10,000 and 10,200 bytes Date Ranges Date ranges select files that were created or last modified at any time between the two dates. For example, /[d12-1-93,12-5-93] selects files that were last modified between December 1, 1993, and December 5, 1993. The time for the starting date defaults to 00:00:00 and the time for the ending date defaults to 23:59:59. You can alter these defaults, if you wish, by including a start and stop time inside the date range. The time is separated from the date with an at sign [@]. For example, the range /[d7-1-94@8:00a,7-3-94@6:00p] selects files that were modified at any time between 8:00 am on July 1, 1994 and 6:00 pm on July 3, 1994. If you prefer, you can specify the times in 24- hour format (e.g., @18:00 for the end time in the previous example). ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 63 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- If you omit the second argument in a date range, the command processor substitutes the current date and time. For example, /[d10-1-93] selects files dated between October 1, 1993 and today. You can use an offset value for either the beginning or ending date, or both. An offset begins with a plus sign [+] or a minus sign [-] followed by an integer. If you use an offset for the second value, it is calculated relative to the first. If you use an offset for the first (or only) value, the current date is used as the basis for calculation. For example: Specification Selects Files /[d10-27-93,+3] modified between 10-27-93 and 10-30-93 /[d10-27-93,-3] modified between 10-24-93 and 10-27-93 /[d-0] modified today (from today minus zero days, to today) /[d-1] modified yesterday or today (from today minus one day, to today) /[d-1,+0] modified yesterday (from today minus one day, to zero days after that) You cannot use offsets in the time portion of a date range (the part after an at sign), but you can combine a time with a date offset. For example, /[d12-8-93@12:00,+2@12:00] selects files that were last modified between noon on December 8 and noon on December 10, 1993. Similarly, /[d-2@15:00,+1] selects files last modified between 3:00 pm the day before yesterday and the end of the day one day after that, i.e., yesterday. The second time defaults to the end of the day because no time is given. Time Ranges A time range specifies a file modification time without reference to the date. For example, to select files modified between noon and 2:00 pm on any date, use /[t12:00p,2:00p]. The times in a time range can either be in 12-hour format, with a trailing "a" for AM or "p" for PM, or in 24-hour format. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 64 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- If you omit the second argument in a time range, you will select files that were modified between the first time and the current time, on any date. You can also use offsets, beginning with a plus sign [+] or a minus sign [-] for either or both of the arguments in a time range. The offset values are interpreted as minutes. Some examples: Specification Selects Files /[t12:00p,+120] modified between noon and 2:00 PM on any date /[t-120,+120] modified between two hours ago and the current time on any date /[t0:00,11:59] modified in the morning on any date Using Ranges If you combine two types of ranges, a file must satisfy both ranges to be included. For example, /[d2-8-94,2-9-94] /[s1024,2048] means files last modified between February 8 and February 9, 1994, which are also between 1,024 and 2,048 bytes long. When you use a date, time, or size range in a command, it should immediately follow the command name. Unlike some command switches which apply to only part of the command line, the range usually applies to all file names specified for the command. Any exceptions are noted in the descriptions of individual commands. For example, to get a directory of all the *.C files dated October 1, 1993, you could use this command: c:\> dir /[d10-1-93,+0] *.c To delete all of the 0-byte files on your hard disk, you could use this command: c:\> del /[s0,0] *.* /s And to copy all of the non-zero byte files that you changed yesterday or today to your floppy disk, you can use this command: c:\> copy /[d-1] /[s1] *.* a: Date, time, and size ranges can be used with the ATTRIB, COPY, DEL, DESCRIBE, DIR, EXCEPT, FOR, LIST, MOVE, RD, REN, SELECT, ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 65 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- and TYPE commands. They cannot be used with filename completion or in filename arguments for variable functions. ## It can be complex to type all of the elements of a range, especially when it involves multiple dates and times. In this case you may find it easier to use aliases for common operations. For example, if you often wish to select from .DAT files modified over the last three days and copy the selected files to the floppy disk, you might define an alias like this: alias workback `select /[d-2] copy (*.dat) a:` For more complex requirements, you may want to use internal variables (e.g. _DATE or _TIME, see page 100) and variable functions (e.g. @DATE, @TIME, @MAKEDATE, @MAKETIME, @FILEDATE, @FILETIME, or @EVAL, see page 108). These variables and functions allow you to perform arithmetic and date / time calculations. 4OS2, The HPFS and NTFS file systems maintain 3 sets of dates and 4NT times for each file: creation, last access, and last modification. By default, date and time ranges work with the last modification time stamp. You can use the "last access" (a) or "created" (c) time stamp in a date or time range with the syntax: /[da...] or /[dc...] or .. /[ta...] or /[tc...] For example, to select files that were last accessed yesterday or today: /[da-1] Multiple Filenames Most file processing commands can work with multiple files at one time. To use multiple file names, you simply list the files one after another on the command line, separated by spaces. You can use wildcards in any or all of the filenames. For example, to copy all .TXT and .DOC files from the current directory to drive A, you could use this command: c:\> copy *.txt *.doc a: If the files you want to work with are not in the default directory, you must include the full path with each filename: c:\> copy a:\details\file1.txt a:\details\file1.doc c: ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 66 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- Multiple filenames are handy when you want to match a group of files which cannot be defined with a single filename and wildcards. They let you be very specific about which files you want to work with in a command. ! When you use multiple filenames with a command that expects both a source and a destination, like COPY or MOVE, be sure that you always include a specific destination on the command line. If you don't, the command will assume that the last filename is the destination and may overwrite important files. Like extended wildcards and include lists (see below), the multiple filename feature will work with internal commands but not with external programs, unless those programs have been written to handle multiple file names on the command line. If you have a list of files to process that's too long to put on the command line or too time-consuming to type, see the SELECT command on page 313 for another way of passing multiple file names to a command. Include Lists Any internal command that accepts multiple filenames will also accept one or more include lists. An include list is simply a group of filenames, with or without wildcards, separated by semicolons [;]. All files in the include list must be in the same directory. You may not add a space on either side of the semicolon. If you used an include list instead of multiple file names for the previous examples, they would look like this: c:\> copy *.txt;*.doc a: c:\> copy a:\details\file1.txt;file1.doc c: Include lists are similar to multiple filenames, but have three important differences. First, you don't have to repeat the path to your files if you use an include list, because all of the included files must be in the same directory. Second, if you use include lists, you aren't as likely to accidentally overwrite files if you forget a destination path for commands like COPY, because the last name in the list will be part of the include list, and won't be seen as the destination file name. (Include lists can only be used as the source parameter - the location files are coming from - for COPY and other similar commands. They cannot be used to specify a destination for files.) ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 67 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- Third, multiple filenames and include lists are processed differently by the DIR and SELECT commands. If you use multiple filenames, all of the files matching the first filename are processed, then all of the files matching the second name, and so on. When you use an include list, all files that match any entry in the include list are processed together, and will appear together in the directory display or SELECT list. You can see this difference clearly if you experiment with both techniques and the DIR command. For example, c:\> dir *.txt *.doc will list all the .TXT files with a directory header, the file list, and a summary of the total number of files and bytes used. Then it will do the same for the .DOC files. However, c:\> dir *.txt;*.doc will display all the files in one list. Like extended wildcards and multiple filenames (see above), the include list feature will work with internal commands, but not with external programs (unless they have been programmed especially to support it). Executable Extensions Normally, when you type a filename (as opposed to an alias or internal command name) as the first word on the command line, the command processor looks for a file with that name to execute. The file's extension may be .EXE or .COM to indicate that it contains a program, or it may have a batch file extension like .BTM (under OS/2, a file's contents may also indicate that it is executable). The exact list of default extensions for executable files varies slightly depending on which operating system you use, because each has its own rules for batch file extensions(see 20 page for details). You can add to this default list of extensions, and have 4DOS, 4OS2, or 4DOS/NT take the action you want with files that are not executable programs or batch files. The action taken is always based on the file's extension. For example, you could start your text editor whenever you type the name of a .DOC file, or start your database manager whenever you type the name of a .DAT file. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 68 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- Environment variables define the internal command, external program, batch file, or alias to run for each defined file extension. To create an executable extension, use the SET command to create a new environment variable. An environment variable is recognized as an executable extension if its name begins with a period. For example, if you want to run a word processor called EDITOR whenever you type the name of a file that has an extension of .EDT, you could use this command: c:\> set .edt=c:\edit\editor.exe The syntax for creating an executable extension is: set .ext=command [options] where .EXT is the executable file extension; command is the name of the internal command, external program, alias, or batch file to run; and [options] are any command-line startup options you want to specify for the program, batch file, or alias. If the command is a batch file or external program, the command processor will search the PATH for it if necessary. However, you can make sure that the correct program or batch file is used, and speed up the executable extension, by specifying the full name including drive, path, filename, and extension. Once an executable extension is defined, any time you name a file with that extension the corresponding program, batch file, or alias is started, with the name of your file passed to it as a parameter. The following example defines QBASIC.EXE as the processor for .BAS files: c:\> set .bas=c:\dos\qbasic.exe /run With this definition, if you have a file named PUSHCART.BAS in the current directory and enter the command: c:\> pushcart the command processor will execute the command: c:\dos\qbasic.exe /run pushcart.bas ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 69 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- The next example defines B.EXE (the Brief text editor) as the processor for .C files: c:\> set .c=c:\brief\b.exe -Mxyz Now, if you have a file called HELLO.C and enter the command c:\> hello -i30 This will be expanded to: c:\brief\b.exe -Mxyz hello.c -i30 Notice that the text from the .C environment variable is inserted at the beginning of the line, including any options, followed by the original file name plus its extension, and then the remainder of the original command line. In order for executable extensions to work, the command, program, batch file, or alias must be able to interpret the command line properly. For example, if a program you want to run doesn't accept a file name on its command line as shown in these examples, then executable extensions won't work with that program. The search for executable files starts in the current directory, then proceeds to each subdirectory specified by the PATH environment variable (if a "." is used in the PATH the current directory is not searched first; see the PATH command on page 290 for details). You may need to take this search order into account when using executable extensions. Using the .BAS example above, if you had a file named FORMAT.BAS in the current directory and entered the command FORMAT A:, your command would run the QBASIC processor specified by the executable extension, instead of finding the standard DOS FORMAT command as you intended. You can get around this by remembering that the DOS FORMAT command is in the file FORMAT.COM. If you entered the command FORMAT.COM A: then the .BAS executable extension would not match, and the search would continue until it found the FORMAT.COM file. ## Executable extensions may include wildcards, so you could, for example, run your text editor for any file with an extension beginning with T by defining an executable extension called .T*. Extended wildcards (e.g., DO[CT] for .DOC and .DOT files) may also be used. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 70 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- ## Advanced Features The next three features are designed for advanced users. If you are a novice user, you might want to skim over this section and return to it as your computing skills and needs progress. Conditional Commands When an internal command or external program finishes, it returns a result called the exit code. Conditional commands allow you to perform tasks based upon the previous command's exit code. Many programs return a 0 if they are successful and a non-zero value if they encounter an error. If you separate two commands by && (AND), the second command will be executed only if the first returns an exit code of 0. For example, the following command will only erase files if the BACKUP operation succeeds: c:\> backup c:\ a: && del c:\*.bak;*.lst If you separate two commands by || (OR), the second command will be executed only if the first returns a non-zero exit code. For example, if the following BACKUP operation fails, then ECHO will display a message: c:\> backup c:\ a: || echo Error in the backup! All internal commands return an exit code, but not all external programs do. Conditional commands will behave unpredictably if you use them with external programs which do not return an explicit exit code. Command Grouping Command grouping allows you to logically group a set of commands together by enclosing them in parentheses. The parentheses are similar in function to the BEGIN and END block statements in some programming languages. There are two primary uses for command grouping. One is to execute multiple commands in a place where normally only a single command is allowed. For example, suppose you want to copy then rename all the .WKQ files on drives A: and B: using the FOR command. You could do it like this: c:\> for %drv in (A B) do copy %drv:*.wkq d:\wksave\ ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 71 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- c:\> for %drv in (A B) do ren %drv:*.wkq *.old But with command grouping you can do the same thing in one command (enter this on one line): c:\> for %drv in (A B) do (copy %drv:*.wkq d:\wksave\ ^ ren %drv:*.wkq *.sav) The COPY and REN commands enclosed in the parentheses appear to FOR as if they were a single command, so both commands are executed for every element of the FOR list. (To try a command like this under 4OS2 or 4DOS/NT, replace the caret [^] with an ampersand [&].) This kind of command grouping is most useful with the EXCEPT, FOR, GLOBAL, and IF commands. You cannot use command grouping to make SELECT execute several commands, because SELECT will assume that the parentheses are marking the list of files from which to select, and will display an error message or give incorrect results if you try to use parentheses for command grouping instead. (You can use a SELECT command inside the command grouping parentheses, you just can't use command grouping to specify a group of commands for SELECT to execute.) The second common use of command grouping is to redirect input or output for several commands without repeatedly using the redirection symbols. For example, consider the following batch file fragment which places some header lines (including today's date) and directory displays in an output file using redirection. The first ECHO command creates the file using >, and the other commands append to the file using >>: echo Data files %_date > filelist dir *.dat >> filelist echo. >> filelist echo Text files %_date >> filelist dir *.txt >> filelist Using command grouping, these commands can be written much more simply. Enter this example on one line (use an ampersand [&] as the command separator if you try this under 4OS2 or 4DOS/NT): (echo Data files %_date ^ dir *.dat ^ echo. ^ echo Text files %_date ^ dir *.txt) > filelist The redirection, which appears outside the parentheses, applies to all the commands within the parentheses. Because the redirection is performed only once, the commands will run ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 72 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- slightly faster than if each command was entered separately. The same approach can be used for input redirection and for piping. You can also use command grouping in a batch file or at the prompt to split commands over several lines. This last example is like the redirection example above, but is entered at the prompt. Note the "More?" prompt after each incomplete line. None of the commands are executed until the command group is completed with the closing parenthesis. This example does not have to be entered on one line: c:\> (echo Data files %_date More? dir *.dat More? echo. More? echo Text files %_date More? dir *.txt) > filelist c:\> A group of commands in parentheses is like a long command line. The total length of the group may not exceed 511 characters in 4DOS, or 2,047 characters in 4OS2 and 4DOS/NT, whether the commands are entered from the prompt, an alias, or a batch file. The limit includes the space required to expand aliases and environment variables invoked within the group. In addition, each line you type at the normal prompt or the More? prompt, and each individual command within the line, must meet the usual length limits: 255 characters in 4DOS, or 1,023 characters in 4OS2 and 4DOS/NT. Escape Character 4DOS, 4OS2, and 4DOS/NT recognize a user-definable escape character. This character gives the following character a special meaning; it is not the same as the ASCII ESC that is often used in ANSI and printer control sequences. The default 4DOS escape character is Ctrl-X (ASCII 24), which will be displayed on your screen as an up arrow (in this ASCII version of our manual, <Ctrl-X> is used to represent this character). The default 4OS2 and 4DOS/NT escape character is a caret [^]. If you don't like using the default escape character, you can pick another character using the SETDOS /E command (see page 324) or the EscapeChar directive in your .INI file (see page 138). If you plan to share aliases or batch files between 4DOS, 4OS2, and 4DOS/NT, see page 74 for details about ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 73 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- choosing compatible escape characters for two or more products. Eight special characters are recognized when they are preceded by the escape character. The combination of the escape character and one of these characters is translated to a single character, as shown below. These are useful for redirecting codes to the printer; <Ctrl-X>e is also useful to generate ANSI "escape sequences" in your PROMPT, ECHO, or other output commands; and <Ctrl-X>r can be used in keystroke aliases. The special characters which can follow the escape character are: b backspace c comma e the ASCII ESC character (ASCII 27) f form feed n line feed r carriage return s space t tab character If you follow the escape character with any other character, the escape character is removed and the second character is copied directly to the command line. This allows you to suppress the normal meaning of special characters (such as ? * / \ | " ` > < and &). For example, to send a form feed followed by the sequence ESC Y to the printer, you can use this command: c:\> echos <Ctrl-X>f<Ctrl-X>eY > prn 4DOS, 4OS2, and 4DOS/NT Compatibility 4DOS, 4OS2, and 4DOS/NT are highly compatible with each other. However, there are minor differences between them. These differences are caused by the different requirements of each operating system and by our design goal of maintaining compatibility between each product and the default command processor which it replaces. We discuss the differences between our products in this manual as part of the description of each feature and command. Most of the differences are minor: different command line lengths, a few different options in some commands, and some commands that only make sense in one or two products. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 74 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- If you use two or more of our products, or if you want to share aliases and batch files with users of different products, you need to be aware of the differences in three important characters: the Command Separator (see page 47), the Escape Character (page 73), and the Parameter Character (page 81). The default values of each of these characters in each product is shown in the following chart: Character 4DOS Default 4OS2 and 4NT Default ----------------- ------------ -------------------- Command Separator ^ & Escape Character <Ctrl-X> ^ Parameter Character & $ In your batch files and aliases, and even at the command line, you can smooth over these differences in two ways: * Select a consistent set of characters with .INI file directives (see page 126) or the SETDOS command (page 322). For example, to set the 4DOS characters to match 4OS2 and 4DOS/NT, use: CommandSep = & EscapeChar = ^ ParameterChar = $ in 4DOS.INI, or use the command: SETDOS /C& /P$ /E<Ctrl-X>^ (Note the use of the old escape character [<Ctrl-X>] before the new one [^]. This is because the new escape character is also the old command separator, and will be interpreted as the end of the command if it does not have an escape character before it!) * Use internal variables that contain the current special character, rather than using the character itself (see page 100). For example, this command: if "%1" == "" (echo Argument missing! ^ quit) will only work if the command separator is a caret. However, this version works regardless of the current command separator: if "%1" == "" (echo Argument missing! %+ quit) ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 75 CHAPTER 3 / USING 4DOS, 4OS2, AND 4DOS/NT ------------------------------------------------------------------- The following chart shows the correspondence between the appropriate SETDOS command options, .INI file directives, and internal variables: Special SETDOS INI File Internal Character Switch Directive Variable ----------------- ------ ---------- -------- Command Separator /C CommandSep %+ Escape Character /E EscapeChar %= Parameter Character /P ParameterChar (none) ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 76 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- CHAPTER 4 / ALIASES AND BATCH FILES This chapter introduces two of the most powerful features of 4DOS, 4OS2, and 4DOS/NT: aliases and batch files. It also discusses the environment (a list of information available to all programs), along with the command processor's internal variables and variable functions. The discussion of the environment, variables, and variable functions is included in this chapter because they are most often used in aliases and batch files. Aliases Much of the power of 4DOS, 4OS2, and 4DOS/NT comes together in aliases, which give you the ability to create your own commands. An alias is a name that you select for a command or group of commands. Simple aliases substitute a new name for an existing command. More complex aliases can redefine the default settings of internal or external commands, operate as very fast in-memory batch files, and perform commands based on the results of other commands. This section of the manual will show you some examples of the power of aliases. See the ALIAS command (page 161) for complete details about writing your own aliases. The simplest type of alias gives a new name to an existing command. For example, you could create a command called ROOT to switch to the root directory this way: c:\> alias root = cd \ After the alias has been defined this way, every time you type the command ROOT, you will actually execute the command CD \. Aliases can also create customized versions of commands. For example, the DIR command can sort a directory in various ways. You can create an alias called DE that means "sort the directory by filename extension, and pause after each page while displaying it" like this: c:\> alias de = dir /oe /p Aliases can be used to execute sequences of commands as well. The following command creates an alias called W which saves the current drive and directory, changes to the WP directory on drive C, runs the program E:\WP60\WP.EXE, and, when the ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 77 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- program terminates, returns to the original drive and directory: c:\> alias w = `pushd c:\wp ^ e:\wp60\wp.exe ^ popd` This alias is enclosed in back-quotes because it contains multiple commands. You must use the back-quotes whenever an alias contains multiple commands, environment variables, parameters (see below), redirection, or piping. See the ALIAS command for full details. Also, please note that throughout this section we use the 4DOS command separator, a caret [^], to separate multiple commands. If you are using 4OS2 or 4DOS/NT, substitute an ampersand [&] for the caret in the examples. Aliases can be nested, that is, one alias can invoke another. For example, the alias above could also be written as: c:\> alias wp = e:\wp60\wp.exe c:\> alias w = `pushd c:\wp ^ wp ^ popd` If you enter W as a command, the command processor will execute the PUSHD command, detect that the next command (WP) is another alias, and execute the program E:\WP60\WP.EXE, and - when the program exits - return to the first alias, execute the POPD command, and return to the prompt. You can use aliases to change the default options for both internal commands and external commands. Suppose that you always want the DEL command to prompt before it erases a file: c:\> alias del = *del /p An asterisk [*] is used in front of the second "del" to show that it is the name of an internal command, not an alias. See page 163 for more information about this use of the asterisk. You may have a program on your system that has the same name as an internal command. Normally, if you type the command name, you will start the internal command rather than the program you desire, unless you explicitly add its full path on the command line. For example, if you have a program named LIST.COM in the C:\UTIL directory, you could run it with the command C:\UTIL\LIST.COM. However, if you simply type LIST, the internal LIST command will be invoked instead. Aliases give you two ways to get around this problem. First, you could define an alias that runs the program in question, but with a different name: ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 78 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- c:\> alias l = c:\util\list.com Another approach is to rename the internal command and use the original name for the external program. The following example renames the LIST command as DISPLAY and then uses a second alias to run LIST.COM whenever you type LIST: c:\> alias display = *list c:\> alias list = c:\util\list.com You can also assign an alias to a key, so that every time you press the key, the command will be invoked. You do so by naming the alias with an at sign [@] followed by a key name. After you enter this next example, you will see a 2-column directory with paging whenever you press Shift-F5, then Enter: c:\> alias @Shift-F5 = *dir /2/p This alias will put the DIR command on the command line when you press Shift-F5, then wait for you to enter file names or additional switches. You must press Enter when you are ready to execute the command. You can change this alias so that it executes the command immediately, and does not display it on the command line or wait for you to type a filename. To do so, use two at signs at the start of the alias name: c:\> alias @@Shift-F5 = *dir /2/p The next example clears the screen whenever you press Alt-F1: c:\> alias @@Alt-F1 = cls Aliases have many other capabilities as well. This example creates a simple command-line calculator. Once you have entered the example, you can type CALC 4*19, for example, and you will see the answer: c:\> alias calc = `echo The answer is: %@eval[%&]` Our last example in this section creates an alias called IN. It will temporarily change directories, run an internal or external command, and then return to the current directory when the command is finished: c:\> alias in = `pushd %1 ^ %2& ^ popd` Now if you type c:\> in c:\letters wp letter.txt ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 79 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- you will change to the C:\LETTERS subdirectory, execute the command WP LETTER.TXT and then return to the current directory. Your copy of 4DOS, 4OS2, or 4DOS/NT includes a sample alias file called ALIASES which contains several useful aliases and demonstrates many alias techniques. Also, see the ALIAS and UNALIAS commands on pages 161 and 350 for more information and examples. See page 87 for tips about using aliases inside your batch files. Batch Files A batch file is a file that contains a list of commands to execute. 4DOS, 4OS2, and 4DOS/NT read and interpret each line as if it had been typed at the keyboard. Like aliases, batch files are handy for automating computing tasks. Unlike aliases, batch files can be as long as you wish. Batch files take up separate disk space for each file, and can't usually execute quite as quickly as aliases, since they must be read from the disk. .BAT, .CMD, and .BTM Files A batch file can run in two different modes. In the first, traditional mode, each line of the batch file is read and executed individually. In the second mode, the entire batch file is read into memory at once. The second mode can be 5 to 10 times faster, especially if most of the commands in the batch file are internal commands. However, only the first mode can be used for self-modifying batch files (which are rare), for batch files which install memory-resident utilities under DOS, and for batch files larger than 64K bytes. The batch file's extension determines its mode. Files with a .BAT extension (in 4DOS and 4DOS/NT), or a .CMD extension (in 4OS2 and 4DOS/NT) are run in the slower, traditional mode. Files with a .BTM extension are run in the faster, more efficient mode. You can change the execution mode inside a batch file with the LOADBTM command (see page 276). ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 80 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- Echoing By default, each line in a batch file is displayed or "echoed" as it is executed. You can change this behavior, if you want, in several different ways: Any batch file line that begins with an [@] symbol will not be displayed. The display can be turned off and on within a batch file with the ECHO OFF and ECHO ON commands. The default setting can be changed with the SETDOS /V command (see page 326) or the BatchEcho directive in the .INI file (see page 137). For example, the following line turns off echoing inside a batch file. The [@] symbol keeps the batch file from displaying the ECHO OFF command: @echo off Your command processor also has a command line echo that is unrelated to the batch file echo setting. See the ECHO command on page 223 for details about both settings. Batch File Parameters Like aliases and application programs, batch files can examine the command line that is used to invoke them. The command tail (everything on the command line after the batch file name) is separated into individual parameters (also called arguments or batch variables) by scanning for the spaces, tabs, and commas that separate the parameters. A batch file can work with the individual parameters or with the command tail as a whole. These parameters are numbered from %1 to %127. %1 refers to the first parameter on the command line, %2 to the second, and so on. It is up to the batch file to determine the meaning of each parameter. You can use quotation marks to pass spaces, tabs, commas, and other special characters in a batch file parameter; see page 123 for details. Parameters that are referred to in a batch file, but which are missing on the command line, appear as empty strings inside the batch file. For example, if you start a batch file and put two parameters on the command line, any reference in the ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 81 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- batch file to %3, or any higher-numbered parameter, will be interpreted as an empty string. A batch file can also work with three special parameters: %0 contains the name of the batch file as it was entered on the command line, %# contains the number of command line arguments, and in 4DOS %n& contains the complete command-line tail starting with argument number "n" (for example, %3& means the third parameter and all those after it). The default value of "n" is 1, so %& contains the entire command tail. The values of these special parameters will change if you use the SHIFT command (see page 330). 4OS2, By default, 4OS2 and 4DOS/NT use a dollar sign [$] instead of 4NT an ampersand [&] to indicate the remainder of the command tail. For example, %$ means all the parameters, and %2$ means the second parameter and all those after it. If you want to share batch files or aliases between 4DOS and these command processors, you can select a new character for any product with the SETDOS /P command (see page 325) or the ParameterChar directive in your .INI file (see page 140). For example, if your batch file interprets the first argument as a subdirectory name then the following line would move to the specified directory: cd %1 A friendlier batch file would check to make sure the directory exists and take some special action if it doesn't: iff isdir %1 then ^ cd %1 else ^ echo Subdirectory %1 does not exist! ^ quit endiff (see the IF and IFF commands on pages 251 and 257). ## Batch files can also use environment variables, internal variables, and variable functions. See pages 100 - 121 for a complete list of the internal variables and variable functions available. You can use these variables and functions to determine system status (e.g., the type of CPU in the system), resource levels (e.g., the amount of free disk space), file information (e.g., the date and time a file was last modified), and other information (e.g., the current date and time). You can also perform arithmetic operations (including date and time arithmetic), manipulate strings and substrings, extract parts of a filename, and perform simple file access. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 82 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- ## To create temporary variables for use inside a batch file, just use the SET command to store the information you want in an environment variable. Pick a variable name that isn't likely to be in use by some other program (for example, PATH would be a bad choice), and use the UNSET command (page 351) to remove these variables from the environment at the end of your batch file. You can use SETLOCAL (page 329) and ENDLOCAL (page 226) to create a "local" environment so that the original environment will be restored when your batch file is finished. ## Environment variables used in a batch file may contain either numbers or text. It is up to you to keep track of what's in each variable and use it appropriately; if you don't (for example, if you use %@EVAL to add a number to a text string), you'll get an error message. Batch File Commands Several 4DOS, 4OS2, and 4DOS/NT commands are particularly suited to batch file processing. Each command is explained in detail in the Command Reference section of this manual, beginning on page 153. Here is a list of some of the commands you might find most useful: BEEP produces a sound of any pitch and duration through the computer's speaker. CALL executes one batch file from within another. CANCEL terminates all batch file processing. CLS and COLOR set the screen display colors. DO starts a loop. The loop can be based on a counter, or on a conditional test like those used in IF and IFF. DRAWBOX draws a box on the screen. DRAWHLINE and DRAWVLINE draw horizontal and vertical lines on the screen. ECHO and ECHOS print text on the screen (the text can also be redirected to a file or device). GOSUB executes a subroutine inside a batch file. The RETURN command terminates the subroutine. GOTO branches to a different location in the batch file. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 83 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- FOR executes commands for each file that matches a set of wildcards, or each entry in a list. IF and IFF execute commands based on a test of string or numeric values, program exit codes, or other conditions. INKEY and INPUT collect keyboard input from the user and store it in environment variables. KEYSTACK places keystrokes into the 4DOS Keystack. LOADBTM changes the batch file operating mode. ON initializes error handling for Ctrl-C / Ctrl-Break, or for program and command errors. PAUSE displays a message and waits for the user to press a key. QUIT ends the current batch file and optionally returns an exit code. REM places a remark in a batch file. SCREEN positions the cursor on the screen and optionally prints a message at the new location. SCRPUT displays a message in color. SETLOCAL saves the current disk drive, default directory, environment, and alias list. ENDLOCAL restores the settings that were saved. SHIFT changes the numbering of the parameters. START starts another session or window in certain multitasking environments. TEXT displays a block of text. ENDTEXT ends the block. TIMER starts or reads a stopwatch. VSCRPUT displays a vertical message in color. These commands, along with the internal variables and variable functions, make the enhanced batch file language extremely powerful. Your copy of 4DOS, 4OS2, or 4DOS/NT includes a number of sample batch files, combined in the file SAMPLES.BTM, that demonstrate some of the many things you can do with batch files. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 84 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- Interrupting a Batch File You can usually interrupt a batch file by pressing Ctrl-C or Ctrl-Break. Whether and when these keystrokes are recognized will depend on whether the command processor or an application program is running, how the application (if any) was written, whether BREAK is ON or OFF under DOS (see page 177), and whether the ON BREAK command is in use (see page 288). If 4DOS, 4OS2, or 4DOS/NT detects a Ctrl-C or Ctrl-Break (and ON BREAK is not in use), it will display a prompt, for example: Cancel batch job C:\CHARGE.BTM ? (Y/N/A) : Enter N to continue, Y to terminate the current batch file and continue with any batch file which called it, or A to end all batch file processing regardless of the batch file nesting level. Answering Y is similar to the QUIT command (page 301); answering A is similar to the CANCEL command (page 180). Automatic Batch Files 4DOS, 4OS2, and 4DOS/NT support three "automatic" batch files, files that run without your intervention, as long as the command processor can find them. Each time 4DOS, 4OS2, or 4DOS/NT starts as either a primary or a secondary shell, it looks for an automatic batch file called 4START.BTM, 4START.BAT (for 4DOS), or 4START.CMD (for 4OS2 and 4DOS/NT). If the 4START batch file is not in the same directory as your command processor itself, you should use the 4StartPath directive in your .INI file (see page 131) to specify its location. 4START is optional, so the command processor will not display an error message if it cannot find the file. 4START is a convenient place to change the color or content of the prompt for each shell, LOG the start of a shell, or put other special startup or configuration commands. Under 4OS2 and 4DOS/NT, it is one way to set aliases and environment variables (under 4DOS, these are normally set in AUTOEXEC.BAT). ## With the exception of some 4DOS initialization switches, the entire startup command line passed to the command processor is available to 4START via batch file parameters (%1, %2, etc.). This can be useful if you want to see the command line passed to a secondary shell by an application. For example, to pause ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 85 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- if any parameters are passed to a secondary shell you could include this command in 4START (enter this on one line): if "%1" != "" .and. "%_shell" gt 0 pause Starting shell %_shell with parameters [%&] 4DOS Whenever it is started as a primary shell, 4DOS runs AUTOEXEC.BAT immediately after 4START. On a DOS system, AUTOEXEC.BAT runs each time the computer boots up. (If COMMAND.COM cannot find AUTOEXEC.BAT, it asks you for the time and date. 4DOS skips that step and immediately displays a prompt.) Normally, AUTOEXEC.BAT must be in the root directory of the boot drive. You can store it in a different location (and even give it a different name) by using the 4DOS.INI directive AutoExecPath (see page 131). You can also pass parameters to AUTOEXEC.BAT using the AutoExecParms directive in 4DOS.INI. 4OS2 and 4DOS/NT do not execute AUTOEXEC.BAT. Whenever a 4DOS, 4OS2, or 4DOS/NT shell ends, it runs a third automatic batch file called 4EXIT.BTM, 4EXIT.BAT (for 4DOS), or 4EXIT.CMD (for 4OS2 and 4DOS/NT). This file, if you use it, should be in the same directory as your 4START batch file. Like 4START, 4EXIT is optional. It is not necessary in most circumstances, but it is a convenient place to put commands to save information such as a history list before a shell ends, or LOG the end of the shell. Under 4DOS, 4START and 4EXIT should not load any memory resident programs (TSRs). Otherwise, these three files can include any commands that could be part of any batch file or any commands which you could type from the command line. ## Detecting 4DOS, 4OS2, or 4DOS/NT From a batch file, you can determine if 4DOS, 4OS2, or 4DOS/NT is loaded by testing for the variable function @EVAL, with a test like this: if "%@eval[2+2]" == "4" echo 4DOS is loaded! This test can never succeed in COMMAND.COM or CMD.EXE. Other variable functions could be used for the same purpose. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 86 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- ## Using Aliases in Batch Files One way to simplify batch file programming is to use aliases to hide unnecessary detail inside a batch file. For example, suppose you want to implement a multiple choice list in a batch file that will let you select among several different applications. This example shows one way to do so: alias in `pushd %1 ^ %2& ^ popd` alias choice `elseiff "%userchoice"=="%1" then` :dispmenu screen 8 0 text Enter your choice: 1. Word Processing 2. Spreadsheet 3. Communications endtext inkey %%userchoice iff "1"=="2" then ^ rem Always fail and go to next line choice 1 ^ in d:\letters c:\wp60\wp.exe choice 2 ^ in d:\finance c:\quattro\q.exe choice 3 ^ in d:\comm c:\comsw\pcplus.exe else scrput 23 0 bri whi on red Invalid choice, try again goto dispmenu endiff unalias in choice The first alias, IN, expects 2 or more command-line arguments. It uses the first as a new working directory and changes to that directory with a PUSHD command. The rest of the command line is interpreted as another command plus possible command line parameters, which the alias executes. This alias could be used from the command line. The second alias, CHOICE, expects one command-line argument. It tests whether an environment variable called userchoice has the same value as the command-line argument. This alias is designed just for this particular batch file. If you try to use CHOICE from the command line, you will see an error because the alias uses ELSEIFF and THEN without the necessary IFF and ENDIFF to define a block. (The last line of the batch file "cleans up" by removing IN and CHOICE from the alias list.) The next 9 lines print a menu on the screen and then get a keystroke from the user and store the keystroke in an environment variable called userchoice. Then the batch file tests the user's keystroke to decide what action to take. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 87 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- Since the CHOICE alias starts with an ELSEIFF command, there has to be an IFF. But the first condition must fail in order to get to the ELSEIFF command in the first CHOICE alias, so the IFF statement starts with a condition that will always be false. The three lines after the IFF are easy to follow and much shorter than they would be without the aliases. If it had to be typed in full, the first choice line would look like this: elseiff "%userchoice"=="1" then pushd d:\letters ^ c:\wp60\wp.exe ^ popd There's another side to aliases in batch files. If you're going to distribute your batch files to others, you need to remember that they may have aliases defined for the commands you're going to use. For example if the user has aliased CD to CDD and you aren't expecting this, your file may not work as you intended. There are two ways to address this problem. First, you can use SETLOCAL, ENDLOCAL, and UNALIAS to clear out aliases before your batch file starts and restore them at the end. For example: setlocal unalias * rem Aliases cleared, set up new aliases alias ... rem Other batch file commands go here endlocal Remember that SETLOCAL and ENDLOCAL will save and restore not only the aliases but also the environment and the current drive and directory. If this method isn't appropriate or necessary for the batch file you're working on, you can also use an asterisk [*] before the name of any command. The asterisk means the command that follows it should not be interpreted as an alias. For example the following command redirects a list of file names to the file FILELIST: dir /b > filelist However, if the user has redefined DIR with an alias this command may not do what you want. To get around this just use: *dir /b > filelist The same can be done for any command in your batch file. If you use the asterisk, it will disable alias processing, and ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 88 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- the rest of the command will be processed normally as an internal command, external command, or batch file. Using an asterisk before a command will work whether or not there is actually an alias defined with the same name as the command. If there is no alias with that name, the asterisk will be ignored and the command will be processed as if the asterisk wasn't there. ## Debugging Batch Files There are several tricks you can use in debugging batch files. Probably the simplest is to turn ECHO on at the beginning of the file while you're testing it, or use SETDOS /V2 to force ECHO on even if an ECHO OFF command is used in the batch file. This will give you a picture of what is happening as the file is executed. It will make your output look messy of course, so just turn it off once things are working. You can also turn ECHO on at the beginning of a group of commands you want to "watch", and off at the end, just by adding ECHO commands at the appropriate spots in your file. If an error occurs in a batch file, the error message will display the name of the file, the number of the line that contained the error, and the error itself. For example, e:\test.bat [3] Invalid parameter "/d" tells you that the file E:\TEST.BAT contains an error on line 3. The first line of the batch file is numbered 1. You can also use the SETDOS /Y1 command to single step through all or part of a batch file (see page 328). Insert the command at the beginning of the portion of the batch file that you wish to single-step through, and add a SETDOS /Y0 command at the end of the section. After 4DOS, 4OS2, or 4DOS/NT executes the SETDOS command, it will display each command before it is executed, followed by a Y/N/R prompt. Press Y to execute the command, N to skip the command and go on to the next, or R or Esc to execute the remainder of the batch file up to the next SETDOS /Y1 command without further prompting. You can also press Ctrl-C or Ctrl-Break at the Y/N/R prompt to halt execution of the remainder of the batch file and return to the command processor prompt. Another trick is to insert PAUSE commands wherever you need them in order to be able to watch what's happening. For complex debugging, you can make an alias that uses INKEY for a similar purpose, but helps you out a little more. For example ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 89 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- (enter this on one line, and use an ampersand [&] as the command separator if you are using 4OS2 or 4DOS/NT): alias step `set skey=^ inkey Step: %%skey ^ iff "%skey"=="S" then ^ set /P ^ elseiff "%skey"=="X" then ^ quit ^ endiff` Now anywhere you insert a STEP command in your file you'll get the Step: prompt during execution. At that point you can type S to do a SET /P and display the current contents of your environment variables, X to exit the batch file, and any other key to go on. (Of course you may need to modify this alias to fit your particular needs.) If you can't figure out how your aliases and variables are expanded, try turning LOG on at the start of the batch file. LOG keeps track of all commands after alias and variable expansion are completed, and gives you a record in a file that you can examine after the batch file is done. If you simply want to see a record of what commands are executed, without the expansion, use LOG /H. You may also want to consider using redirection to capture your batch file output. Simply type the batch file name followed by the redirection symbols, for example: c:\> mybatch >& testout This records all batch file output, including error messages, in the file TESTOUT, so you can go back and examine it. If you have ECHO ON in the batch file you'll get the batch commands intermingled with the output, which can provide a very useful trace of what's happening. Of course, output from full-screen commands and programs that don't write to the standard output devices can't be recorded, but you can still gain a lot of useful information if your batch file does much output. If you're using redirection to see the output, remember that any prompts for input will probably go to the output file and not to the screen, so you need to know in advance the sequence of keystrokes required to get through the entire batch file, and enter them by hand or with KEYSTACK. (As an example, the raw text for the Guided Tour distributed with new copies of 4DOS, 4OS2, and 4DOS/NT was created by writing a 4DOS batch file containing the demonstration commands, testing it to get the proper keystroke sequence, and executing a command which used KEYSTACK to send the keystrokes and redirected the batch file's output to a disk file.) ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 90 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- ## Batch File String Processing As you gain experience with batch files, you're likely to find that you need to manipulate text strings. You may need to prompt a user for a name or password, process a list of files, or find a name in a phone list. All of these are examples of string processing - the manipulation of lines of readable text. 4DOS, 4OS2, and 4DOS/NT include several features that make string processing easier. For example, you can use the INKEY and INPUT commands for user input; the ECHO, SCREEN, SCRPUT, and VSCRPUT commands for output; and the FOR command or the @FILEREAD function to scan through the lines of a file. In addition, variable functions offer a wide range of string handling capabilities (see page 108 for full details). For example, suppose you need a batch file that will prompt a user for a name, break the name into a first name and a last name, and then run a hypothetical LOGIN program. LOGIN expects the syntax /F:first /L:last with both the first and last names in upper case and neither name longer than 8 characters. Here is one way to write such a program: @echo off setlocal unalias * input Enter your name (no initials): %%name set first=%@word[%name,0] set flen=%@len[%first] set last=%@word[%name,1] set llen=%@len[%last] iff %flen gt 8 .or. %llen gt 8 echo First or last name too long quit endiff login /F:%@upper[%first] /L:%@upper[%last] endlocal The SETLOCAL command at the beginning of this batch file saves the environment and aliases. Then the UNALIAS * command removes any existing aliases so they won't interfere with the behavior of the commands in the remainder of the batch file (you can accomplish the same thing by using an asterisk [*] in front of each command). The first block of lines ends with an INPUT command which asks the user to enter a name. The user's input is stored in the environment variable NAME. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 91 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- The second block of lines extracts the user's first and last names from the NAME variable and calculates the length of each. It stores the first and last name, along with the length of each, in additional environment variables. Note that the @WORD function numbers the first word as 0, not as 1. The IFF command in the third block of lines tests the length of both the first and last names. If either is longer than 8 characters, the batch file displays an error message and ends. Finally, in the last block, the batch file executes the LOGIN program with the appropriate parameters, then uses the ENDLOCAL command to restore the original environment and alias list. At the same time, ENDLOCAL discards the temporary variables that the batch file used (NAME, FIRST, FLEN, etc.). When you're processing strings, you also need to avoid some common traps. The biggest one is handling special characters. Suppose you have a batch file with these two commands, which simply accept a string and display it: input Enter a string: %%str echo %str Those lines look safe, but what happens if the user enters the string "some > none" (without the quotes). After the string is placed in the variable STR, the second line becomes echo some > none The ">" is a redirection symbol, so the line echoes the string "some" and redirects it to a file called NONE - probably not what you expected. You could try using quotation marks (see page 123) to avoid this kind of problem, but that won't quite work. If you use back-quotes (ECHO `%STR`), the command will echo the four-character string %STR. Environment variable names are not expanded (replaced by their contents, see page 121) when they are inside back-quotes. If you use double quotes (ECHO "%STR"), the string entered by the user will be displayed properly, and so will the quotation marks. With double quotes, the output would look like this: "some > none" As you can imagine, this kind of problem becomes much more difficult if you try to process text from a file. Special characters in the text can cause all kinds of confusion in your batch files. Text containing back-quotes, double quotes, ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 92 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- or redirection symbols can be virtually impossible to handle correctly. One way to overcome these potential problems is to use the SETDOS /X command (see page 327) to temporarily disable redirection symbols and other special characters. The two- line batch file above would be a lot more likely to produce the expected results if it were rewritten this way: setdos /x-15678 input Enter a string: %%str echo %str setdos /x0 The first line turns off alias processing and disables several special symbols, including the command separator and all redirection symbols. Once the string has been processed, the last line re-enables the features that were turned off in the first line. If you need advanced string processing capabilities beyond those provided by 4DOS, 4OS2, and 4DOS/NT, you may want to consider using the REXX language. Our products support external REXX programs for this purpose; see page 95 for additional details. ## Batch File Compression You can compress your .BTM files with a program called BATCOMP.EXE, which is distributed with 4DOS, 4OS2, and 4DOS/NT. This program condenses batch files by about a third and makes them unreadable with the LIST command and similar utilities. Compressed batch files run at approximately the same speed as regular .BTM files. You may want to consider compressing batch files if you need to distribute them to others and keep your original code secret or prevent your users from altering them. You may also want to consider compressing batch files to save some disk space on the systems where the compressed files are used. (However, you will not save space if you keep your compressed batch files on a disk compressed with a program like DBLSPACE, Stacker, or SuperStor.) The full syntax for the batch compression program is BATCOMP [/O] input file [output file] ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 93 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- You must specify the full name of the input file, including its extension, on the BATCOMP command line. If you do not specify the output file, BATCOMP will use the same base name as the input file and add a .BTM extension. BATCOMP will also add a .BTM extension if you specify a base name for the output file without an extension. For example, to compress MYBATCH.BAT and save the result as MYBATCH.BTM, you can use any of these three commands: c:\> batcomp mybatch.bat c:\> batcomp mybatch.bat mybatch c:\> batcomp mybatch.bat mybatch.btm If the output file (MYBATCH.BTM in the examples above) already exists, BATCOMP will prompt you before overwriting the file. You can disable the prompt by including /O on the BATCOMP command line immediately before the input file name. Even if you use the /O option, BATCOMP will not compress a file into itself. JP Software does not provide a decompression utility to uncompress batch files. If you use BATCOMP.EXE, make sure that you also keep a copy of the original batch file for future inspection or modification. You can adopt one of two strategies for keeping track of your original source files and compressed batch files. First, you may want to create the source files with a traditional .BAT or .CMD extension and reserve the .BTM extension for compressed batch files. The advantage of this approach is that you can modify and test the uncompressed versions at any time, although they will run in the slower, traditional mode unless they begin with a LOADBTM command (see page 276). If you prefer, you can use a .BTM extension for both the source and compressed files. In this case you will have to use a different base name for each file. For example, you might use MYBATCHS.BTM for the source file and MYBATCH.BTM for the compressed file. This may make it more difficult to keep track of the correspondence between the source file and the compressed file, but it allows both files to run automatically in the high-speed .BTM mode. Each of our command processors includes its own version of BATCOMP.EXE, set up to run under the corresponding operating system. However, the output produced by each program is the same, so a batch file compressed with any version of BATCOMP can be used with any JP Software command processor. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 94 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- If you plan to distribute batch files to users of different platforms, be sure to read the compatibility discussion on 74 page . ## REXX Support REXX is a a powerful file and text processing language developed by IBM, and available on many PC and other platforms. You can invoke REXX programs from 4DOS, 4OS2, or 4DOS/NT. REXX is an ideal extension to the 4DOS, 4OS2, and 4DOS/NT batch language, especially if you need advanced string processing capabilities. The REXX language is not built into 4DOS, 4OS2, or 4DOS/NT. Under DOS and Windows NT, you must have a copy of Personal REXX from Quercus Systems in Saratoga, CA in order to use the REXX language. Under IBM OS/2 1.3 and above you can use the built-in REXX language provided by IBM, or use Quercus's Personal REXX for OS/2. (Personal REXX is available from JP Software or directly from Quercus Systems.) 4DOS Under 4DOS, REXX programs are stored in .REX files. To enable REXX support you must install Personal REXX, and define an executable extension (see page 68) that tells 4DOS to load Personal REXX when you invoke a .REX file. For example: set .rex=c:\prexx\rexx.exe 4OS2 Under 4OS2, REXX programs are stored in .CMD files. 4OS2 checks to see if the first two characters on the first line of a .CMD file are [/*], the beginning of a REXX comment. If so, it passes the file to OS/2's built-in REXX facility for processing. If Personal REXX for OS/2 is installed, it automatically replaces OS/2's built-in REXX, and handles all REXX commands passed by 4OS2. 4NT Under 4DOS/NT, REXX programs may be stored in .CMD or .REX files. 4DOS/NT checks to see if the first two characters on the first line of a .CMD or .REX file are [/*]. If so, it passes the file to Personal REXX for Windows NT for processing. You must have Personal REXX for Windows NT installed to enable 4DOS/NT's REXX support. Both Personal REXX and OS/2's built-in REXX extend the interface between REXX and the command processor by allowing you to invoke 4DOS, 4OS2, or 4DOS/NT commands from within a REXX program. For details, or for more information on any aspect of REXX, see your Personal REXX or OS/2 REXX documentation. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 95 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- 4OS2, ## EXTPROC Support 4NT 4OS2 and 4DOS/NT offer an external processor (EXTPROC) option for batch files that lets you define an external program to process a particular .CMD file. To identify a .CMD file to be used with an external processor, place the string "EXTPROC" as the first word on the first line of the file, followed by the name of the external program that should be called. The command processor will start the program and pass it the name of the .CMD file and any command-line arguments that were entered. For example, suppose GETDATA.CMD contains the following lines: EXTPROC D:\DATAACQ\DATALOAD.EXE OPEN PORT1 READ 4000 DISKWRITE D:\DATAACQ\PORT1\RAW Then if you entered the command: [d:\dataacq] getdata /p17 The command processor would read the GETDATA.CMD file, determine that it began with an EXTPROC command, read the name of the processor program, and then execute the command: D:\DATAACQ\DATALOAD.EXE D:\DATAACQ\GETDATA.CMD /p17 The hypothetical DATALOAD.EXE program would then be responsible for reopening the GETDATA.CMD file, ignoring the EXTPROC line at the start, and interpreting the other instructions in the file. It would also have to respond appropriately to the command-line parameter entered (/p17). Do not try to use 4OS2 or 4DOS/NT as the external processor named on the EXTPROC line in the .CMD file. They will interpret the EXTPROC line as a command to re-open themselves. The result will be an infinite loop that will continue until the computer runs out of resources and locks up. Using the Environment The environment is a collection of information about your computer that every program receives. Each entry in the environment consists of a variable name, followed by an equal sign and a string of text. You can automatically substitute the text for the variable name in any command. To create the substitution, include a percent sign [%] and a variable name ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 96 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- on the command line or in an alias or batch file. For example, you can create a variable named BACKUP like this: c:\> set BACKUP=*.bak;*.bk!;*.bk If you then type c:\> del %BACKUP it is equivalent to the following command: del *.bak;*.bk!;*.bk ## The variable names you use this way may contain any alphabetic or numeric characters, the underscore character [_], and the dollar sign [$]. You can force acceptance of other characters by including the full variable name in square brackets, like this: %[AB##2]. You can also "nest" environment variables using square brackets. For example %[%var1] means "the contents of the variable whose name is stored in VAR1". A variable referenced with this technique cannot contain more than 255 characters of information. Nested variable expansion can be disabled with the SETDOS /X command (see page 327). In 4DOS, the size of the environment is specified by the Environment and EnvFree directives in 4DOS.INI (see page 132) or by the /E: startup switch (see the 4DOS Introduction and Installation Guide). In 4OS2 and 4DOS/NT the size of the environment is set automatically. ## Environment variables may contain alias names. The command processor will substitute the variable value for the name, then check for any alias name which may have been included within the variable's value. For example, the following commands would generate a 2-column directory of the .TXT files: c:\> alias d2 dir /2 c:\> set cmd=d2 c:\> %cmd *.txt ## The trailing percent sign that was traditionally required for environment variable names is not usually required in 4DOS, 4OS2, or 4DOS/NT, which accept any character that cannot be part of a variable name as the terminator. However, the trailing percent can be used to maintain compatibility. The trailing percent sign is needed if you want to join two variable values. The following examples show the possible ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 97 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- interactions between variables and literal strings. First, create two environment variables called ONE and TWO this way: c:\> set ONE=abcd c:\> set TWO=efgh Now the following combinations produce the output text shown: %ONE%TWO abcdTWO ("%ONE%" + "TWO") %ONE%TWO% abcdTWO ("%ONE%" + "TWO%") %ONE%%TWO abcdefgh ("%ONE%" + "%TWO") %ONE%%TWO% abcdefgh ("%ONE%" + "%TWO%") %ONE%[TWO] abcd[TWO] ("%ONE%" + "[TWO]") %ONE%[TWO]% abcd[TWO] ("%ONE%" + "[TWO]%") %[ONE]%TWO abcdefgh ("%[ONE]" + "%TWO") %[ONE]%TWO% abcdefgh ("%[ONE]" + "%TWO%") ## If you want to pass a percent sign to a command, or a string which includes a percent sign, you must use two percent signs in a row. Otherwise, the single percent sign will be seen as the beginning of a variable name and will not be passed on to the command. For example, to display the string "We're with you 100%" you would use the command: echo We're with you 100%% You can also use back-quotes around the text, rather than a double percent sign. See page 123 for details. 