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4DOS Version 3.03 A PC-DOS / MS-DOS Command Processor Distributed by: JP Software, Inc. P.O. Box 1470 E. Arlington, MA 02174, USA (617) 646-3975 _______ ____|__ | (tm) --| | |------------------- | ____|__ | Association of | | |_| Shareware |__| o | Professionals -----| | |--------------------- |___|___| MEMBER Written by Rex C. Conn and Tom Rawson JP Software, Inc. P.O. Box 1470 E. Arlington, MA 02174, USA (617) 646-3975 voice (617) 646-0904 fax (800) 368-8777 orders only Electronic mail to: CompuServe 75300,210 BIX "trawson" InterNet, Bitnet, etc.: 75300.210@compuserve.com Program and Documentation Copyright 1988 - 1991, Rex C. Conn and JP Software, Inc. All rights reserved. Portions Copyright 1987, 1988, 1990 Microsoft Corporation Portions Copyright 1987, 1989 Borland International Portions Copyright 1987, 1988, 1989 TurboPower Software 4DOS is a registered trademark of JP Software Inc. PC-DOS, PC, PC XT, PC AT, and PS/2 are trademarks of IBM Corporation. MS-DOS, OS/2, and Windows are trademarks of Microsoft Corporation. 1-2-3 is a trademark of Lotus Development Corporation. dBASE is a trademark of Ashton Tate. 386-To-The-Max and Move-Em are trademarks of Qualitas Inc. DESQview and QEMM are trademarks of Quarterdeck Office Systems Brief is a trademark of UnderWare Inc. 4DOS Reference Manual Copyright 1991, JP Software Inc. ACKNOWLEDGEMENTS We couldn't produce a product like 4DOS without the dedication and quality work of many people. Our thanks to all these folks: JP Software staff: Mike Bessy, Helen Coyne, Hayyim Feldman, Henry Harvey, Susan Mampre, Ellen Stone. Beta testers: Bruce Aldrich, Mike Bessy, David Birnbaum, Jeff Bishop, "Dr. File Finder" (Mike Callahan), Gary Clanfield, John Cooper, Chris DeVoney, Emanuel Donchin, Stan Dvoskin, John Fleming, Doug Frank, Peter Frank, Gary Gibson, Tim Grissom, Ken Harwell, Keith Hawes, Bob Huntley, John James, Tom Kellen, Bob Kertesz, Dave Lemire, Kevin Lockwood, Brad McDonald, John McKown, Burt Model, Stuart Moore, Phil Newman, Jorge Ochoa-Lions, Shakib Otaqui, John Peterson, Ed Phillips, Mike Phillips, Sam Pierce, Chip Rabinowitz, Dan Rawson, David Rodman, Chris Rousseau, Alan Samuels, Guy Scharf, Martin Schiff, Bill Shaffer, Malcolm Shealy, Stephen Spehn, Michael Stein, Ted Thompson, Brian Trainer, Thomas Traubitz, Randy Wallin, Bill Walton, Iram Weinstein, Joe Zott, and anyone else we forgot! Beta test support: David Moskowitz, Guy Scharf, and all the sysops of the CompuServe CONSULT forum. BBS support: Channel 1 sysops Brian Miller and Tess Heder. The 4DOS 3.0 HELP system was originally written by Ross Neilson Wentworth, and is now owned and distributed by JP Software. The following tools are used in creating and maintaining 4DOS: Compilers: Microsoft C 6.0 and Macro Assembler 5.1 Turbo Pascal 5.5 (Borland) Libraries: Turbo Professional 5.0 (TurboPower Software) Editors: Edix (Emerging Technology), Brief (Solution Systems) Debuggers: Periscope (The Periscope Company), Soft-ICE (Nu-Mega Technologies) Version Control: PVCS (Polytron) The following suppliers produce the finished product: Manual Printing: Causeway Print, Boston Disk Duplication: Diversified Systems Group, Issaquah, WA 4DOS Reference Manual Copyright 1991, JP Software Inc. TABLE OF CONTENTS Introduction i Registration Information ii 4DOS License Agreement iii Technical Support vi 4DOS Features 1 Installation 9 4DOS Files 10 Test Driving 4DOS 11 Quick Start 12 Automatic Installation 13 DOS Shells Explained 14 COMSPEC 15 Manual Installation 16 Memory Usage 18 Setting up CONFIG.SYS 19 Startup Options 21 4DSHELL 25 AUTOEXEC and 4START 25 4DOS and COMMAND.COM 26 Using 4DOS 27 Starting 4DOS 27 Command Line Editing 28 Command History and Recall 29 Multiple Commands 30 Conditional Commands 30 Escape Character 31 Command Echoing 32 Argument Quoting 32 Batch Files 33 Aliases 35 Executable Extensions 37 Keystack 39 Environment Variables 40 Variable Functions 42 I/O Redirection 43 Command Parsing 45 4DOS Reference Manual Copyright 1991, JP Software Inc. Command Reference Guide 46 ? 