4DOS Each copy of the command processor maintains its own copy of the environment. The copy of the environment maintained by the primary shell is called the master environment. When using a secondary shell, 4DOS will allow you to access the master environment in the primary shell with the commands SET /M (page 319), UNSET /M (page 351), and ESET /M (page 227), and with the %@MASTER variable function (page 118). Master environment access is not available in 4OS2 or 4DOS/NT. Configuration Variables The following environment variables have special meanings in 4DOS, 4OS2, and 4DOS/NT. CDPATH tells the command processor where to search for directories specified by the CD, CDD, and PUSHD commands and in automatic directory changes. (_CDPATH can be used as an alternative to CDPATH if you are using Microsoft Bookshelf, which uses a CDPATH variable for its own purposes.) CDPATH is composed of a list of directories, ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 98 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- separated by semicolons [;]. See page 44 for more information about using CDPATH. CMDLINE is the fully expanded text of the currently executing command line. CMDLINE is set just before invoking any .COM, .EXE, .BTM, .BAT, or .CMD file. If a command line is prefaced with an "@" to prevent echoing (see page 38), it will not be put in CMDLINE, and any previous CMDLINE variable will be removed from the environment. Under DOS, this allows you to squeeze out the last few bytes of environment space before loading TSRs by prefacing each TSR command with an "@". COLORDIR controls directory display colors used by DIR and SELECT. See page 30 for a complete description of the format of this variable. COMSPEC contains the full path and name of the command processor. COMSPEC is most commonly used by applications which have a "shell to the command prompt" feature. For details on how COMSPEC is set and used, see your Introduction and Installation Guide. DIRCMD is used by some versions of COMMAND.COM and CMD.EXE to hold default options for the DIR command. 4DOS and its cousins do not support this variable, but you can achieve the same effect with an alias. For example, if you want the DIR command to default to a 2- column display with a vertical sort and a pause at the end of each page, you could use this alias: c:\> alias dir = `*dir /2/p/v` If you wish to continue to use DIRCMD for compatibility with systems that do not use 4DOS, you can define the alias this way: c:\> alias dir = `*dir %dircmd` PATH is a list of directories that 4DOS, 4OS2, or 4DOS/NT will search for executable files that aren't in the current directory. PATH may also be used by some application programs to find their own files. See page 20 and the PATH command on page 290 for a full description of this variable. PROMPT defines the command-line prompt. It can be set or changed with the PROMPT command (see page 295). ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 99 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- 4DOS TEMP specifies the directory where 4DOS should store temporary pipe files if the TEMP4DOS variable doesn't exist. Some other programs also use TEMP to define where they should place their temporary files. Temporary pipe files are not used in 4OS2 and 4DOS/NT. 4DOS TEMP4DOS specifies where 4DOS should store temporary pipe files. Temporary pipe files are not used in 4OS2 and 4DOS/NT. 4NT In addition, 4DOS/NT uses the environment to keep track of the default directory on each drive or hard disk volume. DOS and OS/2 keep track of the default directory for each drive letter internally; Windows NT does not. 4DOS/NT overcomes this incompatibility by saving the default directory for each drive in the environment, using variable names that cannot be accessed by the user. Each variable begins with an equal sign followed by the drive letter and a colon (for example, =C:). You can view these variables with the SET command, but you cannot change them with any of the commands in 4DOS/NT. ## Internal Variables Internal variables are special environment variables built into 4DOS, 4OS2, and 4DOS/NT to provide information about your system. They are not actually stored in the environment, but can be used in commands, aliases, and batch files just like any other environment variable. The values of these variables are stored internally in the command processor, and cannot be changed with the SET, UNSET, or ESET command. However, you can override any of these variables by defining a new variable with the same name. These internal variables are often used in batch files and aliases to examine system resources and adjust to the current computer settings. You can examine the contents of any internal variable (except %= or %+) from the command line with a command like this: c:\> echo %variablename The variables are listed below. The first list is by category, to assist you in locating the information you want quickly. The second list includes all the variables in alphabetical order, and defines the meaning of each one. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 100 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- Internal Variable Categories Hardware status: _APMAC _APMBATT _APMLIFE _CPU _KBHIT _MONITOR _NDP _VIDEO Operating system and software status: _ANSI _BOOT _CODEPAGE _COUNTRY _DOS _DOSVER _DPMI _DV _MOUSE _WIN _WINDIR _WINSYSDIR _WINVER Command processor status: _4VER _ALIAS _BATCH _BATCHLINE _BATCHNAME _DNAME _ENV _HLOGFILE _KSTACK _LOGFILE _PID _PIPE _PPID _PTYPE _SHELL _SID _SWAPPING _TRANSIENT _WINTITLE Screen and color: _BG _COLUMN _COLUMNS _FG _ROW _ROWS Drives and directories: _CWD _CWDS _CWP _CWPS _DISK _LASTDISK Dates and times: _DATE _DAY _DOW _DOY _HOUR _MINUTE _MONTH _SECOND _TIME _YEAR Error codes: ? ?? _? _SYSERR Compatibility: = + ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 101 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- Internal Variable Details (In the list below the possible values for most variables are shown in double quotes for ease of understanding. The actual values returned by the variables do not include the double quotes.) ? contains the exit code of the last external command. Many programs return a "0" to indicate success and a non-zero value to signal an error. However, not all programs return an exit code. If no explicit exit code is returned, the value of %? is undefined. 4DOS ?? returns a code which explains how the last program terminated: 0 - program terminated normally. 1 - program terminated by Ctrl-C or Ctrl-Break. 2 - program terminated due to a critical error. 3 - program terminated and stayed resident in memory (TSR). _? contains the exit code of the last internal command. It is set to "0" if the command was successful, "1" if a usage error occurred, "2" if another command processor error or an operating system error occurred, or "3" if the command was interrupted by Ctrl-C or Ctrl-Break. You must use or save this value immediately, because it is set by every internal command. = returns the current escape character. Use this variable, instead of the actual escape character, if you want your batch files and aliases to work regardless of how the escape character is defined. For example, if the escape character is a caret [^] (the default in 4OS2 and 4DOS/NT), both of the commands below will send a form feed to the printer. However, if the escape character has been changed, the first command will send the string "^f" to the printer, while the second command will continue to work as intended. echos ^f > prn echos %=f > prn + returns the current command separator. Use this variable, instead of the actual command separator, if you want your batch files and aliases to work regardless of how the command separator is defined. For example, if the command separator is an ampersand [&] (the default in 4OS2 and 4DOS/NT), both of the commands below will display "Hello" on one line and "world" on the next. However, if the command separator has ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 102 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- been changed the first command will display "Hello & echo world", while the second command will continue to work as intended. echo Hello & echo world echo Hello %+ echo world _4VER is the current 4DOS, 4OS2, or 4DOS/NT version (for example, "5.0"). 4DOS _ALIAS contains the free space in the alias list, in bytes. _ANSI contains "1" if internal flags indicate that ANSI.SYS or a compatible driver is installed; "0" if not. 4OS2 4OS2 always enables OS/2's ANSI support, and assumes that it remains enabled. Therefore _ANSI always returns "1" in 4OS2. 4NT Under 4DOS/NT, _ANSI always returns "0", because there is no ANSI support in Windows NT. 4DOS In 4DOS, the internal flags which determine the value of _ANSI depend on the SETDOS /A option (see page 323) and the ANSI directive in 4DOS.INI (see page 137), as shown in the table below. If SETDOS /A is 0 or ANSI is set to Auto, 4DOS tests for the presence of an ANSI driver. In this case you may need to experiment to see if this variable works properly with your particular driver, because there is no standard and 100% reliable way to detect an ANSI driver. See page 25 for more information on ANSI drivers. SETDOS /A ANSI Directive _ANSI Value 0 (default) Auto (default) Result of test 1 Yes 1 2 No 0 4DOS _APMAC is the Advanced Power Management AC line status ("on", "off", or "unknown"). An empty string is returned if APM is not installed on your system. (See the Glossary on page 381 for a short description of APM.) 4DOS _APMBATT is the Advanced Power Management battery status ("high", "low", "critical", "charging", or "unknown"). An empty string is returned if APM is not installed. 4DOS _APMLIFE is the Advanced Power Management remaining battery life (0 - 100 or "unknown"). An empty string is returned if APM is not installed. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 103 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- _BATCH is the current batch nesting level. It is "0" if no batch file is currently being processed. _BATCHLINE is the current line number in the current batch file. It is "-1" if no batch file is currently being processed. _BATCHNAME is the full pathname of the current batch file. It is an empty string if no batch file is currently being processed. _BG is a string containing the first three characters of the screen background color at the current cursor location (for example, "Bla"). _BOOT is the boot drive letter, without a colon. _CODEPAGE is the current code page number (see CHCP on page ). 184 _COLUMN is the current cursor column (for example, "0" for the left side of the screen). _COLUMNS is the current number of screen columns (for example, "80"). _COUNTRY is the current country code. _CPU is the CPU type: 86 8086 and 8088 386 i386 186 80186 and 80188 486 i486 200 NEC V20 and V30 586 Pentium 286 80286 _CWD is the current working directory in the format d:\pathname. _CWDS has the same value as CWD, except it ends the pathname with a backslash [\]. _CWP is the current working directory in the format \pathname. _CWPS has the same value as CWP, except it ends the pathname with a backslash [\]. _DATE contains the current system date, in the format mm-dd-yy (U.S.), dd-mm-yy (Europe), or yy-mm-dd (Japan). _DAY is the day of the month (1 to 31). ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 104 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- _DISK is the current disk drive, without a colon (for example, "C"). _DNAME is the name of the file used to store file descriptions. It can be changed with the DescriptionName directive in the .INI file (see page 148). _DOS is the operating system type ("DOS", "OS2", or "NT"). 4DOS always returns "DOS", 4OS2 always returns "OS2", and 4DOS/NT always returns "NT". This may be useful if you have batch files running under more than one operating system. _DOSVER is the current operating system version (for example, "6.0"). When running 4DOS in an OS/2 DOS session the version number will be 10.3 for OS/2 1.3, 20.1 for OS/2 2.1, and so on. _DOW is the first three characters of the current day of the week ("Mon", "Tue", "Wed", etc.). _DOY is the day of the year (1 to 366). 4DOS _DPMI returns the DPMI version number, or "0" if DPMI isn't present. (See the Glossary on page 381 for a short description of DPMI.) 4DOS _DV is "1" if DESQview is loaded or "0" otherwise. 4DOS _ENV is the free space in the environment, in bytes. _FG is a string containing the first three letters of the screen foreground color at the current cursor position (for example, "Whi"). _HLOGFILE returns the name of the current history log file (or an empty string if LOG /H is OFF). _HOUR is the current hour (0 - 23). _KBHIT returns "1" if one or more keystrokes are waiting in the keyboard buffer, or "0" if the keyboard buffer is empty. 4DOS _KSTACK returns "1" if KSTACK.COM is loaded or "0" otherwise. _LASTDISK is the last valid drive letter, without a colon. _LOGFILE returns the name of the current log file (or an empty string if LOG is OFF). _MINUTE is the current minute (0 - 59). ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 105 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- 4DOS, _MONITOR is the monitor type ("mono" or "color"). 4OS2 _MONTH is the month of the year (1 to 12). _MOUSE is "1" if a mouse driver is loaded, and "0" otherwise. _NDP is the coprocessor type: 0 no coprocessor is installed 87 8087 287 80287 387 80387, 80486DX, or Pentium 4OS2 _PID is the current process ID number. 4OS2, _PIPE returns "1" if the current process is running inside a 4NT pipe or "0" otherwise. 4OS2 _PPID is the process ID number of the parent process. 4OS2 _PTYPE is the current OS/2 process type: AVIO Character mode, windowed DT Detached (no screen in use) FS Character mode, full-screen PM Presentation Manager _ROW is the current cursor row (for example, "0" for the top of the screen). _ROWS is the current number of screen rows (for example, "25"). _SECOND is the current second (0 - 59). _SHELL is the current shell nesting level. The primary shell is level "0", and each subsequent secondary shell increments the level by 1. 4OS2 _SID is the session ID number. 4DOS _SWAPPING returns the current swapping state. The return value is "OFF" if swapping has been disabled with the SWAPPING command, "EMS" if expanded memory is being used, "XMS" if extended memory is being used, or "Disk" if 4DOS is using disk swapping. The return value is "None" if swapping has been disabled with the 4DOS.INI Swapping directive or if 4DOS failed to initiate memory or disk swapping during initialization. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 106 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- _SYSERR is the error code of the last operating system error. You will need a technical or programmer's manual to understand these error values. _TIME contains the current system time in the format hh:mm:ss. The separator character may vary depending upon your country information. _TRANSIENT is "1" if the current shell is transient (started with a /C, see your Introduction and Installation Guide for details), or "0" otherwise. 4DOS, _VIDEO is the video card type ("mono", "cga", "ega", or 4OS2 "vga"). _WIN is the current Microsoft Windows mode. This variable will always be zero except when 4DOS is running under Microsoft Windows: 0 Windows is not running 1 Windows 2 2 Windows 3 in 386 enhanced mode 3 Windows 3 in real or standard mode 4NT _WINDIR returns the name of the Windows NT directory. 4NT _WINSYSDIR returns the name of the Windows NT system directory. _WINTITLE returns the title of the current window. This variable is valid in 4OS2 and 4DOS/NT, and in 4DOS when it is running in a DOS session under OS/2. If you are using 4DOS running under DOS or DOS plus Windows, the return value is an empty string. 4NT _WINVER returns the current Windows NT version number. _YEAR is the current year (1980 to 2099). For FAT drives under DOS, OS/2, and Windows NT 3.1 the _CWD, _CWDS, _CWP, _CWPS, and _DISK variables will return their result in upper or lower case depending on the value of the SETDOS /U switch (see page 326) or the UpperCase directive in the .INI file (see page 141). On HPFS and NTFS drives, and on FAT drives under Windows NT 3.5 and above,these variables will return names as they are stored on the disk, and no case shifting will be performed (see page 17 for more details). You can use these variables in a wide variety of ways depending on your needs. Here are just a few examples. Some ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 107 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- of these examples rely on the IF command (page 251) or the IFF command (page 257) to test the value of a variable and perform different actions based on that value. In a 4DOS or 4OS2 batch file, set the color based on the video card type: iff "%_video"=="mono" then color bright white on black else color bright white on blue endiff Call another batch file if 4DOS is running under DESQview: if "%_dv" == "1" call dvstart Store the current date and time in a file, then save the output of a DIR command in the same file: echo Directory as of %_date %_time > dirsave dir >> dirsave Set up a prompt for the primary shell which displays the time and current directory, and a different one for secondary shells which includes the shell level rather than the time (see PROMPT on page 295 for details about setting the prompt). Also set different background colors for the two shells, without changing the foreground color. You might use a sequence like this in your 4START file (see page 85): iff %_shell==0 then prompt $t $p$g color %_fg on blue else prompt [$z] $p$g color %_fg on cyan endiff ## Variable Functions Variable functions are like internal variables, but they take one or more arguments (which can be environment variables or even other variable functions) and they return a value. Like all environment variables, these variable functions must be preceded by a percent sign in normal use (%@EVAL, %@LEN, etc.). All variable functions must have square brackets enclosing their argument(s). The argument(s) to a variable ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 108 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- function cannot exceed 255 characters in length for all arguments taken as a group. The variable functions are useful in aliases and batch files to check on available system resources, manipulate strings and numbers, and work with filenames. Some variable functions, like @DISKFREE, are shown with "b|k|m" as one of their arguments. Those functions return a number of bytes, kilobytes, or megabytes based on the "b|k|m" argument: b return the number of bytes K return the number of kilobytes (bytes / 1,024) k return the number of thousands of bytes (bytes / 1,000) M return the number of megabytes (bytes / 1,048,576) m return the number of millions of bytes (bytes / 1,000,000) You can include commas in the results from a "b|k|m" function by appending a "c" to the argument. For example, to add commas to a "b" or number of bytes result, enter "bc" as the argument. ! In variable functions which take a drive letter as an argument, like @DISKFREE or @READY, the drive letter must be followed by a colon. The function will not work properly if you use the drive letter without the colon. ! The @FILEREAD, @FILEWRITE, @FILESEEK, and @FILECLOSE functions allow you to access files based on their file handle. These functions should only be used with file handles returned by @FILEOPEN! If you use them with any other file handle you may damage other files opened by the command processor (or, in a secondary shell, the program which started the command processor), or hang your system. The functions are listed below. The first list is by category, to assist you in locating the function you want quickly. The second list includes all the functions in alphabetical order, and defines the arguments and return value for each one. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 109 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- Variable Function Categories System status: @DOSMEM @EMS @EXTENDED @MASTER @READSCR @XMS Drives and devices: @CDROM @DEVICE @DISKFREE @DISKTOTAL @DISKUSED @FSTYPE @LABEL @LPT @READY @REMOTE @REMOVABLE Files: @ATTRIB @DESCRIPT @EXETYPE @FILEAGE @FILECLOSE @FILEDATE @FILEOPEN @FILEREAD @FILES @FILESEEK @FILESEEKL @FILESIZE @FILETIME @FILEWRITE @FILEWRITEB @FINDCLOSE @FINDFIRST @FINDNEXT @LINE @LINES @SEARCH @TRUENAME @UNIQUE File names: @EXT @FILENAME @FULL @NAME @PATH Strings and characters: @ASCII @CHAR @FORMAT @INDEX @INSTR @LEN @LOWER @REPEAT @SUBSTR @TRIM @UPPER @WORD @WORDS Numbers and arithmetic: @COMMA @DEC @EVAL @INC @INT @NUMERIC @RANDOM Dates and times: @DATE @MAKEAGE @MAKEDATE @MAKETIME @TIME Utility: @ALIAS @EXEC @IF @REXX @SELECT @TIMER ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 110 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- Variable Function Details @ALIAS[name]: Returns the contents of the specified alias as a string, or a null string if the alias doesn't exist. When manipulating strings returned by @ALIAS you may need to disable certain special characters with the SETDOS /X command (see page 327). Otherwise, command separators, redirection characters, and other similar "punctuation" in the alias may be interpreted as part of the current command, rather than part of a simple text string. 4NT @ALTNAME[filename]: Returns the alternate (8.3 FAT-format) name for the specified file. Under Windows NT 3.1 this function returns a valid name on HPFS and NTFS drives only. Under Windows NT 3.5 and above it works on all drives. @ASCII[c]: Returns the numeric value of the specified ASCII character as a string. For example %@ASCII[A] returns 65. You can put an escape character [<Ctrl-X>] before the actual character to process. This allows quotes and other special characters as the argument (e.g., %@ASCII[<Ctrl-X>`]). @ATTRIB[filename[,nrhsda]]: Returns a "1" if the specified file has the matching attribute(s); otherwise returns a "0". The attributes are: N Normal (no attributes set) S System R Read-only D Directory H Hidden A Archive The attributes (other than N) can be combined (for example %@ATTRIB[MYFILE,HS]). ATTRIB will only return a 1 if all of the attributes match. If you do not specify any attributes, @ATTRIB will return the attributes of the specified file in the format RHSAD, rather than a "0" or "1". Attributes which are not set will be replaced with an underscore. For example. if SECURE.DAT has the read-only, hidden, and archive attributes set, %@ATTRIB[SECURE.DAT] would return "RH_A_" (without the quotes). @CDROM[d:]: Returns "1" if the drive is a CD-ROM or "0" otherwise. @CHAR[n]: Returns the character corresponding to an ASCII numeric value. For example %@CHAR[65] returns A. @COMMA[n]: Inserts commas, or the "thousands separator" character for your country ID, into a numeric string. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 111 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- @DATE[mm-dd-yy]: Returns the number of days since January 1, 1980 for the specified date. DATE uses the date format and separators mandated by your country code (for example dd.mm.yy in Germany, or yy-mm-dd in Japan). @DEC[%var]: Returns the same value as @EVAL[%var - 1]. That is, it retrieves and decrements the value of a variable. The variable itself is not changed; to do so, use a command like this: set var=%@dec[%var] @DESCRIPT[filename]: Returns the file description for the specified filename (see the DESCRIBE command on page 201). @DEVICE[name]: Returns "1" if the specified name is a character device (such as a printer or serial port), or "0" if not. @DISKFREE[d:,b|k|m]: Returns the amount of free disk space on the specified drive. @DISKTOTAL[d:,b|k|m]: Returns the total disk space on the specified drive. @DISKUSED[d:,b|k|m]: Returns the amount of disk space in use by files and directories on the specified drive. @DOSMEM[b|k|m]: In 4DOS, returns the amount of free base memory. In 4OS2, returns the size of the largest free memory block (either in physical or virtual memory). In 4DOS/NT, returns the amount of free physical memory. 4DOS @EMS[b|k|m]: Returns the amount of free EMS memory. @EVAL[expression]: Evaluates an arithmetic expression. @EVAL supports addition (+), subtraction (-), multiplication (*), division (/), integer division (\, returns the integer part of the quotient), modulo (%%), and integer exponentiation (**). The expression can contain environment variables and other variable functions. @EVAL also supports parentheses, commas, and decimals. Parentheses can be nested. @EVAL will strip leading and trailing zeros from the result. When evaluating expressions, **, *, /, \, and %% take precedence over + and -. For example, 3 + 4 * 2 will be interpreted as 3 + 8, not as 7 * 2. To change this order of evaluation, use parentheses to specify the order you want. The maximum precision is 16 digits to the left of the decimal point and 8 digits to the right of the decimal point. You can ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 112 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- alter the default precision to the right of the decimal point with the EvalMax and EvalMin .INI file directives (see page 138) and with the SETDOS /F command (see page 322). You can alter the precision for a single evaluation with the construct @EVAL[expression=x.y]. The x value specifies the minimum decimal precision (i.e., the minimum number of decimal places displayed); the y value sets the maximum decimal precision. If x is greater than y, it is ignored. You can specify either or both arguments, for example: @eval[3/7=.4] returns 0.4286 @eval[3/7=2] returns 0.42857143 @eval[3/6=2.4] returns 0.50 Also see @DEC and @INC. @EXEC[command]: Execute the command. The command can be an alias, internal command, external command, .BTM file, or .BAT file. @EXEC is primarily intended for running a program from within the PROMPT. It is a "back-door" entry into command processing and should be used with extreme caution. Incorrect or recursive use of @EXEC may cause stack overflows or hang your system. 4OS2 @EXETYPE[filename]: Returns the application type as a string: DOS DOS .COM, .EXE, or .BAT file (OS/2 2.x only) AVIO OS/2 Character mode, windowed FS OS/2 Character mode, full-screen PM OS/2 Presentation Manager WIN Windows 3 (OS/2 2.x only) UNKNOWN Any other file @EXT[filename]: Returns the extension from a file name, without a leading period. 4DOS @EXTENDED[b|k|m]: Returns the amount of extended memory. @FILEAGE[filename]: Returns the date and time of the file as a single numeric value. The number can be used to compare the relative ages of two or more files. @FILECLOSE[n]: Closes the file whose handle is "n." You cannot close handles 0, 1 or 2. Returns "0" if the file closed OK or "-1" if an error occurs. Be sure to read the cautionary note about file functions on page 109. @FILEDATE[filename]: Returns the date a file was last modified, in the default country format (mm-dd-yy for the US). ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 113 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- @FILENAME[filename]: Returns the name and extension of a file, without a path. @FILEOPEN[filename, read | write | append]: Opens the file in the specified mode and returns the file handle as an integer. Returns "-1" if the file cannot be opened. Be sure to read the cautionary note about file functions on page 109. @FILEREAD[n[,length]]: Reads data from the file whose handle is "n." Returns "**EOF**" if you attempt to read past the end of the file. If "length" is not specified @FILEREAD will read until the next CR or LF (end of line) character. If "length" is specified, @FILEREAD will read "length" bytes regardless of any end of line characters. Be sure to read the cautionary note about file functions on page 109. @FILES[filename [,-nrhsda]]: Returns the number of files that match the filename specification, which may contain wildcards and include lists. Returns an empty string if no files match. The filename must refer to a single directory; to check several directories, use @FILES once for each directory, and add the results together with @EVAL. The second argument, if included, defines the attributes of the files that will be included in the search. The attributes are: N Normal (no attributes set) S System R Read-only D Directory H Hidden A Archive The attributes (other than N) can be combined (for example %@FILES[MYFILE,HS]). @FILES will only find a file if all of the attributes match. You can prefix an attribute with "-" to mean "everything except files with this attribute." @FILESEEK[n,offset,start]: Moves the file pointer "offset" bytes in the file whose handle is "n". Returns the new position of the pointer, in bytes from the start of the file. Set "start" to 0 to seek relative to the beginning of the file, 1 to seek relative to the current file pointer, or 2 to seek relative to the end of the file. The offset value may be negative (seek backward), positive (seek forward), or zero (return current position, but do not change it). Be sure to read the cautionary note about file functions on page 109. @FILESEEKL[n,line]: Moves the file pointer to the specified line in the file whose handle is "n". Returns the new position of the pointer, in bytes from the start of the file. Be sure to read the cautionary note about file functions on page 109. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 114 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- @FILESIZE[filename,b|k|m]: Returns the size of a file, or "-1" if the file does not exist. If the filename includes wildcards or an include list, returns the combined size of all matching files. @FILETIME[filename]: Returns the time a file was last modified, in hh:mm format. @FILEWRITE[n,text]: Writes a line to the file whose handle is "n". Returns the number of bytes written, or "-1" if an error occurred. Be sure to read the cautionary note about file functions on page 109. @FILEWRITEB[n,length,string]: Writes the specified number of bytes from the string to the file whose handle is "n". Returns the number of bytes written, or "-1" if an error occurred. Be sure to read the cautionary note about file functions on page 109. 4NT FINDCLOSE[filename]: Signals the end of a @FINDFIRST / @FINDNEXT sequence. You must use this function to release the directory search handle used for @FINDFIRST / @FINDNEXT. @FINDFIRST[filename [,-nrhsda]]: Returns the name of the first file that matches the filename, which may contain wildcards and "include lists". The second argument, if included, defines the attributes of the files that will be included in the search. Returns an empty string if no files match. The attributes are: N Normal (no attributes set) S System R Read-only D Directory H Hidden A Archive The attributes (other than N) can be combined (for example %@FINDFIRST[MYFILE,HS]). @FINDFIRST will only find a file if all of the attributes match. You can prefix an attribute with "-" to mean "everything except files with this attribute." 4NT After @FINDFIRST or the last @FINDNEXT, you must use @FINDCLOSE to avoid running out of directory search handles. @FINDNEXT[[filename [,-nrhsda]]]: Returns the name of the next file that matches the filename passed to @FINDFIRST. @FINDNEXT should only be used after a successful call to @FINDFIRST. The first argument is included for compatibility with previous versions, but is ignored; it can be omitted if the second argument is not used (e.g. %@FINDNEXT[]). The second argument, if included, defines the attributes of the ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 115 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- files that will be included in the search (see @FINDFIRST for details). Returns an empty string when no more files match. 4NT After the last @FINDNEXT, you must use @FINDCLOSE to avoid running out of directory search handles. @FORMAT[[-][x][.y],string]: Reformats a string, truncating it or padding it with spaces as necessary. If you use the minus [-], the string is left-justified; otherwise, it is right- justified. The x value is the minimum number of characters in the result. The y value is the maximum number of characters in the result. You can combine the options as necessary. For example: %@format[12,JPSoftware] returns " JPSoftware" %@format[.3,JPSoftware] returns "JPS" 4OS2, @FSTYPE[d:]: Returns the file system type for the specified drive. Under 4NT 4OS2, @FSTYPE will return "FAT" for a DOS-compatible drive with a file allocation table, "HPFS" for a drive that uses OS/2's high performance file system, or "CDFS" for a CD-ROM drive. It may return other values if additional file systems have been installed with the IFS= directive in CONFIG.SYS. 4DOS/NT will normally return "FAT", "HPFS", "CDFS", or "NTFS" for a drive that uses the Windows NT file system. @FULL[filename]: Returns the fully qualified path name of a file. @IF[condition,true,false]: Evaluates the condition and returns a string based on the result. The condition can include any of the tests allowed in the IF command (see page 251). If the condition is true, @IF returns the first result string; if it is false, @IF returns the second string. For example, %IF[2==2,Correct!,Oops!] returns "Correct!" @INC[%var]: Returns the same value as %@EVAL[%var + 1]. That is, it retrieves and increments the value of a variable. The variable itself is not changed; to do so, use a command like this: set var=%@inc[%var] @INDEX[string1,string2]: Returns the position of string2 within string1, or "-1" if string2 is not found. The first position in string1 is numbered 0. @INSTR[start, length, string]: The same as @SUBSTR (see page 119). However, the string is at the end of the @INSTR ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 116 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- argument list, so that commas in the string will not be confused with commas separating the arguments. @INT[n]: Returns the integer part of the number n. @LABEL[d:]: Returns the volume label of the specified disk drive. @LEN[string]: Returns the length of a string. @LINE[filename,n]: Returns line "n" from the specified file. The first line in the file is numbered 0. "**EOF**" is returned for all line numbers beyond the end of the file. If you need to scan through the lines of a file in sequence, the @FILEREAD function (above) and the "@filename" construct available in the FOR command (page 237) are much faster than calling the @LINE function repeatedly. @LINE will retrieve input from standard input if you specify CON as the filename. If you are redirecting input to @LINE using this feature, you must use command grouping (see page 71) or the redirection will not work properly. For example: (echo %@line[con,0]) < myfile.dat @LINES[filename]: Returns the line number of the last line in the file, or "-1" if the file is empty. The first line in the file is numbered 0, so (for example) @LINES will return 0 for a file containing one line. @LOWER[string]: Returns the string converted to lower case. 4DOS @LPT[n]: Returns a "1" if the specified printer is ready; otherwise, returns "0". n=1 checks the printer connected to LPT1, n=2 checks LPT2, and n=3 checks LPT3. @MAKEAGE[date[,time]]: Returns the date and time (if included) as a single value in the same format as @FILEAGE. @MAKEAGE can be used to compare the time stamp of a file with a specific date and time, for example: if %@fileage[myfile] lt %@makeage[1/1/85] echo OLD! @MAKEDATE[n]: Returns a date (formatted according to the current country settings). "n" is the number of days since 1/1/80. This is the inverse of @DATE. @MAKETIME[n]: Returns a time (formatted according to the current country settings). "n" is the number of seconds since midnight. This is the inverse of @TIME. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 117 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- 4DOS @MASTER[varname]: Returns the value of a variable from the master environment. @NAME[filename]: Returns the base name of a file, without the path or extension. @NUMERIC[string]: Returns "1" if the argument is composed entirely of digits (0 to 9), signs (+ or -), and the thousands and decimals separators. Otherwise, returns "0". @PATH[filename]: Returns the path from a file name, including the drive letter and a trailing backslash but not including the base name or extension. @RANDOM[min, max]: Returns a random value between min and max, inclusive. Min, max, and the returned value are all integers. @READSCR[row,col,length]: Returns the text displayed on the screen at the specified location. The upper left corner of the screen is location 0,0. @READY[d:]: Returns "1" if the specified drive is ready; otherwise returns "0". @REMOTE[d:]: Returns "1" if the specified drive is a remote (network) drive; otherwise returns "0". @REMOVABLE[d:]: Returns "1" if the specified drive is removable (i.e., a floppy disk or removable hard disk); otherwise returns "0". @REPEAT[c,n]: Returns the character "c" repeated "n" times. 4OS2 @REXX[expr]: Calls the REXX interpreter to execute the 4NT expression. Returns the result string from REXX; if the REXX expression does not return a string, @REXX returns the REXX numeric result code. @SEARCH[filename]: Searches for the filename using the PATH environment variable, appending an extension if one isn't specified. See page 20 for details on the default extensions used when searching the PATH, and the order in which the search proceeds. Returns the fully-expanded name of the file including drive, path, base name, and extension, or an empty string if a matching file is not found. If wildcards are used in the filename, @SEARCH will search for the first file that matches the wildcard specification, and return the drive and path for that file plus the wildcard filename (e.g., E:\UTIL\*.COM). ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 118 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- @SELECT[filename,top,left,bottom,right,title]: Pops up a selection window with the lines from the specified file. Returns the text of the line the scrollbar is on if you press Enter, or an empty string if you press Esc. @SELECT can be used to display menus or other selection lists from a batch file. To select from lines passed through input redirection or a pipe, use CON as the filename. You can move through the selection window with standard navigation keystrokes. To change the navigation keys, see page 146. @SUBSTR[string,start,length]: Returns a substring, starting at the position "start" and continuing for "length" characters. If the length is omitted, it will default to the remainder of the string. If the length is negative, the start is relative to the right side of the string. The first character in the string is numbered 0; if the length is negative, the last character is numbered 0. For example, %@SUBSTR[%_TIME,0,2] gets the current time and extracts the hour. If the string includes commas, it must be quoted with double quotes ["] or back-quotes [`]. The quotes do count in calculating the position of the substring. @INSTR (page 116) performs the same function, and allows commas in the string without quoting. @TIME[hh:mm:ss]: Returns the number of seconds since midnight for the specified time. The time must be in 24-hour format; "am" and "pm" cannot be used. @TIMER[n]: Returns the current split time for a stopwatch started with the TIMER command (see page 344). The value of n specifies the timer to read and can be 1, 2, or 3. @TRIM[string]: Returns the string with the leading and trailing white space (space and tab characters) removed. 4DOS @TRUENAME[filename]: Returns the true, fully-expanded name for a file. TRUENAME will "see through" a JOIN or SUBST, and requires DOS 3.0 or above. Wildcards may not be used in the filename. @TRUENAME can handle simple drive substitutions such as those created by JOIN, SUBST, or most network drive mappings. However it may not be able to correctly determine the true name if you use "nested" JOIN or SUBST commands, or a network which does not report true names properly. @UNIQUE[d:\path]: Creates a zero-length file with a unique name in the specified directory, and returns the full name and path. If no path is specified, the file will be created in the current directory. The file name will be FAT-compatible (8 character name and 3-character extension) regardless of whether the file is created on a FAT, HPFS, or NTFS drive. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 119 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- This function allows you to create a temporary file without overwriting an existing file. @UPPER[string]: Returns the string converted to upper case. @WORD[["xxx",]n,string]: Returns the "nth" word in a string. The first word is numbered 0. If "n" is negative, words are returned from the end of the string. You can use the first argument, "xxx" to specify the separators that you wish to use. If you want to use a double quote as a separator, prefix it with an escape character (see page 73). If you don't specify a list of separators, @WORD will consider only spaces, tabs, and commas as word separators. If the string argument is enclosed in quotation marks, you must enter a list of separators. For example: %@word[2,NOW IS THE TIME] returns "THE" %@word[-0,NOW IS THE TIME] returns "TIME" %@word[-2,NOW IS THE TIME] returns "IS" %@word["=",1,2 + 2=4] returns "4" @WORDS[["xxx"],string]: Returns the number of words in the string. The optional list of delimiters follows the same format as @WORD. If the string argument is enclosed in quotation marks, you must enter a list of delimiters as well. 4DOS @XMS[b|k|m]: Returns the amount of free XMS memory. Examples You can use variable functions in a wide variety of ways depending on your needs. We've included a few examples below to give you an idea of what's possible. To set the prompt to show the amount of free memory (see the PROMPT command, page 295, for details on including variable functions in your prompt): c:\> prompt (%%@dosmem[K]K) $p$g Set up a simple command-line calculator. The calculator is used with a command like CALC 3 * (4 + 5): c:\> alias calc `echo The answer is: %@eval[%&]` The following batch file uses variable functions to implement "once a day" execution of a group of commands. It works by constructing a 6-digit number "yymmdd" from today's date, and comparing that to a number of the same type stored in the file ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 120 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- C:\ONCEADAY.DAT. If today's date is numerically larger than the saved date, and the time is after 6:00 AM, then the "once a day" commands are run, and today's date is saved in the file as the new date for comparison. Otherwise, no action is taken. You can make this file simpler using the %@DATE and %@TIME functions instead of using %@SUBSTR to extract substrings of the %_DATE and %_TIME variables; we used the approach shown to demonstrate the use of %@SUBSTR. rem Temporary variables used to shorten example lines: rem DD is _date, DY is yymmdd date, TM is _time set dd=%_date set dy=%@substr[%dd,6,2]%@substr[%dd,0,2]%@substr[%dd,3,2] set lastdate=0 iff exist c:\onceaday.dat then set lastdate=%@line[onceaday.dat,0] endiff iff %dy gt %lastdate then set tm=%_time iff "%@substr[%tm,0,2]%@substr[%tm,3,2]" gt "0600" then rem Commands to be executed once a day go here echo %dy > c:\onceaday.dat endiff endiff Command Parsing Whenever you type something at the command line and press the Enter key, or include a command in a batch file, you have given a command to 4DOS, 4OS2, or 4DOS/NT, which must figure out how to execute your command. If you understand the general process that is used, you will be able to make the best use of the commands. Understanding these steps can be especially helpful when working with complex aliases or batch file commands. To decide what activity to perform, the command processor goes through several steps. Before it starts, it writes the entire command line (which may contain multiple commands) to the history log file if history logging has been enabled with the LOG /H command (see page 277). Then, if the line contains multiple commands, the first command is isolated for processing. 4DOS, 4OS2, and 4DOS/NT begin by dividing the command into a command name and a command tail. The command name is the first word in the command; the tail is everything that follows the command name. For example, in the command line ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 121 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- dir *.txt /2/p/v the command name is "dir," and the command tail is " *.txt /2/p/v." Next the command processor tries to match the command name against its list of aliases. If it finds a match between the command name and one of the aliases you've defined, it replaces the command name with the contents of the alias. (This substitution is done internally and is not normally visible to you). If the alias included parameters (%1, %2, etc.), the parameter values are filled in from the text on the command line, and any parameters used in this process are removed from the command line. The process of replacing a command name that refers to an alias with the contents of the alias, and filling in the alias parameters, is called alias expansion. This expansion of an alias creates a new command name: the first word of the alias. This new command name is again tested against the list of aliases, and if a match is found the contents of the new alias is expanded just like the first alias. This process, called nested alias expansion, continues until the command name no longer refers to an alias. Once it has finished with the aliases, 4DOS, 4OS2, or 4DOS/NT next tries to match the command name with its list of internal commands. If it is unsuccessful, the command processor knows that it will have to search for a batch file or external program to execute your command. The next step is to locate any batch file or alias parameters, environment variables, internal variables, or variable functions in the command, and replace each one with its value. This process is called variable expansion. The variable expansion process is modified for certain internal commands, like EXCEPT, IFF, and GLOBAL. These commands are always followed by another command, so variable expansion takes place separately for the original command and the command that follows it. Once all of the aliases and environment variables have been expanded, 4DOS, 4OS2, or 4DOS/NT will echo the complete command to the screen (if command-line echo has been enabled) and write it to the log file (if command logging has been turned on). Before it can actually execute your command, the command processor must scan the command tail to see if it includes ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 122 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- redirection or piping. If so, the proper internal switches are set to send output to an alternate device or to a file, instead of to the screen. In 4OS2 and 4DOS/NT, a second process is started at this point, if necessary, to receive any piped output. Finally, it is time to execute the command. If the command name matches an internal command, 4DOS, 4OS2, or 4DOS/NT will perform the activities you have requested. Otherwise, the command processor searches for an executable (.COM or .EXE) file, a batch file, or a file with an executable extension that matches the command name (see the detailed description of this search on page 20). Once the internal command or external program has terminated, the command processor saves the result or exit code that the command generated, cleans up any redirection that you specified, and then returns to the original command line to retrieve the next command. When all of the commands in a command line are finished, the next line is read from the current batch file, or if no batch file is active, the prompt is displayed. You can disable and re-enable several parts of command parsing (for example alias expansion, variable expansion, and redirection) with the SETDOS /X command (see page 327). Argument Quoting As it parses the command line, the command processor looks for command separators (carets [^] in 4DOS, or ampersands [&] in 4OS2 and 4DOS/NT), conditional commands (|| or &&), white space (spaces, tabs, and commas), percent signs [%] which indicate variables to be expanded, and redirection and piping characters (>, <, or |). Normally, these special characters cannot be passed to a command as part of an argument. However, you can include any of the special characters in an argument by enclosing the entire argument in back-quotes [`] or double quotes ["]. Although both back-quotes and double quotes will let you build arguments that include special characters, they do not work the same way. No alias or variable expansion is performed on an argument enclosed in back-quotes. Redirection symbols inside the back- quotes are ignored. The back-quotes are removed from the command line before the command is executed. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 123 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- No alias expansion is performed on expressions enclosed in double quotes. Redirection symbols inside double quotes are ignored. However, variable expansion is performed on expressions inside double quotes. The double quotes themselves will be passed to the command as part of the argument. For example, suppose you have a batch file CHKNAME.BTM which expects a name as its first parameter (%1). Normally the name is a single word. If you need to pass a two-word name with a space in it to this batch file you could use the command: c:\> chkname `MY NAME` Inside the batch file, %1 will have the value MY NAME, including the space. The back-quotes caused the command processor to pass the string to the batch file as a single argument. For a more complex example, suppose the batch file QUOTES.BAT contains the following commands: @echo off echo Arg1 = %1 echo Arg2 = %2 echo Arg3 = %3 and that the environment variable FORVAR has been defined with this command: c:\> set FORVAR=for Now, if you enter the command c:\> quotes `Now is the time %forvar` all good the output from QUOTES.BAT will look like this: Arg1 = Now is the time %forvar Arg2 = all Arg3 = good But if you enter the command c:\> quotes "Now is the time %forvar" all good the output from QUOTES.BAT will look like this: ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 124 CHAPTER 4 / ALIASES AND BATCH FILES ------------------------------------------------------------------- Arg1 = "Now is the time for" Arg2 = all Arg3 = good Notice that in both cases, the quotes keep characters together and reduce the number of arguments in the line. The following example has 7 command-line arguments, while the examples above only have 3: c:\> quotes Now is the time %forvar all good When an alias is defined in a batch file or from the command line, its argument can be enclosed in back-quotes to prevent the expansion of replaceable parameters, variables, and multiple commands until the alias is invoked. See ALIAS on page 161 for details. You can disable and re-enable back-quotes and double quotes with the SETDOS /X command (see page 327). ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 125 CHAPTER 5 / CONFIGURATION ------------------------------------------------------------------- CHAPTER 5 / CONFIGURATION Part of the power of 4DOS, 4OS2, and 4DOS/NT is their flexibility. You can alter their configuration to match your style of computing. This chapter explains how to make the command processor work the way you want. The configuration of 4DOS, 4OS2, and 4DOS/NT is controlled through an optional file of initialization information with the extension .INI. This file is called 4DOS.INI in 4DOS, 4OS2.INI in 4OS2, and 4NT.INI in 4DOS/NT. (For brevity, we refer to all three files as .INI files throughout this manual.) You can create, add to, and edit the .INI file with any ASCII text editor. Each command processor reads its .INI file when it starts, and configures itself accordingly. The .INI file is not re-read when you change it. For changes to take effect, you must reboot your system (under DOS), or restart the session or window in which your command processor is running (under OS/2 or Windows NT). Each item that you can include in the .INI file has a default value. You only need to include entries in the file for settings that you want to change from their default values. If you are happy with all of the default values, you don't need an .INI file at all. Using the .INI File Some settings in the .INI file are initialized when you install 4DOS, 4OS2, or 4DOS/NT, so you may have an .INI file even if you didn't create one yourself. You should not delete this file unless you've checked carefully to be sure that you don't need any of the settings the installation program put there. 4DOS, 4OS2, and 4DOS/NT primary shells search for the .INI file in three places: * If there is an "@d:\path\inifile" option on the SHELL= line in CONFIG.SYS (for 4DOS) or on the startup command line (for 4OS2 and 4DOS/NT), the command processor will use the path and file name specified there, and will not look elsewhere. * If there is no .INI file name on the SHELL= line or startup command line, the search proceeds to the same directory where the command processor program file ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 126 CHAPTER 5 / CONFIGURATION ------------------------------------------------------------------- (4DOS.COM, 4OS2.EXE, or 4NT.EXE) is stored. This is the "normal" location for the .INI file. 4DOS, 4OS2, and 4DOS/NT determine this directory automatically. You can also set it yourself by placing a COMSPEC directory name on the SHELL= line in CONFIG.SYS (for 4DOS), or on the startup command line (for 4OS2 and 4DOS/NT). See your Introduction and Installation Guide for further details on setting the COMSPEC directory. * If the .INI file is not found in the directory where the program file is stored, a final check is made in the root directory of the boot drive. When 4DOS, 4OS2, or 4DOS/NT is loaded as a secondary shell, it does not search for the .INI file. Instead, it retrieves the primary shell's .INI file data, processes the [Secondary] section of the original .INI file if necessary, and then processes any "@d:\path\inifile" option on the secondary shell command line (see your Introduction and Installation Guide for details). You can override this behavior with the NextINIFile directive (see page 148). .INI File Directives Most lines in the .INI file consist of a one-word directive, an equal sign [=], and a value. For example, in the following line, the word "Environment" is the directive and "2048" is the value: Environment = 2048 Any spaces before or after the equal sign are ignored. If you have a long string to enter in the .INI file (for example, for the ColorDir directive), you must enter it all on one line. Strings cannot be "continued" to a second line. Each line may be up to 511 characters long in 4DOS, or 1023 characters long in 4OS2 and 4DOS/NT. The format of the value part of a directive line depends on the individual directive. It may be a numeric value, a single character, a choice (like "Yes" or "No"), a color setting, a key name, a path, a filename, or a text string. The value begins with the first non-blank character after the equal sign and ends at the end of the line or the beginning of a comment. Blank lines are ignored in the .INI file and can be used to separate groups of directives. You can place comments in the ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 127 CHAPTER 5 / CONFIGURATION ------------------------------------------------------------------- file by beginning a line with a semicolon [;]. You can also place comments at the end of any line except one containing a text string value. To do so, enter at least one space or tab after the value, a semicolon, and your comment, like this: Environment = 2048 ;set standard environment size If you try to place a comment at the end of a string value, the comment will become part of the string and will probably cause an error. When the command processor detects an error while processing the .INI file, it displays an error message and prompts you to press a key to continue processing the file. This allows you to note any errors before the startup process continues. The directive in error will retain its previous or default value. Only the most catastrophic errors (like a disk read failure) will terminate processing of the remainder of the .INI file. If you don't want a pause after each error, use a "PauseOnError = No" directive at the beginning of the .INI file. If you need to test different values for an .INI directive without repeatedly editing the .INI file, see the INIQuery directive on page 133. The .INI file has three sections: the first or global section, the [Primary] section, and the [Secondary] section. The global section consists of directives at the beginning of the file, with no section name before them. These directives are effective in all shells. In most cases, this is the only section you will need, particularly for 4OS2 and 4DOS/NT. The [Primary] and [Secondary] sections include directives that are used only in primary and secondary shells respectively (see page 12 for more information on primary and secondary shells). Each section is identified by the section name in square brackets on a line by itself. You don't need to set up these sections unless you want different directives for primary and secondary shells. Directives in the [Primary] section are used for the first or primary shell. The values are passed automatically to all secondary shells, unless overridden by a directive with the same name in the [Secondary] section. Directives in the [Secondary] section are used in secondary shells only, and override any corresponding primary shell settings. For example, these lines in the .INI file: ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 128 CHAPTER 5 / CONFIGURATION ------------------------------------------------------------------- [Primary] ScreenRows = 25 [Secondary] ScreenRows = 50 mean to assume that you have 25 rows on the screen in the primary shell and 50 lines in all secondary shells. Sections that begin with any name other than [Primary] or [Secondary] are ignored. The SETDOS command can override several of the .INI file directives (see page 322). For example, the cursor shape used by 4DOS, 4OS2, and 4DOS/NT can be adjusted either with the CursorIns and CursorOver directives or the SETDOS /S command. The correspondence between SETDOS options and .INI directives is noted under each directive below, and under each option of the SETDOS command. Secondary shells automatically inherit the configuration settings currently in effect in the previous shell. If values have been changed by SETDOS since the primary shell started, the current values will be passed to the secondary shell. If the previous shell's .INI file had a [Secondary] section, it will then be read and processed. If not, the previous shell's settings will remain in effect. For example, you might set BatchEcho to Yes in the .INI file, to enable batch file echo. If you then use SETDOS /V0 to turn off batch file echoing in the primary shell, then any secondary shells will inherit the SETDOS setting, rather than the original value from the .INI file; i.e., batch files in the secondary shell will default to no echo. If you want to force secondary shells to start with a specific value for a particular directive, regardless of any changes made with SETDOS in a previous shell, repeat the directive in the [Secondary] section of the .INI file. 4DOS If you start a secondary shell from a task switching program like Windows, DESQview, or Back & Forth, you can specify an alternate location and name for 4DOS.INI by passing the "@d:\path\inifile" option to 4DOS as a command-line parameter (see your 4DOS Introduction and Installation Guide for details). In this case, the configuration settings in the alternate 4DOS.INI file will supersede any settings inherited from the previous shell. Any values which are not explicitly set in the alternate file will retain the value they had in the previous shell. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 129 CHAPTER 5 / CONFIGURATION ------------------------------------------------------------------- The first section below lists the different types of directives. Subsequent sections list all the individual directives, divided by function and then alphabetically by directive name. At the end we have included a few examples of how to use the .INI file directives (see page 151). Types of Directives There are 8 types of directives in the .INI file. The different types of directives are shown in the lists below as follows: * Name = nnnn (1234): This directive takes a numeric value which replaces the "nnnn." The default value is shown in parentheses. * Name = c (X): This directive accepts a single character as its value. The default character is shown in parentheses. You must type in the actual character; you cannot use a key name. * Name = CHOICE1 | Choice2 | ... : This directive takes a choice value. The possible choices are listed, separated by vertical bars. The default value is shown in all upper case letters in the directive description, but in your file any of the choices can be entered in upper case or lower case. For example, if the choices were shown as "YES | No" then "YES" is the default. * Name = Color: This directive takes a color specification. See page 26 for the format of color names. * Name = Key (Default): This directive takes a key specification. See page 31 for the format of key names. * Name = Path: This directive takes a path specification, but not a filename. The value should include both a drive and path (e.g., C:\4DOS) to avoid any possible ambiguities. A trailing backslash [\] at the end of the path name is acceptable but not required. Any default path is described in the text. * Name = File: This directive takes a filename. We recommend that you use a full filename including the drive letter and path to avoid any possible ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 130 CHAPTER 5 / CONFIGURATION ------------------------------------------------------------------- ambiguities. Any default filename is described in the text. * Name = String: This directive takes a string in the format shown. The text describes the default value and any additional requirements for formatting the string correctly. No comments are allowed. 4DOS, 4OS2, and 4DOS/NT each contain a fixed-length area for storing strings entered in the .INI file, including file names, paths, and other strings. This area is large and is unlikely to overflow; if it does, you will receive an error message. If this occurs, reduce the complexity of your .INI file or contact our technical support department for assistance. Each directive is listed below with its name, type, and default value. In some cases, no default is shown because the default value is different for different products; in these cases, the default is described in the text. Initialization Directives The directives in this section control how your command processor starts and where it looks for its files. 4StartPath = Path: Sets the drive and directory where the 4START and 4EXIT batch files (if any) are located. 4DOS Alias = nnnn (1024): Sets the amount of memory in bytes allocated for the alias list. The allowable range of values is 256 to 32767 bytes. This directive is not needed in 4OS2 or 4DOS/NT because both adjust the size of the alias list dynamically. If you use a global alias list (see page 169), the Alias value is ignored in all shells except the shell which first establishes the global list. 4DOS AutoExecPath = Path | File: Sets the path used to find AUTOEXEC.BAT if 4DOS is started as a primary shell with the /P option in CONFIG.SYS (see your Introduction and Installation Guide). If you include only a path, 4DOS will look for AUTOEXEC.BAT in the specified directory. If you include a complete file name, 4DOS will look for the specified file, and will not look for AUTOEXEC.BAT. The default is the file AUTOEXEC.BAT in the root directory of the boot drive. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 131 CHAPTER 5 / CONFIGURATION ------------------------------------------------------------------- Using AutoExecPath with a complete file name lets you store multiple startup files in a single directory. You may find this useful under DOS if you have multiple boot software and use different startup files under different configurations, or under OS/2 if you have several DOS sessions with different startup files. If you are running under OS/2, using AutoExecPath is equivalent to setting DOS_AUTOEXEC on a session's DOS settings notebook page (see the OS/2 documentation and your Introduction and Installation Guide for details on DOS settings). 4DOS AutoExecParms = String: Sets the parameter or parameters to be passed to AUTOEXEC.BAT, or the file specified with the AutoExecPath directive, above, when 4DOS is started as a primary shell with the /P option in CONFIG.SYS (see your Introduction and Installation Guide). The parameters will be available in your AUTOEXEC.BAT file as %1, %2, etc. DirHistory = nnnn (256): Sets the amount of memory allocated to the directory history in bytes. The allowable range of values is 128 to 2048 bytes. If you use a global directory history list (see page 45), the DirHistory value is ignored in all shells except the shell which first establishes the global list. 4DOS Environment = nnnn (512): Sets the amount of memory allocated to the environment in bytes. The allowable range of values is 256 to 32767 bytes. This directive is not needed in 4OS2 or 4DOS/NT because both adjust the size of the environment dynamically. 4DOS EnvFree = nnnn (128): Sets the minimum amount of memory in bytes that will be available in the environment for secondary shells. 4DOS will enlarge the environment for each secondary shell, if necessary, so that there is at least this much free environment space when the shell starts. The allowable range of values is 128 to 32767 bytes. 4OS2 HelpBook = String: Sets the names of the "books" to be loaded when 4OS2 help is invoked with the HELP command or the F1 key. The default is 4OS2+CMDREF which loads the 4OS2 help and the OS/2 command reference. See the 4OS2 Introduction and Installation Guide for details about this directive. 4DOS HelpOptions = String: Sets default options for the 4DOS help system. For the available options, see your 4DOS Introduction and Installation Guide. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 132 CHAPTER 5 / CONFIGURATION ------------------------------------------------------------------- 4DOS HelpPath = Path: Sets the path used to find 4HELP.EXE when F1 is pressed or the HELP command is used. If this directive is not used, 4DOS will search the current directory and each of the directories in the PATH. History = nnnn (1024): Sets the amount of memory allocated to the command history list in bytes. The allowable range of values is 256 to 8192 bytes. If you use a global history list (see page 39), the History value is ignored in all shells except the shell which first establishes the global list. INIQuery = Yes | NO: If set to Yes, a prompt will be displayed before execution of each subsequent line in the current .INI file. This allows you to modify certain directives when you start the command processor in order to test different configurations. INIQuery can be reset to No at any point in the file. Normally INIQuery = Yes is only used during testing of other .INI file directives. The prompt generated by INIQuery = Yes is: [contents of the line] (Y/N/Q/R/E) ? At this prompt, you may enter: Y = Yes: Process this line and go on to the next. N = No: Skip this line and go on to the next. Q = Quit: Skip this line and all subsequent lines. R = Rest: Execute this and all subsequent lines. E = Edit: Prompt for a new value for this entry. If you choose E for Edit, you can enter a new value for the directive, but not a new directive name. For example, if you have found a compatibility problem you think may be related to 4DOS's swapping or upper memory block usage, you might change your 4DOS.INI file so a part of it read as follows: INIQuery = Yes Swapping = XMS, EMS, C:\ UMBLoad = Yes UMBEnvironment = Yes INIQuery = No You could then choose to process, ignore, or edit the Swapping, UMBLoad, or UMBEnvironment directive each time 4DOS started. This would allow you to test several ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 133 CHAPTER 5 / CONFIGURATION ------------------------------------------------------------------- possible combinations to see if you could resolve the compatibility problem. LocalAliases = Yes | No: The default value is Yes in 4DOS and No in 4OS2 and 4DOS/NT. No forces all copies of the command processor to share the same alias list. Yes keeps the lists for each shell separate. See page 169 for more details on local and global alias lists. LocalDirHistory = Yes | No: The default value is Yes in 4DOS and No in 4OS2 and 4DOS/NT. No forces all copies of the command processor to share the same directory history. Yes keeps the directory histories for each shell separate. See page 45 for more details on local and global directory histories. LocalHistory = Yes | No: The default value is Yes in 4DOS and No in 4OS2 and 4DOS/NT. No forces all copies of the command processor to share the same history list. Yes keeps the lists for each shell separate. See page 39 for more details on local and global history lists. PauseOnError = YES | No: Yes forces a pause with the message "Error in filename, press any key to continue processing" after displaying any error message related to a specific line in the .INI file. No continues processing with no pause after an error message is displayed. 4DOS Swapping = swap type [, swap type] ...: Sets the type of swapping 4DOS should use. 4DOS runs in two parts, a resident portion that is always in memory and a transient portion that is "swapped" to EMS memory, XMS memory, a RAM disk, or your hard disk while application programs are running. The swap area for the transient portion normally requires about 128K bytes of memory or disk space for the primary shell, and 28 - 32K bytes for each secondary shell. The swap type can be EMS to swap to EMS expanded memory, XMS to swap to XMS extended memory, d:\path to swap to the specified drive and path, or None for no swapping. If you use d:\path, 4DOS will create the file 4DOSSWAP.nnn in the specified directory. The file name changes if UniqueSwapName is set to Yes (see page 151). If you use None, the transient portion of 4DOS will remain in memory at all times; this will reduce memory available for application programs by about 128K. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 134 CHAPTER 5 / CONFIGURATION ------------------------------------------------------------------- You can specify multiple swap types and 4DOS will try them in the order listed. Swap type "None" is always appended to your list of possible swap types as a "last resort," even if you don't include it explicitly. The default Swapping specification is EMS, XMS, x:\, None, where x is the boot drive. In most cases you will find that the default setting works without modification. Before changing the Swapping specification, see your 4DOS Introduction and Installation Guide for more detail on swapping types and the way 4DOS uses memory. 4DOS UMBAlias = Yes | NO | 1 | 2 ... | 8: Yes attempts to load global alias list storage into a UMB (Upper Memory Block). If you use a specific region number (1 through 8), 4DOS will attempt to reserve room for the global alias list in that UMB region. Region numbers can be used under MS-DOS / PC-DOS 5.0 and above, and under OS/2's DOS support. To use them, you must enable DOS UMB management with the DOS=UMB or DOS=HIGH,UMB directive in CONFIG.SYS. See your 4DOS Introduction and Installation Guide for complete details on UMBs and UMB regions, and the hardware and software required to support them. If you use an invalid region number, or if region numbers have not been enabled on your system, 4DOS will load the global alias list into the first available region. If no upper memory is available, space for the global alias list will be reserved in low memory. UMBAlias applies to global aliases only, and is only used in the first shell which establishes the global alias area (see page 169 for more information on local and global alias lists). If you specify LocalAliases = Yes, or if the previous shell already created a global alias area, any UMBAlias setting is ignored. 4DOS UMBDirHistory= Yes | NO | 1 | 2 ... | 8: Yes attempts to load global directory history list storage into a UMB (Upper Memory Block). If you use a specific region number (1 through 8), 4DOS will attempt to reserve room for the global directory history list in that UMB region. See page 45 for more information on local and global directory history lists. See UMBAlias (above) for information on the use of UMBs and region numbers. Like UMBAlias, UMBDirHistory will be ignored if a global directory history list is not used. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 135 CHAPTER 5 / CONFIGURATION ------------------------------------------------------------------- 4DOS UMBEnvironment = Yes | NO | 1 | 2 ... | 8: Yes attempts to load the master environment into a UMB (Upper Memory Block). This reduces 4DOS's base memory requirements but may cause problems with some programs that try to access the master environment directly. See UMBAlias (above) for information on the use of UMBs and region numbers. 4DOS UMBHistory = Yes | NO | 1 | 2 ... | 8: Yes attempts to load global history list storage into a UMB (Upper Memory Block). If you use a specific region number (1 through 8), 4DOS will attempt to reserve room for the global history list in that UMB region. See page 39 for more information on local and global history lists. See UMBAlias (above) for information on the use of UMBs and region numbers. Like UMBAlias, UMBHistory will be ignored if a global history list is not used. 4DOS UMBLoad = Yes | NO | 1 | 2 ... | 8: Yes attempts to load the resident portion of 4DOS into a UMB (Upper Memory Block). This reduces the size of the resident portion in base memory from about 3K bytes to 256 bytes. See UMBAlias (above) for information on the use of UMBs and region numbers. 4OS2, WindowState = STANDARD | Maximize | Minimize: Sets the 4NT initial state of the 4OS2 or 4DOS/NT window. Standard puts the window in the default position on the OS/2 or Windows NT desktop, and is the default setting. Maximize maximizes the window; Minimize minimizes it. If you use Maximize or Minimize, you may see the 4OS2 or 4DOS/NT window appear briefly in the Standard position as it is created by the operating system, then switch to the new state. 4OS2, WindowX = nnnn, WindowY = nnnn, WindowWidth = nnnn, 4NT WindowHeight = nnnn: These 4 directives set the initial size and position of the 4OS2 or 4DOS/NT window. The measurements are in pixels or pels. Under 4OS2, WindowX and WindowY refer to the position of the bottom left corner of the window relative to the bottom left corner of the screen. Under 4DOS/NT, WindowX and WindowY refer to the position of the top left corner of the window relative to the top left corner of the screen. Configuration Directives These directives control the way that 4DOS, 4OS2, and 4DOS/NT operate. Some can be changed with the SETDOS command while the command processor is running. Any corresponding SETDOS ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 136 CHAPTER 5 / CONFIGURATION ------------------------------------------------------------------- command is listed in the description of each directive; information on SETDOS begins on page 322. AmPm = Yes | NO | Auto: Yes displays times in 12-hour format with a trailing "a" for AM or "p" for PM. The default of No forces a display in 24-hour time format. Auto formats the time according to the country code set for your system. AmPm controls the time displays used by DIR and SELECT, in LOG files, and the output of the TIMER, DATE, and TIME commands. It has no effect on %_TIME, %@MAKETIME, the $t and $T options of PROMPT, or date and time ranges. 4DOS ANSI = AUTO | Yes | No: Tells 4DOS whether an ANSI driver is installed and should be used for the CLS and COLOR commands. 4DOS normally determines this itself, but if you are using a non-standard ANSI driver or your loading sequence is unusual, you may need to explicitly inform 4DOS. Also see SETDOS /A. This directive is not available in 4OS2 (because 4OS2 assumes that ANSI support is always enabled), or 4DOS/NT (because Windows NT does not offer ANSI support). BatchEcho = YES | No: Sets the default batch ECHO mode. Yes enables echoing of all batch file commands unless ECHO is explicitly set off in the batch file. No disables batch file echoing unless ECHO is explicitly set on. Also see SETDOS /V. BeepFreq = nnnn (440): Sets the default BEEP command frequency in Hz. This is also the frequency for "error" beeps (for example, if you press an illegal key). To disable all error beeps set this or BeepLength to 0. If you do, the BEEP command will still be operable, but will not produce sound unless you explicitly specify the frequency and duration. BeepLength = nnnn (2): Sets the default BEEP length in system clock ticks (approximately 1/18 of a second per tick). BeepLength is also the default length for "error" beeps (for example, if you press an illegal key). CommandSep = c: This is the character used to separate multiple commands on the same line. The default is the caret [^] in 4DOS, and the ampersand [&] in 4OS2 and 4DOS/NT. You cannot use any of the redirection characters (| > < ) or any of the whitespace characters (space, tab, comma, or equal sign). Also see SETDOS /C, the %+ internal variable on page 74, and page 102 for ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 137 CHAPTER 5 / CONFIGURATION ------------------------------------------------------------------- information on using compatible command separators for two or more products. CursorIns = nnnn (100): This is the shape of the cursor for insert mode during command-line editing and all commands which accept line input (DESCRIBE, ESET, etc.). The size is a percentage of the total character cell size, between 0% and 100%. Because of the way video BIOSes and drivers map the cursor shape, you may not get a smooth progression in cursor shapes as CursorIns and CursorOver change. If CursorIns or CursorOver is set to -1, the command processor will not attempt to modify the cursor shape at all; you can use this feature to give another program full control of the cursor shape. Also see SETDOS /S. CursorOver = nnnn (15): This is the shape of the cursor for overtype mode during command-line editing and all commands which accept line input. The size is a percentage of the total character cell size, between 0% and 100%. Also see SETDOS /S. DescriptionMax = nnnn (40): Controls the description length limit for DESCRIBE (see page 201). The allowable range is 20 to 512 characters. Descriptions = YES | No: Turns description handling on or off during the file processing commands COPY, DEL, MOVE, and REN. If set to No, the command processor will not update the description file when files are moved, copied, deleted or renamed. Also see SETDOS /D. EditMode = Insert | OVERSTRIKE: This directive lets you start the command-line editor in either insert or overstrike mode. Also see SETDOS /M. EscapeChar = c : Sets the character used to suppress the normal meaning of the following character. The default is Ctrl-X in 4DOS, and a caret [^] in 4OS2 and 4DOS/NT. See page 73 for a description of the escape character and special escape sequences. You cannot use any of the redirection characters (|, >, or < ) or the whitespace characters (space, tab, comma, or equal sign) as the escape character. Also see SETDOS /E, the %= internal variable on page 102, and page 74 for information on using compatible escape characters for two or more products. EvalMax = nnnn (8): Controls the maximum number of digits after the decimal point in values returned by ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 138 CHAPTER 5 / CONFIGURATION ------------------------------------------------------------------- @EVAL (see page 112). This setting can be overridden with the construct @EVAL[expression=n.n]. The allowable range is 0 to 8. Also see SETDOS /F. EvalMin = nnnn (0): Controls the minimum number of digits after the decimal point in values returned by @EVAL (see page 112). The allowable range is 0 to 8. EvalMin will be ignored if it is larger than EvalMax. This setting can be overridden with the construct @EVAL[expression=n.n]. Also see SETDOS /F. HistCopy = Yes | NO: Controls what happens when you re- execute a line from the command history. If this option is set to Yes, the line is appended to the end of the history list. By default, or if this option is set to No, no copy of the command is made. The original copy of the command is always retained at its original position in the list, regardless of the setting of HistCopy. HistLogName = File: Sets the history log file name and/or path. If only a path is given, the default log file name (4DOSHLOG, 4OS2HLOG, etc.) will be used. Using HistLogName does not turn history logging on; you must use a LOG /H ON command to do so. HistMin = nnnn (0): Sets the minimum command-line size to save in the command history list. Any command line whose length is less than this value will not be saved. Legal values range from 0, which saves everything, to the maximum command-line length plus 1 (i.e., 256 in 4DOS, or 1024 in 4OS2 and 4DOS/NT), which disables all command history saves. HistWinColors = Color: Sets the default colors for the command-line and directory history windows. If this directive is not used the colors will be reversed from the current colors on the screen. HistWinHeight = nn (12): Sets the height of the command- line and directory history windows in lines, including the border. Legal values range from 5 to the height of your screen. Any value which would cause the bottom of the window to be off the screen will be adjusted so that the entire window remains on the screen. HistWinLeft = nn (40): Sets the horizontal position of the left side of the command-line and directory history windows. Legal values range from 0 (the left edge of the screen) to the number of columns on your screen minus 10. Any value which would cause the right side of a minimum- ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 139 CHAPTER 5 / CONFIGURATION ------------------------------------------------------------------- width window to be off the screen will be adjusted so that the entire window remains on the screen. HistWinTop = nn (1): Sets the vertical position of the top of the command-line and directory history windows. Legal values range from 0 (the top of the screen) to the number of rows on your screen minus 5. Any value which would cause the bottom of a minimum-height window to be off the screen will be adjusted so that the entire window remains on the screen. HistWinWidth = nn (36): Sets the width of the command- line and directory history windows in characters, including the border. Legal values range from 10 to the width of your screen. Any value which would cause the right side of the window to be off the screen will be adjusted so that the entire window remains on the screen. 4DOS, LineInput = Yes | NO: This directive controls how 4DOS 4OS2 and 4OS2 get their input from the command line. Yes forces 4DOS and 4OS2 to perform line-by-line input, just as COMMAND.COM and CMD.EXE do, instead of character-by- character input. This will disable command-line editing, history recall, the directory history window, and filename completion, and will reduce the 4OS2 input length limit from 1023 characters to 255 characters. It is normally used only for rare memory-resident programs (TSRs) or applications which do not work properly unless the command processor uses line input. If you have a particular program that requires line input, you can use SETDOS /L to temporarily change modes. See APPNOTES.DOC (for 4DOS) or README.DOC (for 4OS2) for information on programs which require this option. LogName = File: Sets the log file name and/or path. If only a path is given, the default log file name (4DOSLOG, 4OS2LOG, etc.) will be used. Using LogName does not turn logging on; you must use a LOG ON command to do so. NoClobber = Yes | NO: If set to Yes, will prevent standard output redirection (see page 52) from overwriting an existing file, and will require that the output file already exist for append redirection. Also see SETDOS /N. ParameterChar= c: Sets the character used after a percent sign to specify all or all remaining command-line arguments in a batch file or alias (e.g., %& or %n&; see pages 82 and 168). The default is the ampersand [&] for 4DOS and the dollar sign [$] for 4OS2 and 4DOS/NT. Also ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 140 CHAPTER 5 / CONFIGURATION ------------------------------------------------------------------- see SETDOS /P. See page 74 for information on using compatible parameter characters for two or more products.. Printer = devicename: Sets the output device that the LIST command will print to. By default, LPT1 is used. The device can be PRN, LPT1 to 3, COM1 to 4, NUL (which will disable printed output) or any other installed character device. 4DOS ScreenColumns = nnnn: Sets the number of columns used by the video display. Normally the screen size is determined automatically, but if you have a non-standard display you may need to set it explicitly. Systems which need to set OutputBIOS to Yes (see page 150) may also need to use this directive. ScreenRows = nnnn: Sets the number of screen rows used by the video display. Normally the screen size is determined automatically, but if you have a non-standard display you may need to set it explicitly. This value does not affect screen scrolling, which is controlled by your operating system, or (under DOS) your video BIOS or ANSI driver. ScreenRows is used only by the LIST and SELECT commands, the paged output options of other commands (e.g., TYPE /P), and error checking in the screen output commands. Also see SETDOS /R. UpperCase = Yes | NO: Yes specifies that file and directory names should be displayed in the traditional upper-case by internal commands like COPY and DIR. No allows the normal 4DOS, 4OS2, and 4DOS/NT lower-case style. This directive does not affect the display of filenames on HPFS and NTFS drives, or on FAT drives under Windows NT 3.5 and above; see page 17 for more details. Also see SETDOS /U. Color Directives These directives control the colors that 4DOS, 4OS2, and 4DOS/NT use for their displays. Screen border colors can only be set in StdColors. "BORder" color specifications included in other directives will be ignored. For complete details on color names see page 26. 4DOS, BrightBG = Yes | No. If set to Yes, 4DOS and 4OS2 will 4OS2 enable bright background colors. If set to No, bright backgrounds will be disabled but blinking foreground characters will be enabled. If BrightBG is not used, ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 141 CHAPTER 5 / CONFIGURATION ------------------------------------------------------------------- 4DOS and 4OS2 will not adjust the bright background / blinking foreground switch at all. Most color video boards default to a blinking foreground with bright background colors disabled. See also SETDOS /B. Using BrightBG requires careful attention to interactions of display type, mode, and color. For a detailed explanation, see page 28. ColorDir = ext1 ext2 ...:colora;ext3 ext4 ... :colorb; ...: Sets the directory colors used by DIR and SELECT. The format is the same as that used for the COLORDIR environment variable. See page 30 for a detailed explanation of color-coded directories. InputColors = Color: Sets the colors used for command- line input. This setting is useful for making your input stand out from the normal output. InputColors will not work properly under 4DOS unless you have an ANSI driver loaded (see page 25 for more information on ANSI). ListColors = Color: Sets the colors used by the LIST command. If this directive is not used, LIST will use the current default colors set by the CLS or COLOR command or by the StdColors directive, below. ListStatBarColors = Color: Sets the colors used on the LIST status bar. If this directive is not used, LIST will set the status bar to the reverse of the screen color (the screen color is controlled by ListColors, above). SelectColors = Color: Sets the color used by the SELECT command. If this directive is not used, SELECT will use the current default colors set by the CLS or COLOR command or by the StdColors directive, below. SelectStatBarColors = Color: Sets the color used on the SELECT status bar. If this directive is not used, SELECT will set the status bar to the reverse of the screen color (the screen color is controlled by SelectColors, above). StdColors = Color: Sets the standard colors to be used when CLS is used without a color specification, and for LIST and SELECT if ListColors and SelectColors are not used. Using this directive is similar to placing a COLOR command in AUTOEXEC.BAT. StdColors takes effect the first time CLS, LIST, or SELECT is used after 4DOS, 4OS2, or 4DOS/NT starts, but will not affect the color of error ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 142 CHAPTER 5 / CONFIGURATION ------------------------------------------------------------------- or other messages displayed during the loading and initialization process. Under 4DOS, if ANSI.SYS or a compatible driver is not loaded, the colors will not be "sticky" - you may lose them when you run an application. ## Key Mapping Directives The directives in this group allow you to change the keys used for command-line editing and other internal functions. They take effect only inside 4DOS, 4OS2, or 4DOS/NT, and do not affect other programs or the help system. The description of each directive below explains the function of the corresponding key. Using the directive allows you to assign a different or additional key to perform the function described. For example, to use function key F3 to invoke the HELP facility (normally invoked with F1): Help = F3 Any directive can be used multiple times to assign multiple keys to the same function. For example: ListFind = F ;F does a find in LIST ListFind = F5 ;F5 also does a find in LIST Use some care when you reassign keystrokes. If you assign a default key to a different function, it will no longer be available for its original use. For example, if you assign F1 to the AddFile directive (a part of filename completion), the F1 key will no longer invoke the help system, so you will probably want to assign a different key to Help. Please read the information on key names beginning on page 31 before using the key mapping directives. Key assignments are processed before looking for keystroke aliases. For example, if you assign Shift-F1 to HELP and also assign Shift-F1 to a key alias, the key alias will be ignored. Assigning a new keystroke for a function does not deassign the default keystroke for the same function. If you want to deassign one of the default keys, use the NormalKey directive described below or the corresponding directive for keys in the other key groups (NormalEditKey, NormalHWinKey, or NormalListKey). ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 143 CHAPTER 5 / CONFIGURATION ------------------------------------------------------------------- General Input Keys This first set of Key Mapping Directives applies to all input. These directives are in effect whenever 4DOS, 4OS2, or 4DOS/NT requests input from the keyboard, including during command-line editing and the DESCRIBE, ESET, INPUT, LIST, and SELECT commands. See page 35 for more information about command-line editing. Backspace = Key (Bksp): Deletes the character to the left of the cursor. BeginLine = Key (Home): Moves the cursor to the beginning of the line. Del = Key (Del): Deletes the character at the cursor. DelToBeginning = Key (Ctrl-Home): Deletes from the cursor to the start of the line. DelToEnd = Key (Ctrl-End): Deletes from the cursor to the end of the line. DelWordLeft = Key (Ctrl-L): Deletes the word to the left of the cursor. DelWordRight = Key (Ctrl-R, Ctrl-Bksp): Deletes the word to the right of the cursor. See ClearKeyMap on page 148 if you need to remove the default mapping of Ctrl- Bksp to this function. Down = Key (Down): Scrolls the display down one line in LIST; moves the cursor down one line in SELECT and in the command-line history, directory history, or %@SELECT window. (Scrolling down through the command history at the prompt is controlled by NextHistory on page 145, not by this directive.) EndLine = Key (End): Moves the cursor to the end of the line. EraseLine = Key (Esc): Deletes the entire line. ExecLine = Key (Enter): Executes or accepts a line. Ins = Key (Ins): Toggles insert / overstrike mode during line editing. Left = Key (Left): Moves the cursor left one character; scrolls the display left 8 columns in LIST; scrolls the ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 144 CHAPTER 5 / CONFIGURATION ------------------------------------------------------------------- display left 4 columns in the command-line, directory history, or %@SELECT window. NormalKey = Key: Deassigns a general input key in order to disable the usual meaning of the key within 4DOS, 4OS2, or 4DOS/NT and/or make it available for keystroke aliases. This will make the keystroke operate as a "normal" key with no special function. For example: NormalKey = Ctrl-End will disable Ctrl-End, which is the standard "delete to end of line" key. Ctrl-End could then be assigned to a keystroke alias. Another key could be assigned the "delete to end of line" function with the DelToEnd directive (above). Right = Key (Right): Moves the cursor right one character; scrolls the display right 8 columns in LIST; scrolls the display right 4 columns in the command-line history, directory history, or %@SELECT window. Up = Key (Up): Scrolls the display up one line in LIST; moves the cursor up one line in SELECT and in the command-line history, directory history, or %@SELECT window. (Scrolling up through the command history at the prompt is controlled by PrevHistory on page 145, not by this directive.) WordLeft = Key (Ctrl-Left): Moves the cursor left one word; scrolls the display left 40 columns in LIST. WordRight = Key (Ctrl-Right): Moves the cursor right one word; scrolls the display right 40 columns in LIST. Command-Line Editing Keys The following directives apply only to command-line editing. They are only effective at the 4DOS, 4OS2, or 4DOS/NT prompt. AddFile = Key (F10): Keeps the current filename completion entry and inserts the next matching name. CommandEscape = Key (Alt-255): Allows direct entry of a keystroke that would normally be interpreted as an editor command. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 145 CHAPTER 5 / CONFIGURATION ------------------------------------------------------------------- DelHistory = Key (Ctrl-D): Deletes the displayed history list entry and displays the previous entry. EndHistory = Key (Ctrl-E): Displays the last entry in the history list. Help = Key (F1): Invokes the HELP facility. NextFile = Key (F9, Tab): Gets the next matching filename. See ClearKeyMap on page 148 if you need to remove the default mapping of Tab to this function. NextHistory = Key (Down): Recalls the next command from the command history. NormalEditKey = Key: Deassigns a command-line editing key in order to disable the usual meaning of the key while editing a command line, and/or make it available for keystroke aliases. For details see the NormalKey directive on page 145. PopFile = Key (F7, Ctrl-Tab): Opens the filename completion window. You may not be able to use Ctrl-Tab, because not all systems recognize it as a keystroke. See ClearKeyMap on page 148 if you need to remove the default mapping of Ctrl-Tab to this function. PrevFile = Key (F8, Shift-Tab): Gets the previous matching filename. See ClearKeyMap on page 148 if you need to remove the default mapping of Shift-Tab to this function. PrevHistory = Key (Up): Recalls the previous command from the command history. SaveHistory = Key (Ctrl-K): Saves the command line in the command history list without executing it. History and @SELECT Window Keys The following directives apply only to the command history window, the directory history window, and %@SELECT windows. DirWinOpen = Key (Ctrl-PgUp): Opens the directory history window while at the command line. HistWinBegin = Key (Ctrl-PgUp): Moves to the first line of the history when in the history window. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 146 CHAPTER 5 / CONFIGURATION ------------------------------------------------------------------- HistWinDel = Key (Ctrl-D): Deletes a line from within the history window. HistWinEdit = Key (Ctrl-Enter): Moves a line from the history window to the prompt for editing. HistWinEnd = Key (Ctrl-PgDn): Moves to the last line of the history when in the history window. HistWinExec = Key (Enter): Executes the selected line in the history window. HistWinOpen = Key (PgUp): Brings up the history window while at the command line. NormalHWinKey = Key: Deassigns a history window key in order to disable the usual meaning of the key within the history window. For details see the NormalKey directive on page 145. LIST Keys The keys in the last group of Key Mapping Directives are effective only inside the LIST command. ListFind = Key (F): Prompts and searches for a string. ListHex = Key (X): Toggles hexadecimal display mode. ListHighBit = Key (H): Toggles LIST's "strip high bit" option, which can aid in displaying files from certain word processors. ListInfo = Key (I): Displays information about the current file. ListNext = Key (N): Finds the next matching string. ListPrint = Key (P): Prints the file on LPT1. ListWrap = Key (W): Toggles LIST's wrap option on and off. The wrap option wraps text at the right margin. NormalListKey = Key: Deassigns a LIST key in order to disable the usual meaning of the key within LIST. For details see the NormalKey directive on page 145. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 147 CHAPTER 5 / CONFIGURATION ------------------------------------------------------------------- ## Advanced Directives These directives are generally used for unusual circumstances, or for diagnosing problems. Most often they are not needed in normal use. Advanced Directives For 4DOS, 4OS2, and 4DOS/NT The directives in this section work in 4DOS, 4OS2, and 4DOS/NT. ClearKeyMap: Clears all current key mappings. ClearKeyMap is a special directive which has no value or "=" after it. Use ClearKeyMap to make one of the keys in the default map (Tab, Shift-Tab, Ctrl-Tab, or Ctrl-Bksp) available for a keystroke alias, or in the [Secondary] section of the .INI file to clear key mappings inherited from the primary shell. ClearKeyMap should appear before any key mapping directives. If you want to clear some but not all of the default mappings, use ClearKeyMap, then recreate the mappings you want to retain (e.g., with "NextFile=Tab", etc.). DescriptionName = File: Sets the file name in which to store file descriptions. The default file name is DESCRIPT.ION. Use this directive with caution because changing the name from the default will make it difficult to transfer file descriptions to another system. NextINIFile = File. The full path and name of the file must be specified. All subsequent shells will read the specified .INI file, and ignore any [Secondary] section in the original .INI file. Under 4DOS, if you have a diskless or floppy-based workstation, NextINIFile will allow you to shift 4DOS.INI to a network drive for secondary shells, and avoid all access to the original boot drive. Advanced Directives For 4DOS Only 4DOS The following advanced directives apply to 4DOS only, and will not work in 4OS2 or 4DOS/NT. CritFail = Yes | NO: This is the same as /F on the SHELL= line in CONFIG.SYS. It intercepts all DOS critical errors and returns a Fail to each. We do not recommend this on most systems, because you will not have a chance to react to a critical error and correct the ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 148 CHAPTER 5 / CONFIGURATION ------------------------------------------------------------------- problem that caused it. It is intended for use on bulletin boards or other systems where unattended operation is required without user prompts. DiskReset = Yes | NO: Enables or disables disk resets after COPY, DEL/ERASE, DESCRIBE, MOVE, and REN/RENAME, before DIR, and when starting 4DOS. Set to Yes if you have problems with disk change detection on non-standard or cached floppy disk drives, or with network software which doesn't always properly flush data to the disk. Such problems are very rare, so normally No is the best choice. Setting DiskReset to Yes may increase the time required to start a secondary shell, and may reduce the performance of DIR, COPY, MOVE, and RENAME, when using a "staged-write" disk cache such as Microsoft's SmartDrive. See APPNOTES.DOC for details on how specific cache software is affected by the DiskReset setting. DVCleanup = YES | No. Controls the cleanup of 4DOS resources (the shell number and any disk swap file) when you close a 4DOS window from the DESQview menu. See APPNOTES.DOC for more details. FullINT2E = YES | No: Enables full support for the COMMAND.COM "back door" (interrupt 2E) which some programs use to execute commands. Effective only in a primary shell loaded via the SHELL= command in CONFIG.SYS. See Appendix B of the 4DOS Introduction and Installation Guide for details on using INT 2E. Also, see APPNOTES.DOC for information on programs known to require this option. If this directive is set to No, INT 2E will return immediately to the calling program without taking any action. Setting FullINT2E to No reduces the size of the primary shell by about 100 bytes. Inherit = YES | No: .INI file data, aliases, and the history list are normally passed to secondary shells automatically. No disables this feature. MessageServer = YES | No: For compatibility with COMMAND.COM in MS-DOS 4.x and above, 4DOS includes a "message server" that retrieves error message text for DOS external commands like DISKCOPY and FORMAT. The message server increases the size of the resident portion of 4DOS by about 200 bytes. No disables the message server and saves this space, but will cause more cryptic error messages such as "Parse error 3" or "Extended error 7" from some DOS external commands. The message server is automatically enabled by 4DOS in the primary 4DOS ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 149 CHAPTER 5 / CONFIGURATION ------------------------------------------------------------------- shell loaded from CONFIG.SYS when running under MS-DOS 4.x or above, and disabled elsewhere. NetwareNames = Yes | NO. Set to Yes to include strings in the resident portion of 4DOS which Novell Netware searches for when it loads. NetwareNames should be Yes for Netware systems to avoid problems with destroyed environment variables during LOGIN. Setting NetwareNames to Yes increases 4DOS's low DOS memory usage by 112 bytes. OutputBIOS = Yes | NO: Determines whether 4DOS uses the BIOS for all screen displays. If set to No, 4DOS will use direct screen writes for color-coded directories and the DRAWBOX, DRAWHLINE, DRAWVLINE, LIST, SELECT, SCRPUT, and VSCRPUT commands. If set to Yes, 4DOS will perform these commands using BIOS calls. This directive is only needed for compatibility with unusual display adapters, such as those used on Japanese systems running DOS/V. Setting OutputBIOS to Yes may substantially reduce the speed of the affected commands. SDFlush = Yes | NO: Determines whether 4DOS instructs Microsoft SMARTDRV (and other SMARTDRV-compatible disk caching programs) to flush any "write-behind" buffers to the disk before the 4DOS prompt is displayed. Setting SDFlush to Yes may decrease performance, but will ensure that SMARTDRV is instructed to write all modified data to disk before the prompt is displayed. Also, SDFlush does not take into account any changes in the design or behavior of SMARTDRV after the release of 4DOS, or your SMARTDRV startup options. Therefore setting SDFlush to Yes does not guarantee that write-behind data will be written to disk before the prompt is displayed, only that SMARTDRV will be instructed to do so. StackSize = nnnn (4096): Set the 4DOS internal stack size. The allowable range of values is 4096 to 8192. If you use complex combinations of "prefix" commands like DO, EXCEPT, FOR, GLOBAL, IF, IFF, and SELECT on the same command line, and especially if you use these commands in multiple nested batch files or GOSUBs, you may encounter a "4DOS internal stack overflow" error. If you do, you should use this directive to increase the amount of stack space available. For virtually all users, the default stack size will be sufficient. If you increase the stack size, you will increase the size of 4DOS's transient portion in memory, ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 150 CHAPTER 5 / CONFIGURATION ------------------------------------------------------------------- and the size of the 4DOS swap area, by the amount of the stack size increase. You will not normally encounter a stack size problem with 4OS2 or 4DOS/NT, because both can increase the size of the internal stack dynamically. This is not feasible under DOS. SwapReopen = Yes | NO: Set to Yes to enable reopening of the 4DOS swap file if it is closed by another program. This is required when swapping 4DOS to Novell Netware drives or when using other applications which close 4DOS's swap file. In all other circumstances, it is only useful for diagnostic purposes. Setting SwapReopen to Yes also disables the reduced swapping size normally used in 4DOS secondary shells. UniqueSwapName = Yes | No: Set to Yes to change the disk swap file name from 4DOSSWAP.nnn to a unique name generated by 4DOS, with an extension of "4SW" (e.g., A1CD6B11.4SW). This prevents conflicts between swap files in different shells; it is only necessary when you are using disk swapping with a COMMAND.COM primary shell or in an OS/2 2.x DOS session. The default is Yes in OS/2 DOS sessions and No elsewhere. UniqueSwapName only works in DOS 3.0 and above, and in OS/2 DOS sessions, and applies only to disk swapping. Examples The following examples will give you an idea of the types of things that can be done with the .INI file. The comments on each directive explain what it does. First, a very simple 4DOS example that just sets up swapping and environment size, leaving everything else at its default value: Swapping = ems, c:\ ;try EMS, then C: root Environment = 1024 ;set environment size Here's another 4DOS example, for a system which supports Upper Memory blocks (UMBs). Several settings take advantage of UMBs, and others modify the 4DOS configuration to match the user's preferences. Note that the comment for the Swapping directive is on separate lines before the directive itself, as no comments are allowed in string directives: Environment = 3072 ;expand environment to 3K ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 151 CHAPTER 5 / CONFIGURATION ------------------------------------------------------------------- Alias = 6144 ;expand aliases to 6K LocalHistory = No ;use a global history ;for swapping try XMS, then RAM disk H:, then ;hard disk C: Swapping = xms, h:\, c:\ UMBLoad = Yes ;res. part of 4DOS in UMB UMBEnvironment = Yes ;master environment in UMB UMBHistory = Yes ;global history in UMB BatchEcho = No ;default is ECHO OFF EditMode = Insert ;editor in insert mode CursorOver = 100 ;overstrike cursor 100% CursorIns = 10 ;insert cursor 10% This example for 4OS2 configures certain special characters to match 4DOS, and changes other default settings to suit the user's preferences. All of these settings except HelpBook would also work in 4DOS or 4DOS/NT. You must enter the actual escape character, not the string "<Ctrl-X>", in the EscapeChar directive: PauseOnError = No ;don't stop on INI errors CommandSep = ^ ;4DOS command separator EscapeChar = <Ctrl-X> ;4DOS escape character ParameterChar = & ;4DOS parameter character BatchEcho = No ;default to ECHO OFF HelpBook = 4OS2 History = 2048 ;expand history to 2K bytes BeepFreq = 880 ;make beep higher pitch EditMode = Insert ;insert mode for cmd edit CursorOver = 100 ;overstrike cursor 100% CursorIns = 10 ;insert cursor 10% ListFind = F5 ;F5 does a find in LIST ListNext = F6 ;and F6 does a find next StdColors = bri cya on blu ;default colors ListColors = bri whi on blu ;colors for LIST SelectColors = bri whi on blu ;same colors for SELECT colordir = DIRS:bri yel;com exe bat btm cmd:bri whi ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 152 CHAPTER 6 / COMMAND REFERENCE GUIDE ------------------------------------------------------------------- CHAPTER 6 / COMMAND REFERENCE GUIDE The following pages are a complete guide and reference to the 4DOS, 4OS2, and 4DOS/NT commands that are available from the command line, in aliases, and in batch files. All of these commands are internal commands, which means that the command processor performs the activity you have requested without running another program. (See page 19 for more information on internal and external commands.) We offer over 80 internal commands, many more than any version of COMMAND.COM or CMD.EXE. These neither replace nor interfere with external commands like BACKUP, CHKDSK, DISKCOPY, or XCOPY. You can continue to use those utilities like you always have. Also, each of our command processors has been designed to be compatible with virtually all traditional internal commands, and to enhance most of those commands with additional options and capabilities. Once you have installed your new command processor, you can continue using the commands that you already know and get the same results. We have made no attempt to document external DOS, OS/2, and Windows NT commands in this reference, partly because they are explained in your operating system manual, and partly because external commands, and the options available with each command, vary widely from one operating system to another and from one version to another. The 4DOS HELP system does include information about standard DOS external commands, and the 4OS2 HELP system can be configured to display information about OS/2 external commands (see the Introduction and Installation Guide for each product for further details). Most 4DOS, 4OS2, and 4DOS/NT commands are either enhanced traditional commands or are entirely new (a few are the same as traditional commands). If you are comfortable using traditional commands, you can switch to your new command processor without making any changes in your habits. But you will be missing a lot of the power of these enhancements and new commands unless you take a few minutes to see what's available here. Make sure you don't skip a section of this reference just because you already know how to use a traditional command with the same name. If you come across terms or concepts in this chapter that you are unsure about, please refer to Chapter 1 / General Concepts, the Glossary on page 381, or the Index. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 153 CHAPTER 6 / COMMAND REFERENCE GUIDE ------------------------------------------------------------------- Command Categories The best way to learn the commands is to use them and experiment with them. We urge you to browse through this chapter occasionally and look for commands that might help simplify your computing life. The following lists categorize the available commands by topic and will help you find the ones that you need. Commands listed below with an asterisk [*] are not available in all command processors; see the list at the end for details. System configuration: BREAK * CHCP * CLS COLOR CTTY * DATE FREE HISTORY KEYS * KEYBD LH/LOADHIGH* LOG MEMORY PROMPT REBOOT SETDOS SWAPPING * TIME VER VERIFY VOL File and directory management: ATTRIB COPY DEL/ERASE DESCRIBE LIST MOVE REN/RENAME SELECT TRUENAME * TYPE Subdirectory management: CD/CHDIR CDD DIR DIRS MD/MKDIR POPD PUSHD RD/RMDIR Input and output: DRAWBOX DRAWHLINE DRAWVLINE ECHO ECHOS INKEY INPUT KEYSTACK * MSGBOX * SCREEN SCRPUT TEXT VSCRPUT Commands primarily for use in or with batch files and aliases (some work only in batch files; see the individual commands for details): ALIAS BEEP CALL CANCEL DELAY DO ENDLOCAL FOR GLOBAL GOSUB GOTO IF IFF LOADBTM ON PAUSE QUIT REM RETURN SETLOCAL SHIFT TEXT UNALIAS ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 154 CHAPTER 6 / COMMAND REFERENCE GUIDE ------------------------------------------------------------------- Environment and path commands: DPATH * ESET PATH SET UNSET Window management commands: ACTIVATE * TITLE * WINDOW * Other commands: ? DETACH * EXCEPT EXIT FFIND HELP LIST START TEE TIMER Y * Some of these commands are not included in one or more of our command processors. Usually a command is left out of a product when it is not useful or cannot be implemented in that environment (for example, the DETACH command is related to multitasking, and is not available under DOS because DOS does not offer multitasking). The commands that are specific to particular products are: ACTIVATE.....4DOS/NT KEYSTACK......4DOS BREAK........4DOS, 4DOS/NT LH/LOADHIGH...4DOS CHCP.........4DOS, 4OS2 MSGBOX........4DOS/NT CTTY.........4DOS. SWAPPING......4DOS DETACH.......4OS2, 4DOS/NT TITLE.........4DOS/NT DPATH........4OS2. TRUENAME......4DOS KEYS.........4OS2, 4DOS/NT WINDOW........4OS2, 4DOS/NT How to Use the Command Descriptions Each of the internal commands is described in detail on the following pages. The descriptions are arranged alphabetically, and each includes examples that will help you learn to use the commands. Each description begins with the name of the command on the left side of the page. If the command is only available in some of our products, those products are listed next to the command name, and in the page header. Commands marked "New" on the right side of the page are unique to 4DOS, 4OS2, or 4DOS/NT. Those marked "Enhanced" are similar to traditional commands but add new features and options. The commands marked "Compatible" follow the syntax and features of the traditional command with the same name. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 155 CHAPTER 6 / COMMAND REFERENCE GUIDE ------------------------------------------------------------------- The name is followed by a sentence or two that briefly describes the command's purpose or major function. That sentence should help you determine quickly whether you have found the command you are seeking. The next part of each description shows the command's format or syntax. The format line uses certain conventions to describe how the command should be entered and to create reference points for the text describing the command: Words in UPPER CASE must be spelled exactly as they are shown (although you can type them in either upper or lower case, or a combination). If a word is shown partly in upper case (for example BLInk), only the upper case portion is required, the rest is optional. Words shown in italics (for example source or filename) are meant to be replaced by other words or values. Each of these words is explained directly beneath the format line and discussed in more detail in the text description of the command. When the word stands for a file name, you can use a simple name like MYFILE.TXT, or include a drive letter and/or a full path, like C:\MYDIR\MYFILE.TXT. Items followed by an ellipsis (three periods [...]) may be repeated. For example, filename ... means you may enter one or more file names at this point in the command. Text shown in [square brackets] is optional. Text outside of square brackets must be entered literally (if it is capitalized) or replaced by other words or values (if it is in italics). Vertical bars [|] represent a choice; you can pick one option or another but not both. For example, the following format shows that the command may be followed by the word ON or the word OFF, but not both: COMMAND [ ON | OFF ] A slash followed by a letter, like [/X], is an "option" or "switch" which controls the effect of a command. Many commands have several switches, and you are usually free to use none, one, or several to make a command behave as you wish. If you use a single switch, you must precede it with a slash. If you use several switches, in most cases you can put them together with one slash or use separate slashes. For example, if you wanted to use ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 156 CHAPTER 6 / COMMAND REFERENCE GUIDE ------------------------------------------------------------------- switches X, Y, and Z for a command, you could type them three different ways: command /x /y /z command /x/y/z command /xyz A few switches, particularly in the DIR, SELECT, and START commands, use two or more characters. If you need to follow a multi-letter switch with another switch, the second switch must have its own slash to avoid ambiguity. Included in the format section is an explanation of each replaceable argument and a one or two word explanation of each switch. Many descriptions also list related commands to help you find the exact command you want. For file handling commands, a section called "Selection" appears immediately after the format section. This section lists the file-handling features that the command supports. The list may include mention of extended wildcards (see page 59); multiple file names (page 66); include lists (page 67); and date, time, and size ranges (see page 62). Next, you'll find a description of the command's usage. This description normally starts with the basic functions of a command and gradually adds more details. We've also included many examples to help you see the command in action. In the examples, characters in bold type represent input from the user. Characters in normal type represent prompts or responses from the command processor, or lines in a batch file. The last part of each description is a detailed explanation of the options or switches available for each command, in alphabetical order. Occasionally, we've included more examples in this section to demonstrate how a switch is used or how multiple switches interact. Most of the commands and their switches have the same use in 4DOS, 4OS2, and 4DOS/NT. When a command, feature, or switch applies to a single product, we mention it specifically in the text. When an entire paragraph applies to a specific product, we use marginal text to identify that product. When an entire command is only available in one or two products, the products are listed next to the command name, and in the page headings. 4DOS marks information that applies only to 4DOS. 4OS2 marks information that applies only to 4OS2. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 157 CHAPTER 6 / COMMAND REFERENCE GUIDE ------------------------------------------------------------------- 4NT marks information that applies only to 4DOS/NT. Occasionally, a command or switch will be marked with two of these marginal notations when it applies to two different products. An exclamation point [!] to the left of a paragraph means that paragraph contains a caution or warning you should observe when using the feature it discusses. In the Usage and Options sections you may see the symbol ##. This indicates a more in-depth discussion or an advanced topic which you can skip if you are new to the command; come back to this topic later for more details, or if you're having trouble with the command. In most cases the remainder of the section after such a symbol is devoted to similar information. The ## doesn't mean that only advanced users will need the information - you may find it useful even if you're relatively new to computers or to our products. But it does mean that you can skip the marked section and still understand and use the basic features of the command. If a ## appears before the "Usage" heading, it indicates that the entire command is generally used only in unusual situations or by more advanced users. When you see a ## in the list of options, remember that the options are listed alphabetically, so there may be more basic options discussed later in the list, after a more complex or advanced option marked with ##. Don't stop reading the option list the first time you see the mark. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 158 ? ------------------------------------------------------------------- ? (New) Purpose: Display a list of internal commands or prompt for a command. Format: ? ["prompt text" command] Usage: ? by itself displays a list of internal commands. For help with these commands, see the HELP command. When you use the ? command by itselt, you will see a display like this (the partial list below is for 4DOS; you will see a slightly different list for 4OS2 or 4DOS/NT): c:\> ? ? ALIAS ATTRIB BEEP BREAK CALL CANCEL CD CDD CHCP CHDIR CLS COLOR COPY CTTY DATE ..... ..... TIMER TRUENAME TYPE UNALIAS UNSET VER VERIFY VOL VSCRPUT Y If you have disabled a command with SETDOS /I, it will not appear in the list. If you add prompt text and a command, ? will display the prompt followed by "(Y/N)?" and wait for the user's response. If the user presses "Y" or "y", the command will be executed. If the user presses "N" or "n", the command will be ignored. For example, the following command might be used in a batch file: ? "Load the network" call netstart.btm ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 159 [4DOS/NT] ACTIVATE ------------------------------------------------------------------- ACTIVATE [4DOS/NT] (New) Purpose: Activate a window, set its state, or change its title. Format: ACTIVATE "window" [MAX | MIN | RESTORE | CLOSE | "title" ] window: Current title of window to work with. title: New title for window. See also: START, TITLE, and WINDOW. Usage: Both the current name of the window and the new name, if any, must be enclosed in double quotes. The quotes will not appear as part of the title bar text. If no options are used, the window named in the command will become the active window and be able to receive keystrokes and mouse commands. The MAX option expands the window to its maximum size, the MIN option reduces the window to an icon, and the RESTORE option returns the window to its default size and location on the desktop. The CLOSE option closes the window and ends the session running in the window. This example renames and maximizes the window called "4DOS/NT": [c:\] activate "4DOS/NT" max "4DOS/NT is Great!" ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 160 ALIAS ------------------------------------------------------------------- ALIAS (New) Purpose: Create new command names that execute one or more commands or redefine default options for existing commands; assign commands to keystrokes; load or display the list of defined alias names. Format: ALIAS [/P /R file...] [name[=][value]] file: One or more files to read for alias definitions. name: Name for an alias, or for the key to execute the alias. value: Text to be substituted for the alias name. /P(ause) /R(ead file) See also: UNALIAS, and Aliases on page 77. Usage: The ALIAS command lets you create new command names or redefine internal commands. It also lets you assign one or more commands to a single keystroke. An alias is often used to execute a complex series of commands with a few keystrokes or to create "in memory batch files" that run much faster than disk-based batch files. For example, if you would rather type D instead of DIR /W, you would use the command: c:\> alias d = dir /w Now when you type a single d as a command, it will be translated into a DIR /W command. If you define aliases for commonly used application programs, you can often remove the directories they're stored in from the PATH. For example, if you use Quattro Pro and had the C:\QPRO directory in your path, you could define the following alias: c:\> alias qpro = c:\qpro\q.exe With this alias defined, you can probably remove C:\QPRO from your path. Quattro Pro will now load much faster than it would if the command processor had to search the PATH for it. In addition, the PATH can be shorter, which will speed up searches for other programs. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 161 ALIAS ------------------------------------------------------------------- If you apply this technique for each application program, you can often reduce your PATH to just two or three directories containing utility programs, and significantly reduce the time it takes to load most software on your system. Before removing a directory from the PATH, you will need to define aliases for all the executable programs you commonly use which are stored in that directory. Aliases are stored in memory, and are not saved automatically when you turn off your computer or end your current session. See page 167 for information on saving and reloading your aliases. Multiple Commands and Special Characters in Aliases An alias can represent more than one command. For example: c:\> alias letters = `cd \letters ^ text` creates a new command called LETTERS. The command first uses CD to change to a subdirectory called \LETTERS and then runs a program called TEXT. The caret [^] is the 4DOS command separator and indicates that the two commands are distinct and should be executed sequentially. (The 4OS2 and 4DOS/NT command separator is normally an ampersand [&].) Aliases make extensive use of the command separator (see page 47), and the parameter character (see page 140), and may also use the escape character (see page 73). These characters differ between 4DOS and 4OS2 or 4DOS/NT. In the text and examples below, we use the 4DOS characters. The difference is also explained the first time each character is used. Be sure to insert the correct characters for the command processor you are using. If you want to use the same aliases under different command processors, see page 74. When you type alias commands at the command line or in a batch file, you must use back-quotes [`] around the definition if it contains multiple commands, parameters (discussed below), environment variables, redirection, or piping. The back-quotes prevent premature expansion of these arguments. You may use back-quotes around other definitions, but they are not required. (You do not need back-quotes when your aliases are loaded from an ALIAS /R file; see below ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 162 ALIAS ------------------------------------------------------------------- for details.) The examples above and below include back-quotes only when they are required. Nested Aliases Aliases may invoke internal commands, external commands, or other aliases. (However, an alias may not invoke itself, except in special cases where an IF or IFF command is used to prevent an infinite loop.) The two aliases below demonstrate alias nesting (one alias invoking another). The first line defines an alias which runs a program called WP.EXE that is in the E:\WP60\ subdirectory. The second alias changes directories with the PUSHD command, runs the WP alias, and then returns to the original directory with the POPD command: c:\> alias wp = e:\wp60\wp.exe c:\> alias w = `pushd c:\wp ^ wp ^ popd` The second alias above could have included the full path and name of the WP.EXE program instead of calling the WP alias. However, writing two aliases makes the second one easier to read and understand, and makes the first alias available for independent use. If you rename the WP.EXE program or move it to a new directory, only the first alias needs to be changed. Temporarily Disabling Aliases If you put an asterisk [*] immediately before a command in the value of an alias definition (the part after the equal sign), it tells the command processor not to attempt to interpret that command as another (nested) alias. An asterisk used this way must be preceded by a space or the command separator and followed immediately by an internal or external command name. The asterisk is used to signal that the following word is the name of an internal or external command instead of an alias which may have the same name. It also allows two popular uses of aliases. First, by using an asterisk, you can redefine the default options for any internal command. For example, suppose that you always want to use the DIR command with the /2 (two column) and /P (pause at the end of each page) options. The following line will do just that: ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 163 ALIAS ------------------------------------------------------------------- c:\> alias dir = *dir /2/p If you didn't include the asterisk, the second DIR on the line would be the name of the alias itself, and the command processor would repeatedly re-invoke the DIR alias, rather than running the DIR command. This would cause an "Alias loop" or "Command line too long" error. The asterisk forces interpretation of the second DIR as a command, not an alias. Second, an asterisk also helps you keep the names of internal commands from conflicting with the names of external programs. For example, suppose you have a program called LIST.COM. Normally, the internal LIST command will run anytime you type LIST. But two simple aliases will give you access to both the LIST.COM program and the LIST command: c:\> alias list = c:\util\list.com c:\> alias display = *list The first line above defines LIST as an alias for the LIST.COM program. If you stopped there, the external program would run every time you typed LIST and you would not have easy access to the internal LIST command. The second line renames the internal LIST command as DISPLAY. The asterisk is needed in the second command to indicate that the following word means the internal command LIST, not the LIST alias which runs your external program. Another way to understand the asterisk is to remember that a command is always checked for an alias first, then for an internal or external command, or a batch file (see page 121). The asterisk at the beginning of a command name simply skips over the usual check for aliases when processing that command, and allows the command processor to go straight to checking for an internal command, external command, or batch file. You can also use an asterisk before a command that you enter at the command line or in a batch file. If you do, that command won't be interpreted as an alias. This can be useful when you want to be sure you are running the true, original command and not an alias with the same name, or temporarily defeat the purpose of an alias which changes the meaning or behavior of a command. For example, above we defined an alias for DIR which made directories display in 2-column paged mode by default. If you wanted to see a directory ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 164 ALIAS ------------------------------------------------------------------- display in the normal single-column, non-paged mode, you could enter the command *DIR and the alias would be ignored during that one command. Partial Alias Names You can also use an asterisk in the name of an alias. When you do, the characters following the asterisk are optional when you invoke the alias command. (Use of an asterisk in the alias name is unrelated to the use of an asterisk in the alias value discussed above.) For example, with this alias: c:\> alias wher*eis = dir /sp the new command, WHEREIS, can be invoked as WHER, WHERE, WHEREI, or WHEREIS. Now if you type: c:\> where myfile.txt The WHEREIS alias will be expanded to the command: dir /sp myfile.txt Keystroke Aliases If you want to assign an alias to a keystroke, use the keyname on the left side of the equal sign, preceded by an at sign [@]. For example, to assign the command DIR /W to the F5 key, type c:\> alias @F5 = dir /w See page 31 for a complete listing of key names and a description of the key name format. When you define keystroke aliases, the assignments will only be in effect at the command line, not inside application programs. Be careful not to assign aliases to keys that are already used at the command line (like F1 for Help). The command-line meanings take precedence and the keystroke alias will never be invoked. If you want to use one of the command-line keys for an alias instead of its normal meaning, you must first disable its regular use with the NormalKey or NormalEditKey directive in your .INI file. See page 143 for instructions. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 165 ALIAS ------------------------------------------------------------------- If you define a keystroke alias with a single at sign as shown above, then, when you press the F5 key, the value of the alias (DIR /W above) will be placed on the command line for you. You can type additional parameters if you wish and then press Enter to execute the command. With this particular alias, you can define the files that you want to display after pressing F5 and before pressing Enter to execute the command. If you want the keystroke alias to take action automatically without waiting for you to edit the command line or press Enter, you can begin the definition with two at signs [@@]. The command processor will execute the alias "silently," without displaying its text on the command line. For example, this command will assign an alias to the F6 key that uses the CDD command to take you back to the previous default directory: c:\> alias @@f6 = cdd - ## A second method can also be used to make a keystroke alias execute immediately: you can include a carriage return character as the last character in the alias definition. When the command processor finds the carriage return, it executes the alias just as if you had pressed the Enter key. Unlike the "@@" method (above), this method will display the contents of the alias on the screen. If you use this method, do not define the alias with a double at sign as well. If you do, the alias will not work properly. To include the carriage return character, add an escape character followed by an "r" to the end of the alias (see page 73 for more information about the escape character). For example, you could write the above alias as: c:\> alias @f6 = `cdd -<Ctrl-X>r` (If you define your alias at the command line without using back-quotes, you must use two escape characters before the "r". In 4DOS, the default escape character is <Ctrl-X>; in 4OS2 and 4DOS/NT, the default escape character is a caret [^].) ## You can also define a keystroke alias by using "@" or "@@" plus a scan code for one of the permissible keys (see Appendix B on page 371 for a list of scan codes). ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 166 ALIAS ------------------------------------------------------------------- In most cases it will be easier to use key names. Scan codes should only be used with unusual keyboards where a key name is not available for the key you are using. Displaying Aliases If you want to see a list of all current ALIAS commands, type: c:\> alias You can also view the definition of a single alias. If you want to see the definition of the alias LIST, you can type: c:\> alias list Saving and Reloading Your Aliases You can save your aliases to a file called ALIAS.LST this way: c:\> alias > alias.lst You can then reload all the alias definitions in the file the next time you boot up with the command: c:\> alias /r alias.lst This is much faster than defining each alias individually in a batch file. If you keep your alias definitions in a separate file which you load when your system starts, you can edit them with a text editor, reload the edited file with ALIAS /R, and know that the same alias list will be loaded the next time you boot your computer. When you define aliases in a file that will be read with the ALIAS /R command, you do not need back-quotes around the value, even if back-quotes would normally be required when defining the same alias at the command line or in a batch file. To remove an alias, use the UNALIAS command. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 167 ALIAS ------------------------------------------------------------------- Alias Parameters ## Aliases can use command-line arguments or parameters like those in batch files. The command-line arguments are numbered from %0 to %127. %0 contains the alias name. It is up to the alias to determine the meaning of the other parameters. You can use quotation marks to pass spaces, tabs, commas, and other special characters in an alias parameter; see page 123 for details. Parameters that are referred to in an alias, but which are missing on the command line, appear as empty strings inside the alias. For example, if you put two parameters on the command line, any reference in the alias to %3 or any higher-numbered parameter will be interpreted as an empty string. The parameter %n& has a special meaning. 4DOS interprets it to mean "the entire command line, from argument n to the end." If n is not specified, it has a default value of 1, so %& means "the entire command line after the alias name." 4OS2 and 4DOS/NT normally use a dollar sign [$] instead of an ampersand [&] to indicate the remainder of the command tail (for example, use %$ to refer to all parameters under 4OS2 or 4DOS/NT). The special parameter %# contains the number of command-line arguments. For example, the following alias will change directories, perform a command, and return to the original directory: c:\> alias in `pushd %1 ^ %2& ^ popd` When this alias is invoked as: c:\> in c:\comm mycomm /xmodem /2400 the first parameter, %1, has the value c:\comm. %2 is mycomm, %3 is /xmodem, and %4 is /2400. The command line expands into these three separate commands: pushd c:\comm mycomm /xmodem /2400 popd ## This next example uses the IFF command to redefine the defaults for SET. It should be entered on one line: ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 168 ALIAS ------------------------------------------------------------------- c:\> alias set = `iff %# == 0 then ^ *set /p ^ else ^ *set %& ^ endiff` This modifies the SET command so that if SET is entered with no arguments, it is replaced by SET /P (pause after displaying each page), but if SET is followed by an argument, it behaves normally. Note the use of asterisks (*set) to prevent alias loops. ## If an alias uses parameters, command-line arguments will be deleted up to and including the highest referenced argument. For example, if an alias refers only to %1 and %4, then the first and fourth arguments will be used, the second and third arguments will be discarded, and any additional arguments beyond the fourth will be appended to the expanded command (after the value portion of the alias). If an alias uses no parameters, all of the command-line arguments will be appended to the expanded command. ## Aliases also have full access to all variables in the environment, internal variables, and variable functions. For example, you can create a simple command-line calculator this way (enter this on one line): c:\> alias calc = `echo The answer is: %@eval[%&]` Now, if you enter: c:\> calc 5 * 6 the alias will display: The answer is: 30 ## Local and Global Aliases The aliases can be stored in either a "local" or "global" list. With a local alias list, any changes made to the aliases will only affect the current copy of the command processor. They will not be visible in other shells or other sessions. A local alias list is the default under 4DOS. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 169 ALIAS ------------------------------------------------------------------- With a global alias list, all copies of the command processor will share the same alias list, and any changes made to the aliases in one copy will affect all other copies. A global alias list is the default for 4OS2 and 4DOS/NT. You can control the type of alias list with the LocalAliases directive in the .INI file (see page 134), and with the /L and /LA options of the START command (see page 331). There is no fixed rule for determining whether to use a local or global alias list. Depending on your work style, you may find it most convenient to use one type, or a mixture of types in different sessions or shells. We recommend that you start with the default approach for your command processor, then modify it if you find a situation where the default is not convenient. Whenever you start a secondary shell (see page 12) which uses a local alias list, it inherits a copy of the aliases from the previous shell. However, any changes to the alias made in the secondary shell will affect only that shell. If you want changes made in a secondary shell to affect the previous shell, use a global alias list in both shells. 4DOS If you select a global alias list for 4DOS running under DOS, you can share the aliases among all copies of 4DOS. However, if you run 4DOS under OS/2, global lists will apply within each DOS session, but will not allow you to share aliases between different DOS sessions. 4OS2, ## Retaining Global Aliases with SHRALIAS 4NT If you select a global alias list for 4OS2 or 4DOS/NT, you can share the aliases among all copies of the command processor running in any session. When you close all 4OS2 or 4DOS/NT sessions, the memory for the global alias list is released, and a new, empty alias list is created the next time you start 4OS2 or 4DOS/NT. If you want the alias list to be retained in memory even when no command processor session is running, you need to load the SHRALIAS program, which performs this service for both the global alias list and the global ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 170 ALIAS ------------------------------------------------------------------- history list. SHRALIAS is supplied with your copy of 4OS2 or 4DOS/NT. To load SHRALIAS, simply run the SHRALIAS.EXE program, which is normally installed in the same directory as your command processor. You may find it convenient to load SHRALIAS from your 4START file (see page 85), or, under OS/2, from your STARTUP.CMD (see your 4OS2 Introduction and Installation Guide for details on STARTUP.CMD). If you try to load SHRALIAS when there is no 4OS2 or 4DOS/NT session running with a global alias or history list enabled, then SHRALIAS will not be able to find the lists. In this case it will display an error message and exit. If you load SHRALIAS more than once, the second copy will detect the original copy, display an error message, and exit. The original copy will remain loaded. SHRALIAS runs as a "detached" process, which means it does not have a screen display or accept keyboard input. It is shut down automatically when the operating system shuts down. To unload SHRALIAS manually, run SHRALIAS.EXE with the parameter /U. ## The UNKNOWN_CMD Alias If you create an alias with the name UNKNOWN_CMD, it will be executed any time the command processor would normally issue an "Unknown command" error message. This allows you to define your own handler for unknown commands. When the UNKNOWN_CMD alias is executed, the command line which generated the error is passed to the alias for possible processing. ! Use caution when you create the UNKNOWN_CMD alias. If it contains an unknown command, it will be called repeatedly and the command processor will lock up in an infinite loop. Options: /P(ause): This option is only effective when ALIAS is used to display existing definitions. It pauses the display after each page and waits for a keystroke before continuing (see page 50). /R(ead file): This option loads an alias list from a file. The format of the file is the same as that of the ALIAS display: ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 171 ALIAS ------------------------------------------------------------------- name=value where name is the name of the alias and value is its value. You can use an equal sign [=] or space to separate the name and value. Back-quotes are not required around the value. You can add comments to the file by starting each comment line with a colon [:]. You can load multiple files with one ALIAS /R command by placing the names on the command line, separated by spaces: c:\> alias /r alias1.lst alias2.lst Each definition in an ALIAS /R file can be up to 511 characters long in 4DOS, or 2047 characters in 4OS2 and 4DOS/NT. The definitions can span multiple lines in the file if each line, except the last, is terminated with an escape character (see page 73). ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 172 ATTRIB ------------------------------------------------------------------- ATTRIB (Enhanced) Purpose: Change or view file and subdirectory attributes. Format: ATTRIB [/A[[:][-]rhsda] /D /P /Q /S] [+|-[AHRS]] files ... files: A file, directory, or list of files or directories on which to operate. /A(ttribute select) /Q(uiet) /D(irectories) /S(ubdirectories) /P(ause) Attribute flags: A+ Set the archive attribute A- Clear the archive attribute H+ Set the hidden attribute H- Clear the hidden attribute R+ Set the read-only attribute R- Clear the read-only attribute S+ Set the system attribute S- Clear the system attribute Selection: Supports extended wildcards, ranges, multiple file names, and include lists (see pages 59 - 67). Usage: Every file and subdirectory has 4 attributes that can be turned on (set) or turned off (cleared): Archive, Hidden, Read-only, and System. For details on the meaning of each attribute, see page 18. The ATTRIB command lets you set or clear attributes for any file, group of files, or subdirectory. You can view file attributes by entering ATTRIB without specifying new attributes (i.e., without the [+|- [AHRS]] part of the format), or with the DIR /T command. For example, you can set the read-only and hidden attributes for the file MEMO: c:\> attrib +rh memo Attribute options apply to the file(s) that follow the options on the ATTRIB command line. The example below shows how to set different attributes on different files with a single command. It sets the archive attribute for all .TXT files, then sets the system ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 173 ATTRIB ------------------------------------------------------------------- attribute and clears the archive attribute for TEST.COM: c:\> attrib +a *.txt +s -a test.com ## Your operating system also supports "D" (subdirectory) and "V" (volume label) attributes. These attributes cannot be altered with ATTRIB; they are designed to be controlled only by the operating system itself. Options: ## /A(ttribute select): Select only those files that have the specified attribute(s) set. Preceding the attribute character with a hyphen [-] will select files that do not have that attribute set. The attributes are: R Read-only D Subdirectory H Hidden A Archive S System If no attributes are listed at all (e.g., ATTRIB /A ...), ATTRIB will select all files and subdirectories including hidden and system files. If attributes are combined, all the specified attributes must match for a file to be selected. For example, /A:RHS will select only those files with all three attributes set. See page 18 for more information on file attributes. /D(irectories): If you use the /D option, ATTRIB will modify the attributes of subdirectories in addition to files (yes, you can have a hidden subdirectory): c:\> attrib /d +h c:\mydir In addition, the /D option will keep ATTRIB from appending "\*.*" to the end of a directory name and modifying the attributes of all the files in the subdirectory. If you use a directory name instead of a file name, and omit /D, ATTRIB will append "\*.*" to the end of the name and act on all files in that directory, rather than acting on the directory itself. /P(ause): Wait for a key to be pressed after each screen page before continuing the display. Your options at the prompt are explained in detail on page 50. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 174 ATTRIB ------------------------------------------------------------------- /Q(uiet): This option turns off ATTRIB's normal screen output. It is most useful in batch files. /S(ubdirectories): If you use the /S option, the ATTRIB command will be applied to all matching files in the current or named directory and all of its subdirectories. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 175 BEEP ------------------------------------------------------------------- BEEP (New) Purpose: Beep the speaker or play simple music. Format: BEEP [frequency duration ...] frequency: The beep frequency in Hertz (cycles per second). duration: The beep length in 1/18th second intervals. Usage: BEEP generates a sound through your computer's speaker. It is normally used in batch files to signal that an operation has been completed, or that the computer needs attention. Because BEEP allows you to specify the frequency and duration of the sound, you can also use it to play simple music or to create different kinds of signals for the user. You can include as many frequency and duration pairs as you wish. No sound will be generated for frequencies less than 20 Hz, allowing you to insert short delays. The default value for frequency is 440 Hz; the default value for duration is 2. This batch file fragment runs a program called DEMO, then plays a few notes and waits for you to press a key: demo ^ beep 440 4 600 2 1040 6 pause Finished with the demo - hit a key... The following table gives the frequency values for a five octave range (middle C is 262 Hz): C 131 262 523 1046 2093 C#/Db 139 277 554 1108 2217 D 147 294 587 1174 2349 D#/Eb 156 311 622 1244 2489 E 165 330 659 1318 2637 F 175 349 698 1397 2794 F#/Gb 185 370 740 1480 2960 G 196 392 784 1568 3136 G#/Ab 208 415 831 1662 3322 A 220 440 880 1760 3520 A#/Bb 233 466 932 1864 3729 B 248 494 988 1976 3951 ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 176 [4DOS, 4DOS/NT] BREAK ------------------------------------------------------------------- BREAK [4DOS, 4DOS/NT] (Compatible) Purpose: Display, enable, or disable Ctrl-C and Ctrl-Break checking. Format: BREAK [ON | OFF] Usage: The Ctrl-C and Ctrl-Break keys are used by many programs (including 4DOS) as a signal to interrupt the current operation. BREAK controls how often DOS checks to see if you've entered one of these keystrokes. 4NT Ctrl-C and Ctrl-Break checking cannot actually be enabled or disabled under Windows NT. 4DOS/NT supports BREAK as a "do-nothing" command, for compatibility with CMD.EXE. This avoids errors in batch files which use the BREAK command. The additional discussion below applies only to 4DOS, not to 4DOS/NT. Normally, BREAK is turned off, and DOS only checks for Ctrl-C and Ctrl-Break keystrokes during DOS input or output operations involving the screen, keyboard, serial port, and printer. However, many programs don't use DOS for these operations, and it can be difficult to interrupt them. When BREAK is turned on, DOS checks for Ctrl-C and Ctrl-Break every time a program calls DOS. Since most programs use DOS to access files and perform other functions, turning BREAK on makes it much more likely that a Ctrl-C or Ctrl-Break will be noticed. If you turn BREAK on, programs will run slightly slower than normal (the difference is not usually noticeable). Turning BREAK on or off only affects when DOS detects Ctrl-C and Ctrl-Break and notifies the program you're running. Any program can choose to ignore these signals. Also, any external program can change the BREAK setting on its own. Type BREAK plus ON or OFF to set the BREAK status, or BREAK by itself to display the current BREAK status. For example: c:\> break on c:\> break BREAK is ON ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 177 [4DOS, 4DOS/NT] BREAK ------------------------------------------------------------------- BREAK is off by default. You can change the default by adding a BREAK=ON command to your CONFIG.SYS file. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 178 CALL ------------------------------------------------------------------- CALL (Compatible) Purpose: Execute one batch file from within another. Format: CALL file file: The batch file to execute. See also CANCEL and QUIT. Usage: CALL allows batch files to call other batch files (batch file nesting). The calling batch file is suspended while the called (second) batch file runs. When the second batch file finishes, the original batch file resumes execution at the next command. If you execute a batch file from inside another batch file without using CALL, the first batch file is terminated before the second one starts. The following batch file fragment compares an input line to "wp" and calls another batch file if it matches: input Enter your choice: %%option if "%option" == "wp" call wp.bat 4DOS, 4OS2, and 4DOS/NT support batch file nesting up to ten levels deep. The current ECHO state is inherited by a called batch file. ## A called batch file will return to the calling file after processing the last line in the called file, or when a QUIT command is executed. A called batch file should always return in this way, or terminate all batch files with CANCEL. Restarting (or CALLing) the original batch file from within a called file will prevent the command processor from detecting that you've left the second file, and it may cause an infinite loop or a stack overflow. ## CALL returns an exit code which matches the batch file return code. You can test this exit code with the %_? or %? environment variable (see page 102), and use it with conditional commands (&& and ||; see page 71). ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 179 CANCEL ------------------------------------------------------------------- CANCEL (New) Purpose: Terminate batch file processing. Format: CANCEL [value] value: The exit code from 0 to 255 to return to the command processor. See also: CALL and QUIT. Usage: The CANCEL command ends all batch file processing, regardless of the batch file nesting level. Use QUIT to end a nested batch file and return to the previous batch file. You can CANCEL at any point in a batch file. If CANCEL is used from within an alias it will end execution of both the alias and any batch file(s) which are running at the time. The following batch file fragment compares an input line to "end" and terminates all batch file processing if it matches: input Enter your choice: %%option if "%option" == "end" cancel ## If you specify a value, CANCEL will set the ERRORLEVEL or exit code to that value (see the IF command, and the %? variable on page 102). ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 180 CD / CHDIR ------------------------------------------------------------------- CD / CHDIR (Enhanced) Purpose: Display or change the current directory. Format: CD [ path | - ] or CHDIR [ path | - ] path: The directory to change to, including an optional drive name. See also: CDD, MD, PUSHD, RD, and Directory Changes on page 44. Usage: CD and CHDIR are synonyms. You can use either one. CD lets you navigate through the DOS subdirectory structure by changing the current working directory. If you enter CD and a directory name, the named directory becomes the new current directory. For example, to change to the subdirectory C:\FINANCE\MYFILES: c:\> cd \finance\myfiles c:\finance\myfiles> Every disk drive on the system has its own current directory. Specifying both a drive and a directory in the CD command will change the current directory on the specified drive, but will not change the default drive. For example, to change the default directory on drive A: c:\> cd a:\utility c:\> Notice that this command does not change to drive A:. Use the CDD command to change the current drive and directory at the same time. You can change to the parent directory with CD ..; you can also go up one additional directory level with each additional [.]. For example, CD .... will go up three levels in the directory tree (see page 59 for additional details). You can move to a sibling directory - one that branches from the same parent directory as the current subdirectory - with a command like CD ..\newdir. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 181 CD / CHDIR ------------------------------------------------------------------- If you enter CD with no argument or with only a disk drive name, it will display the current directory on the default or named drive. CD saves the current directory before changing to a new directory. You can switch back to the previous directory by entering CD -. (There must be a space between the CD command and the hyphen.) You can switch back and forth between two directories by repeatedly entering CD -. The saved directory is the same for both the CD and CDD commands. Drive changes and automatic directory changes (see page 47) also modify the saved directory, so you can use CD - to return to a directory that you exited with an automatic directory change. Directory changes made with CD are recorded for display in the directory history window (see page 45). ## CD never changes the default drive. If you change directories on one drive, switch to another drive, and then enter CD -, the directory will be restored on the first drive but the current drive will not be changed. ## If CD can't change to the specified directory, it will look for the CDPATH environment variable. See page 44 for details about using CDPATH. The operating system limits the permissible length of the full subdirectory name. See page 15 for more information on directory names. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 182 CDD ------------------------------------------------------------------- CDD (New) Purpose: Change the current disk drive and directory. Format: CDD path path: The name of the directory (or drive and directory) to change to. See also: CD, MD, PUSHD, RD, and Directory Changes on page 44. Usage: CDD is similar to the CD command, except that it also changes the default disk drive if one is specified. CDD will change to the directory and drive you name. To change from the root directory on drive A to the subdirectory C:\WP: a:\> cdd c:\wp c:\wp> You can change to the parent directory with CDD ..; you can also go up one additional directory level with each additional [.]. For example, CDD .... will go up three levels in the directory tree. CDD saves the current drive and directory before changing to a new directory. You can switch back to the previous drive and directory by entering CDD -. (There must be a space between the CDD command and the hyphen.) You can switch back and forth between two drives and directories by repeatedly entering CDD -. The saved directory is the same for both the CD and CDD commands. Drive changes and automatic directory changes (see page 47) also modify the saved directory, so you can use CDD - to return to a directory that you exited with a drive change or an automatic directory change. Directory changes made with CDD are recorded for display in the directory history window (see page 45). ## If CDD can't change to the specified directory, it will look for the CDPATH environment variable. See page 44 for details about using CDPATH. The operating system limits the permissible length of the full subdirectory name. See page 15 for more information on directory names. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 183 [4DOS, 4OS2] CHCP ------------------------------------------------------------------- CHCP [4DOS, 4OS2] (Compatible) Purpose: Display or change the current system code page. Format: CHCP [n] n: A system code page number. ## Usage: Code page switching allows you to select different character sets for language support. To use code page switching, you must have an EGA or VGA display and be running under MS-DOS or PC-DOS 3.3 or above, or OS/2. CHCP is not available in 4DOS/NT. If you enter CHCP without a number, the current code page is displayed. c:\> chcp Active code page: 437 If you enter CHCP plus a code page number, the system code page is changed. For example, to set the code page to multilingual: c:\> chcp 850 4DOS Before using CHCP under DOS, you must first load the device drivers (in CONFIG.SYS), make sure the information file (COUNTRY.SYS) is available, load national language support (using the NLSFUNC command), and prepare the specified code page for the devices (using the MODE command with the CODEPAGE PREPARE option). CHCP accepts one of the prepared system code pages. An error message is displayed if a code page is selected that has not been prepared for the system. See your DOS or OS/2 documentation for more information on CHCP. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 184 CLS ------------------------------------------------------------------- CLS (Enhanced) Purpose: Clear the video display and move the cursor to the upper left corner; optionally change the default display and border colors. Format: CLS [[BRIght] [BLInk] fg ON [BRIght] bg] [BORder bc] fg: The new foreground color bg: The new background color bc: The new border color Usage: CLS can be used to clear the screen without changing colors, or to clear the screen and change the screen colors simultaneously. These three examples show how to clear the screen to the default colors, to bright white letters on a blue background, and to bright yellow letters on a magenta background with a blue border: c:\> cls c:\> cls bright white on blue c:\> cls bri yel on mag bor blu CLS is often used in batch files to clear the screen before displaying text. See page 26 for details about colors and color names, and notes on the use of bright background colors. 4DOS ## Under DOS, if ANSI.SYS or a compatible driver is not loaded, the colors will not be "sticky" - you may lose them after you run an application. If 4DOS thinks you have an ANSI driver loaded, it uses an ANSI clear screen command. Otherwise, 4DOS will call the BIOS to clear the screen. You can force 4DOS to recognize the proper ANSI state with the SETDOS /A option (see page 323) or the ANSI directive in 4DOS.INI (see page 137). 4DOS ## If your display accommodates more than 25 rows by 80 columns and CLS doesn't clear the whole screen, your ANSI driver probably does not support the large display size properly. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 185 COLOR ------------------------------------------------------------------- COLOR (New) Purpose: Change the default display colors. Format: COLOR [BRIght] [BLInk] fg ON [BRIght] bg [BORder bc] fg: The new foreground color bg: The new background color bc: The new border color See also: CLS, and page 26 for details about using colors. Usage: COLOR is normally used in batch files before displaying text. For example, to set screen colors to bright white on blue, you can use this command: c:\> color bright white on blue 4DOS If you have an ANSI driver (such as ANSI.SYS) installed, COLOR will not change anything on the screen. It will only set the default colors for subsequent screen displays. If you are not using an ANSI driver, COLOR will change the display colors of every character on the screen. However, the colors will not be "sticky" - you may lose them after you run an application. 4DOS ## If you see odd characters like "[44;37m" when you try to set the screen colors, 4DOS probably thinks you have an ANSI driver loaded when you don't. Use SETDOS /A2, or ANSI = No in 4DOS.INI, to tell 4DOS you have no ANSI driver. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 186 COPY ------------------------------------------------------------------- COPY (Enhanced) Purpose: Copy data between disks, directories, files, or physical hardware devices (such as your printer or serial port). Format: COPY [/A:[[-]rhsda] /C /H /M /N /P /Q /R /S /T /U /V] source[+] ... [/A /B] destination [/A /B] source: A file or list of files or a device to copy from. destination: A file, directory, or device to copy to. /A(SCII) /P(rompt) /A:(ttribute select) /Q(uiet) /B(inary) /R(eplace) /C(hanged) /S(ubdirectories) /H(idden) /T(otals) /M(odified) /U(pdate) /N(othing) /V(erify) See also: ATTRIB, MOVE, and REN. Selection: Supports extended wildcards, ranges, multiple file names, and include lists (see pages 59 - 67). Date, time, or size ranges anywhere on the line apply to all source files. Usage: The COPY command accepts all traditional syntax and options and adds several new features. The simplest use of COPY is to make a copy of a file, like this example which makes a copy of a file called FILE1.ABC: c:\> copy file1.abc file2.def You can also copy a file to another drive and/or directory. The following command copies FILE1 to the \MYDIR directory on drive E: c:\> copy file1 e:\mydir You can copy several files at once by using wildcards: c:\> copy *.txt e:\mydir (See page 59 for an explanation of how 4DOS interprets the wildcard characters [*] and [?].) ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 187 COPY ------------------------------------------------------------------- You can also list several source files in one command. The following command copies 3 files from the current directory to the \MYDIR directory on drive E: c:\> copy file1 file2 file3 e:\mydir The way COPY interprets your command line depends on how many arguments (file, directory, or device names) are on the line, and whether the arguments are separated with [+] signs or spaces. If there is only one argument on the line, COPY assumes it is the source, and uses the current drive and directory as the destination. For example, the following command copies all the .DAT files on drive A to the current directory on drive C: c:\> copy a:*.dat If there are two or more arguments on the line and [+] signs are not used, then COPY assumes that the last argument is the destination and copies all source files to this new location. If the destination is a drive, directory, or device name then the source files are copied individually to the new location. If the destination is a file name, the first source file is copied to the destination, and any additional source files are then appended to the new destination file. For example, the first of these commands copies the .DAT files from the current directory on drive A individually to C:\MYDIR (which must already exist as a directory); the second appends all the .DAT files together into one large file called C:\DATA (assuming C:\DATA is not a directory): c:>\ copy a:*.dat c:\mydir\ c:>\ copy a:*.dat c:\data When you copy to a directory, if you add a backslash [\] to the end of the name as shown in the first example above, COPY will display an error message if the name does not refer to an existing directory. You can use this feature to keep COPY from treating a mistyped destination directory name as a file name and attempting to append all your source files to a destination file, when you really meant to copy them individually to a destination directory. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 188 COPY ------------------------------------------------------------------- ## A plus [+] tells COPY to append two or more files to a single destination file. If you list several source files separated with [+] and don't specify a destination, COPY will use the name of the first source file as the destination, and append each subsequent file to the first file. In this case the destination file will always be created in the current directory, even if the first source file is in another directory or on another drive. For example, the following command will append the contents of C:\MEMO2 and C:\MEMO3 to C:\MEMO1 and leave the combined contents in the file named C:\MEMO1: c:\> copy memo1+memo2+memo3 To append the same three files but store the result in BIGMEMO: c:\> copy memo1+memo2+memo3 bigmemo To append C:\MEM\MEMO2 and C:\MEM\MEMO3 to D:\DATA\MEMO1, and leave the result in C:\MEM\MEMO1: c:\mem> copy d:\data\memo1+memo2+memo3 ## You cannot append files to a device (such as a printer); if you try to do so, COPY will ignore the [+] signs and copy the files individually. If you attempt to append several source files to a destination directory or disk, COPY will append the files and place the copy in the new location with the same name as the first source file. ## If your destination has wildcards in it, COPY will attempt to match them with the source names. For example, this command copies the .DAT files from drive A to C:\MYDIR and gives the new copies the extension .DX: c:\> copy a:*.dat c:\mydir\*.dx This feature can give you unexpected results if you use it with multiple source file names. For example, suppose that drive A contains XYZ.DAT and XYZ.TXT. The command c:\> copy a:\*.dat a:\*.txt c:\mydir\*.dx ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 189 COPY ------------------------------------------------------------------- will copy A:XYZ.DAT to C:\MYDIR\XYZ.DX. Then it will copy A:XYZ.TXT to C:\MYDIR\XYZ.DX, overwriting the first file it copied. ## COPY also understands include lists (see page 67), so you can specify several different kinds of files in the same command. This command copies the .TXT, .DOC, and .BAT files from the E:\MYDIR directory to the root directory of drive A: c:\> copy e:\mydir\*.txt;*.doc;*.bat a:\ ## You can use date, time, and size ranges to further define the files that you want to copy (see page 62 for information on ranges). This example copies every file in the E:\MYDIR directory, which was created or modified yesterday, and which is also 10,000 bytes or smaller in size, to the root directory of drive A: c:\> copy /[d-1] /[s0,10000] e:\mydir\*.* a:\ ## COPY maintains the hidden and system attributes of files, but not the read-only attribute. The destination file will always have the archive attribute set. 4DOS ## If you are using 4DOS in an OS/2 DOS session, COPY will copy OS/2 extended attributes from the source to the destination, if the file system on the destination drive supports them. 4NT ## If you COPY files with long filenames from an NTFS volume to a FAT volume, 4DOS/NT will store the destination files with their short, FAT-compatible names when running under Windows NT 3.1 (long names are used under Windows NT 3.5 and above; see page 18 for additional details). You can view the short names before executing the COPY with the DIR /X command. Options: The /A(SCII) and /B(inary) options apply to the preceding filename and to all subsequent filenames on the command line until the file name preceding the next /A or /B, if any. The other options (/A:, /C, /H, /M, /N, /P, /Q, /R, /S, /T, /U, /V) apply to all filenames on the command line, no matter where you put them. For example, either of the following commands could be used to copy a font file to the printer in binary mode: c:\> copy /b myfont.dat prn ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 190 COPY ------------------------------------------------------------------- c:\> copy myfont.dat /b prn Some options do not make sense in certain contexts, in which case COPY will ignore them. For example, you cannot prompt before replacing an existing file when the destination is a device such as the printer - there's no such thing as an "existing file" on the printer. If you use conflicting output options, like /Q and /P, COPY will take a "conservative" approach and give priority to the option which generates more prompts or more information. Options used in less common situations have been marked with ## below. Remember that the options are in alphabetical order, so more basic options are interspersed with those marked with ##. ## /A(SCII): If you use /A with a source filename, the file will be copied up to, but not including, the first Ctrl-Z (Control-Z or ASCII 26) character in the file. If you use /A with a destination filename, a Ctrl-Z will be added to the end of the file (some application programs use the Ctrl-Z to mark the end of a file). /A is the default when appending files, or when the destination is a device like NUL or PRN, rather than a disk file. ## /A:(ttribute selecte): Select only those files that have the specified attribute(s) set. Preceding the attribute character with a hyphen [-] will select files that do not have that attribute set. The attributes are: R Read-only D Subdirectory H Hidden A Archive S System If no attributes are listed at all (e.g., COPY /A: ...), COPY will select all files and subdirectories including hidden and system files. If attributes are combined, all the specified attributes must match for a file to be selected. For example, /A:RHS will select only those files with all three attributes set. See page 18 for more information on file attributes. You must include the colon with this option to distinguish it from the /A(SCII) switch, above. ## /B(inary): If you use /B with a source filename, the entire file is copied; Ctrl-Z characters in the file ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 191 COPY ------------------------------------------------------------------- do not affect the copy operation. Using /B with a destination filename prevents addition of a Ctrl-Z to the end of the destination file. /B is the default for normal file copies. /C(hanged files): Copy files only if the destination file exists and is older than the source (see also /U). This option is useful for updating the files in one directory from those in another without copying any newly created files. ## /H(idden): Copy all matching files including those with the hidden and/or system attribute set (see page ). 18 /M(odified): Copy only those files with the archive attribute set (see page 18), i.e., those which have been modified since the last backup. The archive attribute will not be cleared after copying; to clear it use ATTRIB (page 173). /N(othing): Do everything except actually perform the copy. This option is useful for testing what the result of a complex COPY command will be. /P(rompt): Ask the user to confirm each source file. Your options at the prompt are explained in detail on page 50. /Q(uiet): Don't display filenames or the total number of files copied. This option is most often used in batch files. See also /T. /R(eplace): Prompt the user before overwriting an existing file. Your options at the prompt are explained in detail on page 50. /S(ubdirectories): Copy the subdirectory tree starting with the files in the source directory plus each subdirectory below that. The destination must be a directory; if it doesn't exist, COPY will attempt to create it. COPY will also attempt to create needed subdirectories on the tree below the destination, including empty source directories. If you attempt to use COPY /S to copy a subdirectory tree into part of itself, COPY will display an error message and exit. /T(otals): Turns off the display of filenames, like /Q, but does display the total number of files copied. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 192 COPY ------------------------------------------------------------------- /U(pdate): Copy each source file only if it is newer than a matching destination file or if a matching destination file does not exist (see also /C). This option is useful for keeping one directory matched with another with a minimum of copying. ## /V(erify): Verify each disk write. This is the same as executing the VERIFY ON command, but is only active during the COPY. /V does not read back the file and compare its contents with what was written; it only verifies that the data written to disk is physically readable. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 193 [4DOS] CTTY ------------------------------------------------------------------- CTTY [4DOS] (Compatible) Purpose: Change the default console device. Format: CTTY device device: The new console device. ## Usage: Normally, 4DOS uses the keyboard as the standard input device and the display as the standard output device. Together, the keyboard and display are known as the console or CON. The CTTY command allows you to substitute another device that can perform standard character I/O for the console. For example to change the console to the first serial port: c:\> ctty com1 Change the console back to the standard keyboard and display (this command must be entered from the current console, e.g., a terminal attached to COM1, or from a batch file): c:\> ctty con CTTY works only for programs and commands that use standard DOS input and output functions. This includes all 4DOS internal commands except DRAWBOX, DRAWHLINE, DRAWVLINE, LIST, SCREEN, SCRPUT, SELECT, and VSCRPUT. In addition, if you use color-coded directories you should disable them with DIR /D when using CTTY. Otherwise directories will not be displayed correctly. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 194 DATE ------------------------------------------------------------------- DATE (Compatible) Purpose: Display and optionally change the system date. Format: DATE [mm-dd-yy] mm: The month (1 - 12). dd: The day (1 - 31). yy: The year (80 - 99 = 1980 - 1999, or a 4-digit year). See also: TIME. Usage: If you simply type DATE without any parameters, you will see the current system date and time, and be prompted for a new date. Press ENTER if you don't wish to change the date. If you type a new date, it will become the current system date, which is included in the directory entry for each file as it is created or altered: c:\> date Wed Dec 22, 1993 9:30:06 Enter new date (mm-dd-yy): You can also enter a new system date by typing the DATE command plus the new date on the command line: c:\> date 3-16-94 You can use hyphens, slashes, or periods to separate the month, day, and year entries. A full 4-digit year can be entered if you wish. DATE adjusts the format it expects depending on your country settings. When entering the date, use the correct format for the country setting currently in effect on your system. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 195 DEL / ERASE ------------------------------------------------------------------- DEL / ERASE (Enhanced) Purpose: Erase one file, a group of files, or entire subdirectories. Format: DEL [/A[[:][-]rhsda] /F /N /P /Q /S /T /X /Y /Z] file... or ERASE [/A[[:][-]rhsda] /F /N /P /Q /S /T /X /Y /Z] file... file: The file, subdirectory, or list of files or subdirectories to erase. /A(ttribute select) /S(ubdirectories) /F(orce delete) /T(otal) /N(othing) /X (remove empty subdirectories) /P(rompt) /Y(es to all prompts) /Q(uiet) /Z(ap hidden and read-only files) Selection: Supports extended wildcards, ranges, multiple file names, and include lists (see pages 59 - 67). Usage: DEL and ERASE are synonyms, you can use either one. Use the DEL and ERASE commands with caution; the files and subdirectories that you erase may be impossible to recover without specialized utilities and a lot of work. To erase a single file, simply enter the file name: c:\> del letters.txt You can also erase multiple files in a single command. For example, to erase all the files in the current directory with a .BAK or .PRN extension: c:\> del *.bak *.prn If you enter a subdirectory name, or a filename composed only of wildcards (* and/or ?), DEL asks for confirmation (Y or N) unless you specified the /Y option. If you respond with a Y, DEL will delete all the files in that subdirectory (hidden, system, and ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 196 DEL / ERASE ------------------------------------------------------------------- read-only files are only deleted if you use the /Z option). DEL displays the amount of disk space recovered, unless the /Q option is used (see below). It does so by comparing the amount of free disk space before and after the DEL command is executed. This amount may be incorrect if you are using a deletion tracking system which stores deleted files in a hidden directory, or if, under a multitasking system, another program performs a file operation while the DEL command is executing. Remember that DEL removes file descriptions along with files. Most deletion tracking systems will not be able to save or recover a file's description, even if they can save or recover the data in a file. ## DEL returns a non-zero exit code if no files are deleted, or if another error occurs. You can test this exit code with the %_? environment variable (see page 102), and use it with conditional commands (&& and ||; see page 71). Options: ## /A(ttribute select): Delete only those files that have the specified attribute(s) set. Preceding the attribute character with a hyphen [-] will delete files that do not have that attribute set. The attributes are: R Read-only D Subdirectory H Hidden A Archive S System If no attributes are listed at all (e.g., DEL /A ...), DEL will delete all files and subdirectories including hidden and system files. If attributes are combined, all the specified attributes must match for a file to be selected for deletion. For example, /A:RHS will select only those files with all three attributes set. See page 18 for more information on file attributes. ## /F(orce delete): This option is only for use in the 32-bit version of 4OS2, and in 4DOS when running in an OS/2 2.1 or later DOS session. It forces deletion of the file without saving it to the DELDIR directory (if DELDIR is not in use, /F has no effect). ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 197 DEL / ERASE ------------------------------------------------------------------- /N(othing): Do everything except actually delete the file(s). This is useful for testing what the result of a DEL would be. /P(rompt): Prompt the user to confirm each erasure. Your options at the prompt are explained in detail on page 50. /Q(uiet): Don't display filenames as they are deleted, or the number of files deleted or bytes freed. When running 4DOS under DOS, DEL will run fastest if you specify the /Q option and the filename doesn't use the extended 4DOS wildcards. When running 4OS2, 4DOS/NT, or 4DOS under OS/2, /Q will have little or no effect on DEL's speed. See also /T. ! /S(ubdirectories): Delete the specified files in this directory and all of its subdirectories. This is like a GLOBAL DEL, and can be used to delete all the files in a subdirectory tree or even a whole disk. It should be used with caution! /T(otal): Don't display filenames as they are deleted, but display the total number of files deleted plus the amount of free disk space recovered. Unlike /Q, the /T option will not speed up deletions under DOS. ## /X (remove empty subdirectories): Remove empty subdirectories after deleting (only useful when used with /S). ! ## /Y(es): The reverse of /P - it assumes a Y response to everything, including deleting an entire subdirectory tree. 4DOS, 4OS2, and 4DOS/NT normally prompt before deleting files when the name consists only of wildcards or a subdirectory name (see above); /Y overrides this protection, and should be used with extreme caution! ! ## /Z(ap): Delete read-only, hidden, and system files as well as normal files. Files with the read-only, hidden, or system attribute set are normally protected from deletion; /Z overrides this protection, and should be used with caution. Because EXCEPT works by hiding files, /Z will override an EXCEPT command. For example, to delete the entire subdirectory tree starting with C:\UTIL, including hidden and read-only ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 198 DEL / ERASE ------------------------------------------------------------------- files, without prompting (use this command with CAUTION!): c:\> del /sxyz c:\util\ ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 199 DELAY ------------------------------------------------------------------- DELAY (New) Purpose: Pause for a specified length of time. Format: DELAY [seconds] seconds: The number of seconds to delay. Usage: DELAY is useful in batch file loops while waiting for something to occur. To wait for 10 seconds: delay 10 A simple loop could make a tone with the BEEP command to get the operator's attention and then DELAY for a few seconds while waiting for the user to respond. ## For delays shorter than one second, use the BEEP command with an inaudible frequency (below 20 Hz). You can cancel a delay by pressing Ctrl-C or Ctrl- . Break ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 200 DESCRIBE ------------------------------------------------------------------- DESCRIBE (New) Purpose: Create, modify, or delete file and subdirectory descriptions. Format: DESCRIBE [/A[[:][-]rhsda]] file ["description"] ... file: The file or files to operate on. "description": The description to attach to the file. /A(ttribute select) Selection: Supports extended wildcards, ranges, multiple file names, and include lists (see pages 59 - 67). Usage: DESCRIBE adds descriptions to files and subdirectories. The descriptions are displayed by DIR in single-column mode and by SELECT. Descriptions let you identify your files in much more meaningful ways than you can in an eight-character filename. You enter a description on the command line by typing the DESCRIBE command, the filename, and the description in quotation marks, like this: c:\> describe memo.txt "Memo to Bob about party" If you don't put a description on the command line, DESCRIBE will prompt you for it: c:\> describe memo.txt Describe "memo.txt" : Memo to Bob about party If you use wildcards or multiple filenames with the DESCRIBE command and don't include the description text, you will be prompted to enter a description for each file. If you do include the description on the command line, all matching files will be given the same description. Each description can be up to 40 characters long. You can change this limit with the DescriptionMax directive in 4DOS.INI (see page 138). DESCRIBE can edit descriptions longer than DescriptionMax (up to a limit of 200 characters), but will not allow you to lengthen the existing text. The descriptions are stored in each directory in a hidden file called DESCRIPT.ION. Use the ATTRIB command to remove the hidden attribute from this file ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 201 DESCRIBE ------------------------------------------------------------------- if you need to copy or delete it. DESCRIPT.ION is always created as a hidden file, but will not be re- hidden by 4DOS, 4OS2, or 4DOS/NT if you remove the hidden attribute. You can change the description file name with the DescriptionName directive in the .INI file (page 148), and retrieve it with the %_DNAME internal variable (page 105). The description file is modified appropriately whenever you perform an internal command which affects it (such as COPY, MOVE, DEL, or RENAME), but not if you use an external program (such as XCOPY or a visual shell). 4OS2, ! On HPFS and NTFS drives, you will not see file 4NT descriptions in a normal DIR display, because DIR must leave space for the long filenames used on these drives. To view the descriptions, use DIR /Z to display the directory in FAT format. See the DIR command for more details. Options: ## /A(ttribute select): Select only those files that have the specified attribute(s) set. Preceding the attribute character with a hyphen [-] will select files that do not have that attribute set. The attributes are: R Read-only D Subdirectory H Hidden A Archive S System If no attributes are listed at all (e.g., DESCRIBE /A ...), DESCRIBE will select all files and subdirectories including hidden and system files. If attributes are combined, all the specified attributes must match for a file to be selected. For example, /A:RHS will select only those files with all three attributes set. See page 18 for more information on file attributes. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 202 [4OS2, 4DOS/NT] DETACH ------------------------------------------------------------------- DETACH [4OS2, 4DOS/NT] (Compatible) Purpose: Start an OS/2 or Windows NT program in detached mode. Format: DETACH command command: The name of a command to execute, including an optional drive and path specification. The name must be enclosed in quotation marks if it contains any spaces. See also: START. Usage: When you start a program with DETACH, that program cannot use the keyboard, mouse, or video display. It is "detached" from the normal means of user input and output. However, you can redirect the program's standard I/O to other devices if necessary, using redirection symbols (see page 52). The command can be an internal command, external command, alias, or batch file. 4OS2 or 4DOS/NT will detach a copy of itself to execute the command. For example, the following command will detach a copy of the command processor to run the batch file XYZ.BTM: [c:\] detach xyz.btm Once the program has started, 4OS2 or 4DOS/NT returns to the prompt immediately. It does not wait for a detached program to finish. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 203 DIR ------------------------------------------------------------------- DIR (Enhanced) Purpose: Display information about files and subdirectories. Format: DIR [/1 /2 /4 /A[[:][-]rhsda] /B /C[HP] /D /E /F /H /I"text" /J /K /L /M /N /O[[:][-]acdeginrsu] /P /R /S /T[:acw] /U /V /W /X /Z] [file...] file: The file, directory, or list of files or directories to display. /1 (one column) /L(ower case) /2 (two columns) /M (suppress footer) /4 (four columns) /N(ormal) or (New format) /A(ttribute select) /O(rder) /B(are) /P(ause) /C[HP] (Compression) /R (disable wRap) /D(isable color coding) /S(ubdirectories) /E (upper case) /T (aTtribute) or (Time) /F(ull path) /U (sUmmary information) /H(ide dots) /V(ertical sort) /I (match descriptions) /W(ide) /J(ustify names) /X (display short names) /K (suppress header) /Z (use FAT format) See also: ATTRIB, DESCRIBE, SELECT, and SETDOS. Selection: Supports extended wildcards, ranges, multiple file names, and include lists (see pages 59 - 67). Usage: DIR can be used to display information about files from one or more of your disk directories, in a wide range of formats. Depending on the options chosen, you can display the file name, attributes, and size; the time and date of the last change to the file; the file description; and the file's compression ratio. You can also display information in 1, 2, 4, or 5 columns, sort the files several different ways, use color to distinguish file types, and pause after each full screen. The various DIR displays are controlled through options or switches. The best way to learn how to use the many options available with the DIR command is to experiment. You will soon know which options you want to use regularly. You can select those options permanently by using the ALIAS command. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 204 DIR ------------------------------------------------------------------- You may want to mix several options. For example, to display all the files in the current directory, in 2 columns, sorted vertically (down one column then down the next), and with a pause at the end of each page: c:\> dir /2/p/v To set up this format as the default, using an alias: c:\> alias dir=*dir /2/p/v This example displays all the files on all directories of drive C, including hidden and system files, pausing after each page: c:\> dir /s/a/p c:\ DIR allows wildcard characters (* and ?) in the filename. If you don't specify a filename, DIR defaults to *.* (display all non-hidden files and subdirectories in the current directory). To display all of the .WKS files in the current directory: c:\> dir *.wks With the /I option, DIR can select files to display based on their descriptions. DIR will display a file if its description matches the text after the /I switch. The search is not case sensitive. You can use wildcards and extended wildcards as part of the text. For example, to display any file described as a "Test File" you can use this command: c:\> dir /i"test file" If you want to display files that include the words "test file" anywhere in their descriptions, use extended wild cards like this: c:\> dir /i"*test file*" If you link two or more filenames together with spaces, DIR will display all of the files that match the first name and then all of the files that match the second name. You may use a different drive and path for each filename. This example lists all of the .WKS and then all of the .WK1 files in the current directory: c:\> dir *.wks *.wk1 ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 205 DIR ------------------------------------------------------------------- If you use an include list (see page 67) to link multiple filenames, DIR will display the matching filenames in a single listing. Only the first filename in an include list can have a path; the other files must be in the same path. This example displays the same files as the previous example, but the .WKS and .WK1 files are intermixed: c:\> dir *.wks;*.wk1 The default case for filename displays varies depending on which command processor you are using, as follows ("as stored" means filenames will be displayed exactly as they are stored on the disk, whether in upper, lower, or mixed case): 4DOS Lower case on all drives. 4OS2 Lower case on FAT drives, "as stored" on HPFS drives. 4DOS/NT Windows NT 3.1: Lower case on FAT drives, "as stored" on HPFS and NTFS drives. Windows NT 3.5 and above: "As stored" on all drives (see page 18 for more information) You can override these defaults and force filenames to display in upper case with /E, or in lower case with /L. You can display the file and subdirectory names in color by setting the COLORDIR environment variable or using the ColorDir directive in your .INI file. See page 30 for details. ## If you are using color-coded directories and attempt to redirect the output of DIR to a character device, such as a serial port or the printer, non-color-coded file names will be displayed on the device but color- coded names may still be displayed on the screen. This will not occur if the output of DIR is redirected to a disk file. To prevent this problem, use the /D switch to disable color coding when redirecting the output of DIR to a character device. When displaying file descriptions, DIR will wrap long lines to fit on the screen. DIR displays a maximum of 40 characters of text in each line of a description, unless your screen width allows a wider display. If ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 206 DIR ------------------------------------------------------------------- you disable description wrapping with the /R switch, the description is truncated at the right edge of the screen, and a right arrow is added at the end of the line to alert you to the existence of additional description text. If you attempt to redirect the output of DIR to a character device, such as a serial port or the printer, long descriptions will be wrapped at the screen width in the redirected output. If this is not what you want, use /R to disable wrapping. 4NT ## DIR's default output format is different under Windows NT 3.5 and above, where long filenames can be used on on FAT drives (see page 18 for additional information). In this case DIR defaults to HPFS / NTFS-style output, normally selected with /N; you can switch back to standard FAT-style output with /Z. DIR also retains the case in which filenames are stored in Windows NT 3.5 and above, unless you use /E or /L (see page 18 for an explanation). You can override the new default output format with an alias if you wish. For example, to use FAT-style output on all drives, define an alias like this: alias dir=*dir /z To use FAT-style output on FAT drives only you may want to try the following alias or a variation on it. The alias extracts the drive letter from the first argument to DIR (or uses the current drive if there is no argument), then changes the display format based on whether that argument specifies a FAT or non-FAT drive: alias dir=`set _drv=%_disk: & if %# != 0 set _drv=%@fstype[%@substr[%@full[%1],0,2]] & iff "%_drv" == "FAT" then & *dir /z %$ & else & *dir %$ & endiff & unset /q _drv` 4DOS ## If you are using a disk compression program, you can use the /C switch to view the amount of compression achieved for each file. When you do, the compression ratio is displayed instead of the file's description. You can also sort the display by compression ratios with the /O:c switch. Details for both switches are in the Options section, below. See APPNOTES.DOC for a list of compression systems supported by the 4DOS DIR command. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 207 DIR ------------------------------------------------------------------- ## When sorting file names and extensions, 4DOS, 4OS2, and 4DOS/NT normally assume that sequences of digits should be sorted numerically (for example, the file DRAW2 would come before DRAW03 because 2 is numerically smaller than 03), rather than strictly alphabetically (where DRAW2 would come second because "2" is after "0" in alphanumeric order). You can defeat this behavior and force a strict alphabetic sort with the /O:a option. ## If you have selected a specific country code for your system, DIR will display the date in the format for that country. The default date format is U.S. (mm-dd- yy). The separator character in the file time will also be affected by the country code. 4DOS ## DIR can handle directories of any size, limited only by available memory. Under 4DOS, each filename requires 32 bytes of free base memory plus the size of the description (if any). For example, a system with just 128K of free memory can display up to 4,000 files per directory. Memory requirements for DIR are generally not a concern under 4OS2 and 4DOS/NT, because of the virtual memory available under these operating systems. ## Options on the command line apply only to the filenames which follow the option, and options at the end of the line apply to the preceding filename only. This allows you to specify different options for different groups of files, yet retains compatibility with the traditional DIR command when a single filename is specified. Options: /1: Single column display - display the filename, size, date, time, and description. This is the default. If /T is used the attributes are displayed instead of the description; if /C or /O:c is used the compression ratio is displayed instead of the description. /2: Two column display - display the filename, size, date, and time. If you use /2 (or /4) on an HPFS or NTFS drive under 4OS2 or 4DOS/NT, DIR will only display the file names. Also, the number of columns may be reduced to one for names too long to fit on half the screen. Due to these restrictions, /2 is normally most useful on HPFS and NTFS drives when used with /Z to force the display to FAT format. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 208 DIR ------------------------------------------------------------------- /4: Four column display - display the filename and size, in K (kilobytes) or M (megabytes). The note under /2 above regarding HPFS and NTFS drives applies to /4 as well. ## /A(ttribute select): Display only those files that have the specified attribute(s) set. Preceding the attribute character with a hyphen [-] will display files that do not have that attribute set. The attributes are: R Read-only D Subdirectory H Hidden A Archive S System If no attributes are listed at all (e.g., DIR /A ...), DIR will display all files and subdirectories including hidden and system files. If attributes are combined, all the specified attributes must match for a file to be included in the listing. For example, /A:RHS will display only those files with all three attributes set. See page 18 for more information on file attributes. ## /B(are): Suppress the header and summary lines, and display file or subdirectory names only, in a single column. This option is most useful when you want to redirect a list of names to a file or another program. If you use /B with /S, DIR will show the full path of each file instead of simply its name and extension. 4DOS /C(ompression): Display per-file and total compression ratio on compressed drives. The compression ratio is displayed instead of the file description or attributes. The ratio is left blank for directories and files with a length of 0 bytes, and for files on non-compressed drives. /C only works in single-column mode; it is ignored if /2, /4, or /W is used. See APPNOTES.DOC for a list of supported compression systems. The numerator of the displayed compression ratio is the amount of space which would be allocated to the file if the compression utility were not in use, based on the compressed drive's cluster size (usually 8K bytes). The denominator is the space actually allocated for the compressed file. For example, if a file is allocated 6,144 bytes when compressed, and would require 8,192 bytes if uncompressed, the ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 209 DIR ------------------------------------------------------------------- displayed compression ratio would be 8,192 / 6,144, or 1.3 to 1. Using /CH displays compression ratios like /C, but bases the calculation on the host drive's cluster size. This gives a more accurate picture of the space saved through compression than is given by /C. This option will occasionally display compression ratios slightly less than 1.0 to 1.0 for files which have actually expanded when stored on the compressed drive. If /CP is used instead of /C, the compression is displayed as a percentage (e.g., 33%) instead of a ratio (e.g., 3 to 1). If /CHP is used instead of /CH, the host compression is displayed as a percentage. The /CHP option must be entered as shown; you can not use /CPH. ## /D(isable color coding): Temporarily disable directory color coding. May be required when color- coded directories are used and DIR output is redirected to a character device like the printer (e.g., PRN or LPT1) or serial port (e.g., COM1 or COM2). /D is not required when DIR output is redirected to a file. /E: Display filenames in the traditional upper case; also see SETDOS /U (page 326) and the UpperCase directive in 4DOS.INI (page 141). ## /F(ull path): Display each filename with its drive letter and path in a single column, without other information. /H(ide dots): Suppress the display of the "." and ".." directories. /I: Display filenames by matching text in their descriptions. The text can include wild cards and extended wildcards. The search text must be enclosed in quotation marks. /I may be used to select files even if descriptions are not displayed (for example, if /2 is used). However, /I will be ignored if /C or /O:c is used. /J(ustify names): Justify (align) filename extensions and display them in the traditional format. ## /K: Suppress the header (disk and directory name) display. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 210 DIR ------------------------------------------------------------------- /L(ower case): Display file and directory names in lower case; also see SETDOS /U (page 326) and the UpperCase directive in 4DOS.INI (page 141). ## /M: Suppress the footer (file and byte count totals) display. 4DOS /N: Reset the DIR options to the default values. This is useful when you want to display some files in one format, and then change back to the defaults for another set of files. 4OS2, /N: Use the HPFS or NTFS display format, even if the files are 4NT stored on a FAT file system volume. (This is the default for all drives under Windows NT 3.5 and above). See also /Z. /O(rder): Set the sorting order. You may use any combination of the following sorting options; if multiple options are used, the listing will be sorted with the first sort option as the primary key, the next as the secondary key, and so on: - Reverse the sort order for the next option a Sort names and extensions in standard ASCII order, rather than sorting numerically when digits are included in the name or extension. c Sort by compression ratio (the least compressed file in the list will be displayed first). For single-column directory displays, the compression ratios will be used as the basis of the sort and will also be displayed. For wider displays (/2, /4, and /W), the compression ratios will be used to determine the order but will not be displayed. If /O:c is used with /CH or /CHP, the sort will be based on the host- drive compression ratios. d Sort by date and time (oldest first); for HPFS and NTFS drives also see /T. e Sort by extension. g Group subdirectories first, then files. i Sort by the file description (ignored if /C or /O:c is also used). n Sort by filename (this is the default). r Reverse the sort order for all options. s Sort by size. u Unsorted. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 211 DIR ------------------------------------------------------------------- /P(ause): Wait for a key to be pressed after each screen page before continuing the display. Your options at the prompt are explained in detail on page . 