48 ALIAS 49 ATTRIB 52 BEEP 53 BREAK 54 CALL 55 CANCEL 56 CD / CHDIR 57 CDD 58 CHCP 59 CLS 60 COLOR 61 COPY 62 CTTY 64 DATE 65 DEL / ERASE 66 DELAY 67 DESCRIBE 68 DIR 69 DIRS 72 DRAWBOX 73 DRAWHLINE 74 DRAWVLINE 75 ECHO 76 ENDLOCAL 77 ESET 78 EXCEPT 79 EXIT 80 FOR 81 FREE 82 GLOBAL 83 GOSUB 84 GOTO 85 HELP 86 HISTORY 87 IF 88 IFF 91 INKEY 92 INPUT 93 KEYSTACK 94 LIST 95 LOG 97 MD / MKDIR 98 MEMORY 99 MOVE 100 PATH 102 PAUSE 103 POPD 104 PROMPT 105 PUSHD 107 4DOS Reference Manual Copyright 1991, JP Software Inc. QUIT 108 RD / RMDIR 109 REM 110 REN / RENAME 111 RETURN 112 SCREEN 113 SCRPUT 114 SELECT 115 SET 117 SETDOS 119 SETLOCAL 122 SHIFT 123 SWAPPING 124 TEE 125 TEXT 126 TIME 127 TIMER 128 TYPE 129 UNALIAS 130 UNSET 131 VER 132 VERIFY 133 VOL 134 Y 135 Appendix A - Error messages 136 Appendix B - ASP 146 Appendix C - Key codes 148 Appendix D- Programming 149 Appendix E - Tips and Troubleshooting 150 Glossary 162 Index 173 4DOS Reference Manual Copyright 1991, JP Software Inc. Introduction Welcome, and thanks for trying 4DOS! 4DOS is designed to help you get the most out of your IBM PC or compatible system. It replaces COMMAND.COM, the command interpreter that comes with all versions of MS-DOS and PC-DOS. You'll find 4DOS provides a wide variety of capabilities COMMAND.COM can't, ranging from a vastly enhanced DIR command, to point-and-shoot file selection for any command, to the ability to completely redefine your system's commands. Yet 4DOS is fully compatible with COMMAND.COM. 4DOS is a "DOS shell" (a program that gives you access to DOS functions and commands), but it's unlike most DOS shells on the market. Virtually all of these shells are designed to isolate the novice user from the DOS command line. 4DOS, on the other hand, is intended to make DOS easier to use and to make you more productive while working at the command line. It provides enhancements to most of the DOS commands, as well as more than 40 new commands. These improvements make 4DOS a much richer and more powerful working environment than COMMAND.COM, without sacrificing the compatibility, flexibility and control you get from working at the command line. If you're tired of the limitations of COMMAND.COM, you'll love 4DOS! 4DOS is distributed as shareware, which means if you've downloaded it from a bulletin board or obtained it from a friend, you can try it out before you decide whether you'd like to keep it. Like all shareware, if you do decide to keep 4DOS, you must pay a registration fee. 4DOS is also distributed through normal retail channels. If you purchased a retail copy of 4DOS, it includes a shareware disk which you can share with your friends and associates. The following pages include information on registration, the 4DOS license agreement, and technical support for 4DOS. The text in this ASCII manual is essentially the same as that in the printed manual. Changes from the original version 3.0 manual have been made to correct typographical errors or document small changes in the software, but a few significant new features which would require repagination of the text are not included. For complete documentation on changes in versions 3.01 through 3.03 see the file UPDATE30.DOC. 4DOS Reference Manual Copyright 1991, JP Software Inc. i Registration Information 4DOS is a copyrighted program protected by both U.S. and international copyright law. If you obtained 4DOS from a shareware disk vendor, an on-line computer service or bulletin board, a friend or colleague, or another similar source, you have an unregistered (trial) copy. You are authorized to use this copy without charge for a limited period of time under the terms of the 4DOS license agreement. After this time is up, you must register and pay for 4DOS to continue using it. This method of distribution is known as shareware. It allows you to determine whether 4DOS meets your needs before you pay for it. The registration fee for a single copy of 4DOS is $50. Payment of this fee entitles you to: ∙ A disk with the latest version of 4DOS, registered to you, and a copy of the typeset-quality printed and bound 4DOS manual. ∙ An upgrade to the next major release of 4DOS. (There is no charge from JP Software for downloading an upgrade or maintenance release. For an upgrade on diskette there will be a minimal charge to cover our cost in sending it to you.) ∙ Technical support via electronic mail or telephone. ∙ A subscription to the 4DOS newsletter. If you prefer, you may register for $35 and receive only the disk and notices of future upgrades. Multi-system licenses are also available; contact JP Software for more information. If you purchased a complete copy of 4DOS with printed manual from a software dealer, your copy came with a yellow registration card. Return this card promptly to JP Software to ensure you are registered with us, and to receive technical support and notices of future upgrades. If you purchased 4DOS directly from JP Software and paid the full $35 or $50 fee, you are already registered, and no registration card is necessary. 4DOS Reference Manual Copyright 1991, JP Software Inc. ii 4DOS License Agreement (1) Copyright: The 4DOS program and all other programs and documentation distributed or shipped with it are Copyright 1988 - 1991, Rex C. Conn and JP Software Inc., or are distributed under license to JP Software Inc., and are protected by U.S. and international copyright law. In the rest of this document, this collection of programs is referred to simply as "4DOS". You are granted a license to use your copy of 4DOS only under the terms and conditions specified in this license agreement. (2) Definitions: 4DOS is distributed in two forms. A "registered" copy of 4DOS is a copy distributed on diskette, purchased from JP Software or from a dealer, and which includes a serial number and the legend "licensed" or "registered" in the program sign-on message and on the diskette label. A "shareware" copy of 4DOS is a copy distributed on diskette or via an electronic bulletin board, on-line service, or other electronic means, obtained from a shareware disk vendor, or obtained from another individual, and which displays the legend "shareware" in the program sign-on message, and in most cases on the diskette label as well (if applicable). Throughout this document the term "JP Software" refers to JP Software Inc., a Massachusetts corporation. (3) Shareware Copies: Shareware copies of 4DOS are distributed to allow you to try the program before you pay for it. They are Copyright 1988 - 1991, Rex C. Conn and JP Software Inc., and do not constitute "free" or "public domain" software. You may use a shareware copy of 4DOS at no charge for a trial period of up to 21 days. If you wish to continue using 4DOS after that period, you must purchase a registered copy. If you choose not to purchase a registered copy, you must stop using 4DOS, though you may keep copies and pass them along to others. (4) Registered Copies: Registered copies of 4DOS are distributed to those who have purchased them. Your registered copy of 4DOS may only be used on the number of computers specified on the diskette label and program sign-on screen. (5) Use of One Copy on Two Computers: If you have a registered copy of 4DOS which is licensed for use on a single computer, you may install it on two computers used at two different locations (for example, at work and at home), provided there is no possibility that the two computers will be in use at the same time, and provided that you yourself have purchased 4DOS, or if 4DOS was purchased by your employer, that you have your employer's explicit permission to install 4DOS on two systems as described in this paragraph. The right to install one copy of 4DOS on two computers is limited to copies originally licensed for use on a single computer, and may not be used to expand the number of systems covered under a multi-system license. 4DOS Reference Manual Copyright 1991, JP Software Inc. iii (6) Use of 4DOS on Networks or Multiple Systems: You may install your registered copy of 4DOS on a computer attached to a network, or remove it from one computer and install it on a different one, provided there is no possibility that your copy will be used by more users than it is licensed for. A "user" is defined as one keyboard which is connected to a computer on which 4DOS is installed, regardless of whether or not the user of the keyboard is aware of the installation or use of 4DOS in the system. (7) Making Copies: You may copy any version of 4DOS for normal backup purposes, and you may give copies of the shareware version to other individuals, which they may