50 /R (disable wRap): Forces long descriptions to be displayed on a single line, rather than wrapped onto two or more lines. Use /R when output is redirected to a character device, such as a serial port or the printer; or when you want descriptions truncated, rather than wrapped, in the on-screen display. /S(ubdirectories): Display file information from the current directory and all of its subdirectories. DIR will only display headers and summaries for those directories which contain files that match the filename(s) and attributes (if /A is used) that you specify on the command line. ## /T (aTtribute display): Display the filenames and attributes. /T is ignored if /C or /O:c is also used. The attributes are displayed in the format RHSA, where: R Read-only S System H Hidden A Archive 4OS2, If you wish to add another option after /T, you must start the next 4NT option with a forward slash. If you don't, the command processor will interpret the /T as the /T:acw time display switch (see below) and the following character as a valid or invalid time selector. For example: [c:\] dir /tz incorrect, will display error [c:\] dir /t/z correct 4OS2, /T:acw (Time display): Specify which of the date and time fields on 4NT an NTFS or HPFS drive should be displayed and used for sorting: a last access time c creation time w last write time (default) /U (sUmmary information): Only display the number of files, the total file size, and the total amount of disk space used. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 212 DIR ------------------------------------------------------------------- /V(ertical sort): Display the filenames sorted vertically rather than horizontally (use with the /2, /4 or /W options). /W(ide): Display filenames only, horizontally across the screen (5 columns on an 80-character wide display). 4NT /X: Display both the short (8-character name plus 3- character extension) and the long name of files on an NTFS drive. 4OS2, /Z: Display an HPFS or NTFS directory, or any 4NT directory under Windows NT 3.5 and above, in FAT format. Long names will be truncated to 12 characters. If the name is longer than 12 characters, it will be followed by a right arrow to show that one or more characters have been truncated. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 213 DIRS ------------------------------------------------------------------- DIRS (New) Purpose: Display the current directory stack. Format: DIRS See also: PUSHD and POPD. Usage: The PUSHD command adds the current default drive and directory to the directory stack, a list that 4DOS, 4OS2, and 4DOS/NT maintain in memory. The POPD command removes the top entry of the directory stack and makes that drive and directory the new default. The DIRS command displays the contents of the directory stack, with the most recent entries on top (i.e., the next POPD will retrieve the first entry that DIRS displays). For example, to change directories and then display the directory stack: c:\> pushd c:\database c:\database> pushd d:\wordp\memos d:\wordp\memos> dirs c:\database c:\ The directory stack holds 255 characters, enough for 10 to 20 typical drive and directory entries. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 214 DO ------------------------------------------------------------------- DO (New) Purpose: Create loops in batch files. Format: DO [n | FOREVER] or DO varname = start TO end [BY n] or DO [WHILE | UNTIL] condition ... [ITERATE] [LEAVE] ... ENDDO n, start, end: An integer between 0 and 2,147,483,647 inclusive, or an internal variable or variable function that evaluates to such a value. varname: The environment variable that will hold the loop counter. condition: A test to determine if the loop should be executed. Usage: DO can only be used in batch files. DO can be used to create 3 different kinds of loops. The first, introduced by DO n, is a counted loop. The batch file lines between DO and ENDDO are repeated n times. You can also specify "forever" for n if you wish to create an endless loop. For example: do 5 beep enddo The second type of loop is similar to a "for loop" in programming languages like BASIC. DO creates an environment variable, varname, and sets it equal to the value start (if varname already exists in the environment, it will be overwritten). DO then begins the loop process by comparing the value of varname with the value of end. If varname is less than or equal to end, DO executes the batch file lines up to the ENDDO. Next, DO adds 1 to the value of varname, or adds the value n if BY n is specified, and repeats ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 215 DO ------------------------------------------------------------------- the compare and execute process until varname is greater than end. This example displays the even numbers from 2 through 20: do i = 2 to 20 by 2 echo %i enddo DO can also count down, rather than up. If n is negative, varname will decrease by n with each loop, and the loop will stop when varname is less than end. For example, to display the even numbers from 2 through 20 in reverse order, replace the first line of the example above with: do i = 20 to 2 by -2 The third type of loop is called a "while loop" or "until loop." DO evaluates the condition, which can be any of the tests supported by the IF command (see page 251), and executes the lines between DO and ENDDO as long as the condition is true. The loop ends when the condition becomes false. WHILE tests the condition at the start of the loop; UNTIL tests it at the end. If you use WHILE, the loop may never be executed (if the condition is false at the start of the loop); if you use UNTIL, the loop will always be executed at least once. Two special commands, ITERATE and LEAVE, can only be used inside a DO / ENDDO loop. ITERATE ignores the remaining lines inside the loop and returns to the beginning of loop for another iteration (unless DO determines that the loop is finished). LEAVE exits from the current DO loop and continues with the line following ENDDO. Both ITERATE and LEAVE are most often used in an IF or IFF command (see pages 251 and 257): do while "%var" != "%val1" ... if "%var" == "%val2" leave enddo You can nest DO loops up to 15 levels deep. ! ## You can exit from all DO / ENDDO loops by using GOTO to a line past the last ENDDO. However, be sure to read the cautionary notes about GOTO and DO under the ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 216 DO ------------------------------------------------------------------- GOTO command (page 246) before using a GOTO inside any DO loop. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 217 [4OS2] DPATH ------------------------------------------------------------------- DPATH [4OS2] (Compatible) Purpose: Specify the subdirectories which applications will search to find files that are not in the current directory. Format: DPATH [directory[;directory...]] directory: The full name of a directory to include in the DPATH (data path) setting. See also: PATH, SET, and ESET. Usage: When most OS/2 and Windows NT applications try to open a data file, they look for the file in the current directory first. If they fail to find the file there, they search each of the directories in the DPATH setting in the order that they are included. Internal commands like TYPE do not search the DPATH directories for files. For example, the following DPATH command directs applications to look for files in this order: the current directory, the INIT directory on C, and the CONFIG directory on D: [c:\] dpath c:\init;d:\config The listing of directories to be searched can be set or viewed with DPATH. The list is stored as an environment string with the variable name DPATH, and can also be set or viewed with the SET command and edited with the ESET command. Directory names in the DPATH must be separated with semicolons [;]. 4OS2 and 4DOS/NT will not shift directory names in the DPATH to upper case as they do with those in the PATH setting. If you want the names in the DPATH to be in upper case you must enter them that way. If you enter DPATH with no parameters, 4OS2 and 4DOS /NT display the current DPATH search list. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 218 DRAWBOX ------------------------------------------------------------------- DRAWBOX (New) Purpose: Draw a box on the screen. Format: DRAWBOX ulrow ulcol lrrow lrcol style [BRIght] [BLInk] fg ON [BRIght] bg [FILl [BRIght] bgfill] [ZOOm] [SHAdow] ulrow: Row for upper left corner ulcol: Column for upper left corner lrrow: Row for lower right corner lrcol: Column for lower right corner style: Box drawing style: 0 No lines (box is drawn with blanks) 1 Single line 2 Double line 3 Single on top and bottom, double on sides 4 Double on top and bottom, single on sides fg: Foreground character color bg: Background character color bgfill: Background fill color (for the inside of the box) See also: DRAWHLINE and DRAWVLINE. Usage: DRAWBOX is useful for creating attractive screen displays in batch files. For example, to draw a box around the entire screen with bright white lines on a blue background: drawbox 0 0 24 79 1 bri whi on blu fill blu See page 26 for details about colors and color names, and notes on the use of bright background colors. If you use ZOOM, the box appears to grow in steps to its final size. The speed of the zoom operation depends on the speed of your video system. If you use SHADOW, a drop shadow is created by changing the characters in the row under the box and the 2 columns to the right of the box to normal intensity text with a black background (this will make characters displayed in black disappear entirely). The row and column values are zero-based, so on a standard 25 line by 80 column display, valid rows are 0 - 24 and valid columns are 0 - 79. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 219 DRAWBOX ------------------------------------------------------------------- DRAWBOX checks for valid row and column values, and displays a "Usage" error message if any values are out of range. Unlike DRAWHLINE and DRAWVLINE, DRAWBOX does not automatically connect boxes to existing lines on the screen with the proper connector characters. If you want to draw lines inside a box and have the proper connectors drawn automatically, draw the box first, then use DRAWHLINE and DRAWVLINE to draw the lines. DRAWBOX uses the standard line and box drawing characters in the U.S. English extended ASCII character set. If your system is configured for a different country or language, the box may not appear on your screen as you expect. 4DOS ## DRAWBOX normally writes text directly to the screen. If you have an unusual display adapter which does not support direct video output, see the OutputBIOS directive on page 150. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 220 DRAWHLINE ------------------------------------------------------------------- DRAWHLINE (New) Purpose: Draw a horizontal line on the screen. Format: DRAWHLINE row column len style [BRIght] [BLInk] fg ON [BRIght] bg row: Starting row column: Starting column len: Length of line style: Line drawing style: 1 Single line 2 Double line fg: Foreground character color bg: Background character color See also: DRAWBOX and DRAWVLINE. Usage: DRAWHLINE is useful for creating attractive screen displays in batch files. It detects other lines and boxes on the display, and creates the appropriate connector characters when possible (not all types of lines can be connected with the available characters). For example, the following command draws a double line along the top row of the display with green characters on a blue background: drawhline 0 0 80 2 green on blue The row and column values are zero-based, so on a standard 25 line by 80 column display, valid rows are 0 - 24 and valid columns are 0 - 79. DRAWHLINE checks for a valid row and column, and displays a "Usage" error message if either value is out of range. See page 26 for details about colors and color names, and notes on the use of bright background colors. DRAWHLINE uses the standard line and box drawing characters in the U.S. English extended ASCII character set. If your system is configured for a different country or language, the line may not appear on your screen as you expect. 4DOS ## DRAWHLINE normally writes text directly to the screen. If you have an unusual display adapter which does not support direct video output, see the OutputBIOS directive on page 150. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 221 DRAWVLINE ------------------------------------------------------------------- DRAWVLINE (New) Purpose: Draw a vertical line on the screen. Format: DRAWVLINE row column len style [BRIght][BLInk] fg ON [BRIght] bg row: Starting row column: Starting column len: Length of line style: Line drawing style: 1 Single line 2 Double line fg: Foreground character color bg: Background character color See also: DRAWBOX and DRAWHLINE. Usage: DRAWVLINE is useful for creating attractive screen displays in batch files. It detects other lines and boxes on the display, and creates the appropriate connector characters when possible (not all types of lines can be connected with the available characters). For example, to draw a double width line along the left margin of the display with bright red characters on a black background: drawvline 0 0 25 2 bright red on black The row and column values are zero-based, so on a standard 25 line by 80 column display, valid rows are 0 - 24 and valid columns are 0 - 79. DRAWVLINE checks for a valid row and column, and displays a "Usage" error message if either value is out of range. See page 26 for details about colors and color names, and notes on the use of bright background colors. DRAWVLINE uses the standard line and box drawing characters in the U.S. English extended ASCII character set. If your system is configured for a different country or language, the line may not appear on your screen as you expect. 4DOS ## DRAWVLINE normally writes text directly to the screen. If you have an unusual display adapter which does not support direct video output, see the OutputBIOS directive on page 150. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 222 ECHO ------------------------------------------------------------------- ECHO (Enhanced) Purpose: Display a message, enable or disable batch file or command-line echoing, or display the echo status. Format: ECHO [ON | OFF | message] message: Text to display. See also: ECHOS, SCREEN, SCRPUT, SETDOS and TEXT. Usage: 4DOS, 4OS2, and 4DOS/NT have a separate echo capability for batch files and for the command line. The command-line ECHO state is independent of the batch file ECHO state; changing ECHO in a batch file has no effect on the display at the command prompt, and vice versa. To see the current echo state, use the ECHO command with no arguments. This displays either the batch file or command-line echo state, depending on where the ECHO command is performed. In a batch file, if you turn ECHO on, each line of the file is displayed before it is executed. If you turn ECHO off, each line is executed without being displayed. ECHO can also be used in a batch file to display a message on the screen. Regardless of the ECHO state, a batch file line that begins with the [@] character will not be displayed. To turn off batch file echoing, without displaying the ECHO command, use this line: @echo off ECHO commands in a batch file will send messages to the screen while the batch file executes, even if ECHO is set OFF. For example, this line will display a message in a batch file: echo Processing your print files... If you want to echo a blank line from within a batch file, enter: echo. You cannot use the command separator character ([^] in 4DOS or [&] in 4OS2 and 4DOS/NT) or the redirection symbols (| > <) in an ECHO message, unless you enclose ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 223 ECHO ------------------------------------------------------------------- them in quotes (see page 123) or precede them with the escape character (see page 73). ECHO defaults to ON in batch files. The current ECHO state is inherited by called batch files. You can change the default setting to ECHO OFF with the SETDOS /V0 command or the BatchEcho directive in the .INI file (see page 137). If you turn the command-line ECHO on, each command will be displayed before it is executed. This will let you see the command line after expansion of all aliases and variables. The command-line ECHO is most useful when you are learning how to use advanced features. This example will turn command-line echoing on: c:\> echo on ECHO defaults to OFF at the command line. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 224 ECHOS ------------------------------------------------------------------- ECHOS (New) Purpose: Display a message without a trailing carriage return and line feed. Format: ECHOS message See also: ECHO, SCREEN, SCRPUT, TEXT, and VSCRPUT. Usage: ECHOS is useful for text output when you don't want to add a carriage return / linefeed pair at the end of the line. For example, you can use ECHOS when you need to redirect control sequences to your printer; this example sends the sequence Esc P to the printer on LPT1: c:\> echos <Ctrl-X>eP > lpt1: You cannot use the command separator character ([^] in 4DOS and [&] in 4OS2 and 4DOS/NT) or the redirection symbols [|><] in an ECHOS message, unless you enclose them in quotes (see page 123) or precede them with the escape character (see page 73). ## ECHOS does not translate or modify the message text. For example, carriage return characters are not translated to CR/LF pairs. ECHOS sends only the characters you enter (after escape character and back- quote processing). The only character you cannot put into an ECHOS message is the NUL character (ASCII 0). ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 225 ENDLOCAL ------------------------------------------------------------------- ENDLOCAL (New) Purpose: Restore the saved disk drive, directory, environment, and alias list. Format: ENDLOCAL See also: SETLOCAL. ## Usage: The SETLOCAL command in a batch file saves the current disk drive, default directory, all environment variables, and the alias list. ENDLOCAL restores everything that was saved by the previous SETLOCAL command. For example, this batch file fragment saves the drive, current working directory, and environment variables, removes all aliases so that any user aliases will not affect batch file commands, changes the drive and directory, sets some environment variables, runs the program TEST1, and then restores the original values: setlocal unalias * cdd d:\test set path=c:\;c:\dos;c:\util set lib=d:\lib test1 endlocal SETLOCAL and ENDLOCAL can only be used in batch files, not in aliases or from the command line. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 226 ESET ------------------------------------------------------------------- ESET (New) Purpose: Edit environment variables and aliases. Format: ESET [/A /M] variable name... variable name: The name of an environment variable or alias to edit. /A(lias) /M(aster environment) See also: ALIAS, UNALIAS, SET, and UNSET. Usage: ESET allows you to edit environment variables and aliases using line editing commands (see page 35). For example, to edit the executable file search path: c:\> eset path path=c:\;c:\dos;c:\util - To create and then edit an alias: c:\> alias d = dir /d/j/p c:\> eset d d=dir /d/j/p - ESET will search for environment variables first and then aliases. If you have an environment variable and an alias with the same name, ESET will edit the environment variable and ignore the alias unless you use the /A option. Environment variable and alias names are normally limited to 80 characters, and their contents to 255 characters in 4DOS, or 1,023 characters in 4OS2 and 4DOS/NT. However, if you use special techniques to create a longer environment variable, ESET will edit it provided the variable contains no more than 511 characters of text in 4DOS, or 2,047 characters in 4OS2 and 4DOS/NT. If you have enabled global aliases (see page 169), any changes made to an alias with ESET will immediately affect all other copies of the command processor which are using the same alias list. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 227 ESET ------------------------------------------------------------------- Option: ## /A(lias): Edit the named alias even if an environment variable of the same name exists. If you have an alias and an environment variable with the same name, you must use this switch to be able to edit the alias. 4DOS /M(aster environment): Edit an environment variable in the master environment rather than the local environment. This option is only useful from a secondary command shell (for example, when an application has "shelled to DOS"). /M only works for environment variables; it cannot be used to edit the primary shell's aliases. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 228 EXCEPT ------------------------------------------------------------------- EXCEPT (New) Purpose: Perform a command on all available files except those specified. Format: EXCEPT (file) command file: The file or files to exclude from the command. command: The command to execute, including all appropriate arguments and switches. See also: ATTRIB. Selection: Supports extended wildcards, ranges, multiple file names, and include lists (see pages 59 - 67). Date, time, or size ranges must appear immediately after the EXCEPT keyword. Usage: EXCEPT provides a means of executing a command on a group of files and/or subdirectories, and excluding a subgroup from the operation. The command can be an internal command or alias, an external command, or a batch file. You may use wildcards to specify the files to exclude from the command. The first example erases all the files in the current directory except those beginning with MEMO, and those whose extension is .WKS. The second example copies all the files and subdirectories on drive C to drive D except those in C:\MSC and C:\DOS, using the COPY command: c:\> except (memo*.* *.wks) erase *.* c:\> except (c:\msc c:\dos) copy c:\*.* d:\ /s ## Date, time, and size ranges can be used immediately after the word EXCEPT to further qualify which files should be excluded from the command. If the command is an internal command that supports ranges, an independent range can also be used in the command itself. ## ! EXCEPT prevents operations on the specified file(s) by setting the hidden attribute, performing the command, and then clearing the hidden attribute. If the command is aborted in an unusual way, you may need to use the ATTRIB command to remove the hidden attribute from the file(s). ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 229 EXCEPT ------------------------------------------------------------------- ! ## EXCEPT will not work with programs or commands that ignore the hidden attribute or which work explicitly with hidden files, including DEL /Z, and the /H (process hidden files) switch available in some 4DOS, 4OS2, and 4DOS/NT file processing commands. ## You can use command grouping (see page 71) to execute multiple commands with a single EXCEPT. For example, the following command copies all files in the current directory whose extensions begin with .DA, except the .DAT files, to the D:\SAVE directory, then changes the first two characters of the extension of the copied files to .SA. This example should be entered on one line: c:\data> except (*.dat) (copy *.da* d:\save ^ ren *.da* *.sa*) ## If you use filename completion (see page 41) to enter the filenames inside the parentheses, type a space after the open parenthesis before entering a partial filename or pressing Tab. Otherwise, the command-line editor will treat the open parenthesis as the first character of the filename to be completed. 4DOS ## ! If you receive a stack overflow error when using EXCEPT in complex, nested command sequences, see the notes under the StackSize directive on page 150. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 230 EXIT ------------------------------------------------------------------- EXIT (Enhanced) Purpose: Return from the command processor. Format: EXIT [value] value: The exit code to return (0 - 255). Usage: EXIT terminates the current copy of the command processor. Use it to return to an application when you have "shelled out" to work at the prompt, or to end a command-line session under Windows, OS/2, or Windows NT. To close the session, or to return to the application that started the command processor, type: c:\> exit ## If you specify a value, EXIT will return that value to the program that started the command processor. For example: c:\> exit 255 ## The value is a number you can use to inform the program of some result, such as the success or failure of a batch file. This feature is most useful for systems which use batch files to automate their operation, such as bulletin boards, or custom application programs like databases that shell to the command processor to perform certain tasks. 4DOS ## You cannot EXIT from the primary 4DOS shell under DOS. If EXIT does not seem to have any effect, you are probably in the primary shell. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 231 FFIND ------------------------------------------------------------------- FFIND (New) Purpose: Search for files by name or contents. Format: FFIND [/A[[:][-]rhsda] /B /C /D[list] /E /K /L /M /O[[:][-]acdeginrsu] /P /S /[T|X]"xx" /V] file... list: A list of disk drive letters (without colons). file: The file, directory, or list of files or directories to display. /A(ttribute select) /M (no footers) /B(are) /O(rder) /C(ase sensitive) /P(ause) /D(rive) /S(ubdirectories) /E (upper case display) /T"xx" (text search string) /K (no headers) /V(erbose) /L(ine numbers) /X["xx"] (hex display / search string) Selection: Supports extended wildcards, ranges, multiple file names, and include lists (see pages 59 - 67). Usage: FFIND is a flexible search command that looks for files based on their names and their contents. Depending on the options you choose, FFIND can display filenames, matching text, or a combination of both in a variety of formats. If you want to search for files by name, FFIND works much like the DIR command. For example, to generate a list of all the .BTM files in the current directory, you could use the command c:\> ffind *.btm The output from this command is a list of full pathnames, followed by the number of files found. If you want to limit the output to a list of *.BTM files which contain the string color, you could use this command instead: c:\> ffind /t"color" *.btm The output from this version of FFIND is a list of files that contain the string color along with the first line in each file that contains that string. By default, FFIND uses a case-insensitve search, so the command above will include files that contain COLOR, ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 232 FFIND ------------------------------------------------------------------- Color, color, or any other combination of upper-case and lower-case letters. You can use extended wildcards in the search string to increase the flexibility of FFIND's search. For example, the following command will find .TXT files which contain either the string June or July (it will also find Juny and Jule). The /C option makes the search case-sensitive: c:\> ffind /c/t"Ju[nl][ey]" *.txt At times, you may need to search for data that cannot be represented by ASCII characters. You can use FFIND's /X option to represent the search string in hexadecimal format. With /X, the search must be represented by pairs of hexadecimal digits separated by spaces; a search of this type is always case- sensitive (41 63 65 is the hex code for "Ace"):"" c:\> ffind /x"41 63 65" *.txt You can use FFIND's other options to further specify the files for which you are searching and to modify the way in which the output is displayed. 4DOS ## If you are using a disk compression program, you can sort the display by compression ratios with the /O:c switch. See APPNOTES.DOC for a list of supported compression systems. Options: /A(ttribute select): Find only those files that have the specified attribute(s) set. Preceding the attribute character with a hyphen [-] will display files that do not have that attribute set. The attributes are: R Read-only D Subdirectory H Hidden A Archive S System If no attributes are listed at all (e.g., FFIND /A ...), FFIND will search all files and subdirectories including hidden and system files. If attributes are combined, all the specified attributes must match for a file to be included in the listing. For example, /A:RHS will search only those files with all three attributes set. See page 18 for more information on file attributes. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 233 FFIND ------------------------------------------------------------------- /B(are): Display file names only and omit the text that matches the search. This option is only useful in combination with /T or /X, which normally force FFIND to display file names and matching text. /C(ase sensitive): Perform a case-sensitive search. This option is only valid with /T, which defaults to a case-insenitive search. It is not needed with a /X hexadecimal search, which is always case-sensitive. /D(rive): Search all files on one or more drives. If you use /D without a list of drives, FFIND will search the drives specified in the list of files. If no drive letters are listed, FFIND will search the default drive. You can include a list of drives or a range of drives to search as part of the /D option. For example, to search drives C:, D:, E:, and G:, you can use either of these commands: c:\> ffind /dcdeg ... c:\> ffind /dc-eg ... /E: Display filenames in the traditional upper case; also see SETDOS /U (page 326) and the UpperCase directive in 4DOS.INI (page 141). /K (No headers): Suppress the display of the header or filename for each matching text line. /L(ine numbers): Include the line number for each text line displayed. /M (No footers): Suppress the footer (the number of files and number of matches) at the end of FFIND's display. /O(rder): Set the sort order for the files that FFIND displays. You may use any combination of the following sorting options; if multiple options are used, the listing will be sorted with the first sort option as the primary key, the next as the secondary key, and so on: - Reverse the sort order for the next option a Sort names and extensions in standard ASCII order, rather than sorting numerically when digits are included in the name or extension. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 234 FFIND ------------------------------------------------------------------- 4DOS c Sort by compression ratio (the least compressed file in the list will be displayed first). d Sort by date and time (oldest first); for HPFS and NTFS drives also see /T. e Sort by extension. g Group subdirectories first, then files. i Sort by the file description (ignored if /C or /O:c is also used). n Sort by filename (this is the default). r Reverse the sort order for all options. s Sort by size. u Unsorted. /P(ause): Wait for a key to be pressed after each screen page before continuing the display. Your options at the prompt are explained in detail on page . 50 /S(ubdirectories): Display matches from the current directory and all of its subdirectories. /T"xx" (Text search): Specify the text search string. /T must be followed by a text string in double quotes (e.g., /t"color"). FFIND will perform a case- insensitive search unless you also use the /C option. For a hexadecimal search and/or hexadecimal display of the location where the search string is found, see /X. You can specify a search string with either /T or /X, but not both. /V(erbose): Show every matching line. FFIND's default behavior is to show only the first matching line then and then go on to the next file. This option is only valid with /T or /X. /X["xx"] (Hexadecimal display / search): Specify hexadecimal display and an optional hexadecimal search string. If /X is followed by one or more pairs of hexadecimal digits in quotes (e.g., /x"44 63 65"), FFIND will search for that exact sequence of characters or data bytes without regard to the meaning of those bytes as text. If those bytes are found, the offset is displayed (also in hexadecimal). A search of this type will always be case-sensitive. If /X is not followed by a hexadecimal search string it must be used in conjunction with /T, and will ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 235 FFIND ------------------------------------------------------------------- change the output format to display hexadecimal offsets rather than actual text lines when the search string is found. For example, this command uses /T to display the first line in each BTM file containing the word "hello": c:\>ffind /t"hello" *.btm ---- c:\test.btm echo hello 1 line in 1 file If you use the same command with /X, the hexadecimal offset is displayed instead of the text: c:\>ffind /t"hello" /x *.btm ---- c:\test.btm Offset: 1A 1 line in 1 file You can specify a search string with either /T or /X, but not both. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 236 FOR ------------------------------------------------------------------- FOR (Enhanced) Purpose: Repeat a command for several values of a variable. Format: FOR [/A[[:][-]rhsda] /D /H] %var IN ([@]set) [DO] command ... %var: The variable to be used in the command ("FOR variable"). set: A set of values for the variable. command: A command or group of commands to be executed for each value of the variable. /A(ttribute select) /H(ide dots) /D(isable "/") Selection: Supports extended wildcards, ranges, multiple file names, and include lists (see pages 59 - 67). Date, time, or size ranges must appear immediately after the FOR keyword. Usage: FOR begins by creating a set. It then executes a command for every member of the set. The command can be an internal command, an alias, an external command, or a batch file. Normally, the set is a list of files specified with wildcards. For example, if you use this line in a batch file: for %x in (*.txt) do list %x then LIST will be executed once for each file in the current directory with the extension .TXT. The FOR variable %x is set equal to each of the file names in turn, then the LIST command is executed for each file. (You could do the same thing more easily with a simple LIST *.TXT. We used FOR here so you could get a feel for how it operates, using a simple example.) The set can include multiple files or an include list, like this: for %x in (d:\*.txt;*.doc;*.asc) do type %x If the set includes filenames, the file list can be further refined by using date, time, and size ranges (see page 62). The range must be placed immediately after the word FOR. The range will be ignored if no wildcards are used inside the parentheses. For ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 237 FOR ------------------------------------------------------------------- example, this set is made up of all of the *.TXT files that were created or updated on October 4, 1993: for /[d10-4-93,+0] %x in (*.txt) do ... If the command is an internal command that supports ranges, an independent range can also be used in the command itself. The set can also be made up of text instead of file names. For example, to display the free space on drives C:, D:, and E:, you could use: for %drive in (c d e) do free %drive: When the set is made up of text or several separate file names (not an include list), the elements must be separated by spaces, tabs, commas, or the switch character (normally a slash [/]). ## You can also set the FOR variable equal to each line in a file by placing an [@] in front of the file name. If you have a file called DRIVES.TXT that contains a list of drives on your computer, one drive name per line (with a ":" after each drive letter), you can print the free space on each drive this way: for %d in (@drives.txt) do free %d > prn ## Because the [@] is also a valid filename character, FOR first checks to see if the file exists with the [@] in its name (i.e., a file named @DRIVES.TXT). If so, the filename is treated as a normal argument. If it doesn't exist, FOR uses the filename (without the [@]) as the file from which to retrieve text. ## You can use either % or %% in front of the variable name. Either form will work, whether the FOR command is typed from the command line or is part of an alias or batch file (some of the traditional command processors require a single % if FOR is used at the command line, but use %% if it is used in a batch file). The variable name can be up to 80 characters long. The word DO is optional. ## If you use a single-character FOR variable name, that name is given priority over any environment variable which starts with the same letter, in order to maintain compatibility with the traditional FOR command. For example, the following command tries to ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 238 FOR ------------------------------------------------------------------- add a: and b: to the end of the PATH, but will not work as intended: c:\> for %p in (a: b:) do path %path;%p The "%p" in "%path" will be interpreted as the FOR variable %p followed by the text "ath", which is not what was intended. To get around this, use a different letter or a longer name for the FOR variable, or use square brackets around the variable name (see page 97). ## The following example uses FOR with variable functions to delete the .BAK files for which a corresponding .TXT file exists in the current directory (this should be entered on one line): c:\docs> for %file in (*.txt) do del %@name[%file].bak ## You can use command grouping (see page 71) to execute multiple commands for each element in the list. For example, the following command copies each .WKQ file in the current directory to the D:\WKSAVE directory, then changes the extension of each file in the current directory to .SAV. This should be entered on one line: c:\text> for %file in (*.wkq) do (copy %file d:\wksave\ ^ ren %file *.sav) (Use an ampersand [&] as the separator character if you are using 4OS2 or 4DOS/NT.) ## In a batch file you can use GOSUB to execute a subroutine for every element in the set. Within the subroutine, the FOR variable can be used just like any environment variable. This is a convenient way to execute a complex sequence of commands for every element in the set without CALLing another batch file. ## One unusual use of FOR is to execute a collection of batch files or other commands with the same parameter. For example, you might want to have three batch files all operate on the same data file. The FOR command could look like this (enter this on one line): c:\> for %cmd in (filetest fileform fileprnt) do %cmd datafile ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 239 FOR ------------------------------------------------------------------- This line will expand to three separate commands: filetest datafile fileform datafile fileprnt datafile ## The variable that FOR uses (the %CMD in the example above) is created in the environment and then erased when the FOR command is done. However, for compatibility with COMMAND.COM and CMD.EXE, single- character FOR variables do not overwrite existing environment variables with the same name. As a result, when using a multi-character variable name you must be careful not to use the name of one of your environment variables as a FOR variable. For example, a command that begins c:\> for %path in ... will write over your current path setting and then erase the path variable completely. ## FOR statements can be nested. Under 4DOS, the permissible nesting level depends on the amount of free space in 4DOS's internal stack. 4DOS ! ## If you receive a stack overflow error when using FOR in complex, nested command sequences, see the notes under the StackSize directive on page 150. Options: ## /A(ttribute select): Process only those files that have the specified attribute(s). /A will be used only when processing wildcard file names in the set. It will be ignored for filenames without wildcards or other items in the set. Preceding the attribute character with a hyphen [-] will process files that do not have that attribute set. The attributes are: R Read-only D Subdirectory H Hidden A Archive S System If no attributes are listed (e.g., FOR /A ...), FOR will process all files including hidden and system files. If attributes are combined, all the specified attributes must match for a file to be included. For example, /A:RHS will include only those files with all three attributes set. See page 18 for more information on file attributes. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 240 FOR ------------------------------------------------------------------- For example, to process only those files with the archive attribute set: for /a:a %f in (*.*) echo %f needs a backup! 4DOS ## /D(isable "/"): Disables the special processing of the forward slash [/] character in the FOR set. COMMAND.COM and 4DOS normally treat a forward slash inside the set as an "escape" character, discard the slash, and return the character after the slash, followed by the remainder of the string. This behavior can be used in batch files to separate a string into individual characters (although 4DOS provides a much easier method with the %@INSTR and %@SUBSTR variable functions). The /D option must follow the FOR keyword and come before the variable name. These examples show the effects of /D: c:\> for %s in (/abcdef) do echo %s a bcdef c:\> for /d %s in (/abcdef) do echo %s /abcdef /H(ide dots): Suppress the assignment of the "." and ".." directories to the var. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 241 FREE ------------------------------------------------------------------- FREE (New) Purpose: Display the total disk space, total bytes used, and total bytes free on the specified (or default) drive(s). Format: FREE [drive: ...] drive: One or more drives to include in the report. See also: MEMORY. Usage: FREE provides the same disk information as the external command CHKDSK, but without the wait, since it does not check the integrity of the file and directory structure of the disk. A colon [:] is required after each drive letter. This example displays the status of drives A and C: c:\> free a: c: Volume in drive A: is unlabeled 1,213,952 bytes total disk space 1,115,136 bytes used 98,816 bytes free Volume in drive C: is DEVELOPMENT 42,496,000 bytes total disk space 36,851,712 bytes used 5,644,288 bytes free If you are using DOS 4.0 or later, OS/2, or Windows NT, the volume serial number will appear after the drive label or name. 4DOS Some DOS networks with large server disk drives (256 MB or more) may report disk space values that are too small when FREE is used. If this occurs, it is because the network software does not report the proper values to 4DOS. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 242 GLOBAL ------------------------------------------------------------------- GLOBAL (New) Purpose: Execute a command in the current directory and its subdirectories. Format: GLOBAL [/H /I /P /Q] command command: The command to execute, including arguments and switches. /H(idden directories) /P(rompt) /I(gnore exit codes) /Q(uiet) Usage: GLOBAL performs the command first in the current directory and then in every subdirectory under the current directory. The command can be an internal command, an alias, an external command, or a batch file. This example copies the files in every directory on drive A to the directory C:\TEMP: a:\> global copy *.* c:\temp If you use the /P option, GLOBAL will prompt for each subdirectory before performing the command. You can use this option if you want to perform the command in most, but not all subdirectories of the current directory. ## You can use command grouping (see page 71) to execute multiple commands in each subdirectory. For example, the following command copies each .TXT file in the current directory and all of its subdirectories to drive A. It then changes the extension of each of the copied files to .SAV: c:\> global (copy *.txt a: ^ ren *.txt *.sav) 4DOS ## ! If you use GLOBAL in complex, nested command sequences, see the cautionary note on page 150. Options: ## /H(idden directories): Forces GLOBAL to look for hidden directories. If you don't use this switch, hidden directories are ignored. ## /I(gnore exit codes): If this option is not specified, GLOBAL will terminate if the command returns a non-zero exit code. Use /I if you want command to continue in additional subdirectories even ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 243 GLOBAL ------------------------------------------------------------------- if it returns an error in a previous subdirectory. Even if you use /I, GLOBAL will halt execution in response to Ctrl-C or Ctrl-Break. /P(rompt): Forces GLOBAL to prompt with each directory name before it performs the command. Your options at the prompt are explained in detail on page 50. /Q(uiet): Do not display the directory names as each directory is processed. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 244 GOSUB ------------------------------------------------------------------- GOSUB (New) Purpose: Execute a subroutine in the current batch file. Format: GOSUB label label: The batch file label at the beginning of the subroutine. See also: CALL, GOTO and RETURN. Usage: GOSUB can only be used in batch files. 4DOS, 4OS2, and 4DOS/NT allow subroutines in batch files. A subroutine must start with a label (a colon [:] followed by a one-word label name) which appears on a line by itself. Case differences are ignored when matching labels. The subroutine must end with a RETURN statement. The subroutine is invoked with a GOSUB command from another part of the batch file. After the RETURN, processing will continue with the command following the GOSUB command. For example, the following batch file fragment calls a subroutine which displays the directory and returns: echo Calling a subroutine gosub subr1 echo Returned from the subroutine quit :subr1 dir /a/w return If the label doesn't exist, the batch file is terminated with the error message "Label not found." GOSUB saves the IFF state, so IFF statements inside a subroutine won't interfere with IFF statements in the part of the batch file from which the subroutine was called. ## Subroutines can be nested. Under 4DOS, the permissible nesting level depends on the amount of free space in 4DOS's internal stack; if you receive a stack overflow error when using GOSUB in complex, nested command sequences, see the notes under the StackSize directive on page 150. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 245 GOTO ------------------------------------------------------------------- GOTO (Compatible) Purpose: Branch to a specified line inside the current batch . file Format: GOTO [/I] label label: The batch file label to branch to. /I(FF and DO continue) See also: GOSUB. Usage: GOTO can only be used in batch files. After a GOTO command in a batch file, the next line to be executed will be the one immediately after the label. The label must begin with a colon [:] and appear on a line by itself. The colon is required on the line where the label is defined, but is not required in the GOTO command itself. Case differences are ignored when matching labels. This batch file fragment checks for the existence of the file CONFIG.SYS. If the file exists, the batch file jumps to C_EXISTS and copies all the files from the current directory to the root directory on A:. Otherwise, it prints an error message and exits. if exist config.sys goto C_EXISTS echo CONFIG.SYS doesn't exist - exiting. quit :C_EXISTS copy *.* a:\ If the label doesn't exist, the batch file is terminated with the error message "Label not found." ! ## To avoid errors in the processing of nested statements and loops, GOTO cancels all active IFF statements and DO /ENDDO loops unless you use /I. This means that a normal GOTO (without /I) may not branch to any label that is between an IFF and the corresponding ENDIFF or between a DO and the corresponding ENDDO. Options: ## /I(FF and DO continue): Prevents GOTO from canceling IFF statements and DO loops. Use this option only if you are absolutely certain that your GOTO command is branching entirely within any current IFF statement and any active DO / ENDDO block. Using /I under any ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 246 GOTO ------------------------------------------------------------------- other conditions will cause an error later in your batch file. You cannot branch into another IFF statement, another DO loop, or a different IFF or DO nesting level, whether you use the /I option or not. If you do, you will eventually receive an "unknown command" error (or execution of the UNKNOWN_CMD alias) on a subsequent ENDDO, ELSE, ELSEIFF, or ENDIFF statement. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 247 HELP ------------------------------------------------------------------- HELP (Enhanced, External command) Purpose: Display help for internal commands. Help for external commands is also available under DOS, and optionally under OS/2. Format: HELP [topic] topic: A help topic, internal command, or external command. Usage: Online help is available for 4DOS, 4OS2, and 4DOS/NT. The 4OS2 and 4DOS/NT help systems use the operating system's help facility. 4DOS uses its own help program. See page 48 for more details on getting help at the command line. See the Introduction and Installation Guide that was supplied with your version of 4DOS, 4OS2, or 4DOS/NT for a more thorough explanation of the online help available with the program you use. If you type the command HELP by itself (or press F1 when the command line is empty), the table of contents is displayed. If you type HELP plus a topic name, that topic is displayed. For example, help copy displays information about the COPY command and its options. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 248 HISTORY ------------------------------------------------------------------- HISTORY (New) Purpose: Display, add to, clear, or read the history list. Format: HISTORY [/A command /F /P /R filename] /A(dd) /P(ause) /F(ree) /R(ead) See also: LOG. Usage: 4DOS, 4OS2, and 4DOS/NT keep a list of the commands you have entered on the command line. See page 36 for information on command recall, which allows you to use the history list to repeat or edit commands you have typed. The HISTORY command lets you view and manipulate the command history list directly. If no parameters are entered, HISTORY will display the current command history list: c:\> history With the options explained below, you can clear the list, add new commands to the list without executing them, save the list in a file, or read a new list from a file. The number of commands saved in the history list depends on the length of each command line. The history list size can be specified at startup from 256 to 8192 characters (see page 133). The default size is 1024 characters. Your history list can be stored either locally (a separate history list for each copy of the command processor) or globally (all copies of the command processor share the same list). For full details see the discussion of local and global history lists beginning on page 39. ## You can use the HISTORY command as an aid in writing batch files by redirecting the HISTORY output to a file and then editing the file appropriately. However, it is easier to use the LOG /H command for this purpose. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 249 HISTORY ------------------------------------------------------------------- ## You can disable the history list or specify a minimum command-line length to save with the HistMin directive in the .INI file. Options: ## /A(dd): Add a command to the history list. This performs the same function as the Ctrl-K key at the command line (see page 36). /F(ree): Erase all entries in the command history list. /P(rompt): Wait for a key after displaying each page of the list. Your options at the prompt are explained in detail on page 50. ## /R(ead): Read the command history from the specified file and append it to the history list currently held in memory. Each line in the file must fit within the command-line length limit for your command processor (see page 50). You can save the history list by redirecting the output of HISTORY to a file. This example saves the command history to a file called HISTFILE and reads it back again immediately. If you leave out the HISTORY /F command on the second line, the contents of the file will be appended to the current history list instead of replacing it: c:\> history > histfile c:\> history /f c:\> history /r histfile If you need to save your history at the end of each day's work, you might use commands like this in your AUTOEXEC.BAT or other startup file: if exist c:\histfile history /r c:\histfile alias shut*down `history > c:\histfile` This restores the previous history list if it exists, then defines an alias which will save the history before shutting off the system. ## If you are creating a HISTORY /R file by hand, and need to create an entry that spans multiple lines in the file, you can do so by terminating each line, except the last, with an escape character (see page 73). However, you cannot use this method to exceed the command-line length limit. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 250 IF ------------------------------------------------------------------- IF (Enhanced) Purpose: Execute a command if a condition or set of conditions is true. Format: IF [NOT] condition [.AND. | .OR. | .XOR. [NOT] condition ...] command condition: A test to determine if the command should be executed. command: The command to execute if the condition is true. See also: IFF; @IF on page 116. Usage: IF is normally used only in aliases and batch files. It is always followed by one or more conditions and then a command. First, the conditions are evaluated. If they are true, the command is executed. Otherwise, the command is ignored. If you add a NOT before a condition, the command is executed only when the condition is false. You can link conditions with .AND., .OR., or .XOR., and you can nest IF statements. The conditions can test strings, numbers, the existence of a file or subdirectory, the exit code returned by the preceding external command, and the existence of alias names and internal commands. The command can be an alias, an internal command, an external command, or a batch file. The entire IF statement, including all conditions and the command, must fit on one line. ## You can use command grouping (see page 71) to execute multiple commands if the condition is true. For example, the following command tests if any .TXT files exist. If they do, they are copied to drive A: and their extensions are changed to .TXO: if exist *.txt (copy *.txt a: ^ ren *.txt *.txo) (Change the command separator to an ampersand [&] to use a command like this under 4OS2 or 4DOS/NT. Also, note that the IFF command provides a more structured method of executing multiple commands if a condition or set of conditions is true.) ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 251 IF ------------------------------------------------------------------- 4DOS ! ## If you receive a stack overflow error when using IF in complex, nested command sequences, see the notes under the StackSize directive on page 150. Conditions: The following conditional tests are available in both the IF and IFF commands. They fit into two categories: string and numeric tests, and status tests. The tests can use environment variables, internal variables and variable functions, file names, literal text, and numeric values as their arguments. Spaces are required on either side of the test condition in all cases, except == which will work with or without spaces around it. String and Numeric Tests Six test conditions can be used to test character strings. The same conditions are available for both numeric and normal text strings (see below for details). In each case you enter the test as: string1 operator string2 The operator defines the type of test (equal, greater than or equal, and so on). The operators are: Operator Tests -------- ---------------------------------- EQ or == string1 equal to string2 NE or != string1 not equal to string2 LT string1 less than string2 LE string1 less than or equal to string2 GE string1 greater than or equal to string2 GT string1 greater than string2 When IF compares two character strings, it will use either a numeric comparison or a string comparison. A numeric comparison treats the strings as numeric values and tests them arithmetically. A string comparison treats the strings as text. The difference between numeric and string comparisons is best explained by looking at the way two values are tested. For example, consider comparing the values 2 and 19. Numerically, 2 is smaller, but as a string it is "larger" because its first digit is larger than the ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 252 IF ------------------------------------------------------------------- first digit of 19. So the first of these conditions will be true, and the second will be false: if 2 lt 19 ... if "2" lt "19" ... IF determines which kind of test to do by examining the first character of each string. If both strings begin with a numeric character (a digit, sign, or decimal point), a numeric comparison is used. If either value does not begin with a numeric character, a string comparison is used. To force a string comparison when both values are or may be numeric, use double quotes around the values you are testing, as shown above. Because the double quote is not a numeric character, it forces IF to do a string comparison. Case differences are ignored in string comparisons. If two strings begin with the same text but one is shorter, the shorter string is considered to be "less than" the longer one. For example, "a" is less than "abc", and "hello_there" is greater than "hello". When you compare text strings, you should always enclose the arguments in double quotes in order to avoid syntax errors which may occur if one of the argument values is empty. Numeric comparisons work with both integer and decimal values. The values to be compared must contain only numeric digits, decimal points, and an optional sign (+ or -). The number to the left of the decimal point may not exceed 2,147,483,648 (the maximum possible 32- bit positive integer). The number of digits to the right of the decimal point is limited only by the length of the command line. Internal variables (page 100) and variable functions (page 108) are very powerful when combined with string and numeric comparisons. They allow you to test the state of your system, the characteristics of a file, date and time information, or the result of a calculation. You may want to review the variables and variable functions when determining the best way to set up an IF test. This first example is a batch file fragment which runs a program called MONOPROG if a monochrome monitor is attached to the system (this example will work in 4DOS ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 253 IF ------------------------------------------------------------------- or 4OS2; 4DOS/NT does not include the _MONITOR variable): if "%_monitor" == "mono" monoprog The second batch file fragment tests for a string value: input "Enter your selection : " %%cmd if "%cmd" == "WP" goto wordproc if "%cmd" NE "GRAPHICS" goto badentry This example calls GO.BTM if the first two characters in the file MYFILE are "GO" (enter this example on one line): if "%@instr[0,2,%@line[myfile,0]]"=="GO" call go.btm The next two examples test whether there is more than 500 KBytes of free memory or more than 2 MBytes of free EMS memory (the EMS example only applies to 4DOS): c:\> if %@dosmem[k] gt 500 echo Over 500K free c:\> if %@ems[m] gt 2 echo Over 2 MB EMS free Status Tests These conditions test the system or command processor status. You can use internal variables and variable functions to test many other parts of the system status. ERRORLEVEL [operator] n This test retrieves the exit code of the preceding external program. By convention, programs return an exit code of 0 when they are successful and a number between 1 and 255 to indicate an error. The condition can be any of the operators listed above (EQ, !=, GT, etc.). If no operator is specified, the default is GE. The comparison is done numerically. Not all programs return an explicit exit code. For programs which do not, the behavior of ERRORLEVEL is undefined. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 254 IF ------------------------------------------------------------------- EXIST filename If the file exists, the condition is true. You can use wildcards in the filename, in which case the condition is true if any file matching the wildcard name exists. ISALIAS aliasname If the name is defined as an alias, the condition is true. ISDIR | DIREXIST path If the subdirectory exists, the condition is true. For compatibility with DR DOS and Novell DOS, DIREXIST may be used as a synonym for ISDIR. ISINTERNAL command If the specified command is an active internal command, the condition is true. Commands can be activated and deactivated with the SETDOS /I command. 4NT ISWINDOW "title" If a window with the title exists, the condition is true. Double quotes must be used around the title. The first batch file fragment below tests for the existence of A:\JAN.DOC before copying it to drive C. if exist a:\jan.doc copy a:\jan.doc c:\ This example tests the exit code of the previous program and stops all batch file processing if an error occurred: if errorlevel==0 goto success echo "External Error -- Batch File Ends!" cancel ## Combining Tests You can negate the result of any test with NOT, and combine tests of any type with .AND., .OR., and .XOR. Test conditions are always scanned from left to right ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 255 IF ------------------------------------------------------------------- - there is no implied order of precedence, as there is in some programming languages. When two tests are combined with .AND., the result is true if both individual tests are true. When two tests are combined with .OR., the result is true if either (or both) individual tests are true. When two tests are combined with .XOR., the result is true only if one of the tests is true and the other is false. This example runs a program called HIGHRES if either an EGA or VGA video adapter is in use (this will work in 4DOS or 4OS2; 4DOS/NT does not include the _VIDEO variable): if "%_video"=="EGA" .or. "%_video"==vga highres ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 256 IFF ------------------------------------------------------------------- IFF (New) Purpose: Perform IF / THEN / ELSE conditional execution of commands. Format: IFF [NOT] condition [.AND. | .OR. | .XOR. [NOT] condition ...] THEN ^ commands [ELSEIFF condition THEN ^ commands] ... [ELSE ^ commands] ^ ENDIFF condition: A test to determine if the command(s) should be executed. commands: One or more commands to execute if the condition(s) is true. If you use multiple commands, they must be separated by command separators or be placed on separate lines of a batch file. See also: IF. Usage: IFF is similar to the IF command, except that it can perform one set of commands when a condition or set of conditions is true and different commands when the conditions are false. IFF can execute multiple commands when the conditions are true or false; IF normally executes only one command. IFF imposes no limit on the number of commands and is generally a "cleaner" and more structured command than IF. IFF is always followed by one or more conditions. If they are true, the commands that follow the word THEN are executed. Additional conditions can be tested with ELSEIFF. If none of these conditions are true, the commands that follow the word ELSE are executed. In both cases, after the selected commands are executed, processing continues after the word ENDIFF. If you add a NOT before the condition, the THEN commands are executed only when the condition is false and the ELSE commands are executed only when the condition is true. The commands may be separated by command separators, or may be on separate lines of a batch file. You should include a command separator or a line break after a THEN, before an ELSEIFF, and before and after an ELSE. Note that the syntax above and the examples below use the default 4DOS command separator, a caret ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 257 IFF ------------------------------------------------------------------- [^]. Replace the caret with an ampersand [&] if you are using 4OS2 or 4DOS/NT. You can link conditions with .AND., .OR., or .XOR., and you can nest IFF statements up to 15 levels deep. The conditions can test strings or numbers, the existence of a file or subdirectory, the errorlevel returned from the preceding external command, and the existence of alias names and internal commands. See the IF command for a list of the possible conditions. The commands can include any internal command, alias, external command, or batch file. The following batch file fragment for 4DOS or 4OS2 tests the monitor type (monochrome or color), and sets the appropriate colors and prompt (enter the "prompt" lines on one line of the batch file): iff "%_monitor" == "color" then color bright white on blue ^ cls prompt=$e[s$e[1;1f$e[41;1;37m$e[K Path: $p$e[u$e[44;37m$n$g else prompt=$e[s$e[1;1f$e[0;7m$e[K Path: $p$e[u$e[0m$n$g endiff (The above example uses ANSI color sequences in the prompt, which work in 4DOS if an ANSI driver is loaded, and in 4OS2. They will not work in 4DOS/NT, because Windows NT does not offer ANSI support. See PROMPT for additional details.) The alias in this second example checks to see if the argument is a subdirectory. If so, the alias deletes the subdirectory's files and removes it (enter this on one line): c:\> alias prune `iff isdir %1 then ^ del /sxz %1 ^ else ^ echo Not a directory!^endiff` ! ## Be sure to read the cautionary notes about GOTO and IFF under the GOTO command (page 246) before using a GOTO inside an IFF statement. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 258 INKEY ------------------------------------------------------------------- INKEY (New) Purpose: Get a single keystroke from the user and store it in an environment variable. Format: INKEY [/C /D /K"keys" /P /Wn /X] [prompt] %%varname prompt: Optional text that is displayed as a prompt. varname: The variable that will hold the user's keystroke. /C(lear buffer) /P(assword) /D(igits only) /W(ait) /K (valid keystrokes) /X (no carriage return) See also: INPUT and KEYSTACK. Usage: INKEY optionally displays a prompt. Then it waits for a specified time or indefinitely for a keystroke, and places the keystroke into an environment variable. It is normally used in batch files and aliases to get a menu choice or other single-key input. Along with the INPUT command, INKEY allows great flexibility in reading input from within a batch file or alias. If prompt text is included in an INKEY command, it is displayed while INKEY waits for input. The following batch file fragment prompts for a character and stores it in the variable NUM: inkey Enter a number from 1 to 9: %%num INKEY reads standard input for the keystroke, so it will accept keystrokes from a redirected file or from the Keystack under 4DOS. You can supply a list of valid keystrokes with the /K option. Standard keystrokes with ASCII values between 1 and 255 are stored directly in the environment variable. Extended keystrokes (for example, function keys and cursor keys) are stored as a string in decimal format, with a leading @ (for example, the F1 key is @59). The Enter key is stored as an extended keystroke, with the code @28. See Appendix B (page 371) for a list of the ASCII and extended key codes. If you press Ctrl-C or Ctrl-Break while INKEY is waiting for a key, execution of an alias will be terminated, and execution of a batch file will be ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 259 INKEY ------------------------------------------------------------------- suspended while you are asked whether to cancel the batch job (see page 85). In a batch file you can handle Ctrl-C and Ctrl-Break yourself with the ON BREAK command (see page 288). Options: /C(lear buffer): Clears the keyboard buffer before INKEY accepts keystrokes. If you use this option, INKEY will ignore any keystrokes which you type, either accidentally or intentionally, before INKEY is ready to accept input. /D(igits only): Prevents INKEY from accepting any keystroke except a digit from 0 to 9. /K["keys"]: Specify the permissible keystrokes. The list of valid keystrokes should be enclosed in double quotes. For alphabetic keys the validity test is not case-sensitive. You can specify extended keys by enclosing their names in square brackets (within the quotes), for example: inkey /k"ab[Alt-F10]" Enter A, B, or Alt-F10 %%var See page 31 for a complete listing of the key names you can use within the square brackets, and a description of the key name format. If an invalid keystroke is entered, the command processor will echo the keystroke if possible, beep, move the cursor back one character, and wait for another keystroke. /P(assword): Prevents INKEY from echoing the character. /W(ait): Timeout period, in seconds, to wait for a response. If no keystroke is entered by the end of the timeout period, INKEY returns with the variable unchanged. You can specify /W0 to return immediately if there are no keys waiting in the keyboard buffer. For example, the following batch file fragment waits up to 10 seconds for a character, then tests to see if a "Y" was entered: set net=N inkey /K"YN" /w10 Load the network (Y/N)? %%net iff "%net" == "Y" then rem Commands to load the network go here ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 260 INKEY ------------------------------------------------------------------- endiff /X (no carriage return): Prevents INKEY from displaying a carriage return and line feed after the user's entry. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 261 INPUT ------------------------------------------------------------------- INPUT (New) Purpose: Get a string from the keyboard and save it in an environment variable. Format: INPUT [/C /D /E /Ln /N /P /Wn /X] [prompt] %%varname prompt: Optional text that is displayed as a prompt. varname: The variable that will hold the user's input. /C(lear buffer) /N(o colors) /D(igits only) /P(assword) /E(dit) /W(ait) /L(ength) /X (no carriage return) See also: INKEY and KEYSTACK. Usage: INPUT optionally displays a prompt. Then it waits for a specified time or indefinitely for your entry. It places any characters you type into an environment variable. INPUT is normally used in batch files and aliases to get multi-key input. Along with the INKEY command, INPUT allows great flexibility in reading user input from within a batch file or alias. If prompt text is included in an INPUT command, it is displayed while INPUT waits for input. Standard command-line editing keys may be used to edit the input string as it is entered. If you use the /P password option, INPUT will echo asterisks instead of the keys you type. All characters entered up to, but not including, the carriage return are stored in the variable. The following batch file fragment prompts for a string and stores it in the variable FNAME: input Enter the file name: %%fname INPUT reads standard input, so it will accept text from a re-directed file or from the KEYSTACK. If you press Ctrl-C or Ctrl-Break while INPUT is waiting for input, execution of an alias will be terminated, and execution of a batch file will be suspended while you are asked whether to cancel the batch job (see page 85). In a batch file you can ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 262 INPUT ------------------------------------------------------------------- handle Ctrl-C and Ctrl-Break yourself with the ON BREAK command (see page 288). Option: /C(lear buffer): Clears the keyboard buffer before INPUT accepts keystrokes. If you use this option, INPUT will ignore any keystrokes which you type, either accidentally or intentionally, before INPUT is ready. /D(igits only): Prevents INPUT from accepting any keystrokes except digits from 0 to 9. /E(dit): Allows you to edit an existing value. If there is no existing value for varname, INPUT proceeds as if /E had not been used, and allows you to enter a new value. /Ln (Length): Sets the maximum number of characters which INPUT will accept to "n". If you attempt to enter more than this number of characters, INPUT will beep and prevent further input (you will still be able to edit the characters typed before the limit was reached). /N(o colors): Disables the use of input colors defined in the InputColor directive in the .INI file, and forces INPUT to use the default display colors. /P(assword): Tells INPUT to echo asterisks, instead of the characters you type. /W(ait): Timeout period, in seconds, to wait for a response. If no keystroke is entered by the end of the timeout period, INPUT returns with the variable unchanged. If you enter a key before the timeout period, INPUT will wait indefinitely for the remainder of the line. You can specify /W0 to return immediately if there are no keys waiting in the keyboard buffer. /X (no carriage return): Prevents INPUT from displaying a carriage return and line feed after the user's entry. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 263 KEYBD ------------------------------------------------------------------- KEYBD (New) Purpose: Set the state of the keyboard toggles: Caps Lock, Num Lock, and Scroll Lock. Format: KEYBD [/Cn /Nn /Sn] /C(aps lock) /S(croll lock) /N(um lock) n can be 0 to turn off the toggle, or 1 to turn it on. Usage: Most keyboards have 3 toggle keys, the Caps Lock, Num Lock, and Scroll Lock. The toggle key status is usually displayed by three lights at the top right corner of the keyboard. This command lets you turn any toggle key on or off. It is most useful in batch files and aliases if you want the keys set a particular way before collecting input from the user. For example, to turn off the Num Lock and Caps Lock keys, you can use this command: c:\> keybd /c0 /n0 If you use the KEYBD command with no switches, it will display the present state of the toggle keys. 4DOS ## In 4DOS, KEYBD works by performing a BIOS setting. Some memory resident programs that monitor the physical keyboard rather than BIOS settings may not recognize that the state of the toggle keys has changed after a KEYBD command. 4OS2 ## In OS/2, the toggle key state is different for each session. Changes made with KEYBD will affect the session in which the command is executed, but will not affect other sessions. 4NT ## In Windows NT, the toggle key state is the same for all sessions. Changes made in one session will affect all other sessions. Options: /C(aps lock): Turn the Caps Lock key on or off. /N(um lock): Turn the Num Lock key on or off. /S(croll lock): Turn the Scroll Lock key on or off. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 264 [4OS2, 4DOS/NT] KEYS ------------------------------------------------------------------- KEYS [4OS2, 4DOS/NT] (Enhanced) Purpose: Enable, disable, or display the history list. Format: KEYS [ON | OFF | LIST] See also: HISTORY. Usage: This command is provided for compatibility with KEYS command in CMD.EXE, which controls the history list in OS/2 and Windows NT. The same functions are available by setting the HistMin directive in the .INI file, and by using the HISTORY command. The history list collects the commands you type for later recall, editing, and viewing. You can view the contents of the list through the history list window or by typing any of the following commands: [c:\] history [c:\] history /p [c:\] keys list The first command displays the entire history list. The second displays the entire list and pauses at the end of each full screen. The third command produces the same output as the first, except that each line is numbered. You can disable the collection and storage of commands in the history list by typing: [c:\] keys off You can turn the history back on with the command: [c:\] keys on If you issue the KEYS command without any parameters, 4OS2 or 4DOS/NT will show you the current status of the history list. 4OS2 KEYS also affects the way 4OS2 reads input from the keyboard. KEYS OFF will force 4OS2 into line input mode; KEYS ON will return input to the usual character by character method. See the LineInput directive on page 140, or the /L option of the SETDOS command on page 325, for details on line input mode. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 265 [4DOS] KEYSTACK ------------------------------------------------------------------- KEYSTACK [4DOS] (New) Purpose: Feed keystrokes to a program or command automatically. Format: KEYSTACK [/Wn] ["abc"] [keyname] [!] ... "abc": Literal characters to be placed in the Keystack. keyname: Name or code for a key to be placed in the Keystack. !: Signal to clear the Keystack and the keyboard buffer. /W(ait) Usage: KEYSTACK takes a series of keystrokes and feeds them to a program or command as if they were typed at the keyboard. When the program has used all of the keystrokes in the keystack buffer, it will begin to read the keyboard for input, as it normally would. The KEYSTACK command must be executed before running the program which is going to receive the keystrokes. This places the keystrokes into the buffer first, so the program can find them when it runs. KEYSTACK will only work if the memory-resident program KSTACK.COM has been loaded. KSTACK is usually loaded from the AUTOEXEC.BAT file (see page 86). If KSTACK is not loaded, the KEYSTACK command will display an error message. If you are using a multitasking system such as DESQview or Windows, see your Introduction and Installation Guide for information on loading KSTACK within a window. Characters entered within double quotes ("abc") will be stored "as is" in the keyboard buffer. The only items allowed outside double quotes are key names, key codes, and the ! and /W options. See page 31 for a complete listing of key names and a description of the key name format. An exclamation mark [!] will clear all pending keystrokes, both in the KEYSTACK buffer and in the keyboard buffer. For example, to start ProComm Plus and skip the opening screen you could use the command: ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 266 [4DOS] KEYSTACK ------------------------------------------------------------------- c:\comm> keystack 32 ^ pcplus This places a space (ASCII code 32) in the buffer, then runs ProComm Plus. When ProComm looks for a keystroke to end the display of the opening screen the keystroke is already in the buffer, and the opening screen is removed immediately. You can store a maximum of 255 characters in the KEYSTACK buffer. Each time the KEYSTACK command is executed, it will clear any remaining keystrokes stored by a previous KEYSTACK command. You may need to experiment with your programs and insert delays (see the /W option) to find a keystroke sequence that works for a particular program. Programs that bypass DOS and the BIOS for keyboard input cannot read keystrokes entered with KEYSTACK. If you use KEYSTACK and then run such a program, the keystrokes will not appear in the program, but may appear at the prompt when you exit the program and return to 4DOS. ## KEYSTACK treats the number 0 as a special case; it is used with programs that flush the keyboard buffer. When KEYSTACK processes a key value of 0, it tells the program the buffer is clear, so subsequent keystrokes will be accepted normally. Some programs will require several "0"s before they will accept input; you may need to experiment to determine the correct number. For example, the following batch file starts Lotus 1- 2-3 and loads the file specified on the command line when the batch file is invoked (the KEYSTACK command should be entered on one line): pushd c:\123 keystack 0 Enter 0 Enter 0 Enter 0 Enter 0 Enter "/FR" 0 "%1" Enter 123 popd The sequence of "0 Enter" pairs tells 1-2-3 that the keyboard buffer is empty, then passes 1-2-3 a carriage return, repeating this sequence five times. This gets 1-2-3 to a point where an empty spreadsheet is displayed. The rest of the KEYSTACK line issues a File Retrieve command (/FR), simulates an empty keyboard buffer once more, enters the file name passed ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 267 [4DOS] KEYSTACK ------------------------------------------------------------------- on the batch command line (%1), and finally enters a carriage return to end the file name. ## Here's the same command defined as an alias (enter this on one line): alias 321 `pushd c:\123 ^ keystack 0 Enter 0 Enter 0 Enter 0 Enter 0 Enter "/FR" 0 "%1" Enter ^ 123 ^ popd` ## KEYSTACK mimics the BIOS by stacking both an ASCII code and a scan code for each key. It does so by calculating the code for each character, whether it is entered as part of a quoted string, as a key name, or as an ASCII value less than 128. However, if you are stacking keys for a program which distinguishes between keys with the same symbol, like the plus on the keyboard and the gray plus, you will have to calculate the codes for the keys on the numeric keypad yourself. Calculate the value ((256 * scan code) + ASCII code) and enter that numeric value as an argument for KEYSTACK. For example, for the Enter key on the numeric keypad, the scan code is 224 and the ASCII code is 13, so to stack both values use ((256 * 224) + 13) or KEYSTACK 57357. Try this approach if a "normal" KEYSTACK command does not work (for example, if you use "KEYSTACK Enter" for the Enter key and the program doesn't see the correct character). To stack combined key codes you must use the numeric value, not the key name. See Appendix B on page 371 for a complete list of ASCII codes and scan codes. Options: ## /W(ait): Delay the next keystroke in the KEYSTACK buffer by a specified number of clock "ticks". A clock tick is approximately 1/18 second. The number of clock ticks to delay should be placed immediately after the W, and must be between 1 and 65535 (65535 ticks is about 1 hour). You can use the /W option as many times as desired and at any point in the string of keystrokes except within double quotes. Some programs may need the delays provided by /W in order to receive keystrokes properly from KEYSTACK. The only way to determine what delay is needed is to experiment. Sometimes a combination of a delay and an "empty buffer" signal (a 0) are required. For example, to start the program CADX and send it an F7, a delay of one second, an indication that the keyboard buffer is empty, and a carriage return: c:\> keystack F7 /W18 0 Enter ^ cadx ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 268 [4DOS] LH / LOADHIGH ------------------------------------------------------------------- LH / LOADHIGH [4DOS] (Compatible) Purpose: Load a memory resident program into an Upper Memory Block (UMB). Format: LH [/L:r1,n1;r2,n2;... /S] filename or LOADHIGH [/L:r1,n1;r2,n2;... /S] filename filename: The name of the program to load into high memory. /L(oad region) /S(hrink) Usage: LH and LOADHIGH are synonyms. You can use either one. LOADHIGH requires version 5.0 or later of MS-DOS, PC- DOS, DR DOS, or Novell DOS, or an OS/2 2.x DOS session. If you load memory-resident programs into UMBs, you will have more room in base memory for application programs. If your system has no UMBs, or if the program is larger than the largest UMB, then LOADHIGH will load the program into conventional base memory. For example, to load the program C:\UTIL\CACHE.EXE into high memory: c:\> loadhigh c:\util\cache.exe If you are running MS-DOS / PC-DOS 5.0 or above, or an OS/2 2.x DOS session, LOADHIGH requires the DOS=UMB command in your CONFIG.SYS file. It can only be used to load programs into UMBs managed by version 5.0 or later of MS-DOS, PC-DOS, DR DOS, or Novell DOS; or by OS/2 2.x DOS sessions. ! If you use a memory manager like 386MAX or QEMM to manage your UMBs, rather than the MS-DOS DOS=UMB directive, then LOADHIGH will not work, and you must use the equivalent command supplied with your memory manager in order to load programs high. See your 4DOS Introduction and Installation Guide for complete details on UMBs and UMB regions, and the hardware and software required to support them. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 269 [4DOS] LH / LOADHIGH ------------------------------------------------------------------- ## The /L and /S switches are designed to aid in optimizing the use of upper memory by selecting one or more UMB regions for a particular memory-resident program to use. They are fully compatible with the MS-DOS 6.0 and above memory optimizer, MEMMAKER, and may also be used under MS-DOS 5.0 and in OS/2 2.x DOS sessions. (They are not used by other memory optimizers, such as QEMM's OPTIMIZE or 386MAX's MAXIMIZE.) While a complete discussion of memory optimization techniques is well beyond the scope of this manual, the basic technique is to load each memory-resident program into a specific region to free up the maximum possible amount of base memory. Optimizing UMB usage requires a detailed knowledge of the memory requirements for your memory-resident programs. This information can be very difficult to obtain, because some programs require more memory when starting and less when running, and each program is unique. However, if you know these memory requirements, you may be able to use /L and /S to optimize the use of upper memory, or to improve on the optimization done by MEMMAKER or another memory optimizer. Options: ## /L:r1,n1;r2,n2;... (Load region): Specifies which region(s) should be used for the program, and optionally the minimum free space required in a region before the program is allowed access to that region. If /L is not used, all upper memory regions are available to the program. If /L is used, you must specify one or more regions (r1, r2, etc.); only those regions will be made available. Upper memory regions are numbered sequentially beginning with 1 (region 0 refers to low memory, and is normally used only by MEMMAKER). If only a region number is given, the entire region is made available to the program (assuming there is free space in the region). If a size is given for a particular region (n1, n2, etc.), then the region is only made available if the free space in the region is equal to or greater than that size. All sizes are in bytes. Any region not available to a particular program is "locked out" while that program is loading and made available again once the program is loaded. If the combination of /L values you use does not ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 270 [4DOS] LH / LOADHIGH ------------------------------------------------------------------- provide sufficient upper memory space for the program to load, it will be loaded in low memory. You can combine /L values in several ways. In each of the following examples, if the requested space is not available or is insufficient the program is loaded into low memory: lh /l:2 filename The program can use region 2 only. lh /l:2;3 filename The program can use regions 2 and 3 only. lh /l:2,2048 filename The program can use region 2 only, and only if it has 2048 or more bytes free. lh /l:2,2048;3 filename The program can use region 2 if it has 2048 or more bytes free, and region 3 regardless of how many bytes it has free ## /S(hrink): Shrinks each region selected by /L to the minimum size used in /L before loading the program. This prevents memory-resident programs which take all available memory from using more than you want them to. This switch is primarily intended for use by MEMMAKER. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 271 LIST ------------------------------------------------------------------- LIST (New) Purpose: Display a file, with forward and backward paging and scrolling. Format: LIST [/A[[:][-]rhsda] /H /S /W /X] file... file: A file or list of files to display. /A(ttribute select) /W(rap) /H(igh bit off) /X (heX display mode) /S(tandard input) See also: TYPE. Selection: Supports extended wildcards, ranges, multiple file names, and include lists (see pages 59 - 67). Usage: LIST provides a much faster and more flexible way to view a file than TYPE, without the overhead of loading and using a text editor. LIST is most often used for displaying ASCII text files. Most other files contain non-alphabetic characters and may be unreadable, except in hex mode. For example, to display a file called MEMO.DOC: c:\> list memo.doc LIST uses the cursor pad to scroll through the file. The following keys have special meanings: Home Display the first page of the file. End Display the last page of the file. Esc Exit the current file. Ctrl-C Quit LIST. Up Arrow Scroll up one line. Down Arrow Scroll down one line. Left Arrow Scroll left 8 columns. Right Arrow Scroll right 8 columns. Ctrl-Left Arrow Scroll left 40 columns. Ctrl-Right Arrow Scroll right 40 columns. F1 Display online help B Go back to the previous file in the current group of files. F Prompt and search for a string. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 272 LIST ------------------------------------------------------------------- G Go to a specific line or, in hex mode, to a specific hexadecimal offset. H Toggle the "strip high bit" (/H) option. I Display information on the current file (the full name, size, date, and time). N Find next matching string. P Print the current page or the entire file. W Toggle the "line wrap" (/W) option. X Toggle the hex-mode display (/X) option. Text searches performed with F and N are not case- sensitive. However, if the display is currently in hexadecimal mode and you press F, you will be prompted for whether you want to search in hexadecimal as well. If you answer Y, you should then enter the search string as a sequence of 2-digit hexadecimal numbers separated by spaces, for example 41 63 65 (these are the ASCII values for the string "Ace"; see Appendix B on page 371 for a complete list of ASCII codes). Hexadecimal searches are case-sensitive, and search for exactly the string you enter. You can use wildcards in the search string. For example, you can search for the string "to*day" to find the next line which contains the word "to" followed by the word "day" later on the same line, or search for the numbers "101" or "401" with the search string "[14]01". See page 59 for complete information on wildcards. LIST saves the search string used by F and N, so you can LIST multiple files and search for the same string simply by pressing N in each file, or repeat your search the next time you use LIST. LIST normally allows long lines in the file to extend past the right edge of the screen. You can use the horizontal scrolling keys (see above) to view text that extends beyond the screen width. If you use the W command or /W switch to wrap the display, each line is wrapped when it reaches the right edge of the screen, and the horizontal scrolling keys are disabled. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 273 LIST ------------------------------------------------------------------- If you print the file which LIST is displaying, you will be asked whether you wish to print the entire file or the current display page. The print format will match the display format. If you have switched to hexadecimal or wrapped mode, that mode will be used for the printed output as well. If you print in wrapped mode, long lines will be wrapped at the width of the display. If you print in normal display mode without line wrap, long lines will be wrapped or truncated by the printer, not by LIST. Printed output normally goes to device LPT1. If you wish to send the printed output to another device, use the Printer directive in the .INI file (see page 141). ## Most of the LIST keystrokes can be reassigned with .INI file directives (see pages 143 and 147). ## You can set the colors used by LIST with the ListColors and ListStatBarColors directives in the .INI file. If ListColors is not used, the LIST display will use the current default colors. If ListStatBarColors is not used, the status bar will use the reverse of the LIST display colors. 4DOS ## LIST normally writes text directly to the screen. If you have an unusual display adapter which does not support direct video output, see the OutputBIOS directive on page 150. Options: ## /A(ttribute select): Select only those files that have the specified attribute(s) set. Preceding the attribute character with a hyphen [-] will select files that do not have that attribute set. The attributes are: R Read-only D Subdirectory H Hidden A Archive S System If no attributes are listed at all (e.g., LIST /A ...), LIST will select all files and subdirectories including hidden and system files. If attributes are combined, all the specified attributes must match for a file to be selected. For example, /A:RHS will select only those files with all three attributes set. See page 18 for more information on file attributes. ## /H(igh bit off): Strip the high bit from each character before displaying. This is useful when ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 274 LIST ------------------------------------------------------------------- displaying files created by some word processors that turn on the high bit for formatting purposes. You can toggle this option on and off from within LIST with the H key. /S(tandard input): Read from standard input rather than a file. This allows you to redirect command output and view it with LIST. For example, to use LIST to display the output of DIR: c:\> dir | list /s /W(rap): Wrap the text at the right edge of the screen. This option is useful when displaying files that don't have a carriage return at the end of each line. The horizontal scrolling keys do not work when the display is wrapped. You can toggle this option on and off from within LIST with the W key. /X (hex mode): Display the file in hexadecimal (hex) mode. This option is useful when displaying executable files and other files that contain non-text characters. Each byte of the file is shown as a pair of hex characters. The corresponding text is displayed to the right of each line of hexadecimal data. You can toggle this mode on and off from within LIST with the X key. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 275 LOADBTM ------------------------------------------------------------------- LOADBTM (New) Purpose: Switch a batch file to or from BTM mode. Format: LOADBTM [ON | OFF] Usage: 4DOS, 4OS2, and 4DOS/NT recognize two kinds of batch files: .BAT or .CMD, and .BTM. Batch files executing in BTM mode run two to five times faster than in BAT or CMD mode. (However, BTM mode should not be used to load memory-resident programs in DOS, nor should BTM mode be used for self-modifying batch files.) Batch files automatically start in the mode indicated by their extension. For more information on .BTM, .BAT, and .CMD files, see page 80. The LOADBTM command turns BTM mode on and off. It can be used to switch modes in either a .BAT .CMD or / .BTM file. If you use LOADBTM with no argument, it will display the current batch mode: LOADBTM ON or LOADBTM OFF. LOADBTM can only be used within a batch file. It is most often used to switch a .BAT file into BTM mode after memory-resident programs are loaded, to convert a .BAT or .CMD file to BTM mode without changing its extension, or to switch a .BTM file into BAT mode in order to load memory-resident programs under DOS. Using LOADBTM to repeatedly switch modes within a batch file is not efficient. In most cases the speed gained by running some parts of the file in BTM mode will be more than offset by the speed lost through repeated loading of the file each time BTM mode is invoked. The following .BAT file fragment loads some memory resident programs (TSRs), and then switches to BTM mode: rem Because this file has a .BAT extension, rem the initial default state is LOADBTM OFF rem Loading TSRs... ansi.com mouse.com rem Switch to high-speed (BTM) mode now that rem TSRs are loaded loadbtm on path c:\;c:\util;c:\dos alias /r c:\aliases ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 276 LOG ------------------------------------------------------------------- LOG (New) Purpose: Save a log of commands to a disk file. Format: LOG [/H /W file] [ON | OFF | text] file: The name of the file to hold the log. text: An optional message that will be added to the log. /H(istory log) /W(rite to). See also: HISTORY. Usage: LOG keeps a record of all internal and external commands you use. Each entry includes the current system date and time, along with the actual command after any alias or variable expansion (see page 121 for more information on alias and variable expansion). You can use the log file as a record of your daily activities. LOG with the /H option keeps a similar record, but it does not record the date and time for each command. In addition, it records commands before aliases and variables are expanded. By default, LOG writes to the file 4DOSLOG, 4OS2LOG, or 4NTLOG (depending on which command processor you are using), in the root directory of the boot drive. The corresponding default file names for LOG /H are 4DOSHLOG, 4OS2HLOG, and 4NTHLOG. Entering LOG or LOG /H with no parameters displays the name of the log file and the log status (ON or OFF): c:\> log LOG (C:\4DOSLOG) is OFF To enable or disable logging, add the word "ON" or "OFF" after the LOG command: c:\> log on or c:\> log /h on ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 277 LOG ------------------------------------------------------------------- Entering LOG or LOG /H with text writes a message to the log file, even if logging is set OFF. This allows you to enter headers in the log file: c:\> log "Started work on the database system" The LOG file format looks like this: [mm-dd-yy hh:mm:ss] command The LOG /H output can be used as the basis for writing batch files. Start LOG /H, then execute the commands that you want the batch file to execute. When you are finished, turn LOG /H off. The resulting file can be turned into a batch file that performs the same commands with little or no editing. You can have both a regular log (with time and date stamping) and a history log (without the time stamps) enabled simultaneously. Options: /H(istory log): This option turns on (or off) the history log, which saves commands without the time and date stamp. For example, to turn on history logging and write to the file C:\LOG\HLOG: c:\> log /h /w c:\log\hlog /W(rite): This switch specifies a different filename for the LOG or LOG /H output. It also automatically performs a LOG ON command. For example, to turn logging on and write the log to C:\LOG\LOGFILE: c:\> log /w c:\log\logfile Once you select a new file name with the LOG /W or LOG /H/W command, LOG will use that file until you issue another LOG /W or LOG /H/W command, or until you reboot your computer. Turning LOG or LOG /H off or on does not change the file name. You can set the default log file names when your command processor starts with the LogName and HistLogName directives in the .INI file. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 278 MD / MKDIR ------------------------------------------------------------------- MD / MKDIR (Enhanced) Purpose: Create a subdirectory. Format: MD [/S] pathname... or MKDIR [/S] pathname... pathname: The name of one or more directories to create. /S(ubdirectories) See also: RD. Usage: MD and MKDIR are synonyms. You can use either one. MD creates a subdirectory anywhere in the directory tree. To create a subdirectory from the root, start the pathname with a backslash [\]. For example, this command creates a subdirectory called MYDIR in the root directory: c:\> md \mydir If no path is given, the new subdirectory is created in the current directory. This example creates a subdirectory called DIRTWO in the current directory: c:\mydir> md dirtwo To create a directory from the parent of the current directory (that is, to create a sibling of the current directory), start the pathname with two periods and a backslash [..\]. The operating system limits the permissible length of the full subdirectory name. See page 16 for details. Option: /S(ubdirectories): MD creates one directory at a time unless you use the /S option. If you need to create the directory C:\ONE\TWO\THREE and none of the named directories exist, you can use /S to have MD create all of the necessary subdirectories for you in a single command: c:\> md /s \one\two\three ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 279 MEMORY ------------------------------------------------------------------- MEMORY (New) Purpose: Display the amount and status of system RAM. Format: MEMORY Usage: MEMORY displays information about the RAM in your system. 4DOS In 4DOS, MEMORY lists the amount of total RAM in your system and the amount available for applications after DOS, 4DOS, and memory-resident programs have been laoded; the amount of EMS expanded memory, XMS extended memory, and non-XMS extended memory; the HMA status; and the amount of memory 4DOS is using for environment variable space, alias space, and history : space c:\> memory 655,360 bytes total RAM 534,464 bytes free 1,687,552 bytes total EMS memory 1,097,728 bytes free 914,432 bytes total XMS memory (HMA in use) 512 bytes total environment 195 bytes free 1,024 bytes total alias 452 bytes free 1,024 bytes total history You can use the information from the MEMORY display to fine tune your system, to aid in setting the proper alias and environment sizes in 4DOS.INI, and to be sure that you have sufficient memory for your largest applications. If you compare the free RAM displayed by MEMORY with the free RAM displayed by CHKDSK and some memory map programs, MEMORY will usually show a slightly higher value. The difference is the size of the environment passed to these external programs; most memory mapping programs do not count the passed environment as free space, but MEMORY does. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 280 MEMORY ------------------------------------------------------------------- The MEMORY command displays for 4OS2 and 4DOS/NT are somewhat different to reflect the way in which OS/2 and Windows NT organize the computer's memory. 4OS2 A typical MEMORY display using 4OS2 is shown below: 16,379,904 bytes total physical RAM 40,546,048 bytes total resident RAM 5,050,368 bytes largest free block 3,145,728 bytes total swap file 4,096 bytes total environment 2,451 bytes free 4,096 bytes total alias 1,910 bytes free 1,024 bytes total history 4NT A typical MEMORY display using 4DOS/NT is shown below: 21 % Memory load 16,449,536 bytes total physical RAM 3,665,920 bytes available physical RAM 37,715,968 bytes total page file 19,038,208 bytes available page file 4,096 bytes total environment 3,192 bytes free 32,768 bytes total alias 32,767 bytes free 1,024 bytes total history ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 281 MOVE ------------------------------------------------------------------- MOVE (New) Purpose: Move files to a new directory and drive. Format: MOVE [/A[[:][-]rhsda] /C /D /F /H /M /N /P /Q /R /S /T /U /V] source... destination source: A file or list of files to move. destination: The new location for the files. /A(ttribute select) /P(rompt) /C(hanged) /Q(uiet) /D(irectory) /R(eplace) /F(orce delete) /S(ubdirectory tree) /H(idden and system) /T(otal) /M(odified files) /U(pdate) /N(othing) /V(erify) See also: COPY and RENAME. Selection: Supports extended wildcards, ranges, multiple file names, and include lists (see pages 59 - 67). Date, time, or size ranges anywhere on the line apply to all source files. Usage: The MOVE command moves one or more files from one directory to another, whether the directories are on the same drive or not. It has the same effect as copying the files to a new location and then deleting the originals. Like COPY and RENAME, MOVE works with single files, multiple files, and sets of files specified with an include list. The simplest MOVE command moves a single source file to a new location and, optionally, gives it a new name. These two examples both move one file from drive C: to the root directory on drive A: c:\> move myfile.dat a:\ c:\> move myfile.dat a:\savefile.dat In both cases, MYFILE.DAT is removed from drive C: after it has been copied to drive A:. If a file called MYFILE.DAT in the first example, or SAVEFILE.DAT in the second example, already existed on drive A:, it would be overwritten. (This demonstrates the difference between MOVE and RENAME. MOVE will move files between drives and will overwrite the destination file if it exists; RENAME will not.) ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 282 MOVE ------------------------------------------------------------------- If you MOVE multiple files, the destination must be a directory name. MOVE will move each file into the destination directory with its original name (if the target is not a directory, MOVE will display an error message and exit): c:\> move *.wks *.txt c:\finance\myfiles You cannot move a file to a character device like the printer, or to itself. When you move files to another directory, if you add a backslash [\] to the end of the destination name MOVE will display an error message if the name does not refer to an existing directory. You can use this feature to keep MOVE from treating a mistyped destination directory name as a file name, and attempting to move all source files to that name. The /D option performs the same function but will also prompt to see if you want to create the destination directory if it doesn't exist. ! Be careful when you use MOVE with the SELECT command. If you SELECT multiple files and the target is not a directory (for example, because of a misspelling), MOVE will assume it is a file name. In this case each file will be moved in turn to the target file, overwriting the previous file, and then the original will be erased before the next file is moved. At the end of the command, all of the original files will have been erased and only the last file will exist as the target file. You can avoid this problem by using square brackets with SELECT instead of parentheses (be sure that you don't allow the command line to get too long - watch the character count in the upper left corner while you're selecting files). MOVE will then receive one list of files to move instead of a series of individual filenames, and it will detect the error and halt. You can also add a backslash [\] to the end of the destination name to ensure that it is the name of a subdirectory (see above). ## MOVE first attempts to rename the file(s), which is the fastest way to move files between subdirectories on the same drive. If that fails (the destination is on a different drive or already exists), MOVE will copy the file(s) and then delete the originals. ## If you are using 4DOS in an OS/2 DOS session, MOVE will copy OS/2 extended attributes from the source to ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 283 MOVE ------------------------------------------------------------------- the destination, provided the file system on the destination drive supports them. ## If MOVE must physically copy the files and delete the originals, rather than renaming them (see above), then some disk space may be freed on the source drive. The free space may be the result of moving the files to another drive, or of overwriting a larger destination file with a smaller source file. MOVE displays the amount of disk space recovered unless the /Q option is used (see below). It does so by comparing the amount of free disk space before and after the MOVE command is executed. However, this amount may be incorrect if you are using a deletion tracking system which stores deleted files in a hidden directory, or if, under a multitasking system, another program performs a file operation while the MOVE command is executed. ## When physically copying files, MOVE preserves the hidden, system, and read-only attributes of the source files, and sets the archive attribute of the destination files. However, if the files can be renamed, and no copying is required, then the source file attributes are not changed. 4NT ## If you MOVE files with long filenames from an NTFS volume to a FAT volume, 4DOS/NT will now store the destination files with their short, FAT-compatible names when running under Windows NT 3.1 (long names are used under Windows NT 3.5 and above; see page 18 for additional details). You can view the short names before executing the MOVE with the DIR /X command. Options: ## /A(ttribute select): Select only those files that have the specified attribute(s) set. Preceding the attribute character with a hyphen [-] will select files that do not have that attribute set. The attributes are: R Read-only D Subdirectory H Hidden A Archive S System If no attributes are listed at all (e.g., MOVE /A ...), MOVE will select all files and subdirectories including hidden and system files. If attributes are combined, all the specified attributes must match for a file to be selected. For example, /A:RHS will select only those files with all three attributes set. See page 18 for more information on file attributes. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 284 MOVE ------------------------------------------------------------------- /C(hanged files): Move files only if the destination file exists and is older than the source (see also /U). This option is useful for updating the files in one directory from those in another without moving any newly-created files. /D(irectory): Requires that the destination be a directory. If the destination does not exist, MOVE will prompt to see if you want to create it. If the destination exists as a file, MOVE will fail with an "Access denied" error. Use this option to avoid having MOVE accidentally interpret your destination name as a file name when it's really a mistyped directory name. ## /F(orce delete): This option is only for use in the 32-bit version of 4OS2, and in 4DOS when running in an OS/2 2.1 or later DOS session. It forces deletion of the source file without saving it to the DELDIR directory (if DELDIR is not in use, /F has no effect). ## /H(idden): Move all files, including hidden and system files. /M(odified files): Move only files that have the archive bit set. The archive bit will remain set after the MOVE; to clear it use ATTRIB (page 173). /N(othing): Do everything except actually move the file(s). This option is most useful for testing what a complex MOVE command will do. /P(rompt): Prompt the user to confirm each move. Your options at the prompt are explained in detail on page 50. /Q(uiet): Don't display filenames, the total number of files moved, or the amount of disk space recovered, if any. This option is most often used in batch files. See also /T. /R(eplace): Prompt for a Y or N response before overwriting an existing destination file. /S(ubdirectories): Move an entire subdirectory tree to another location. MOVE will attempt to create the destination directories if they don't exist, and will remove empty subdirectories after the move. When /D is used with /S, you will be prompted if the first destination directory does not exist, but ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 285 MOVE ------------------------------------------------------------------- subdirectories below that will be created automatically by MOVE. If you attempt to use /S to move a subdirectory tree into part of itself, MOVE will display an error message and halt. /T(otal): Don't display filenames as they are moved, but display the total number of files deleted and the amount of free disk space recovered, if any. /U(pdate): Move each source file only if it is newer than a matching destination file or if a matching destination file does not exist (also see /C). This option is useful for moving new or changed files from one directory to another. ## /V(erify): Verify each disk write. This is the same as executing the VERIFY ON command, but is only active during the MOVE. /V does not read back the file and compare its contents with what was written; it only verifies that the data written to disk is physically readable. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 286 [4DOS/NT] MSGBOX ------------------------------------------------------------------- MSGBOX [4DOS/NT] (New) Purpose: Display a message box and collect the user's response. Format: MSGBOX OK | OKCANCEL | YESNO | YESNOCANCEL ["title"] prompt title: Text for the title bar of the message box. prompt: Text that will appear inside the message box. Usage: MSGBOX can display one of 4 kinds of message boxes and wait for the user's response. You can use title and prompt to display any text you wish. 4DOS/NT automatically sizes and locates the box on the screen. The message box may have 1, 2, or 3 response buttons. The command MSGBOX OK creates a single-button box; the user must simply acknowledge the prompt text. The OKCANCEL and YESNO forms have 2 buttons each. The YESNOCANCEL form has 3 buttons. The button the user chooses is returned in the 4DOS/NT variable %_?. Be sure to save the return value in another variable or test it immediately; the value of %_? changes with every internal command. The following list shows the value returned for each possible selection: Yes 10 No 11 OK 10 Cancel 12 If you exit the message box without selecting one of these options (for example, some message boxes allow you to exit by pressing Esc or double-clicking the close button), MSGBOX will set %_? to 0. If there is an error in the MSGBOX command itself, %_? will be set as described on page 102. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 287 ON ------------------------------------------------------------------- ON (New) Purpose: Execute a command in a batch file when a specific condition occurs. Format: ON BREAK [command] or ON ERROR [command] Usage: ON can only by used in batch files. ON sets a "watchdog" that remains in effect for the duration of the current batch file. Whenever a BREAK or ERROR condition occurs after ON has been executed, the command is automatically executed. ON BREAK will execute its command if the user presses Ctrl-C or Ctrl-Break. ON ERROR will execute its command after any command processor or operating system error (including critical errors; see page 51). That is, ON ERROR will detect errors such as a disk write error, and 4DOS, 4OS2, or 4DOS/NT errors such as a COPY command that fails to copy any files, or the use of an unacceptable command option. ON BREAK and ON ERROR are independent of each other. You can use either one, or both, in any batch file. Each time ON BREAK or ON ERROR is used, it defines a new command to be executed for a break or error, and any old command is discarded. If you use ON BREAK or ON ERROR with no following command, that type of error handling is disabled. Error handling is also automatically disabled when the batch file exits. ON BREAK and ON ERROR only affect the current batch file. If you CALL another batch file, the first batch file's error handling is suspended, and the CALLed file must define its own error handling. When control returns to the first batch file, its error handling is reactivated. The command can be any command that can be used on a batch file line by itself. Frequently, it is a GOTO or GOSUB command. For example, the following fragment traps any user attempt to end the batch file by pressing Ctrl-C or Ctrl-Break. It scolds the user for ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 288 ON ------------------------------------------------------------------- trying to end the batch file and then continues displaying the numbers from 1 to 1000: on break gosub gotabreak do i = 1 to 1000 echo %i enddo quit :gotabreak echo Hey! Stop that!! return You can use a command group (see page 71) as the command if you want to execute multiple commands, for example: on break (echo Oops, got a break!^quit) ON BREAK and ON ERROR always assume that you want to continue executing the batch file. After the command is executed, control automatically returns to the next command in the batch file (the command after the one that was interrupted by the break or error). The only way to avoid continuing the batch file after a break or error is for the command to transfer control to another point with GOTO, end the batch file with QUIT or CANCEL, or start another batch file (without CALLing it). When handling an error condition with ON ERROR, you may find it useful to use internal variables (see page 100), particularly %_? and %_SYSERR, to help determine the cause of the error. ! If a break or error occurs while the command specified in ON BREAK or ON ERROR is executing, the command will be restarted. This means you must use caution to avoid or handle any possible errors in the commands invoked by ON ERROR, since such errors can cause an infinite loop and/or a stack overflow condition. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 289 PATH ------------------------------------------------------------------- PATH (Enhanced) Purpose: Display or alter the list of directories that 4DOS, 4OS2, or 4DOS/NT will search for executable files, batch files, and files with executable extensions that are not in the current directory. Format: PATH [directory[;directory...]] directory: The full name of a directory to include in the path setting. See also: ESET and SET. Usage: When the command processor is asked to execute an external command (a .COM, .EXE, .BTM, .BAT, or .CMD file or executable extension), it first looks for the file in the current directory. If it fails to find an executable file there, it then searches each of the directories specified in the PATH setting. See page 20 for more details on how the path is searched. For example, after the following PATH command, the command processor will search for an executable file in four directories: the current directory, then the root directory on drive C, then the DOS subdirectory on C, and then the UTIL subdirectory on C: c:\> path c:\;c:\dos;c:\util The list of directories to search can be set or viewed with the PATH command. The list is stored as an environment string, and can also be set or viewed with SET, and edited with ESET. Directory names in the path must be separated by semicolons [;]. Each directory name is shifted to upper case to maintain compatibility with programs which can only recognize upper case directory names in the path. If you modify your path with the SET or ESET command, you may include directory names in lower case. These may cause trouble with some programs, which assume that all path entries have been shifted to upper case. If you enter PATH with no parameters, the current path is displayed: c:\> path PATH=C:\;C:\DOS;C:\UTIL ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 290 PATH ------------------------------------------------------------------- Entering PATH and a semicolon clears the search path so that only the current directory is searched for executable files (this is the default at system startup). Some applications also use the PATH to search for their data files. ## If you include an explicit file extension on a command name (for example, WP.EXE), the search will find files with that name and extension in the current directory and every directory in the path. It will not locate other executable files with the same base name. ## If you have an entry in the path which consists of a single period [.], the current directory will not be searched first, but instead will be searched when the command processor reaches the "." in the path. This allows you to delay the search of the current directory for executable files and files with executable extensions. In rare cases, this feature may not be compatible with applications which use the path to find their files; if you experience a problem, you will have to remove the "." from the path while using any such application. 4DOS ## In normal use, 4DOS can create a path as long as 250 characters (the command-line limit is 255 characters, and "PATH " takes five). However, some DOS applications expect a path no longer than the traditional limit of 123 characters. If you extend your path beyond this limit and experience problems with application programs, see Appendix A of the 4DOS Introduction and Installation Guide for tips on resolving the difficulty. ## To create a path longer than the command-line length limit, use PATH repeatedly to append additional directories to the path: path [first list of directories] path %path;[second list of directories] ... You cannot use this method to extend the path beyond 506 characters in 4DOS or 2042 characters in 4OS2 and 4DOS/NT (the internal buffer limits, with room for "PATH"). It is usually more efficient to use aliases to load application programs than to create a long PATH. See ALIAS on page 161 for details. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 291 PATH ------------------------------------------------------------------- If you specify an invalid directory in the path, it will be skipped and the search will continue with the next directory in the path. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 292 PAUSE ------------------------------------------------------------------- PAUSE (Enhanced) Purpose: Suspend batch file or alias execution. Format: PAUSE [text] text: The message to be displayed as a user prompt. Usage: A PAUSE command will suspend execution of a batch file or alias, giving you the opportunity to change disks, turn on the printer, etc. PAUSE waits for any key to be pressed and then continues execution. You can specify the text that PAUSE displays while it waits for a keystroke, or let 4DOS use the default message: Press any key when ready... For example, the following batch file fragment prompts the user before erasing files (the PAUSE command should be entered on one line): pause Press Ctrl-C to abort, any other key to erase all .LST files erase *.lst If you press Ctrl-C or Ctrl-Break while PAUSE is waiting for a key, execution of an alias will be terminated, and execution of a batch file will be suspended while you are asked whether to cancel the batch job (see page 85). In a batch file you can handle Ctrl-C and Ctrl-Break yourself with the ON BREAK command (see page 288). ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 293 POPD ------------------------------------------------------------------- POPD (New) Purpose: Return to the disk drive and directory at the top of the directory stack. Format: POPD [*] See also: DIRS and PUSHD. Usage: Each time you use the PUSHD command, it saves the current disk drive and directory on the internal directory stack. POPD restores the last drive and directory that was saved with PUSHD and removes that entry from the stack. You can use these commands together to change directories, perform some work, and return to the starting drive and directory. Directory changes made with POPD are recorded for display in the directory history window (see page 45). This example saves and changes the current disk drive and directory with PUSHD, and then restores it. The current directory is shown in the prompt: c:\> pushd d:\database\test d:\database\test> pushd c:\wordp\memos c:\wordp\memos> pushd a:\123 a:\123> popd c:\wordp\memos> popd d:\database\test> popd c:\> You can use the DIRS command to see the complete list of saved drives and directories (the directory stack). The POPD command followed by an asterisk [*] clears the directory stack without changing the current drive and directory. ## If the directory on the top of the stack is not on the current drive, POPD will switch to the drive and directory on the top of the stack without changing the default directory on the current drive. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 294 PROMPT ------------------------------------------------------------------- PROMPT (Enhanced) Purpose: Change the command-line prompt. Format: PROMPT [text] text: Text to be used as the new command-line prompt. Usage: You can change and customize the command-line prompt at any time. The prompt can include normal text, and system information such as the current drive and directory, the time and date, and the amount of memory available. You can create an informal "Hello, Bob!" prompt or an official-looking prompt full of impressive information. The prompt text can contain special commands in the form $?, where ? is one of the characters listed below: b The vertical bar character [|]. c The open parenthesis [(]. d Current date, in the format: Fri Jan 7, 1994. D Current date, in the format: Fri 1-07-94 (the month, day, and year are formatted according to your current country settings). e The ASCII ESC character (decimal 27). f The close parenthesis [)]. g The > character. h Backspace over the previous character. i Display the OS/2 prompt header line, which reminds you of how to return to the OS/2 desktop, or get help. l The < character. m Time in hours and minutes using 24-hour format. M Time in hours and minutes using the default country format and retaining "a" or "p", e.g. 4:07p. n Current drive letter. p Current drive and directory (lower case). P Current drive and directory (upper case). q The = character. r The numeric exit code of the last external command. s The space character. t Current 24-hour time, in the format hh:mm:ss. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 295 PROMPT ------------------------------------------------------------------- T Current 12-hour time, in the format hh:mm:ss[a|p]. v Operating system version number, in the format 3.10. xd: Current directory on drive d:, in lower case. (Uses the actual case of the directory name as stored on the disk for HPFS and NTFS drives, and FAT drives under Windows NT 3.5 and above; see page 17 for details). Xd: Current directory on drive d:, in upper case. z Current shell nesting level; the primary command processor is shell 0. $ The $ character. _ CR/LF (go to beginning of a new line). For example, to set the prompt to the current date and time, with a ">" at the end: c:\> prompt $d $t $g Fri Dec 3, 1993 10:29:19 > To set the prompt to the current date and time, followed by the current drive and directory in upper case on the next line, with a ">" at the end: c:\> prompt $d $t$_$P$g Fri Dec 3, 1993 10:29:19 C:\> Under DOS, you can include the PROMPT command in your AUTOEXEC.BAT file to set the prompt whenever your system is rebooted. The 4OS2 prompt can be set in CONFIG.SYS (see below), and the prompt for any command processor can be set in 4START (see page 85), or in any batch file that runs when the command processor starts. 4DOS The default prompt is $n$g (drive name plus ">") on drives A and B, and $p$g (current drive and directory plus ">") on all other drives. If you use 4DOS under OS/2, the SET PROMPT statement in the OS/2 CONFIG.SYS file (see next paragraph) will override the default 4DOS prompt. You must delete this statement if you want to use the default prompt. 4OS2 The 4OS2 default prompt is [$n] (drive name in square brackets) on floppy drives, and [$p] (current drive and directory in square brackets) on all other drives. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 296 PROMPT ------------------------------------------------------------------- When OS/2 is installed, it inserts a SET PROMPT statement in CONFIG.SYS to set the prompt to $i[$p]. This prompt will override the 4OS2 defaults. The $i adds a header line to the default prompt to remind you of certain OS/2 keystrokes. You must delete this statement if you want to use the default prompt. 4NT The 4DOS/NT default prompt is [$n] (drive name in square brackets) on floppy drives, and [$p] (current drive and directory in square brackets) on all other drives. If you enter PROMPT with no arguments, the prompt will be reset to its default value. The PROMPT command sets the environment variable PROMPT, so to view the current prompt setting use the command: c:\> set prompt (If the prompt is not set at all, the PROMPT environment variable will not be used, in which case the SET command above will give a "Not in environment" error.) ## Along with literal text, special characters, and ANSI sequences (under DOS and OS/2), you can include the text of any environment variable, internal variable, or variable function (see pages 100 and 108) in a prompt. For example, if you want to include the amount of free memory in the command prompt, plus the current drive and directory, you could use this command: c:\> prompt (%%@dosmem[K]K) $p$g (601K) c:\data> Notice that the @DOSMEM function is shown with two leading percent signs [%]. If you used only one percent sign, the @DOSMEM function would be expanded once when the PROMPT command was executed, instead of every time the prompt is displayed. As a result, the amount of memory would never change from the value it had when you entered the PROMPT command. You can also use back-quotes to delay expanding the variable function until the prompt is displayed: c:\> prompt `(%@dosmem[K]K) $p$g` ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 297 PROMPT ------------------------------------------------------------------- 4DOS, ## If you have an ANSI-compatible driver installed 4OS2 under 4DOS, or are running 4OS2, you can include ANSI escape sequences in the PROMPT text. See your online help for complete details on ANSI. This example uses ANSI sequences to set a prompt that displays the shell level, date, time and path in color on the top line of the screen (enter the command as one line): c:\> prompt $e[s$e[1;1f$e[41;1;37m$e[K[$z] $d Time: $t$h$h$h Path: $p$e[u$e[0;32m$n$g 4NT You cannot use ANSI escape sequences in your prompt in 4DOS/NT, because Windows NT does not provide ANSI support. ## A few older batch files use the PROMPT command to transmit ANSI.SYS control sequences to the screen (for example, to redefine function keys). This technique will not work with 4DOS and 4OS2, because they don't display a prompt within batch files; hence, the characters in the PROMPT string are never sent to ANSI.SYS. To send ANSI sequences in 4DOS and 4OS2, use the ECHO command, substituting an escape character followed by an e for $e in the PROMPT string (see page 73 for more information on the escape character). ## You may find it helpful to define a different prompt in secondary shells, perhaps including $z in the prompt to display the shell level. To do so, place a PROMPT command in your 4START file and use IF or IFF statements to set the appropriate prompt for different shells (for an example, see page 108). ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 298 PUSHD ------------------------------------------------------------------- PUSHD (New) Purpose: Save the current disk drive and directory, optionally changing to a new drive and directory. Format: PUSHD [pathname] pathname: The name of the new default drive and directory. See also: DIRS, POPD and Directory Changes on page . 44 Usage: PUSHD saves the current drive and directory on a "last in, first out" directory stack. The POPD command returns to the last drive and directory that was saved by PUSHD. You can use these commands together to change directories, perform some work, and return to the starting drive and directory. The DIRS command displays the contents of the directory stack. To save the current drive and directory, without changing directories, use the PUSHD command by itself, with no pathname. If a pathname is specified as part of the PUSHD command, the current drive and directory are saved and PUSHD changes to the specified drive and directory. If the pathname includes a drive letter, PUSHD changes to the specified directory on the new drive without changing the current directory on the original drive. This example saves the current directory and changes to C:\WORDP\MEMOS, then returns to the original directory: c:\> pushd \wordp\memos c:\wordp\memos> popd c:\> Directory changes made with PUSHD are recorded for display in the directory history window (see page 45). ## The directory stack can hold up to 255 characters, or about 10 to 20 entries (depending on the length of the names). If you exceed this limit, the oldest entry is removed before adding a new entry. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 299 PUSHD ------------------------------------------------------------------- ## If PUSHD can't change directly to the specified directory, it will look for the CDPATH variable. See page 44 for details on CDPATH. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 300 QUIT ------------------------------------------------------------------- QUIT (New) Purpose: Terminate the current batch file. Format: [value] QUIT value: The exit code from 0 to 255 to return to the command processor or to the previous batch file. See also: CANCEL. Usage: QUIT provides a simple way to exit a batch file before reaching the end of the file. If you QUIT a batch file called from another batch file, you will be returned to the previous file at the line following the original CALL. This example batch file fragment checks to see if the user entered "quit" and exits if true. input Enter your choice : %%option if "%option" == "quit" quit QUIT only ends the current batch file. To end all batch file processing, use the CANCEL command. ## If you specify a value, QUIT will set the ERRORLEVEL or exit code (see the IF command, and the %? variable on page 102) to that value. ## You can also use QUIT to terminate an alias. If you QUIT an alias while inside a batch file, QUIT will end both the alias and the batch file and return you to the command prompt or to the calling batch file. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 301 RD / RMDIR ------------------------------------------------------------------- RD / RMDIR (Enhanced) Purpose: Remove one or more subdirectories. Format: RD [/S] pathname... or RMDIR [/S] pathname... pathname: The name of a subdirectory to remove. 4NT /S(ubdirectories) See also: MD. Selection: Supports extended wildcards, ranges, multiple file names, and include lists (see pages 59 - 67). Usage: RD and RMDIR are synonyms. You can use either one. RD removes directories from the directory tree. For example, to remove the subdirectory MEMOS from the subdirectory WP, you can use this command: c:\> rd \wp\memos Before using RD, you must delete all files and subdirectories (and their files) in the pathname you want to remove. Remember to remove hidden and read- only files as well as normal files (you can use DEL /Z to delete hidden and read-only files). You can use wildcards in the pathname. ## You cannot remove the root directory, the current directory (.), any directory above the current directory in the directory tree, or any directory in use by another process in a multitasking system. Options: /S(ubdirectories): This option is included only for compatibility with Windows NT's CMD.EXE, and should be 4NT ! ## used with EXTREME CAUTION! It deletes all files (including hidden and system files) in the named directory and all of its subdirectories, then removes all empty subdirectories. This option does not prompt for permission before deleting files and subdirectories, and can potentially erase all files on a drive with a single command. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 302 REBOOT ------------------------------------------------------------------- REBOOT (New) Purpose: Do a warm or cold system reboot. Format: REBOOT [/C /L /S /V] /C(old reboot) /S(hutdown) /L(ogoff) /V(erify) ## Usage: REBOOT will completely restart your computer. It normally performs a warm reboot, which is comparable to pressing Ctrl-Alt-Delete under DOS or OS/2, or to a shutdown and restart under Windows NT. Under DOS, REBOOT can also perform a cold reboot, which is comparable to turning the power off and back on or pressing the reset button. A reboot is necessary to activate any changes to your CONFIG.SYS file in DOS and OS/2, and may also be used if you wish to restart DOS with an altered 4START or AUTOEXEC.BAT file. The following example prompts you to verify the reboot, then does a warm boot: c:\> reboot /v REBOOT defaults to performing a warm boot, with no prompting. REBOOT flushes the disk buffers, resets the drives, and waits one second before rebooting, to allow disk caching programs to finish writing any cached data. 4OS2 and 4DOS/NT issue the proper commands to shut down the operating system before rebooting. 