also use and copy subject to the terms of this agreement. If you copy the shareware version of 4DOS for others, you must include all of the files distributed with it, including this one. You may not give copies of the registered version to any other person for any purpose, and you may not make any copies of the printed and bound 4DOS manual without explicit written permission from JP Software. (8) Distribution Restrictions: You may NOT distribute 4DOS other than through individual copies of the shareware version passed to friends and associates for their individual use. Specifically, you may not place 4DOS or any part of the 4DOS package in any user group or commercial library, or distribute it with any other product or as an incentive to purchase any other product, without express written permission from JP Software, and you may not distribute for a fee, or in any way sell copies of 4DOS or any part of the 4DOS package. However if you are a shareware disk vendor approved by the Association of Shareware Professionals (ASP), or a non-profit, tax-exempt user group, you may place 4DOS in your library without prior written permission, provided you notify JP Software within 15 days of doing so; and for shareware disk vendors, provided your application has been fully approved in writing by the ASP, and is not simply submitted or awaiting review. (9) Use of 4DOS: 4DOS is a powerful program. While we have attempted to build in reasonable safeguards, if you do not use 4DOS properly you may destroy files or cause other damage to your computer software and data. You assume full responsibility for the selection and use of 4DOS to achieve your intended results. As stated below, JP Software limits its warranty to replacement of a defective program diskette or manual. (10) LIMITED WARRANTY: JP Software warrants to owners of registered copies of 4DOS that the software will operate in accordance with the description given in the documentation, and that the diskette and manual will be free of physical defects which interfere with normal use. BOOT.SYS and the software on the 4DOS Utility Disk which was not created by JP Software, as stated in the documentation provided on the disk, is not warranted to operate in accordance with its documentation, and is sold AS-IS AND WITHOUT WARRANTY OF ANY KIND BY JP SOFTWARE. For a period of 90 days from the date of your purchase of 4DOS, 4DOS Reference Manual Copyright 1991, JP Software Inc. iv JP Software will, at its sole option and subject to the restrictions above and below, repair or replace any defective item(s), or refund the purchase price of any diskette and/or manual and/or any other parts or components of 4DOS found to be defective, if such defect is the fault of JP Software and not the result of misuse or abuse. Such a refund, repair, or replacement shall be your sole remedy for any defects, program error(s), or documentation error(s). In no event shall JP Software be responsible for any other costs or damages whatsoever due to errors in usage or your failure to read, understand, or follow instructions in the documentation. JP SOFTWARE MAKES NO OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE WARRANTIES OF MERCHANTABILITY AND OF FITNESS FOR A PARTICULAR PURPOSE. JP Software's warranty is expressly limited to the cost of replacement of any defective diskette or other part. (11) Satisfaction Guarantee: If you are dissatisfied with a registered copy of 4DOS for any reason (whether or not you find a software error or defect), you may return the entire package at any time up to 90 days after purchase for a full refund of your original registration fee. 4DOS Reference Manual Copyright 1991, JP Software Inc. v Technical Support Technical support for 4DOS is available to registered users. If you are not a registered user, we will provide you with assistance to install a shareware copy of 4DOS and evaluate it during the 21 day evaluation period, but we cannot provide continuing support beyond that until you purchase 4DOS. The best way to contact us for support is by modem, in one of the following public 4DOS support conferences. The numbers in parentheses indicate the usual delay, in days, to receive a reply to a message. CompuServe / PCMagNet: Primary support is via the JP Software section of the CompuServe PCVENB forum (GO PCVENB) (1 day). We also monitor the CompuServe CONSULT and IBMSYS forums, and the PCMagNet UTILFORUM (2-5 days). Bulletin Boards: Primary support is via the 4DOS conferences on the Channel 1 BBS, Boston, MA, 617-354-8873 (1-3 days). Additional support is available from many local BBSes via the 4DOS conferences on the InterLink, PC Relay, FidoNet, and SmartNet BBS Networks (3-5 days). Please note that Channel 1 is an independent bulletin board which has agreed to serve as a home base for 4DOS support, but is not owned or operated by JP Software. BIX: Support is available via the ibm.dos conference, topic 4DOS (3-5 days). In addition, you can contact JP Software for support by mail, telephone, fax, or electronic mail. Addresses and phone numbers are listed on the first page of this manual. We prefer support via one of the electronic services listed above, or via electronic mail, as it allows correspondence at convenient times regardless of time zones and work schedules, and it provides a record of the communication. However, telephone and fax support are also provided to those users who do not have a modem or who need an quick response. 4DOS Reference Manual Copyright 1991, JP Software Inc. vi 4DOS Features 4DOS is a complete replacement for COMMAND.COM, the command processor provided with MS-DOS or PC-DOS. (References in this manual to MS-DOS also apply to PC-DOS.) 4DOS is compatible with MS-DOS versions 2.0 to 4, and the OS/2 DOS compatibility box, and adds many enhancements to your MS-DOS prompt, including: Minimal Memory Usage 4DOS requires less than 4K of your precious RAM for its resident portion (less than 1K with XMS swapping!), and can use EMS, XMS, or disk for swapping its transient portion. Fast Batch Files 4DOS 3.0 adds a new batch file extension (.BTM, "batch to memory") that is compatible with 99% of your existing batch files, but runs several times faster. Executable Extensions In addition to the normal executable file extensions (.COM, .EXE, .BAT, and .BTM), 4DOS allows you to define additional extensions and the programs they should invoke. For example, entering a document name could automatically invoke your word processor. On-line Help 4DOS provides help for all of its internal commands, as well as the MS-DOS external commands. You can get help by pressing the F1 key at the command prompt. The 4DOS help facility is extensible, so you can add help for your own programs. (Modifications to the help facility require the 4DOS utility disk, which contains the source text and help file compiler.) Command Line Editing 4DOS provides command line editing, including insert and delete, and full cursor key support. 4DOS also offers interactive expansion of wildcard filenames on the command line. 4DOS Reference Manual Copyright 1991, JP Software Inc. 1 Command History 4DOS lets you view, search, modify, and reexecute your previous commands. The commands are saved in memory, and can be recalled with the cursor keys. The command history list size is user-defined, from 512 to 8192 characters. Flexible File Wildcards 4DOS offers more flexible wildcards than COMMAND.COM. For example, you can display all the files that have a "2" anywhere in their filename by entering: dir *2*.* File Descriptions 4DOS allows you to provide descriptions (up to 40 characters) for each of your files and directories. The descriptions are displayed with the filenames when you use the DIR or SELECT commands. The description goes with a file when you COPY, ERASE, MOVE, or RENAME it. Multiple Commands on a Single Line You can enter several commands on a line by separating them with a ^ (caret), or other user-defined character. Expanded and Editable Environment 4DOS provides a user-defined environment size from 512 to 32000 characters. You can interactively edit environment entries with the ESET command. Environment Variables Environment variables allow you to associate a string of characters with a variable name, substituting that string when the name is used. 4DOS provides a number of predefined variables, including system date and time, current directory, and default disk, and "variable functions," for returning substrings, the parts of a filename (path, name, extension), etc. 4DOS Reference Manual Copyright 1991, JP Software Inc. 2 Aliases Aliases allow you to rename or reconfigure commands (for example, to pass default parameters to a command, or to give MS-DOS the look and feel of a different operating system), or to define a new command as a combination of several other commands. Aliases support batch file-like arguments (%1, %2, etc.) and environment variables, so when combined with the multiple commands feature, they act as very fast batch files. Expanded Command Line 4DOS expands the MS-DOS command input line from 127 to 255 characters for internal commands. (Because MS-DOS truncates the command line for external commands to 127 characters, 4DOS makes the full command line available to your programs through the CMDLINE environment variable.) Conditional Commands 4DOS includes two new command line operators: || (OR) and && (AND). They allow you to control the execution of subsequent commands based on the result of the previous command. Additional Redirection Options In addition to redirection of standard input and standard output, 4DOS supports redirection of standard error, and the option to prevent overwriting existing files. 4DOS also provides TEE and Y "pipe fittings." EGA/VGA Support 4DOS supports Monochrome, CGA, EGA and VGA displays with any number of lines and columns per screen. Networks 4DOS supports MS-DOS compatible networks, including 3Com 3+ and Novell Netware. 4DOS Reference Manual Copyright 1991, JP Software Inc. 3 New and Enhanced Commands 4DOS provides many new internal commands, and new options for existing commands. Most 4DOS commands can take multiple arguments. For example, you can delete several files with a single DEL command: del *.bak test.wks oldfile.txt You can also copy several files with a single COPY command (the target directory here is a:\): copy *.wks memo.doc *.c a:\ The following list is intended to give you a sampling of some of the new and enhanced commands. See the Command Reference Guide for full details. ALIAS / UNALIAS Define aliases for commonly used commands, allowing you to execute a complex series of commands with a few keystrokes. ATTRIB Display or change the file attributes (read-only, hidden, system, and archive) for the specified files and/or directories. CDD Change the default drive and directory. COLOR Set the screen foreground and background colors. COPY COPY includes new switches for copying only updated files (where the source is newer than the target), and to prompt for confirmation before overwriting existing files. 4DOS Reference Manual Copyright 1991, JP Software Inc. 4 DESCRIBE Add 40-character descriptions to filenames. The descriptions are displayed when using DIR and SELECT. DIR Display the disk directory with a wide variety of options, including 1, 2, 4, or 5 column display; sorted by name, extension, description, size, or date/time; display subdirectories; display file attributes; and display subtotals only. ESET Interactively edit environment variables and aliases. EXCEPT Execute a command except on the specified file(s). FREE Display the total and free disk space for the specified drive(s). GLOBAL Execute a command in the current directory and all of its subdirectories. HELP Display a pop-up help window for 4DOS internal commands and MS-DOS external commands. HISTORY Display, clear or load the command history list. LIST Display a file on the screen. LIST provides forward and backward paging, vertical and horizontal scrolling, text search, and printing. 4DOS Reference Manual Copyright 1991, JP Software Inc. 5 LOG Keep a disk log of each command executed, with the date and time. MEMORY Display the amount of total and available DOS, expanded, XMS, and extended memory, and environment space. MOVE Move files between directories and/or drives, and optionally prompt before overwriting existing files. PUSHD / POPD / DIRS Use a "directory stack" to change directories, perform some work, and then return to the original directory. RENAME In addition to renaming files, 4DOS also allows you to rename files to another directory, and to rename directories. SELECT Perform a command on selected files (using point-and-shoot selection). SETDOS Configure the 4DOS internal parameters, including the default line editing mode (insert or overstrike), the default batch echo mode, the compound command character, the escape character, screen size, and cursor shape. TIMER A system stopwatch for timing events, including split times. 