4DOS ! Under DOS, some system BIOSes, memory managers, multitaskers, or memory-resident programs (TSRs) may intercept attempts to reboot your system and defeat them entirely, convert a cold boot request to a warm boot or vice versa, or in very rare cases, hang the system - requiring a reboot! As a result you may need to experiment with which reboot options work best for your system hardware and software configuration, and under rare circumstances REBOOT may not be usable on your system. 4OS2 ! ## Under OS/2, REBOOT must use the DOS.SYS device driver to reboot your system. DOS.SYS is loaded via a DEVICE= statement in your CONFIG.SYS file. If DOS.SYS is not loaded, REBOOT will not work. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 303 REBOOT ------------------------------------------------------------------- Options: /C(old): Do a "cold" reboot. This is similar to turning the power off and back on, and may be necessary to properly initialize the system. 4DOS REBOOT /C may not physically reset all hardware devices as thoroughly as actually turning off the power; its effect depends on the internal design of each hardware device and on your system configuration. 4NT /L(ogoff): Log off Windows NT, but do not reboot. This option is equivalent to Logoff choice on the Program Manager's File menu in Windows NT. 4OS2, /S(hutdown): Shut down the system, but do not reboot. 4NT This option is equivalent to clicking the "Shutdown" choice on the OS/2 2.x Workplace Shell popup menu, or using the Shutdown choice on the Program Manager's File menu in Windows NT. /V(erify): Prompt for confirmation (Y or N) before rebooting or taking the action specified by other REBOOT options. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 304 REM ------------------------------------------------------------------- REM (Compatible) Purpose: Put a comment in a batch file. Format: REM [comment] comment: The text to include in the batch file. Usage: The REM command lets you place a remark or comment in a batch file. Batch file comments are useful for documenting the purpose of a batch file and the procedures you have used. For example: rem This batch file provides a rem menu-based system for accessing rem word processing utilities. rem rem Clear the screen and get selection cls REM must be followed by a space or tab character and then your comment. Comments can be up to 255 characters long in 4DOS, or 1023 characters long in 4OS2 and 4DOS/NT. 4DOS, 4OS2, and 4DOS/NT will normally ignore everything on the line after the REM command, including quote characters, redirection symbols, and other commands (see below for the exception to this rule). If ECHO is ON, the comment is displayed. Otherwise, it is ignored. If ECHO is ON and you don't want to display the line, preface the REM command with an at sign [@]. ## You can use REM to create a zero-byte file if you use a redirection symbol immediately after the REM command. For example, to create the zero-byte file C:\FOO: c:\> rem>foo (This capability is included for compatibility with COMMAND.COM and CMD.EXE. A simpler method for creating a zero-byte file with 4DOS, 4OS2, or 4DOS/NT is to enter >filename as a command, with no actual command before the [>] redirection character.) ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 305 REN / RENAME ------------------------------------------------------------------- REN / RENAME (Enhanced) Purpose: Rename files or subdirectories. Format: REN [/A[[:][-]rhsda] /N /P /Q /S /T] old_name... new_name or RENAME [/A[[:][-]rhsda] /N /P /Q /S /T] old_name... new_name old_name: Original name of the file(s) or subdirectory. new_name: New name to use, or new path on the same drive. /A(ttribute select) /Q(uiet) /N(othing) /S(ubdirectory) /P(rompt) /T(otal) See also: COPY and MOVE. Selection: Supports extended wildcards, ranges, multiple file names, and include lists (see pages 59 - 67). Usage: REN and RENAME are synonyms. You may use either one. REN lets you change the name of a file or a subdirectory, or move one or more files to a new subdirectory on the same drive. (If you want to move files to a different drive, use MOVE.) In its simplest form, you simply give REN the old_name of an existing file or subdirectory and then a new_name. The new_name must not already exist - you can't give two files the same name (unless they are in different directories). The first example renames the file MEMO.TXT to MEM.TXT. The second example changes the name of the \WORD directory to \WP: c:\> rename memo.txt mem.txt c:\> rename \word \wp You can also use REN to rename a group of files that you specify with wildcards, as multiple files, or in an include list. When you do, the new_name must use one or more wildcards to show what part of each filename to change. Both of the next two examples change the extensions of multiple files to .SAV: ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 306 REN / RENAME ------------------------------------------------------------------- c:\> ren config.sys autoexec.bat 4start.btm *.sav c:\> ren *.txt *.sav REN can move files to a different subdirectory on the same drive. When it is used for this purpose, REN requires one or more filenames for the old_name and a directory name for the new_name: c:\> ren memo.txt \wp\memos\ c:\> ren oct.dat nov.dat \data\save\ The final backslash in the last two examples is optional. If you use it, you force REN to recognize the last argument as the name of a directory, not a file. The advantage of this approach is that if you accidentally mistype the directory name, REN will report an error instead of renaming your files in a way that you didn't intend. Finally, REN can move files to a new directory and change their name at the same time if you specify both a path and file name for new_name. In this example, the files are renamed with an extension of .SAV as they are moved to a new directory: c:\> ren *.dat \data\save\*.sav When new_name refers to a file or files (rather than a directory), the file(s) must not already exist. Also, you cannot rename a subdirectory to a new location on the directory tree. ## REN does not change a file's attributes. The new_name file(s) will have the same attributes as old_name. Options: ## /A(ttribute select): Rename only those files that have the specified attribute(s) set. Preceding the attribute character with a hyphen [-] will select files that do not have that attribute set. The attributes are: R Read-only D Subdirectory H Hidden A Archive S System If no attributes are listed at all (e.g., REN /A ...), REN will rename all files and subdirectories including hidden and system files. If attributes are combined, all the specified attributes must match for a file to be selected. For example, /A:RHS will select only ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 307 REN / RENAME ------------------------------------------------------------------- those files with all three attributes set. See page 18 for more information on file attributes. /N(othing): Do everything except actually rename the file(s). This option is useful for testing what a REN command will actually do. /P(rompt): Prompt the user to confirm each rename operation. Your options at the prompt are explained in detail on page 50. /Q(uiet): Don't display filenames or the number of files renamed. This option is most often used in batch files. See also /T. /S(ubdirectory): Normally, you can rename a subdirectory only if you do not use any wildcards in the new_name. This prevents subdirectories from being renamed inadvertently when a group of files is being renamed with wildcards. /S will let you rename a subdirectory even when you use wildcards. /T(otal): Don't display filenames as they are renamed, but report the number of files renamed. See also /Q. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 308 RETURN ------------------------------------------------------------------- RETURN (New) Purpose: Return from a GOSUB (subroutine) in a batch file. Format: RETURN See also: GOSUB. Usage: 4DOS, 4OS2, and 4DOS/NT allow subroutines in batch files. A subroutine begins with a label (a colon followed by a word) and ends with a RETURN command. The subroutine is invoked with a GOSUB command from another part of the batch file. When a RETURN command is encountered the subroutine terminates, and execution of the batch file continues on the line following the original GOSUB. The following batch file fragment calls a subroutine which displays the files in the current directory: echo Calling a subroutine gosub subr1 echo Returned from the subroutine quit :subr1 dir /a/w return ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 309 SCREEN ------------------------------------------------------------------- SCREEN (New) Purpose: Position the cursor on the screen and optionally display a message. Format: SCREEN row column [text] row: The new row location for the cursor. column: The new column location for the cursor. text: Optional text to display at the new cursor location. See also: ECHO, SCRPUT, TEXT, and VSCRPUT. Usage: SCREEN allows you to create attractive screen displays in batch files. You use it to specify where a message will appear on the screen. You can use SCREEN to create menu displays, logos, etc. The following batch file fragment displays a menu: @echo off cls screen 3 10 Select a number from 1 to 4: screen 6 20 1 - Word Processing screen 7 20 2 - Spreadsheet screen 8 20 3 - Telecommunications screen 9 20 4 - Quit SCREEN does not change the screen colors. If you have ANSI.SYS installed and have set colors with CLS or COLOR, those colors will be used for the display. To display text in specific colors, use SCRPUT or VSCRPUT. SCREEN always leaves the cursor at the end of the displayed text. The row and column values are zero-based, so on a standard 25 line by 80 column display, valid rows are 0 - 24 and valid columns are 0 - 79. You can also specify the row and column as offsets from the current cursor position. Begin the value with a plus sign [+] to move the cursor down the specified number of rows or to the right the specified number of columns, or with a minus sign [-] to move the cursor up or to the left. This example prints a string 3 lines above the current position, in absolute column 10: screen -3 10 Hello, World! ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 310 SCREEN ------------------------------------------------------------------- SCREEN checks for a valid row and column, and displays a "Usage" error message if either value is out of range. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 311 SCRPUT ------------------------------------------------------------------- SCRPUT (New) Purpose: Position text on the screen and display it in color. Format: SCRPUT row col [BRIght] [BLInk] fg ON [BRIght] bg text row: Starting row col: Starting column fg: Foreground character color bg: Background character color text: The text to display See also: CLS, ECHO, SCREEN, TEXT, and VSCRPUT. Usage: SCRPUT allows you to create attractive screen displays in batch files. You use it to specify where a message will appear on the screen and what colors will be used to display the message text. You can use SCRPUT to create menu displays, logos, etc. SCRPUT works like SCREEN, but allows you to specify the display colors. It writes directly to the screen and does not require ANSI support. It always leaves the cursor in its current position. See page 26 for details about colors and color names, and notes on the use of bright background colors. The row and column are zero-based, so on a standard 25 line by 80 column display, valid rows are 0 - 24 and valid columns are 0 - 79. You can also specify the row and column as offsets from the current cursor position. Begin the value with a plus sign [+] to move down the specified number of rows or to the right the specified number of columns, or with a minus sign [-] to move up or to the left. The following batch file fragment displays a menu in color: cls white on blue scrput 3 10 bri whi on blu Select an option: scrput 6 20 bri red on blu 1 - Word Processing scrput 7 20 bri yel on blu 2 - Spreadsheet scrput 8 20 bri gre on blu 3 - Communications scrput 9 20 bri mag on blu 4 - Quit 4DOS ## If you have an unusual display adapter which does not support the direct video output used by SCRPUT, see the OutputBIOS directive on page 150. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 312 SELECT ------------------------------------------------------------------- SELECT (New) Purpose: Interactively select files for a command. Format: SELECT [/A[:][-]rhsda /C[HP] /D /E /H /I"text" /O[:][-]acdeginrsu /Z] [command]... (files...)... command: The command to execute with the selected files. files: The files from which to select. File names may be enclosed in either parentheses or square brackets. The difference is explained below. /A(ttribute select) /H(ide dots) /C[HP] (Compression) /I (match descriptions) /D(isable color coding) /O(rder) /E (use upper case) /Z (use FAT format) Selection: Supports extended wildcards, ranges, multiple file names, and include lists (see pages 59 - 67). Date, time, or size ranges must appear immediately after the SELECT keyword. Usage: SELECT allows you to select files for internal and external commands by using a full-screen "point and shoot" display. You can have SELECT execute a command once for each file you select, or have it create a list of files for a command to work with. The command can be an internal command, an alias, an external command, or a batch file. If you use parentheses around the files, SELECT executes the command once for each file you have selected. During each execution, one of the selected files is passed to the command as an argument. If you use square brackets around files, the SELECTed files are combined into a single list, separated by spaces. The command is then executed once with the entire list presented as its command-line arguments. SELECT uses the cursor up, cursor down, PgUp, and PgDn keys to scroll through the file list. Press the L key to view the current highlighted file with LIST. When you exit from LIST, the SELECT screen will be restored. Use the + key or the spacebar to select a file (or unselect a marked file), and the - key to unselect a file. The * key will reverse all of the current marks ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 313 SELECT ------------------------------------------------------------------- (excluding subdirectories), and the / key will unmark everything. After marking the files, press Enter to execute the command. You can select a single file by moving the scroll bar to the filename and pressing Enter without marking any other files. To skip the files listed in the current display and go on to the next file specification inside the parentheses or brackets (if any), press the Esc key. To cancel the current SELECT command entirely, press Ctrl-C or Ctrl-Break. In the simplest form of SELECT, you merely specify the command and then the list of files from which you will make your selection(s). For example: c:\> select copy (*.com *.exe) a:\ will let you select from among the .COM and .EXE files on the current drive. It will then invoke the COPY command to copy each file you select to drive A:. You will be able to select first from a list of all .COM files in the current directory, and then from a list of all .EXE files. If you want to select from a list of all the .COM and .EXE files mixed together, create an include list inside the parentheses by inserting a semicolon (see page 67 for information on include lists): c:\> select copy (*.com;*.exe) a:\ Finally, if you want the SELECT command to send a single list of files to COPY, instead of invoking COPY once for each file you select, put the file names in square brackets instead of parentheses: c:\> select copy [*.com;*.exe] a:\ If you use brackets, you have to be sure that the resulting command (the word COPY, the list of files, and the destination drive in this example) is no more than 255 characters long for internal commands and no more than 127 characters long for external commands under 4DOS. The line length limit for 4OS2 and 4DOS/NT is 1,023 characters for both internal and external commands. The current line length is ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 314 SELECT ------------------------------------------------------------------- displayed by SELECT while you are marking files to help you to conform to these limits. The parentheses or brackets enclosing the file name(s) can appear anywhere within the command; SELECT assumes that the first set of parentheses or brackets it finds is the one containing the list of files from which you wish to make your selection. The list of files from which you wish to select can be further refined by using date, time, and size ranges (see page 62). The range must be placed immediately after the word SELECT. If the command is an internal command that supports ranges, an independent range can also be used in the command itself. ## If you don't specify a command, the selected filename(s) will become the command. For example, this command defines an alias called UTILS that selects from the executable files in the directory C:\UTIL, and then executes them in the order marked (enter the alias on one line): c:\> alias utils select (c:\util\*.com;*.exe;*.btm;*.bat) ## If you want to use filename completion (see page 41) to enter the filenames inside the parentheses, type a space after the opening parenthesis. Otherwise the command-line editor will treat the open parenthesis as the first character of the filename. ## You can set the default colors used by SELECT with the SelectColors and SelectStatBarColors directives in the .INI file (see page 141). If SelectColors is not used, the SELECT display will use the current default colors. If SelectStatBarColors is not used, the status bar will use the reverse of the SELECT display colors. You can display the filenames in color by setting the COLORDIR environment variable or using the ColorDir directive in your .INI file. See page 30 for details. To disable directory color coding within SELECT, use the /D option. When displaying descriptions, SELECT adds a right arrow at the end of the line if the description is too long to fit on the screen. This symbol will alert you to the existence of additional description text. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 315 SELECT ------------------------------------------------------------------- You can use the left and right arrow keys to scroll the screen horizontally and view the additional text. ## With the /I option, you can select files based on their descriptions. SELECT will display files if their description matches the text after the /I switch. The search is not case sensitive. You can use wildcards and extended wild cards as part of the text. ## When sorting file names and extensions for the SELECT display, 4DOS, 4OS2, and 4DOS/NT normally assume that sequences of digits should be sorted numerically (for example, the file DRAW2 would come before DRAW03 because 2 is numerically smaller than 03), rather than strictly alphabetically (where DRAW2 would come second because "2" comes after "0"). You can defeat this behavior and force a strict alphabetic sort with the /O:a option. 4DOS ## SELECT normally writes text directly to the screen. If you have an unusual display adapter which does not support direct video output, see the OutputBIOS directive on page 150. 4DOS ## ! If you receive a stack overflow error when using SELECT in complex, nested command sequences, see the notes under the StackSize directive on page 150. Options: ## /A(ttribute select): Display only those files that have the specified attribute set. Preceding the attribute character with a minus [-] will display files that do not have that attribute set. Attributes can also be combined. The attributes are: R Read-only D Subdirectory H Hidden A Archive S System If no attributes are listed at all (e.g., SELECT /A ...), SELECT will display all files and subdirectories including hidden and system files. If attributes are combined, all the specified attributes must match for a file to be included in the listing. For example, /A:RHS will display only those files with all three attributes set. See page 18 for more information on file attributes. 4DOS /C(ompression): Display compression ratios on compressed drives. The compression ratio is displayed ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 316 SELECT ------------------------------------------------------------------- instead of the file description. The ratio is left blank for directories, for files with a length of 0 bytes, and for files on non-compressed drives. See APPNOTES.DOC for a list of supported compression systems. Using /CH displays compression ratios like /C, but bases the calculation on the host drive's cluster size. This gives a more accurate picture of the space saved through compression than is given by /C. If /CP is used instead of /C, the compression is displayed as a percentage instead of a ratio. If /CHP is used instead of /CH, the host compression is displayed as a percentage. The /CHP option must be entered as shown; you can not use /CPH. See the DIR /C documentation on page 209 for more details on how compression ratios are calculated. ## /D(isable color coding): Temporarily turn off directory color coding within SELECT. /E (use upper case): Display filenames in the traditional upper case format; also see SETDOS /U and the UpperCase directive in the .INI file. /H(ide dots): Suppress the display of the "." and ".." directories. /I (match descriptions): Display filenames by matching text in their descriptions. The text can include wild cards and extended wildcards. The search text must be enclosed in quotation marks. /I will be ignored if /C or /O:c is also used. /O(rder): Set the sort order for the files. The order can be any combination of the following options: - Reverse the sort order for the next option a Sort names and extensions in standard ASCII order, rather than sorting numerically when digits are included in the name or extension c Sort by compression ratio (the least compressed file in the list will be displayed first). The compression ratios will be used as the basis of the sort and will also be displayed. If /O:c is used with /CH or /CHP, the sort will be based on the host-drive compression ratios. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 317 SELECT ------------------------------------------------------------------- d Sort by date and time (oldest first) e Sort by extension g Group subdirectories together i Sort by the file description (ignored if /C or /O:c is also used) n Sort by filename (this is the default) r Reverse the sort order for all options s Sort by size u Unsorted 4OS2, /Z: Display HPFS and NTFS filenames in FAT format. 4NT Long names will be truncated to 12 characters. If the name is longer than 12 characters, it will be followed by a right arrow to show that one or more characters have been truncated. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 318 SET ------------------------------------------------------------------- SET (Enhanced) Purpose: Display, create, modify, or delete environment variables. Format: SET [/M /P /R filename...] [name[=][value]] filename: The name of a file containing variable definitions. name: The name of the environment variable to define or modify. value: The new value for the variable. /M(aster) /R(ead from file) /P(ause) See also: ESET and UNSET. Usage: Every program and command inherits an environment, which is a list of variable names, each of which is followed by an equal sign and some text. Many programs use entries in the environment to modify their own actions. 4DOS, 4OS2, and 4DOS/NT use several environment variables (see page 98). See pages 21 and 96 for more information on the environment. If you simply type the SET command with no options or arguments, it will display all the names and values currently stored in the environment. Typically, you will see an entry called COMSPEC, an entry called PATH, an entry called CMDLINE, and whatever other environment variables you and your programs have established: c:\> set COMSPEC=C:\4DOS.COM PATH=C:\;C:\DOS;C:\UTIL CMDLINE=E:\UTIL\MAPMEM.EXE To add a variable to the environment, type SET, a space, the variable name, an equal sign, and the text: c:\> set mine=c:\finance\myfiles The variable name is converted to upper case by 4DOS and 4OS2 (for compatibility with CMD.EXE, 4DOS/NT does not shift variable names to upper case). The text after the equal sign will be left just as you entered ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 319 SET ------------------------------------------------------------------- it. If the variable already exists, its value will be replaced with the new text that you entered. ! Normally you should not put a space on either side of the equal sign. A space before the equal sign will become part of the name; a space after the equal sign will become part of the value. ! If you use SET to create a variable with the same name as one of the 4DOS, 4OS2, or 4DOS/NT internal variables (see page 100), you will disable the internal variable. If you later execute a batch file or alias that depends on that internal variable, it may not operate correctly. To display the contents of a single variable, type SET plus the variable name: c:\> set mine You can edit environment variables with the ESET command. To remove variables from the environment, use UNSET, or type SET plus a variable name and an equal sign: c:\> set mine= The variable name is limited to a maximum of 80 characters. Under 4DOS, the name and value together cannot be longer than 255 characters. In 4OS2 and 4DOS/NT, the maximum length for the name and value together is 1,023 characters. 4DOS ## Unless you use /M, SET only affects the environment of the current command processor and the programs it executes. If you EXIT to a parent command processor, the original environment will be unchanged. In 4DOS, the size of the environment is specified by the Environment and EnvFree directives in 4DOS.INI (see page 132) or by the /E: startup switch (see the 4DOS Introduction and Installation Guide). In 4OS2 and 4DOS/NT the size of the environment is set automatically. Options: ## /M(aster): Display or modify the master environment 4DOS rather than the local environment. This option only makes sense in a secondary shell. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 320 SET ------------------------------------------------------------------- /P(ause): Wait for a key to be pressed after each screen page before continuing the display. Your options at the prompt are explained in detail on page 50. ## /R(ead): Read environment variables from a file. This is much faster than loading variables from a batch file with multiple SET commands. Each entry in the file must fit within the command-line length limit for your command processor: 255 bytes for 4DOS and 1,023 bytes for 4OS2 and 4DOS/NT. The file is in the same format as the SET display, so SET /R can accept as input a file generated by redirecting SET output. For example, the following commands will save the environment variables to a file, and then reload them from that file: set > varlist set /r varlist You can load variables from multiple files by listing the filenames individually after the /R. You can add comments to a variable file by starting the comment line with a colon [:]. If you are creating a SET /R file by hand, and need to create an entry that spans multiple lines in the file, you can do so by terminating each line, except the last, with an escape character (see page 73). However, you cannot use this method to exceed the command-line length limit. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 321 SETDOS ------------------------------------------------------------------- SETDOS (New) Purpose: Display or set the 4DOS, 4OS2, or 4DOS/NT configuration. Format: SETDOS [/A? /B? /C? /D /E? /Fn.n /I+|- command /L? /M? /N? /P? /R? /S?:? /U? /V? /X[+|-]n /Y] /A(NSI) /N(o clobber) /B(right background) /P(arameter character) /C(ompound) /R(ows) /D(escriptions) /S(hape of cursor) /E(scape character) /U(pper case) /F(ormat for @EVAL) /V(erbose) /I(nternal commands) /X (expansion) /L(ine) /Y (single step) /M(ode for editing) Usage: SETDOS allows you to customize certain aspects of 4DOS, 4OS2, or 4DOS/NT to suit your personal tastes or the configuration of your system. Each of these options is described below. You can display the value of all SETDOS options by entering the SETDOS command with no parameters. Most of the SETDOS options can be initialized when the command processor executes the directives in the .INI file (see page 136). The name of the corresponding directive is listed in square brackets [ ] with each option below; if none is listed, that option cannot be set from the .INI file. You can also define the SETDOS options in your AUTOEXEC.BAT, 4START, or other startup file (see page 85), in aliases, or at the command line. Secondary shells automatically inherit most configuration settings currently in effect in the previous shell. If values have been changed by SETDOS since 4DOS, 4OS2, or 4DOS/NT started, the new values will be passed to the secondary shell. For details on inheritance of SETDOS values by secondary shells and their relationship to the .INI file, see page 129. SETDOS /I settings are not inherited by secondary shells. If you want to use SETDOS /I- to disable commands in all shells, place the SETDOS command(s) in your 4START file (see page 85), which is executed when any shell starts. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 322 SETDOS ------------------------------------------------------------------- Many of the options below are marked with ##. If you are a new user, skip these and read the /M, /S, and /U options, which are more common. Options: ## /A(NSI) [ANSI]: The ANSI option determines whether 4DOS will attempt to use ANSI escape sequences for the 4DOS CLS and COLOR commands. 4DOS normally determines this itself, but if you are using a non-standard ANSI driver or your loading sequence is unusual, you may need to explicitly inform 4DOS. /A0 allows 4DOS to determine automatically whether an ANSI driver is installed (the default). /A1 forces 4DOS to assume an ANSI driver is installed. /A2 forces 4DOS to assume an ANSI driver is not installed. See page 25 for more information on ANSI drivers. 4OS2 The /A(NSI) option and the corresponding ANSI directive are not available in 4OS2. ANSI support is automatically turned on by 4OS2, which assumes that it remains enabled. 4NT The /A(NSI) option and the corresponding ANSI directive are not available in 4DOS/NT because Windows NT does not provide ANSI support. 4DOS, /B(right background) [BrightBG]: The BRIGHTBG option 4OS2 determines whether 4DOS and 4OS2 configure your video adapter for blinking text (/B0, the default) or bright background colors (/B1). See page 26 for a detailed discussion of this option. ## /C(ompound character) [CommandSep]: The COMPOUND option sets the character used for separating multiple commands on the same line. The default is the caret [^] in 4DOS and the ampersand [&] in 4OS2 and 4DOS/NT. You cannot use any of the redirection characters (| > <), or the blank, tab, comma, or equal sign as the command separator. This example changes the COMPOUND character to a tilde [~]: c:\> setdos /c~ If you want to share batch files or aliases between 4DOS and 4OS2 or 4DOS/NT, see page 102 for information on the %+ variable, which retrieves the current command separator, and page 74 for details on using compatible command separators for all the products you use. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 323 SETDOS ------------------------------------------------------------------- ## /D(escriptions) [Descriptions]: The DESCRIPTIONS option controls whether file processing commands like COPY, DEL, MOVE, and REN process file descriptions along with the files they belong to. /D1 turns description processing on, which is the default. /D0 turns description processing off. ## /E(scape character) [EscapeChar]: The ESCAPE option sets the character used to suppress the normal meaning of the following character. Any character following the escape character will be passed unmodified to the command. The default escape character is Ctrl-X (ASCII 24, which appears on screen as an up-arrow) in 4DOS, and the caret [^] in 4OS2 and 4DOS/NT. You cannot use any of the redirection characters (| > <) or the blank, tab, comma, or equal sign as the escape character. Certain characters (b, c, e, f, n, r, s, and t) have special meanings when immediately preceded by the escape character. See page 73 for additional details on the escape character. If you want to share batch files or aliases between 4DOS and 4OS2 or 4DOS/NT, see page 102 for information on the %= variable, which retrieves the current escape character, and page 74 for details on using compatible escape characters for all the products you use. /F(ormat for @EVAL) [EvalMax, EvalMin]: The FORMAT option lets you set default decimal precision for the @EVAL variable function (see page 112). The maximum precision is 16 digits to the left of the decimal point and 8 digits to the right of the decimal point. By default, the minimum precision to the right of the decimal point is 0. The general form of this option is /Fx.y, where the x value sets the minimum number of digits to the right of the decimal place and the y value sets the maximum number of digits. Both values can range from 0 to 8; if x is greater than y, it is ignored. You can specify either or both values: /F2.5, /F2, and /F.5 are all valid entries. See the @EVAL function on page 112 if you want to set the precision for a single computation. ## /I(nternal): The INTERNAL option allows you to disable or enable internal commands. To disable a ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 324 SETDOS ------------------------------------------------------------------- command, precede the command name with a minus [-]. To re-enable a command, precede it with a plus [+]. For example, to disable the internal LIST command to force 4DOS to use an external command: c:\> setdos /i-list 4DOS, ## /L(ine) [LineInput]: The LINE option controls how 4OS2 4DOS or 4OS2 gets its input from the command line. /L0 tells the command processor to use character input (the default). /L1 tells it to use line input (like COMMAND.COM and CMD.EXE). /L1 will disable command- line editing, history recall, filename completion, and the directory history window, and will reduce the 4OS2 input length limit from 1023 characters to 255 characters. It should only be used if it is needed for compatibility with a specific program. If you have a program that requires line input, you can use the following line in an alias or batch file to change the line input option just for that single program (change the command separator to an ampersand [&] for 4OS2): setdos /L1 ^ program %& ^ setdos /L0 See APPNOTES.DOC (for 4DOS) or README.DOC (for 4OS2) for information on programs which require this option. /M(ode) [EditMode]: The MODE option controls the initial line editing mode. To start in overstrike mode at the beginning of each command line, use /M0 (the default). To start in insert mode, use /M1. ## /N(o clobber) [NoClobber]: The NOCLOBBER option controls output redirection (see page 52). /N0 means existing files will be overwritten by output redirection (with >) and that appending (with >>) does not require the file to exist already. This is the default. /N1 means existing files may not be overwritten by output redirection, and that when appending the output file must exist. A /N1 setting can be overridden with the [!] character. If you use /N1, you may have problems with a few unusual programs that shell out to run a command with redirection, and expect to be able to overwrite an existing file. ## /P(arameter character) [ParameterChar]: This option sets the character used after a percent sign to specify all or all remaining command-line arguments in a batch file or alias (e.g., %& or %n&; see pages 82 ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 325 SETDOS ------------------------------------------------------------------- and 168). The default is the ampersand [&] for 4DOS and the dollar sign [$] for 4OS2 and 4DOS/NT. If you want to share batch files or aliases between 4DOS and 4OS2 or 4DOS/NT, see page 74 for details on selecting compatible parameter characters for all the products you use. ## /R(ows) [ScreenRows]: The ROWS option sets the number of screen rows used by the video display. Normally 4DOS, 4OS2, and 4DOS/NT detect the screen size, but if you have a non-standard display you may need to set it explicitly. This option does not affect screen scrolling (that is controlled by your video driver or, under 4DOS, the BIOS or ANSI.SYS); it is used only for LIST, SELECT, the paged output options (i.e., TYPE /P), and error checking in the screen output commands. /S(hape) [CursorOver, CursorIns]: The SHAPE option sets the cursor shape. The format is /So:i where o is the cursor size for overstrike mode, i the cursor size for insert mode. The size is entered as a percentage of the total character height. The default values are 10:100 (an underscore cursor for overstrike mode, and a block cursor for insert mode). Because of the way video BIOSes and drivers remap the cursor shape, you may not get a smooth progression in the cursor size from 0% - 100%. To disable the cursor, enter /S0:0. If either value is -1, , the command processor will not attempt to modify the cursor shape at all. You can use this feature to give another program full control of the cursor shape. /U(pper) [UpperCase]: The UPPER option controls the default case (upper or lower) for file and directory names displayed by internal commands like COPY and DIR. /U0 displays file names in lower case (the default). /U1 displays file names in the traditional upper case. The /U setting is ignored for HPFS and NTFS filenames under 4OS2 and 4DOS/NT, and FAT filenames under Windows NT 3.5 and above. HPFS and NTFS names are always displayed in the case in which they are stored; see page 17 for more details. ## /V(erbose) [BatchEcho]: The VERBOSE option controls the default for command echoing in batch files. /V0 disables echoing of batch file commands unless ECHO is explicitly set ON. /V1, the default setting, enables ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 326 SETDOS ------------------------------------------------------------------- echoing of batch file commands unless ECHO is explicitly set OFF. /V2 forces echoing of all batch file commands, even if ECHO is set OFF or the line begins with an "@". This allows you to turn echoing on for a batch file without editing the batch file and removing the ECHO OFF command(s) within it. /V2 is intended for debugging, and can be set with SETDOS, but not with the BatchEcho directive in 4DOS.INI. For more information on batch file debugging see page 89, and /Y (below). ## /X[+|-]n (expansion and special characters): This option enables and disables alias and environment variable expansion, and controls whether special characters have their usual meaning or are treated as text. It is most often used in batch files to process text strings which may contain special characters. See page 91 for further details on string processing in batch files, and page 121 for details on alias expansion, variable expansion, and special characters. The features enabled or disabled by /X are numbered. All features are enabled when the command processor starts, and you can re-enable all features at any time by using /X0. To disable a particular feature, use /X-n, where n is the feature number from the list below. To re-enable the feature, use /X+n. To enable or disable multiple individual features, list their numbers in sequence after the + or - (e.g. /X-345 to disable features 3, 4, and 5). The features are: 1 All alias expansion. 2 Nested alias expansion only. 3 All variable expansion (includes environment variables, batch file parameters, and alias parameters). 4 Nested variable expansion only. 5 Multiple commands, conditional commands, and piping (affects the command separator, ||, &&, |, and |&). 6 Redirection (affects < , >, >&, >&>, etc.). 7 Quoting (affects back-quotes [`] and double quotes ["]). 8 Escape character. If nested alias expansion is disabled, the first alias of a command is expanded but any aliases it invokes ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 327 SETDOS ------------------------------------------------------------------- are not expanded. If nested variable expansion is disabled, each variable is expanded once, but variables containing the names of other variables are not expanded further. For example, to disable all features except alias expansion while you are processing a text file containing special characters: setdos /x-35678 ... [perform text processing here] setdos /x0 ## /Y (single step): /Y1 enables single-stepping through a batch file. Each command is displayed on the screen along with a Y/N/R (yes / no / remainder) prompt. Press Y to execute the command, N to omit the command and go on to the next, or R to execute the remainder of the batch file (up to the next SETDOS /Y1 command). You may also press Ctrl-C or Ctrl-Break to terminate the batch file. For more information on batch file debugging, see page 89, and /V (above). ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 328 SETLOCAL ------------------------------------------------------------------- SETLOCAL (New) Purpose: Save a copy of the current disk drive, directory, environment, and alias list. Format: SETLOCAL See also: ENDLOCAL. Usage: SETLOCAL is used in batch files to save the default disk drive and directory, the environment, and the alias list to a reserved block of memory. You can then change their values and later restore the original values with the ENDLOCAL command. For example, this batch file fragment saves everything, removes all aliases so that user aliases will not affect batch file commands, changes the disk and directory, modifies a variable, runs a program, and then restores the original values: setlocal unalias * cdd d:\test set path=c:\;c:\dos;c:\util rem run some program here endlocal SETLOCAL and ENDLOCAL are not nestable within a batch file. However, you can have multiple SETLOCAL / ENDLOCAL pairs within a batch file, and nested batch files can each have their own SETLOCAL / ENDLOCAL. You cannot use SETLOCAL in an alias or at the command line. An ENDLOCAL is performed automatically at the end of a batch file if you forget to do so. If you invoke one batch file from another without using CALL, the first batch file is terminated, and an automatic ENDLOCAL is performed. The second batch file inherits the drive, directory, aliases, and environment variables as they were prior to any unterminated SETLOCAL. 4DOS ! Do not load memory-resident programs (TSRs) from a batch file while SETLOCAL is in effect. If you do, when ENDLOCAL is executed and the memory used by SETLOCAL is released, a "hole" will be left in memory below the TSR. This is not usually harmful, but wastes memory. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 329 SHIFT ------------------------------------------------------------------- SHIFT (Enhanced) Purpose: Allows the use of more than 127 batch file parameters in a batch file. Format: SHIFT [n] n: Number of positions to shift. Usage: SHIFT is provided for compatibility with older batch files, where it was used to access more than 10 parameters. 4DOS, 4OS2, and 4DOS/NT support 128 parameters (%0 to %127), so you may not need to use SHIFT for batch files running exclusively under JP Software command processors. SHIFT moves each of the batch file parameters n positions to the left. The default value for n is 1. SHIFT 1 moves the parameter in %1 to position %0, the parameter in %2 becomes %1, etc. You can reverse a SHIFT by giving a negative value for n (i.e., after SHIFT -1, the former %0 is restored, %0 becomes %1, %1 becomes %2, etc.). SHIFT also affects the parameters %n& (command-line tail; %n$ in 4OS2 and 4DOS/NT) and %# (number of command arguments). For example, create a batch file called TEST.BAT: echo %1 %2 %3 %4 shift echo %1 %2 %3 %4 shift 2 echo %1 %2 %3 %4 shift -1 echo %1 %2 %3 %4 Executing TEST.BAT produces the following results: c:\> test one two three four five six seven one two three four two three four five four five six seven three four five six ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 330 START ------------------------------------------------------------------- START (New) Purpose: Start a program in another session or window. Format: The format for START depends on which command processor you are using (see the Options section below for additional minor differences in valid options under 4DOS and 4OS2): 4DOS, START ["program title"] [/B[G] /C /DOS[=optfile] /F[G] 4OS2 /FS /ICON=iconfile /INV /K /L /LA /LD /LH /MAX /MIN /N /PGM progname /PM /POS=row,col,width,height /WIN /WIN3[=optfile] /WIN3S[=optfile]] [command] 4NT START ["program title"] [/B /C /Dpath /HIGH /I /INV /K /L /LA /LD /LH /LOW /MAX /MIN /NORMAL /PGM progname /POS=row,col,width,height /REALTIME /SEPARATE /SIZE=rows,columns /WAIT] [command] program title: Title to appear on title bar. optfile: Option settings file. iconfile: Name of icon (.ICO) file. progname: Program name (not the session name). path: Startup directory. command: Command to be executed. /B (no new console) /LOW (priority) /B[G] (background ) /MAX(imized) /C(lose when done) /MIN(imized) /D(irectory) /N(o CMD.EXE) /DOS (DOS session) /NORMAL (priority) /F[G] (foreground ) /PGM (program name) /FS (full screen) /PM (PM application) /HIGH (priority) /POS(ition of window) /I(nherit environment) /REALTIME (priority) /ICON (name .ICO file) /SEPARATE (virtual machine) /INV(isible) /SIZE (of screen buffer) /K(eep when done) /WAIT (for session to finish) /L(ocal lists) /WIN(dowed session) /LA (local aliases) /WIN3 (enhanced mode) /LD (local dir history) /WIN3S (standard mode) /LH (local history list) See also: DETACH. Usage: START is used to begin a new OS/2 session or Windows NT window and, optionally, to run a program in that session or window. If you use START with no parameters, it will begin a new session or window. If ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 331 START ------------------------------------------------------------------- you add a command, START will begin a new session or window and execute that command. The program title, if it is included, will appear on the title bar, on the Presentation Manager task list (OS/2 version 1.x) or window list (OS/2 version 2.x), or on the task list and Alt-Tab displays (Windows NT). The program title must be enclosed in quotation marks and cannot exceed 60 characters in 4OS2 and 4DOS, or 127 characters in 4DOS/NT. If the program title is omitted, the program name will be used as the title. You can use START if you are running 4OS2, 4DOS/NT, or 4DOS in an OS/2 2.1 or later DOS session. START will not work when running 4DOS under DOS, or DOS plus Windows. Although the START command has the same purpose in 4DOS, 4OS2, and 4DOS/NT, there are several subtle differences between platforms. The 4DOS and 4OS2 versions of START are similar because both rely on the services of the OS/2 operating system. The 4DOS/NT version of START has different options available, partly to maintain compatibility with the START command in the Windows NT version of CMD.EXE, and partly because of the features of and limitations imposed by Windows NT. START offers a large number of switches to control the session you start. In most cases you need only a few switches to accomplish what you want. The list below summarizes the most commonly used START options, and how you can use them to control the way a session is started: /MAX, /MIN, and /POS allow you to start a character-mode windowed session in a maximized window, a minimized window, or a window with a specified position and size. The default is to let the operating environment choose the position and size of the window. /C allows you to close the session when the command is finished (the default for DOS, OS/2 Presentation Manager, and Windows NT graphical sessions); /K allows you to keep the session open and go to a prompt (the default for OS/2 and Windows NT character mode sessions). ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 332 START ------------------------------------------------------------------- 4OS2, /BG and /FG allow you to start the session in the 4DOS background (does not respond to keystrokes until selected) or foreground (responds to keystrokes until deselected). /FG is the default if /DOS, /FS, /WIN, or /PM is used; otherwise, /BG is the default. 4OS2, /FS and /WIN control whether a character-mode 4DOS session is started in full-screen or windowed mode. The default is to start a session of the same type as the current session, if the application can be run in such a session. 4OS2, Under 4OS2 and 4DOS/NT, START determines the 4NT application type automatically and starts the session in the appropriate mode: OS/2, Windows, DOS, full- screen, windowed, or Presentation Manager for OS/2; DOS, 16-bit Windows, 32-bit Windows, 32-bit Windows NT (both graphical and character mode), 16-bit OS/2 1.x character mode, or POSIX for Windows NT. START gives you some flexibility in determining the session mode. For example, if the command is the name of a batch file (either a .BTM or .CMD file), you can use the /FS or /WIN options to run the batch file as part of a new 4OS2 session in either full-screen or windowed mode. However, you cannot start a session in a mode that is inappropriate for the application type. A DOS application cannot be run as part of a Presentation Manager session, for example, even if you use the /PM switch. Invalid or conflicting options will be ignored. 4OS2 and 4DOS/NT will always attempt to run the command in the appropriate type of session. 4DOS The 4DOS START command is unable to determine the application type. If you don't specify the type on the command line, 4DOS will start a new OS/2 session to run it. 4OS2 ## If the program is a DOS application or .BAT file, 4OS2 will return an error message in OS/2 version 1.x. In OS/2 version 2.x, 4OS2 will start a new DOS session to run the program or batch file. The DOS session will close itself automatically as soon as the program or batch file ends, unless /K is used. If you want the session to wait for a keystroke before it closes itself, you can use the syntax: ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 333 START ------------------------------------------------------------------- [c:\] start /DOS command ^^ pause (Because the caret [^] is the default 4OS2 escape character, two carets must be used in order to pass one on to 4DOS as a command separator.) 4OS2, If you want to start a DOS command-line session in 4DOS OS/2 version 2.x, you can use the command: [c:\] start /DOS 4OS2, ! ## Under OS/2, you can specify settings for DOS and 4DOS Windows sessions by using a settings options file, and loading it with the /DOS=, /WIN3=, or /WIN3S= option. This allows you to start DOS and Windows sessions with specific settings without creating a desktop object and modifying the settings manually. Before using this capability you should read the description of it under /DOS= (below) very carefully, since errors in the settings file can occasionally hang your system. Options: Unlike most commands, the options below are not in strictly alphabetical order. Instead, they are divided first by product, then alphabetically. The following options are available in 4OS2, 4DOS/NT, and 4DOS: /C(lose): The session or window is closed when the application ends. /INV(isible): Start the session or window as invisible. No icon will appear and the session will only be accessible through the Task Manager or Window List. /K(eep session or window at end): The session or window continues after the application program ends. Use the EXIT command to end the session. /L(ocal lists): Start the command processor with local alias, history, and directory history lists. Under 4OS2 or 4DOS/NT, this option combines the effects of /LA, /LD, and /LH (below). /LA: Start the command processor with a local alias list. See page 169 for information on local and global aliases. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 334 START ------------------------------------------------------------------- /LD: Start the command processor with a local directory history list. See page 45 for information on local and global directory history. /LH: Start the command processor with a local history list. See page 39 for information on local and global history lists. /MAX(imized): Start the session or window maximized. /MIN(imized): Start the session or window minimized. /PGM: The string following this option is the program name. The first quoted string on the line will be used as the session and task list title, and not as the program name. /POS(ition): Start the window at the specified screen position. The syntax is /POS=row, col, width, height where the values are specified in pixels or pels. Under 4DOS and 4OS2, row and col refer to the position of the bottom left corner of the window relative to the bottom left corner of the screen. Under 4DOS/NT, row and col refer to the position of the top left corner of the window relative to the top left corner of the screen. 4OS2, The following options are available in 4OS2 and 4DOS, 4DOS but not in 4DOS/NT: /BG: The session is started as a background session. /BG may be abbreviated to /B. /DOS[=filename]: Start a DOS session under OS/2 version 2.x. This option is not available in OS/2 version 1.x, which doesn't allow multiple DOS sessions. If you include the =filename, OS/2 will load DOS settings from the specified file. This option is available only in the 32-bit version of 4OS2, and in 4DOS. ! Starting a session with specific DOS settings is an undocumented feature which was implemented within OS/2 with little error checking. It is ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 335 START ------------------------------------------------------------------- included in START because it substantially eases a complex task, but you must experiment carefully to ensure that the settings you select will work properly on the systems on which you plan to use them. Incorrect settings may be ignored, but they may also hang your session or stop the entire system. Be sure your experiments are not conducted while critical tasks are in process. Each line in the file must have a name, an equal sign [=], and a value. The names are those shown in OS/2's DOS Settings dialog box. Do not use spaces on either side of the equal sign. The names in the DOS Settings dialog box will vary depending on the device drivers and other settings in your CONFIG.SYS file, though many are available on all systems. You must ensure that the names you use are valid for the systems on which you use them. For example, if you replace IBM's COM.SYS and VCOM.SYS with different communications drivers, the COM_ settings will probably not be valid for the new drivers. If you have a settings file which contains settings defined by a particular driver, and use it on a system where the corresponding driver is not loaded, the results are undefined. The values in your settings file must be numeric for settings which show a numeric value under DOS Settings (e.g., DOS_FILES=30), and must be text strings for settings shown with a string (e.g., DOS_SHELL=C:\4DOS.COM C:\4DOS /P). Strings should be entered without trailing blanks. For values shown as multiple choice on the DOS Settings page you must specify a numeric value, typically "0" for Off and 1 for On (e.g., DOS_HIGH=1). Items with choices other than Off and On may use different values, or may not work at all; experimentation is usually required to find out what works. Attempting to use strings for choice items (e.g., DOS_HIGH=ON) will not work, and can hang your system. This is due to the internal operation of OS/2, and is not a problem in 4OS2 or 4DOS. A typical DOS settings file might look like this: DOS_FILES=30 DOS_HIGH=1 ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 336 START ------------------------------------------------------------------- DOS_SHELL=C:\4DOS\4DOS.COM C:\4DOS /P MOUSE_EXCLUSIVE_ACCESS=0 VIDEO_FASTPASTE=1 You can include comments in a settings file by beginning any line with a colon [:]. /FG: Start the session as the foreground session. /FG may be abbreviated to /F. /FS: Start the session as a full-screen session. /ICON=filename: Use the specified icon file. If you don't use /ICON, 4OS2 or 4DOS will look for an .ICO file with the same file name and in the same directory as the program file. Some versions of OS/2 may ignore this option and use the default icon for the session. If you encounter this problem, check whether an update to OS/2 has been released which addresses it. /N(o CMD.EXE): Under 4OS2, start an OS/2 program directly, without a command processor. The command cannot be an internal command or batch file. This is the default for PM applications. Under 4DOS, start a DOS program directly. /PM: Start a program in the PM session. /WIN(dowed): Start the session in a window. /WIN3[=filename]: Run the program in an enhanced-mode Windows 3.x session. The session will run seamless (on the OS/2 desktop) if started from 4OS2, or full-screen if started from 4DOS. (To start a Windows application in full- screen mode from 4OS2, use /FS rather than /WIN3). You can include an equal sign and the name of an options file to set options for the specific session and application (see /DOS= above for details). The setting names in the file should be taken from those shown in OS/2's WIN-OS/2 Settings dialog box. Available only in the 32-bit version of 4OS2, and in 4DOS. /WIN3S[=filename]: Equivalent to /WIN3, but runs the program in standard mode rather than enhanced mode. Available only in 4OS2/32 and 4DOS. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 337 START ------------------------------------------------------------------- 4OS2, The following options are available in 4OS2 and 4NT 4DOS/NT, but cannot be used under 4DOS: /I(nherit environment): Inherit the default environment specified in CONFIG.SYS, if any, rather than the current environment. /WAIT: Wait for the new session or window to finish before continuing. Cannot be used with /WIN3 or /WIN3S. 4NT The final group of options is only available under 4DOS/NT: /B: The program is started without creating a new window or console. /D(irectory): Specifies the startup directory. Include the directory immediately after the /D, with no intervening spaces or punctuation. /HIGH: Start the window at high priority. /LOW: Start the window at low priority. /NORMAL: Start the window at normal priority. /REALTIME: Start the window at realtime priority. /SEPARATE: Start a 16-bit Windows application in a separate virtual machine (Windows NT 3.5 and above only). /SIZE: Start the window with the specified screen buffer size. The full syntax is /SIZE=rows, columns, where rows is the number of text rows and columns is the number of text columns. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 338 [4DOS] SWAPPING ------------------------------------------------------------------- SWAPPING [4DOS] (New) Purpose: Enable or disable 4DOS swapping, or display the swapping state. Format: SWAPPING [ON | OFF] ## Usage: SWAPPING temporarily disables or enables the swapping of the transient portion of 4DOS to expanded memory, extended memory, to XMS or to disk (see page 134). Setting SWAPPING OFF is particularly useful for speeding up batch files (including AUTOEXEC.BAT) when 4DOS is using disk swapping. When you are running several small programs from a batch file, disk swapping can sometimes cause a noticeable delay. However, if you disable swapping, there will be about 128K less memory available for large application programs. The following batch file fragment disables swapping, runs several programs, and then re-enables swapping: swapping off c:\util\mouse c:\video\ansi.com cls bright white on blue c:\bin\cache.com swapping on If you enter SWAPPING with no arguments, 4DOS displays the current swapping type (XMS, EMS, Disk, or None) and state: c:\> swapping SWAPPING (XMS) is ON Setting SWAPPING OFF does not close the disk swap file or release any reserved EMS or XMS memory. You may have trouble if you load memory-resident programs (TSRs) with SWAPPING OFF and unload them with SWAPPING ON, or vice versa. Many TSRs expect the system to be in the same state when they unload that it was in when they loaded, and variation from this norm may cause the TSR to unload improperly or hang your system. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 339 TEE ------------------------------------------------------------------- TEE (New) Purpose: Copy standard input to both standard output and a file. Format: TEE [/A] file... file: One or more files that will receive the "tee-d" output. /A(ppend) See also: Y, and the redirection options (page 52). ## Usage: TEE is normally used to "split" the output of a program so that you can see it on the display and also save it in a file. It can also be used to capture intermediate output before the data is altered by another program or command. TEE gets its input from standard input (usually the piped output of another command or program), and sends out two copies: one goes to standard output, the other to the file or files that you specify. TEE is not likely to be useful with programs which do not use standard output, because these programs cannot send output through a pipe. See page 55 for more information on pipes. For example, to search the file DOC for any lines containing the string "4DOS", make a copy of the matching lines in 4.DAT, sort the lines, and write them to the output file 4D.DAT: c:\> find "4DOS" doc | tee 4.dat | sort > 4d.dat If you are typing at the keyboard to produce the input for TEE, you must enter a Ctrl-Z to terminate the input. 4DOS When using TEE with a pipe under 4DOS, the previous command writes its output to a temporary file. When that command finishes, TEE begins operation and can read the temporary file, display the output, and write it to the file(s) named in the TEE command. 4OS2, When using TEE with a pipe under 4OS2 or 4DOS/NT, the 4NT programs on the two ends of the pipe run simultaneously, not sequentially as in 4DOS. See page 56 for more information. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 340 TEE ------------------------------------------------------------------- Option: /A(ppend): Append the output to the file(s) rather than overwriting them. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 341 TEXT ------------------------------------------------------------------- TEXT (New) Purpose: Display a block of text in a batch file. Format: TEXT . . . ENDTEXT See also: ECHO, SCREEN, SCRPUT, and VSCRPUT. Usage: TEXT can only be used in batch files. The TEXT command is useful for displaying menus or multi-line messages. TEXT will display all subsequent lines in the batch file until terminated by ENDTEXT. Both TEXT and ENDTEXT must be entered as the only command on the line. To redirect the entire block of text, use redirection on the TEXT command itself, but not on the actual text lines or the ENDTEXT line. No environment variable expansion or other processing is performed on the lines between TEXT and ENDTEXT; they are displayed exactly as they are stored in the batch file. 4DOS, If you are running 4OS2, or 4DOS with an ANSI driver 4OS2 loaded, you can change screen colors by inserting ANSI escape sequences anywhere in the text block. This will not work in 4DOS/NT, because Windows NT does not provide ANSI support. You can also use a CLS or COLOR command in 4DOS, 4OS2, or 4DOS/NT to set the screen color before executing the TEXT command. The following batch file fragment displays a simple menu: @echo off cls screen 2 0 text Enter one of the following: 1 - Spreadsheet 2 - Word Processing 3 - DOS Utilities Enter your selection : endtext ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 342 TIME ------------------------------------------------------------------- TIME (Compatible) Purpose: Display or set the current system time. Format: TIME [hh[:mm[:ss]]] [AM | PM] hh: The hour (0 - 23). mm: The minute (0 - 59). ss: The second (0 - 59). See also: CHCP and DATE Usage: If you don't enter any parameters, TIME will display the current system time and prompt you for a new time. Press Enter if you don't wish to change the time; otherwise, enter the new time: c:\> time Wed Dec 22, 1993 9:30:10 New time (hh:mm:ss): TIME defaults to 24-hour format, but you can optionally enter the time in 12-hour format by appending "a", "am", "p", or "pm" to the time you enter. For example, to enter the time as 9:30 am: c:\> time 9:30 am The operating system adds the system time and date to the directory entry for every file you create or modify. If you keep both the time and date accurate, you will have a record of when you last updated each file. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 343 TIMER ------------------------------------------------------------------- TIMER (New) Purpose: TIMER is a system stopwatch. Format: TIMER [ON] [/1 /2 /3 /S] ON: Force the stopwatch to restart /1 (stopwatch #1) /3 (stopwatch #3) /2 (stopwatch #2) /S(plit) Usage: The TIMER command turns a system stopwatch on and off. When you first run TIMER, the stopwatch starts: c:\> timer Timer 1 on: 12:21:46 When you run TIMER again, the stopwatch stops and the elapsed time is displayed: c:\> timer Timer 1 off: 12:21:58 Elapsed time: 0:00:12.06 There are three stopwatches available (1, 2, and 3) so you can time multiple overlapping events. By default, TIMER uses stopwatch #1. TIMER is particularly useful for timing events in batch files. For example, to time both an entire batch file, and an intermediate section of the same file, you could use commands like this: rem Turn on timer 1 timer rem Do some work here rem Turn timer 2 on to time the next section timer /2 rem Do some more work echo Intermediate section completed rem Display time taken in intermediate section timer /2 rem Do some more work rem Now display the total time timer The smallest interval TIMER can measure depends on the operating system you are using, your hardware, and the interaction between the two. However, it should never be greater than .06 second. The largest interval is 23 hours, 59 minutes, 59.99 seconds. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 344 TIMER ------------------------------------------------------------------- Options: /1: Use timer #1 (the default). /2: Use timer #2. /3: Use timer #3. /S(plit): Display a split time without stopping the timer. To display the current elapsed time but leave the timer running: c:\> timer /s Timer 1 elapsed: 0:06:40.63 ON: Start the timer regardless of its previous state (on or off). Otherwise the TIMER command toggles the timer state (unless /S is used). ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 345 [4DOS/NT] TITLE ------------------------------------------------------------------- TITLE [4DOS/NT] (Compatible) Purpose: Change the window title. Format: TITLE "title" title: The new window title See also: ACTIVATE and WINDOW. Usage: TITLE changes the text that appears in the caption bar at the top of the 4DOS/NT window. It is included only for compatibility with CMD.EXE. You can also change the window title with the WINDOW command or the ACTIVATE command. The title text must be enclosed in double quotes. The quotes will not appear as part of the actual title. To change the title of the current window to "4DOS for Windows NT": [c:\] title "4DOS for Windows NT" ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 346 [4DOS] TRUENAME ------------------------------------------------------------------- TRUENAME [4DOS] (New) Purpose: Find the full, true path and file name for a file. Format: TRUENAME file file: The file whose name TRUENAME will report. See also: @TRUENAME variable function on page 119. Usage: Default directories, as well as the JOIN and SUBST external commands, can obscure the true name of a file. TRUENAME "sees through" these obstacles and reports the fully qualified name of a file. The following example uses TRUENAME to get the true pathname for a file: c:\> subst d: c:\util\test c:\> truename d:\test.exe c:\util\test\test.exe TRUENAME requires MS-DOS or PC-DOS 3.0 or above, DR DOS or Novell DOS 6.0 or above, or OS/2 version 2.0 or above. TRUENAME can handle simple drive substitutions such as those created by JOIN, SUBST, or most network drive mappings. However it may not be able to correctly determine the true name if you use "nested" JOIN or SUBST commands, or a network which does not report true names properly. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 347 TYPE ------------------------------------------------------------------- TYPE (Enhanced) Purpose: Display the contents of the specified file(s). Format: TYPE [/A[[:][-]rhsda] /L /P] file... file: The file or list of files that you want to display. /A(ttribute select) /P(ause) /L(ine numbers) See also: LIST. Selection: Supports extended wildcards, ranges, multiple file names, and include lists (see pages 59 - 67). Usage: The TYPE command displays a file. It is normally only useful for displaying ASCII text files. Executable files (.COM and .EXE) and many data files may be unreadable when displayed with TYPE because they include non-alphanumeric characters. To display the files MEMO1 and MEMO2: c:\> type /p memo1 memo2 You can press Ctrl-S to pause TYPE's display and then any key to continue. You will probably find LIST to be more useful for displaying files. However, the TYPE /L command used with redirection (see page 52) is useful if you want to add line numbers to a file. Options: ## /A(ttribute select): Select only those files that have the specified attribute(s) set. Preceding the attribute character with a hyphen [-] will select files that do not have that attribute set. The attributes are: R Read-only D Subdirectory H Hidden A Archive S System If no attributes are listed at all (e.g., TYPE /A ...), TYPE will select all files and subdirectories including hidden and system files. If attributes are combined, all the specified attributes must match for a file to be selected. For example, /A:RHS will ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 348 TYPE ------------------------------------------------------------------- select only those files with all three attributes set. See page 18 for more information on file attributes. /L(ine numbers): Display a line number preceding each line of text. /P(ause): Prompt after displaying each page. Your options at the prompt are explained in detail on page 50. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 349 UNALIAS ------------------------------------------------------------------- UNALIAS (New) Purpose: Remove aliases from the alias list. Format: UNALIAS [/Q] alias... or UNALIAS * alias: One or more aliases to remove from memory. /Q(uiet) See also: ALIAS and ESET. Usage: 4DOS, 4OS2, and 4DOS/NT maintain a list of the aliases that you have defined. The UNALIAS command will remove aliases from that list. You can remove one or more aliases by name, or you can delete the entire alias list by using the command UNALIAS *. For example, to remove the alias DDIR: c:\> unalias ddir To remove all the aliases: c:\> unalias * Options: /Q(uiet): Prevents UNALIAS from displaying an error message if one or more of the aliases does not exist. This option is most useful in batch files, for removing a group of aliases when some of the aliases may not have been defined. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 350 UNSET ------------------------------------------------------------------- UNSET (New) Purpose: Remove variables from the environment. Format: UNSET [/M /Q] name... or UNSET * name: One or more variables to remove from the environment. /M(aster environment) /Q(uiet) See also: ESET and SET. Usage: UNSET removes one or more variables from the environment. For example, to remove the variable CMDLINE: c:\> unset cmdline If you use the command UNSET *, all of the environment variables will be deleted: c:\> unset * UNSET is often used in conjunction with the SETLOCAL and ENDLOCAL commands in order to clear the environment of variables that may cause problems for some applications. For more information on environment variables, see the SET command and the general discussions on pages 21 and 96. ! Use caution when removing environment variables, and especially when using UNSET *. Many programs will not work properly without certain environment variables; for example, 4DOS depends on PATH and COMSPEC, and 4OS2 uses PATH and DPATH. Options: ## /M(aster): Remove the variable from the master 4DOS environment rather than the local environment. This option only makes sense if used in a secondary shell. /Q(uiet): Prevents UNSET from displaying an error message if one or more of the variables does not exist. This option is most useful in batch files, for removing a group of variables when some of the variables may not have been defined. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 351 VER ------------------------------------------------------------------- VER (Enhanced) Purpose: Display the current command processor and operating system versions. Format: VER [/R] /R(evision level) Usage: Version numbers consist of a one-digit major version number, a period, and a one- or two-digit minor version number. The VER command displays both version numbers: c:\> ver 4DOS 5.0 DOS 6.0 4DOS 4DOS's VER command will automatically detect OS/2 and DR DOS or Novell DOS and display the corresponding operating system name and version number. For example: c:\> ver 4DOS 5.0 OS/2 2.1 Option: /R(evision level): Display the command processor and operating system internal revision level (if any), plus your 4DOS, 4OS2, or 4DOS/NT serial number and registered name. Under 4DOS, /R also displays whether DOS is loaded into the high memory area (HMA), is resident in ROM, or is in normal base memory. This output is only meaningful in MS-DOS or PC-DOS version 5.0 or above or in an OS/2 2.x DOS session. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 352 VERIFY ------------------------------------------------------------------- VERIFY (Compatible) Purpose: Enable or disable disk write verification or display the verification state. Format: VERIFY [ON | OFF] Usage: DOS and OS/2 maintain an internal verify flag. When the flag is on, the operating system attempts to verify each disk write by making sure that the data written to the disk can be read back successfully into the computer. It does not compare the data written with the data actually placed on disk. 4NT Disk write verification cannot actually be enabled or disabled under Windows NT. 4DOS/NT supports VERIFY as a "do-nothing" command, for compatibility with CMD.EXE. This avoids "unknown command" errors in batch files which use the VERIFY command. The additional discussion below applies only to 4DOS and 4OS2, and not to 4DOS/NT. If used without any parameters, VERIFY will display the state of the verify flag: c:\> verify VERIFY is OFF VERIFY is off when the system boots up. Once it is turned on with the VERIFY ON command, it stays on until you use the VERIFY OFF command or until you reboot. Verification will slow your disk write operations slightly (the effect is not usually noticeable). ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 353 VOL ------------------------------------------------------------------- VOL (Enhanced) Purpose: Display disk volume label(s). Format: VOL [d:] ... d: The drive or drives to search for labels. Usage: Each disk may have a volume label, created when the disk is formatted or with the external LABEL command. Also, every floppy disk formatted with DOS version 4.0 or above, OS/2, or Windows NT has a volume serial number. The VOL command will display the volume label and, if available, the volume serial number of a disk volume. If the disk doesn't have a volume label, VOL will report that it is "unlabeled." If you don't specify a drive, VOL displays information about the current drive: c:\> vol Volume in drive C: is MYHARDDISK If available, the volume serial number will appear after the drive label or name. To display the disk labels for drives A and B: c:\> vol a: b: Volume in drive A: is unlabeled Volume in drive B: is BACKUP_2 ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 354 VSCRPUT ------------------------------------------------------------------- VSCRPUT (New) Purpose: Display text vertically in the specified color. Format: VSCRPUT row col [BRIght] [BLInk] fg ON [BRIght] bg text row: Starting row number. col: Starting column number. fg: Foreground text color. bg: Background text color. text: The text to display. See also: SCRPUT. Usage: VSCRPUT writes text vertically on the screen rather than horizontally. Like the SCRPUT command, it uses the colors you specify to write the text. VSCRPUT can be used for simple graphs and charts generated by batch files. It always leaves the cursor in its current position. See page 26 for details about colors and color names, and notes on the use of bright background colors. The row and column are zero-based, so on a standard 25 line by 80 column display, valid rows are 0 - 24 and valid columns are 0 - 79. You can also specify the row and column as offsets from the current cursor position. Begin the value with a plus sign [+] to move down the specified number of rows or to the right the specified number of columns before displaying text, or with a minus sign [-] to move up or to the left. The following batch file fragment displays an X and Y axis and labels them: cls bright white on blue drawhline 20 10 40 1 bright white on blue drawvline 2 10 19 1 bright white on blue scrput 21 20 bright red on blue X axis vscrput 8 9 bright red on blue Y axis VSCRPUT checks for a valid row and column, and displays a "Usage" error message if either value is out of range. 4DOS ## VSCRPUT normally writes text directly to the screen. If you have an unusual display adapter which does not ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 355 VSCRPUT ------------------------------------------------------------------- support direct video output, see the OutputBIOS directive on page 150. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 356 [4OS2, 4DOS/NT] WINDOW ------------------------------------------------------------------- WINDOW [4OS2, 4DOS/NT] (New) Purpose: Minimize or maximize the current window, restore the default window size, or change the window title. Format: WINDOW [MIN | MAX | RESTORE] [/POS=row,col,width, height] [/SIZE=rows,columns] ["title"] title: A new title for the window. /POS(ition) /SIZE (of screen buffer) See also: ACTIVATE and TITLE. Usage: WINDOW is used to control the appearance and title of the current window. WINDOW MIN reduces the window to an icon, WINDOW MAX enlarges it to its maximum size, and WINDOW RESTORE returns the window to its default size and location on the desktop. You can use the /POS option to set the location and size of the window on the desktop. The row and column values of the /POS option select the window's origin while the width and height values determine its size. If you specify a new title, the title text must be enclosed in double quotes. The quotes will not appear as part of the actual title. Options: /POS(ition): Set the window screen position and size. The syntax is /POS=row, col, width, height where the values are specified in pixels or pels. Under 4OS2, row and col refer to the position of the bottom left corner of the window relative to the bottom left corner of the screen. Under 4DOS/NT, row and col refer to the position of the top left corner of the window relative to the top left corner of the screen. /SIZE (of screen buffer): Specify the screen buffer size. The full syntax is /SIZE=rows, columns, where rows is the number of text rows and columns is the number of text columns. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 357 Y ------------------------------------------------------------------- Y (New) Purpose: Copy standard input to standard output, and then copy the specified file(s) to standard output. Format: Y file ... file: The file or list of files to send to standard output. See also: TEE. ## Usage: The Y command copies input from standard input (usually the keyboard) to standard output (usually the screen). Once the input ends, the named files are appended to standard output. For example, to get text from standard input, append the files MEMO1 and MEMO2 to it, and send the output to MEMOS: c:\> y memo1 memo2 > memos The Y command is most useful if you want to add redirected data to the beginning of a file instead of appending it to the end. For example, this command copies the output of DIR, followed by the contents of the file DIREND, to the file DIRALL: c:\> dir | y dirend > dirall If you are typing at the keyboard to produce input text for Y, you must enter a Ctrl-Z to terminate the input. ! When using Y with a pipe under 4OS2 or 4DOS/NT, you must take into account that the programs on the two ends of the pipe run simultaneously, not sequentially. 56 See page for more information. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 358 APPENDIX A / ERROR MESSAGES ------------------------------------------------------------------- APPENDIX A / ERROR MESSAGES This appendix lists error messages generated by 4DOS, 4OS2, and 4DOS/NT, and includes a recommended course of action for most errors. If you are unable to resolve the problem, look through your Introduction and Installation Guide for any additional troubleshooting recommendations, then contact JP Software for technical support (see page 7). Error messages relating to files are generally reports of errors returned by the operating system. You may find some of these messages (for example, "Access denied") vague enough that they are not always helpful. 4DOS, 4OS2, and 4DOS/NT include the file name in file error messages, but are often unable to determine a more accurate explanation of these errors. The message shown is the best information available based on the error codes returned by the operating system. For some errors you are instructed to "restart the session or reboot the system." This means that you should attempt to correct the error by closing and restarting the current session under OS/2, Windows NT, or a DOS task switcher or multitasker (including Windows). Under DOS without a multitasker or task switcher, you will probably have to reboot the system to correct the problem. The following list includes all error messages, in alphabetical order: 4DOS 4DOS internal stack overflow: You attempted to nest batch files or commands like DO, EXCEPT, FOR, IF, IFF, GLOBAL, or SELECT too deep, and 4DOS ran out of stack space. Restructure your command, alias, or batch file, or use the StackSize directive in 4DOS.INI to increase 4DOS's internal stack size. 4DOS 4DOS initialization error --: An error occurred during the 4DOS startup process. Look up the rest of the message in this list for a more specific explanation. 4DOS 4DOS server error --: An error occurred in communication between 4DOS's resident and transient portions. A more specific error message follows. 4DOS 4DOS swapping failed, loading in non-swapping mode: None of the swapping options worked, so 4DOS loaded in non-swapping mode, which requires about 128K more memory than swapping mode. Check your Swapping specification in 4DOS.INI, and/or free some XMS or EMS memory or disk space. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 359 APPENDIX A / ERROR MESSAGES ------------------------------------------------------------------- 4DOS 4DOS unrecoverable error XX: An error occurred in the resident portion of 4DOS. These errors will terminate secondary shells and, and may require you to reboot the system or restart the session if they occur during a primary shell or if 4DOS cannot continue. The error codes are: BI Bad function code. Contact JP Software. DI Same as Disk swap file corrupted. DR Same as Swap file read error. DS Same as Swap file seek error. EI Same as EMS mapping error. NS No number for new shell. You have started too many 4DOS secondary shells without properly exiting some of them, perhaps by closing DESQview windows rather than EXITing. Clean up any work in process and reboot the system or restart the session. PT Illegal process termination. Contact JP Software. TS Terminated inactive shell. Contact JP Software. XI Same as XMS move failed. Access denied: You tried to write to or erase a read-only file, rename a file or directory to an existing name, create a directory that already exists, remove a read-only directory or a directory with files or subdirectories still in it, or access a file in use by another program in a multitasking system. 4DOS Address table missing: Your 4DOS.COM file is invalid. If you used an executable file compression program on 4DOS.COM, the compression may not be compatible with 4DOS. Re-install 4DOS.COM from diskette, or download a new copy. Alias loop: An alias refers back to itself either directly or indirectly (i.e., a = b = a), or aliases are nested more than 16 deep. Correct your alias list. 4DOS Attempt to exit from root shell: Another program has probably destroyed a portion of 4DOS's memory. Reboot the system or restart the session; if the error persists, contact JP Software. Bad disk unit: Generally caused by a disk drive hardware failure. 4DOS Bad environment: The DOS environment has a bad structure, probably because a program destroyed 4DOS's master environment space. Reboot the system or restart the session. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 360 APPENDIX A / ERROR MESSAGES ------------------------------------------------------------------- Batch file missing: 4DOS, 4OS2, or 4DOS/NT can't find the batch (.BAT or .CMD) file it was running. It was either deleted, renamed, moved, or the disk was changed. Correct the problem and rerun the file. Can't copy file to itself: You cannot COPY or MOVE a file to itself. 4DOS, 4OS2, and 4DOS/NT perform full path and filename expansion before copying to ensure that files aren't inadvertently destroyed. Can't create: The command processor can't create the specified file. The disk may be full or write protected, or the file already exists and is read-only, or the root directory is full. Can't delete: The command processor can't delete the specified file or directory. The disk is probably write protected. Can't get directory: The command processor can't read the directory. The disk drive is probably not ready. Can't make directory entry: The command processor can't create the filename in the directory. This is usually caused by a full root directory. Create a subdirectory and move some of the files to it. Can't open: The command processor can't open the specified file. Either the file doesn't exist or the disk directory or File Allocation Table is damaged. Can't remove current directory: You attempted to remove the current directory, which the operating system does not allow. Change to the parent directory and try again. 4DOS Can't set up disk swap file: The disk swap file you specified cannot be opened. The path or drive is invalid, the disk is full, DOS is out of file handles, or there is a hardware problem. Check 4DOS.INI to be sure your Swapping directive is correct. Command line too long: A single command exceeded 255 characters in 4DOS or 1023 characters in 4OS2 or 4DOS/NT, or the entire command line exceeded 511 characters in 4DOS, or 2047 characters in 4OS2 or 4DOS/NT, during alias and variable expansion. Reduce the complexity of the command or use a batch file. Also check for an alias which refers back to itself either directly or indirectly. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 361 APPENDIX A / ERROR MESSAGES ------------------------------------------------------------------- Command only valid in batch file: You have tried to use a batch file command, like DO or GOSUB, from the command line or in an alias. A few commands can only be used in batch files (see the individual commands for details). 4DOS Command tail too long, truncated: A program attempted to pass a command in an improper format or a command longer than 126 characters to a 4DOS secondary shell. This is probably a bug in the program from which 4DOS was loaded. Contact the author of the program or JP Software for technical assistance. Contents lost before copy: COPY was appending files, and found one of the source files is the same as the target. That source file is skipped, and appending continues with the next file. Data error: The operating system can't read or write properly to the device. On a floppy drive, this error is usually caused by a defective floppy disk, dirty disk drive heads, or a misalignment between the heads on your drive and the drive on which the disk was created. On a hard drive, this error may indicate a drive that is too hot or too cold, or a hardware problem. Retry the operation; if it fails again, correct the hardware or diskette problem. Directory stack empty: POPD or DIRS can't find any entries in the directory stack. Disk is write protected: The disk cannot be written to. Check the disk and remove the write-protect tab or close the write-protect window if necessary. 4DOS Disk swap file corrupted: The 4DOS disk swapping file (4DOSSWAP.nnn or xxxxxxxx.4SW) has been moved, deleted, or damaged by another program. Reboot the system or restart the session. Drive not ready -- close door: The floppy disk drive door is open. Close the door and try again. 4DOS EMS deallocation failed: 4DOS can't deallocate EMS memory when exiting from a secondary shell. The EMS map has been corrupted or the memory area used by 4DOS or the EMS driver has been destroyed by a program. Clean up any work in process and reboot the system or restart the session. 4DOS EMS map save or restore failed: 4DOS cannot save or restore the EMS page map. The EMS map has been corrupted, memory has been destroyed by a program, or you have an incompatible EMS ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 362 APPENDIX A / ERROR MESSAGES ------------------------------------------------------------------- driver. If this error recurs, try another swapping method, update your EMS driver, or contact JP Software. 4DOS EMS mapping failed: 4DOS can't map EMS pages when swapping to or from EMS. The EMS map has been corrupted or the memory area used by the loader or the EMS driver has been destroyed by a program. Reboot the system or restart the session. Environment already saved: You have already saved the environment with a previous SETLOCAL command. You cannot nest SETLOCAL / ENDLOCAL pairs. Error in command-line directive: You used the //iniline option to place an .INI directive on the startup command line, or, under 4DOS, on the SHELL= line in CONFIG.SYS, but the directive is in error. A more specific error message follows. Error on line [nnnn] of [filename]: There is an error in your .INI file. The following message explains the error in more detail. Correct the line in error and restart the command processor for your change to take effect. Error reading: The operating system experienced an I/O error when reading from a device. This is usually caused by a bad disk, a device not ready, or a hardware error. Error writing: The operating system experienced an I/O error when writing to a device. This is usually caused by a full disk, a bad disk, a device not ready, or a hardware error. Exceeded batch nesting limit: You have attempted to nest batch files more than 10 levels deep. 4DOS Fatal error -- please reboot: 4DOS cannot continue due to the previous error. Reboot the system or restart the session. File Allocation Table bad: The operating system can't access the FAT on the specified disk. This can be caused by a bad disk, a hardware error, or an unusual software interaction. File exists: The requested output file already exists, and the command processor won't overwrite it. File is empty: You attempted to LIST a file with no data (a zero-byte file). File not found: 4DOS, 4OS2, or 4DOS/NT couldn't find the specified file. Check the spelling and path name. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 363 APPENDIX A / ERROR MESSAGES ------------------------------------------------------------------- General failure: This is usually a hardware problem, particularly a disk drive failure or a device not properly connected to a serial or parallel port. Try to correct the problem, or reboot and try again. Also see Data error above; the problems described there can sometimes cause a general failure rather than a data error. 4DOS I/O error in [filename], some directives may not have been processed: An I/O error occurred while reading your 4DOS.INI file. There may be a physical problem with data on the disk or a sharing error on a multitasking system. Check your 4DOS.INI file and try again. Infinite COPY or MOVE loop: You tried to COPY or MOVE a directory to one of its own subdirectories and used the /S switch, so the command would run forever. Correct the command and try again. Insufficient disk space: COPY or MOVE ran out of room on the destination drive. Remove some files and retry the operation. 4DOS Insufficient load space: There is not enough room in 4DOS's internal memory areas to include all of the options you requested in 4DOS.INI. Contact JP Software for assistance. 4DOS Internal DOS error: DOS encountered an internal bug and failed. Reboot the system. 4DOS Invalid AUTOEXEC filename: You specified an invalid path or filename for the AUTOEXEC file with the /P: startup switch, or with the DOS_AUTOEXEC setting in an OS/2 DOS session. The default name will be used instead. Correct the filename, then reboot the system or restart the session. Invalid character value: You gave an invalid value for a character directive in the .INI file. Invalid choice value: You gave an invalid value for a "choice" directive (one that accepts a choice from a list, like "Yes" or "No") in the .INI file. Invalid color: You gave an invalid value for a color directive in the .INI file. Invalid date: An invalid date was entered. Check the syntax and reenter. Invalid directive name: 4DOS, 4OS2, or 4DOS/NT can't recognize the name of a directive in your .INI file. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 364 APPENDIX A / ERROR MESSAGES ------------------------------------------------------------------- 4DOS Invalid DOS version: You need a newer version of DOS to execute the specified command. Invalid drive: A bad or non-existent disk drive was specified. 4DOS Invalid INI file path or name, file not processed: The path or name for the initialization file on the SHELL= line in CONFIG.SYS, or on the startup command line, is invalid. Correct the @d:\path\inifile option to name the correct file. Invalid key name: You tried to make an invalid key substitution in the .INI file, or you used an invalid key name in a keystroke alias or command. Correct the error and retry the operation. Invalid numeric [or character] value: You gave an invalid value for a numeric directive in the .INI file, or for a character directive in 4DOS.INI. Invalid parameter: The command processor didn't recognize a parameter. Check the syntax and spelling of the command you entered. Invalid path: The specified path does not exist. Check the disk specification and/or spelling. Invalid path or file name: You used an invalid path or filename in a directive in the .INI file. 4DOS Invalid startup switch, ignored: You passed 4DOS an invalid option on the SHELL= line in CONFIG.SYS or on the startup command line for a secondary shell. Correct the switch. 4DOS Invalid Swapping option or path: The swap type or disk swap path in the 4DOS.INI Swapping directive is invalid. 4DOS ignores the bad swap type or path and attempts to scan the rest of the Swapping specification for a valid option. Multiple errors in the Swapping directive will cause this message to repeat. Correct 4DOS.INI and reboot the system or restart the session. Invalid time: An invalid time was entered. Check the syntax and reenter. Keystroke substitution table full: 4DOS, 4OS2, or 4DOS/NT ran out of room to store keystroke substitutions entered in the .INI file. Reduce the number of key substitutions or contact JP Software for assistance. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 365 APPENDIX A / ERROR MESSAGES ------------------------------------------------------------------- 4DOS KSTACK.COM not loaded: You attempted to execute a KEYSTACK command without loading KSTACK.COM. See the KEYSTACK command for more information. Label not found: A GOTO or GOSUB referred to a non-existent label. Check your batch file. 4DOS Memory [allocation | deallocation] error: 4DOS can't allocate or deallocate memory while loading, or while reserving or releasing memory for internal use. DOS memory allocation has been corrupted, or another application has reserved memory incorrectly. Reboot the system or restart the session. 4DOS Memory destroyed: The DOS memory control blocks have been corrupted. Reboot the system or restart the session. Missing ENDTEXT: A TEXT command is missing a matching ENDTEXT. Check the batch file. Missing GOSUB: The command processor cannot perform the RETURN command in a batch file. You tried to do a RETURN without a GOSUB, or your batch file has been corrupted. Missing SETLOCAL: An ENDLOCAL was used without a matching SETLOCAL. No aliases defined: You tried to display aliases but no aliases have been defined. No closing quote: 4DOS, 4OS2, or 4DOS/NT couldn't find a second matching back-quote [`] or double-quote ["] on the command line. No expression: The expression passed to the %@EVAL variable function is empty. Correct the expression and retry the operation. 4DOS No file handle available: This is an internal 4DOS disk swapping error. Change to another swapping method if possible, and contact JP Software. No room for INI file name: 4DOS, 4OS2, or 4DOS/NT does not have enough space to pass the name of your .INI file to secondary shells; see String area overflow for more details. Any [Secondary] section in 4DOS.INI will be ignored in secondary shells until the problem is corrected and the system or session is restarted. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 366 APPENDIX A / ERROR MESSAGES ------------------------------------------------------------------- 4DOS No UMBs; loading low: The LOADHIGH (or LH) command can't find any UMBs for your program. The program is loaded into base memory. LH and LOADHIGH only work with MS-DOS 5.0 and above, when the DOS=UMB directive is included in CONFIG.SYS and sufficient upper memory space is available for the program. 4DOS No upper memory available, low memory will be used for [resident portion | master environment | global aliases | global history]: You asked 4DOS to load the block of memory named in the message into a UMB via the corresponding directive in 4DOS.INI (UMBLoad, UMBEnvironment, etc.), but no UMB was available. Check that your XMS driver is properly installed and/or free up some UMB space in use by another program. 4DOS Non-DOS disk: DOS can't read the disk. Either the disk is bad, or it has been formatted by a different operating system. Reformat it as a DOS disk. Also see Data error above; the problems described there can sometimes cause a non-DOS disk error rather than a data error. Not an alias: The specified alias is not in the alias list. Not in environment: The specified variable is not in the environment. 4DOS Not in swapping mode: You attempted to turn swapping on or off with the SWAPPING command, but 4DOS is loaded in non- swapping mode. Not ready: The specified device can't be accessed. Not same device: This error usually appears in RENAME. You cannot rename a file to a different disk drive. 4DOS Out of environment/alias space: 4DOS has run out of space for environment variables or aliases. Edit the SHELL line in CONFIG.SYS or the Environment directive in 4DOS.INI to increase the environment size, or the Alias directive in 4DOS.INI to increase the alias list size. Out of memory: The command processor or the operating system had insufficient memory to execute the last command, or under DOS, the memory control blocks have been destroyed. If this error occurs in a 4DOS secondary shell, return to the primary shell before running the command. Otherwise, try to free some memory by removing memory-resident programs (under DOS), or closing other sessions (under OS/2 and Windows NT). If the error persists, contact JP Software for assistance. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 367 APPENDIX A / ERROR MESSAGES ------------------------------------------------------------------- 4DOS Under 4DOS, if the base memory (DOS RAM) figures reported by MEMORY are unreasonable, the memory control blocks have probably been destroyed and you must reboot the system or restart the session. If you receive this error from DIR when MEMORY shows sufficient memory for the directory you are displaying, memory has probably been "fragmented," and contains a free area larger than 8K but not large enough for the entire directory. Use a memory mapping program like PMAP, MAPMEM, or the DOS MEM utility to locate the fragmentation, and experiment with your TSRs and applications to determine and remove its cause. Out of paper: The operating system detected an out-of-paper condition on one of the printers (LPT1, LPT2, or LPT3). Check your printer and add paper if necessary. Overflow: An arithmetic overflow occurred in the %@EVAL variable function. Check the values being passed to %@EVAL. %@EVAL can handle 16 digits to the left of the decimal point and 8 to the right. Read error: The operating system encountered a disk read error; usually caused by a bad or unformatted disk. 4DOS Region unavailable, using first available region for [resident portion | master environment | global aliases | global history]: You used a 4DOS.INI directive to load the block of memory named in the message into a specific UMB region, but that region was unavailable. Check the use of upper memory for device drivers and other programs loaded before 4DOS, and/or change the requested region number. Sector not found: BIOS disk error, usually caused by a bad or unformatted disk. Seek error: The operating system can't seek to the proper location on the disk. This is generally caused by a bad disk or drive. Sharing violation: You tried to access a file in use by another program in a multitasking system or on a network. Wait for the file to become available, or change your method of operation so that another program does not have the file open while you are trying to use it. String area overflow: The command processor ran out of room to store the text from string directives in the .INI file. Reduce the complexity of the .INI file or contact JP Software for assistance. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 368 APPENDIX A / ERROR MESSAGES ------------------------------------------------------------------- 4DOS Swap file [seek | read | write] failed: 4DOS encountered an I/O error while accessing the disk swap file (4DOSSWAP.nnn or xxxxxxx.4SW). The disk was changed, the file has been destroyed by a program, or 4DOS's memory area has been overwritten by another program. Reboot the system or restart the session. Syntax error: A command or variable function was entered in an improper format. Check the syntax and correct the error. 4DOS Syntax error in region number or size: You specified an invalid region number or size in the LH or LOADHIGH command. Correct the command. 4DOS Too many DR DOS SETs in CONFIG.SYS: The SET commands in your DR DOS or Novell DOS CONFIG.SYS file exceeded the size of 4DOS's buffer area. Reduce the length of the commands or contact JP Software for assistance. 4DOS, Too many open files: DOS or OS/2 has run out of file handles. Try increasing the 4OS2 FILES setting in CONFIG.SYS. 4DOS Transient memory [allocation | deallocation] error: 4DOS could not reserve or release memory for its transient portion (probably in a SWAPPING OFF or SWAPPING ON command). The memory control blocks have been destroyed, or a program has fragmented memory. Reboot the system or restart the session. Unbalanced parentheses: The number of left and right parentheses did not match in an expression passed to the %@EVAL variable function. Correct the expression and retry the operation. Unknown command: A command was entered that 4DOS, 4OS2, or 4DOS/NT didn't recognize and couldn't find in the current search path. Check the spelling or PATH specification. You can handle unknown commands with the UNKNOWN_CMD alias (see 171 page ). Variable loop: A nested environment variable refers to itself, or variables are nested more than 16 deep. Correct the error and retry the command. 4OS2, Window title not found: The ACTIVATE or WINDOW command cannot find a 4NT window with the title you specified. Correct the command and try again. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 369 APPENDIX A / ERROR MESSAGES ------------------------------------------------------------------- Write error: The operating system encountered a disk write error; usually caused by a bad or unformatted disk. 4DOS XMS deallocation failed: 4DOS could not deallocate XMS memory when exiting a secondary shell. XMS memory has been destroyed; reboot the system or restart the session. 4DOS XMS move failed: 4DOS could not move data between base memory and XMS memory while swapping itself. XMS memory has been destroyed; reboot the system or restart the session. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 370 APPENDIX B / ASCII AND KEY CODES ------------------------------------------------------------------- APPENDIX B / ASCII AND KEY CODES The tables in this section are based on U.S. English conventions. Your system may differ if it is configured for a different country or language. See your operating system documentation for more information about country and language support. ASCII To represent the text you type, computers must translate each letter to and from a number. The code used by all PC- compatible computers for this translation is called ASCII (American Standard Code for Information Interchange). Function keys, cursor keys, and Alt keys do not generate ASCII codes. For details on these keys and a reference table, see Keys and Key Codes later in this Appendix. The ASCII table on the following pages is in three parts. Each part is described below. The first two parts cover the 128 standard ASCII characters; the third covers the 128 extended ASCII characters used on the IBM PC and compatible computers. All the tables include a Char column showing the visual representation of the character, a Dec column showing the decimal numeric value of the character in the ASCII set, and a Hex column showing the hexadecimal (base-16) value. ASCII Control Characters have numeric values between 0 and 31, and include non-printing characters like carriage return and line feed. The ASCII standard does not define a visual representation for these characters, but the IBM PC character set does define one for most control characters as shown in the Char column of the table. You can enter these characters using the key combination shown in the Ctrl column, with a caret [^] representing the Ctrl key. For example, to enter character 4, the diamond symbol (^D), press the Ctrl and D keys together. You can also enter control characters with the Alt key and the numeric keypad, like extended ASCII codes (see below). The Name column shows a two or three character "name" given to each control character as part of the ASCII standard. ASCII Printing Characters have numeric values between 32 and 127, and include the entire English-language character set as well as punctuation and other special marks. You enter these characters by pressing the corresponding keyboard key. Character 127 has no keyboard key, but can be entered on many systems by typing Ctrl-Backspace. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 371 APPENDIX B / ASCII AND KEY CODES ------------------------------------------------------------------- Extended ASCII Characters have values between 128 and 255 and include international language characters, line-drawing characters, and other symbols. You can enter extended ASCII codes (or other character codes) on the keyboard by holding down the Alt key, entering the decimal numeric value of the key on the numeric keypad, and then releasing the Alt key. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 372 APPENDIX B / ASCII AND KEY CODES ------------------------------------------------------------------- ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 373 APPENDIX B / ASCII AND KEY CODES ------------------------------------------------------------------- ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 374 APPENDIX B / ASCII AND KEY CODES ------------------------------------------------------------------- Keys and Key Codes When you press a single key or a key combination, software built into your computer (the BIOS or Basic Input / Output System) translates your keystroke into two numbers: a scan code, representing the actual key that was pressed, and an ASCII code, representing the ASCII value for that key. The BIOS returns these numbers the next time a program requests keyboard input. This section explains how key codes work; for information on using them with 4DOS, 4OS2, and 4DOS/NT see the .INI file (page 143), keystroke aliases (page 165), INKEY 259 (page ), and KEYSTACK (page 266). Most 4DOS, 4OS2, and 4DOS/NT commands that use the numeric key codes listed here also use key names, which are usually more convenient to use than the numeric codes. See page 31 for more information on key names. As PCs have evolved, the structure of keyboard codes has evolved somewhat haphazardly with them, resulting in a bewildering array of possible key codes. We'll give you a basic explanation of how key codes work. For a more in-depth discussion, refer to a BIOS or PC hardware reference manual. The nuances of how your keyboard behaves depends on the keyboard manufacturer, the computer manufacturer who provides the built-in BIOS, and your operating system. As a result, we can't guarantee the accuracy of the information below for every system, but the discussion and reference table should be accurate for most systems. Our discussion is based on the 101-key "enhanced" keyboard commonly used on 286, 386, 486, and Pentium computers, but virtually all of it is applicable to the 84-key keyboards on older systems. The primary difference is that older keyboards lack a separate cursor pad and only have 10 function keys. All keys have a scan code, but not all have an ASCII code. For example, function keys and cursor keys are not part of the ASCII character set (see page 371) and have no ASCII value, but they do have a scan code. Some keys have more than one ASCII code. The A, for example, has ASCII code 97 (lower case "a") if you press it by itself. If you press it along with Shift, the ASCII code changes to 65 (upper case "A"). If you press Ctrl and A the ASCII code changes to 1. In all these cases, the scan code (30) is unchanged because you are pressing the same physical key. Things are different if you press Alt-A. Alt keystrokes have no ASCII code, so the BIOS returns an ASCII code of 0, along ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 375 APPENDIX B / ASCII AND KEY CODES ------------------------------------------------------------------- with the A key's scan code of 30. This allows a program to detect all the possible variations of A, based on the combination of ASCII code and scan code. Some keys generate more than one scan code depending on whether Shift, Ctrl, or Alt is pressed. This allows a program to differentiate between two different keystrokes on the same key, neither of which has a corresponding ASCII value. For example, F1 has no ASCII value so it returns an ASCII code of 0, and the F1 scan code of 59. Shift-F1 also returns an ASCII code 0; if it also returned a scan code of 59, a program couldn't distinguish it from F1. The BIOS or operating system translates scan codes for keys like Shift-F1 (and Ctrl-F1 and Alt-F1) so that each variation returns a different scan code along with an ASCII code of 0. On the 101-key keyboard there's one more variation: non-ASCII keys on the cursor keypad (such as up-arrow) return the same scan code as the corresponding key on the numeric keypad, for compatibility reasons. If they also returned an ASCII code of 0, a program couldn't tell which key was pressed. Therefore, these keys return an ASCII code of 224 rather than 0. This means that older programs, which only look for an ASCII 0 to indicate a non-ASCII keystroke like up-arrow, may not detect these cursor pad keys properly. The number of different codes returned by any given key varies from one (for the spacebar) to four, depending on the key, the design of your keyboard, and the BIOS or operating system. Some keys, like Alt, Ctrl, and Shift by themselves or in combination with each other, plus Print Screen, SysReq, Scroll Lock, Pause, Break, Num Lock, and Caps Lock keys, do not have any code representations at all. The same is true of keystrokes with more than one modifying key, like Ctrl-Shift- A. The BIOS or operating system may perform special actions automatically when you press these keys (for example, it switches into Caps Lock mode when you press Caps Lock), but it does not report the keystrokes to whatever program is running. Programs which detect such keystrokes access the keyboard hardware directly, a subject which is beyond the scope of this manual. The following table lists all of the keys on the 101-key "enhanced" keyboard. The keys are arranged roughly in scan code order, which is generally left to right, moving from the top of the keyboard to the bottom. Column 1 shows the key's keycap symbol or name. Columns 2 and 3 show the scan code, and the ASCII code if the key is unshifted. Columns 4 and 5 contain the codes for the shifted ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 376 APPENDIX B / ASCII AND KEY CODES ------------------------------------------------------------------- key. Columns 6 and 7 show the codes for Ctrl plus the key. The last column contains the scan code for Alt plus the key (Alt keystrokes have no ASCII code and always generate an ASCII code of 0, which is not shown). Key names prefaced by np are on the numeric keypad. Those prefaced by cp are on the cursor keypad between the main typing keys and the number keypad. The numeric keypad values are valid if Num Lock is turned off. If you need to specify a number key from the numeric keypad, use the scan code shown for the keypad and the ASCII code shown for the corresponding typewriter key. For example, the keypad "7" has a scan code of 71 (the np Home scan code) and an ASCII code of 54 (the ASCII code for "7"). The chart is blank for key combinations that are not reported at all by the BIOS, like Ctrl-1 and Alt-PgUp. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 377 APPENDIX B / ASCII AND KEY CODES ------------------------------------------------------------------- Scan Codes and Key Codes for Top Two Keyboard Rows Shift Shift Ctrl Ctrl Alt Key Cap Scan ASCII Scan ASCII Scan ASCII Scan Symbol Code Code Code Code Code Code Code Esc 1 27 1 27 1 27 1 1 ! 2 49 2 33 120 2 @ 3 50 3 64 3 0 121 3 # 4 51 4 35 122 4 $ 5 52 5 36 123 5 % 6 53 6 37 124 6 ^ 7 54 7 94 7 30 125 7 & 8 55 8 38 126 8 * 9 56 9 42 127 9 ( 10 57 10 40 128 0 ) 11 48 11 41 129 - _ 12 45 12 95 12 31 130 = + 13 61 13 43 131 Backspace 14 8 14 8 14 127 14 Tab 15 9 15 0 148 0 165 Q 16 113 16 81 16 17 16 W 17 119 17 87 17 23 17 E 18 101 18 69 18 5 18 R 19 114 19 82 19 18 19 T 20 116 20 84 20 20 20 Y 21 121 21 89 21 25 21 U 22 117 22 85 22 21 22 I 23 105 23 73 23 9 23 O 24 111 24 79 24 15 24 P 25 112 25 80 25 16 25 [ { 26 91 26 123 26 27 26 ] } 27 93 27 125 27 29 27 Enter 28 13 28 13 28 10 28 ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 378 APPENDIX B / ASCII AND KEY CODES ------------------------------------------------------------------- Scan Codes and Key Codes for Bottom Two Keyboard Rows Shift Shift Ctrl Ctrl Alt Key Cap Scan ASCII Scan ASCII Scan ASCII Scan Symbol Code Code Code Code Code Code Code A 30 97 30 65 30 1 30 S 31 115 31 83 31 19 31 D 32 100 32 68 32 4 32 F 33 102 33 70 33 6 33 G 34 103 34 71 34 7 34 H 35 104 35 72 35 8 35 J 36 106 36 74 36 10 36 K 37 107 37 75 37 11 37 L 38 108 38 76 38 12 38 ; : 39 59 39 58 39 ' " 40 39 40 34 40 ` ~ 41 96 41 126 41 \ | 43 92 43 124 43 28 43 Z 44 122 44 90 44 26 44 X 45 120 45 88 45 24 45 C 46 99 46 67 46 3 46 V 47 118 47 86 47 22 47 B 48 98 48 66 48 2 48 N 49 110 49 78 49 14 49 M 50 109 50 77 50 13 50 , < 51 44 51 60 51 . > 52 46 52 62 52 / ? 53 47 53 63 53 Space 57 32 57 32 57 32 57 ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 379 APPENDIX B / ASCII AND KEY CODES ------------------------------------------------------------------- Scan Codes and Key Codes for Key Pads and Function Keys Shift Shift Ctrl Ctrl Alt Key Cap Scan ASCII Scan ASCII Scan ASCII Scan Symbol Code Code Code Code Code Code Code F1 59 0 84 0 94 0 104 F2 60 0 85 0 95 0 105 F3 61 0 86 0 96 0 106 F4 62 0 87 0 97 0 107 F5 63 0 88 0 98 0 108 F6 64 0 89 0 99 0 109 F7 65 0 90 0 100 0 110 F8 66 0 91 0 101 0 111 F9 67 0 92 0 102 0 112 F10 68 0 93 0 103 0 113 F11 133 0 135 0 137 0 139 F12 134 0 136 0 138 0 140 np * 55 42 55 42 150 0 55 np Home 71 0 71 55 119 0 cp Home 71 224 71 224 119 224 151 np Up 72 0 72 56 141 0 cp Up 72 224 72 224 141 224 152 np PgUp 73 0 73 57 132 0 cp PgUp 73 224 73 224 132 224 153 np Minus 74 45 74 45 142 0 74 np Left 75 0 75 52 115 0 cp Left 75 224 75 224 115 224 155 np 5 76 0 76 53 143 0 np Right 77 0 77 54 116 0 cp Right 77 224 77 224 116 224 157 np Plus 78 43 78 43 144 0 78 np End 79 0 79 49 117 0 cp End 79 224 79 224 117 224 159 np Down 80 0 80 50 145 0 cp Down 80 224 80 224 145 224 160 np PgDn 81 0 81 51 118 0 cp PgDn 81 224 81 224 118 224 161 np Ins 82 0 82 48 146 0 cp Ins 82 224 82 224 146 224 162 np Del 83 0 83 46 147 0 cp Del 83 224 83 224 147 224 163 np / 224 47 224 47 149 0 164 np Enter 224 13 224 13 224 10 166 ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 380 GLOSSARY ------------------------------------------------------------------- GLOSSARY Some items in this glossary refer to features or to terms which are discussed in more detail elsewhere in this manual. Be sure to check the index to see if more information is available on a particular feature or term. 4EXIT: A batch file which is executed whenever a secondary 4DOS, 4OS2, or 4DOS/NT shell ends. 4START: A batch file which is executed whenever 4DOS, 4OS2, or 4DOS/NT is started, either as a primary shell or a secondary shell. Alias: A shorthand name for a command or series of commands. Alias Parameter: A numbered variable (e.g. %2) included in an alias definition, allowing a different value to be used in the alias each time it is executed. AND: A logical combination of two true or false conditions. If both conditions are true, the result is true; if either condition is false, the result is false. ANSI.SYS: A device driver supplied with DOS which provides enhanced screen display and keyboard macros, or one of the many similar programs. APM: A standardized system used by manufacturers of battery- powered computers to report battery status and control power management features. Append: Concatenation of one file or string onto the end of another (this use is not related to the DOS and OS/2 external command named APPEND). Application: A program run from the command prompt or a batch file. Used broadly to mean any program other than the command processor; and more narrowly to mean a program with a specific purpose such as a spreadsheet or word processing program, as opposed to a utility. Archive: A file attribute indicating that the file has been modified since the last backup (most backup programs clear this attribute). Also sometimes refers to a single file (such as a .ZIP file) which contains a number of other files in compressed form. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 381 GLOSSARY ------------------------------------------------------------------- Argument: See Parameter. ASCII: The American Standard Code for Information Interchange, which defines numeric values for 128 different characters comprising the English alphabet, numbers, punctuation, and some control characters. ASCII File: A file containing ASCII text, as opposed to a binary file which may contain numbers, or other information that cannot be sensibly interpreted as text. Attribute: A characteristic of a file which can be set or cleared. The standard attributes are Read-Only, Hidden, System, and Archive. Automatic Directory Change: A 4DOS, 4OS2, and 4DOS/NT feature which allows you to change directories by typing the directory name and a backslash [\] at the prompt. Base Memory: Under DOS, the portion of your computer's memory available for use by DOS, the command processor, and application programs. On most PCs this area consists of the first 640K or 655,360 bytes of the computer's memory. Base Name: The file name without a drive, path, or extension. For example, in the file name C:\DIR1\LETTER.DAT the base name is LETTER. BAT File: Same as a Batch File. Batch File: A text file containing a sequence of commands for the command processor to execute. Batch files are used to save command sequences so that they can be re-executed at any time, transferred to another system, etc. Batch File Parameter: A numbered variable (e.g. %2) used within a batch file, allowing a different value to be used at that spot in the file each time it is executed. Binary File: A file containing information which does not represent or cannot sensibly be interpreted as text. See also ASCII File. Block Device: A physical device for input or output which can transmit or receive large blocks of data while the computer is engaged in other activities. Examples include disk, tape, and CD-ROM drives. See also Character Device. Boot: The process of starting the computer and loading the operating system into memory. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 382 GLOSSARY ------------------------------------------------------------------- Boot Directory: The current directory at the time the system is booted, usually the root directory of the boot drive. Boot Drive: The disk drive that the system is booted from, usually A: (the floppy disk) or C: (the hard disk). Break: A signal sent to a program to tell it to halt what it is doing. The Ctrl-C key or Ctrl-Break key is used to send this signal. Some external commands abort when they receive a break signal; others return to a previous screen or menu, or abort the current operation. BTM File: A special type of batch file which is loaded into memory to speed up execution. Buffer: An area of memory set aside for storage. For example, disk buffers are used to save information as it is transferred between your program and the disk, and the keyboard buffer holds keystrokes until a program can use them. Character Device: A physical device for input or output which must communicate with your computer one character at a time. Examples include the console, communications ports, and printers. See also Block Device. Code Page: A set of definitions which tells DOS or OS/2 how to get and display date, time, and other information in the format appropriate to a particular country. Command Completion: A 4DOS, 4OS2, and 4DOS/NT feature which allows you to recall a previous command by typing the first few letters of the command, then an up-arrow or down-arrow. Command Echoing: A feature which displays commands as they are executed. Echoing can be turned on and off. Command History: A 4DOS, 4OS2, and 4DOS/NT feature which retains commands you have executed, so that they can be modified and re-executed later. Command History Window: A pop-up window used by 4DOS, 4OS2, and 4DOS/NT to display the command history, allowing you to choose a previous command to modify and/or execute. Command Processor: A program which interprets commands and executes other programs. Sometimes also called a Command Interpreter. Command Recall: See Command History. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 383 GLOSSARY ------------------------------------------------------------------- Command Tail: The portion of a command consisting of all the arguments, i.e., everything but the command name itself. Compound Command: See Multiple Commands. COMSPEC: An environment variable which defines where to find the command processor to start a secondary shell. Conditional Commands: A 4DOS, 4OS2, and 4DOS/NT feature allowing commands to be executed or skipped depending on the results of a previous command. See also Exit Code. Console: The PC keyboard and display. Control Character: A character which is part of the ASCII code, but does not have a normal text representation, and which can be generated by pressing the Ctrl key along with another key. Country Code: See Code Page. CPU: The Central Processing Unit which performs all logic and calculations in a computer. In PC-compatible systems, the CPU is on a single microprocessor chip. CR: The ASCII character "carriage return", generated by pressing the Enter key on the keyboard, and stored in most ASCII files at the end of each line. Critical Error: An error, usually related to a physical or hardware problem with input, output, or network access, which prevents a program from continuing. Current Directory: The directory in which all file operations will take place unless otherwise specified. Date Range: A 4DOS, 4OS2, and 4DOS/NT feature which allows you to select files based on the date and time they were last modified. Description: A string of characters assigned to describe a file with the 4DOS, 4OS2, or 4DOS/NT DESCRIBE command. Destination: In file processing commands (e.g. COPY or MOVE), the name or directory files should have after any copying or modification has taken place, generally the last specification on the command line. See also Source. Device: A physical device for input or output such as the console, a communications port, or a printer. Sometimes ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 384 GLOSSARY ------------------------------------------------------------------- "device" is used to refer to character devices, and excludes block devices. Device Driver: A program which allows the operating system to communicate with a device, and which is loaded into memory when the system boots. Device drivers are also used to manage memory or for other similar internal functions. Directory: A portion of any disk, identified by a name and a relationship to other directories in a "tree" structure, with the tree starting at the root directory. A directory separates files on the disk into logical groups, but does not represent a physical division of the data on the disk. Directory History: A 4DOS, 4OS2, and 4DOS/NT feature which allows you to recall recently-used directory names in a window and choose one to switch to. Disk Swapping: A type of swapping in which the transient portion of 4DOS is stored on disk while an application is running. DOS Memory: See Base Memory. DOS Session: See Session. Echo: See Command Echoing. EMS Memory: Under DOS, memory which conforms to the Lotus / Intel / Microsoft Expanded Memory Specification (LIM EMS), which allows programs to access large amounts of memory outside of base memory or extended memory. EMS Swapping: A type of swapping in which the transient portion of 4DOS is stored in EMS memory while an application is running. Environment: An area of memory which contains multiple entries in the form "NAME=value". See also Master Environment and Passed Environment. Environment Variable: The name of a single entry in the environment. Errorlevel: A numeric value between 0 and 255 returned from an external command to indicate its result (e.g., success, failure, response to a question). See also Exit Code. Escape Character: In some contexts, the 4DOS, 4OS2, or 4DOS/NT escape character, which is used to suppress the normal ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 385 GLOSSARY ------------------------------------------------------------------- meaning of or give special meaning to the following character. In other cases, the specific ASCII character ESC. The meaning must be determined from the context. Executable Extensions: A 4DOS, 4OS2, and 4DOS/NT feature which allows you to specify the application to be executed when a file with a particular extension is named at the command prompt. Executable File: A file, usually with the extension .COM or .EXE, which can be loaded into memory and run as a program. Exit Code: The result code returned by an external command or an internal command. 4DOS, 4OS2, and 4DOS/NT internal commands return an exit code of 0 if successful, or non-zero if unsuccessful. See also Errorlevel. Expansion: The process 4DOS, 4OS2, and 4DOS/NT go through when they scan a command line and substitute the appropriate actual values for aliases, alias parameters, batch file parameters, and environment variables. See also Parsing. Extended ASCII Character: A character which is not part of the standard set of 128 ASCII characters, but is used on the PC as part of an extended set of 256 characters. These characters include international language symbols, and box and line drawing characters. Extended Memory: Any memory on a 286-based (PC-AT compatible), 386, 486, or Pentium-based computer system which is above the 1 MB (one megabyte, or 1024*1024 bytes) of memory that DOS can address directly. See also XMS. Extended Parent Directory Names: A 4DOS, 4OS2, and 4DOS/NT feature which allows you to use additional periods in a directory name to represent directories which are successively higher in the directory tree. Extended Wildcard: A 4DOS, 4OS2, and 4DOS/NT feature which allows you to use multiple wildcard characters, extending the traditional wildcard syntax. See also Wildcard. Extension: The final portion of a file name, preceded by a period. For example, in the file name C:\DIR1\LETTER.DAT the extension is .DAT. External Command: A program which resides in an executable file, as opposed to an internal command which is part of the command processor. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 386 GLOSSARY ------------------------------------------------------------------- FAT File System: The traditional file system used by DOS to store files on diskettes and hard disks; also supported by OS/2 and Windows NT. Uses a File Allocation Table to keep track of allocated and unallocated space on the disk. File Attribute: See Attribute. File Description: See Description. Filename Completion: A 4DOS, 4OS2, and 4DOS/NT feature which allows you to type part of a filename on the command line, and have the command processor fill in the rest for you. Free Memory: Usually, the amount of base memory (under DOS) or total memory (under OS/2 and Windows NT) which is unoccupied and available for applications. Hidden: A file attribute indicating that the file should not be displayed with a normal DIR command, and should not be made available to programs unless they specifically request access to hidden files. History: See Command History. History Window: See Command History Window and Directory History. HPFS or High Performance File System: A file system distributed with OS/2 and Windows NT which allows longer file names and provides better performance than the traditional FAT file system. Include List: A concise method of specifying several files or groups of files in the same directory, for use with all 4DOS, 4OS2, and 4DOS/NT commands which take file names as arguments. .INI File: The 4DOS, 4OS2, or 4DOS/NT initialization file containing directives which set the initial configuration of the command processor. Insert Mode: When editing text, a mode in which newly typed characters are inserted into the line at the cursor position, rather than overwriting existing characters on the line. See also Overstrike Mode. Internal Command: A command which is part of the command processor, as opposed to an external command. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 387 GLOSSARY ------------------------------------------------------------------- Keyboard Buffer: A buffer which holds keystrokes you have typed that have not yet been used by the currently executing program. Keystroke Alias: An alias assigned to a key, so that it can be invoked or recalled with a single keystroke. Label: A marker in a batch file, with the format :name, allowing GOTO and GOSUB commands to "jump" to that point in the file. See also Volume Label. LF: The ASCII character "line feed", not usually generated from the keyboard, but stored in most ASCII files at the end of each line, after the CR character. Master Environment: The master copy of the environment maintained by the command processor. Memory Resident Mode: A method of installing 4DOS in which swapping is disabled, and all of 4DOS remains permanently resident in memory. Modulo: The remainder after an integer division. For example 11 modulo 3 is 2, because when 11 is divided by 3 the remainder is 2. Multiple Commands: A 4DOS, 4OS2, and 4DOS/NT feature which allows multiple commands to be placed on a line, separated by a caret [^] in 4DOS, an ampersand [&] in 4OS2 and 4DOS/NT, or another, user-defined character. Multitasking: A capability of some software (and the related hardware) which allows two or more programs to run apparently simultaneously on the same computer. Multitasking software for PC compatible systems includes programs like OS/2, Windows, Windows NT, and DESQview. NTFS or New Technology File System: A file system distributed with Windows NT with characteristics similar to HPFS. See also HPFS. Non-Swapping Mode: See Memory Resident Mode. Operating System: A collection of software which loads when the computer is started, provides services to other software, and ensures that programs don't interfere with each other while they are running. Option: See Switch. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 388 GLOSSARY ------------------------------------------------------------------- OR: A logical combination of two true or false conditions. If both conditions are false the result is false; if either condition is true the result is true. Overstrike Mode: When editing text, a mode in which newly typed characters overwrite existing characters on the line, rather than being inserted into the line at the cursor position. See also Insert Mode. Parameter: A piece of additional information placed after a command or function name. For example, in the command DIR XYZ, XYZ is a parameter. Also used to refer to an alias parameter or batch file parameter. Parsing: The process 4DOS, 4OS2, and 4DOS/NT perform when they analyze the command line, perform alias and environment variable expansion, and find the appropriate internal command or external command to execute. Passed Environment: A copy of the master environment created before running an application, so that any changes made by the application will not affect the master environment. Path: A specification of all the directories a file resides in. For example, the path for C:\WPFILES\MYDIR\MEMO.TXT is C:\WPFILES\MYDIR\. Also used to refer to the environment variable PATH, which contains a series of path specifications used when searching for external commands and batch files. Pipe: A method for collecting the standard output of one program and passing it on as the standard input of the next program to be executed, signified by a vertical bar "|" on the command line. See also Redirection. Primary Shell: The copy of the command processor which is loaded by the operating system when the system boots or a session opens. RAM Disk: A pseudo "disk drive", created by software, which appears like a normal physical disk drive to programs. Sometimes also called a "virtual disk." Range: See Date Range, Size Range, and Time Range. Read-Only: A file attribute indicating that the file can be read, but not written or deleted by the operating system or the command processor unless special commands are used. Reboot: The process of restarting the computer, usually by pressing the Ctrl, Alt, and Del keys simultaneously. ------------------------------------------------------------------- Copr. 1994, JP Software Inc. 4DOS, 4OS2, 4DOS/NT Reference / 389 GLOSSARY ------------------------------------------------------------------- Redirection: A method for collecting output from a program in a file, and/or of providing the input for a program from a file. See also Pipe. Resident Portion: The small portion of 4DOS stored permanently in memory when swapping mode is in use, as opposed to the larger transient portion. Root Directory: The first directory on any disk, from which all other directories are "descended." The root directory is referenced with a