4DOS Reference Manual Copyright 1991, JP Software Inc. 6 Enhanced Batch Processor The batch processor in 4DOS is compatible with batch files written for COMMAND.COM, and includes several new and enhanced commands to make batch file programming easier and more powerful, including: BEEP Beep the speaker at the specified frequency and for the specified duration. CALL Execute nested batch files without loading a secondary copy of the command processor. CANCEL Terminate nested batch file processing. DELAY Wait for the specified period of time before continuing batch processing. DRAWBOX / DRAWHLINE / DRAWVLINE Draw boxes, horizontal, and vertical lines in single or double widths, in your choice of colors. These commands automatically make connectors when crossing other lines. GOSUB / RETURN Call subroutines within a batch file. IF Many new comparison tests, (including less than, greater than, etc), and tests for memory, disk, and display type. 4DOS Reference Manual Copyright 1991, JP Software Inc. 7 IFF / THEN / ELSEIFF / ELSE / ENDIFF Allows nested IF / THEN / ELSE tests in batch files and aliases, and supports all of the new IF tests (see above). INPUT / INKEY Input variables from the keyboard while in a batch file, with an optional timeout period. KEYSTACK Send keystrokes to a program, as if entered from the keyboard. QUIT Exit the current batch file. SCREEN Position the cursor and (optionally) display text. SCRPUT Position the cursor and display text in the specified colors. SETLOCAL / ENDLOCAL Define a local environment within a batch file, saving the original environment, disk, and directory, and restoring them when finished. SHIFT Optionally specify how many positions to shift, including reverse SHIFTs. TEXT / ENDTEXT Display a block of text. 4DOS Reference Manual Copyright 1991, JP Software Inc. 8 Installation 4DOS is written for the IBM PC, PC/XT, PC/AT, PS/2 (all models), and compatibles. It requires MS-DOS 2 or above (MS-DOS 3.1 or above is recommended), and uses less than 4K of RAM in swapping mode, or about 70K in resident mode. If you are new to 4DOS, read through this section until you get to "Automatic Installation." If you have a diskette copy of 4DOS, you can follow the automatic installation procedure, and come back later to read the section on manual installation and configuration. If you would like to try out 4DOS before fully installing it, see the section Test Driving 4DOS. If you are an experienced 4DOS user, do not have 4DOS on diskette, or prefer manual installation for any other reason, read through this section before installing 4DOS. See the Quick Start section for brief instructions for experienced users on how to install 4DOS. 4DOS Files The files listed below are part of 4DOS. Depending on where you obtained your copy, you may find the files in a compressed form, usually in a file with the extension .ZIP or .ARC. These files may change from time to time. See the file README.DOC for up to date information on which files are included with your copy of 4DOS. INSTALL.BAT* The automatic installation batch file. Note that INSTALL.BAT will only work with copies of 4DOS distributed on diskette. 4DOS.COM The 4DOS shell loader and swapper. 4DOS88.EXE Replaces COMMAND.COM as the default MS-DOS command processor on any PC compatible system. 4DOS286.EXE A version of 4DOS optimized for 80186, 80286, 80386, 80486, V20 and V30 processors. 4DOS286 is slightly smaller and faster than 4DOS88. 4DOS Reference Manual Copyright 1991, JP Software Inc. 9 4DOS.DOC The 4DOS manual. KEYSTACK.SYS This device driver provides the support for the 4DOS KEYSTACK command. HELP.EXE This is the on-line help program for 4DOS. It provides help for all of the internal 4DOS commands, and for the external MS-DOS commands. DOS.HLP The text file for HELP.EXE. ALIASES Sample predefined 4DOS aliases. PKUNZIP.EXE* Program used to uncompress the .ZIP files. PKUNZIP.DOC* Documentation for PKUNZIP.EXE. COMPAT.DOC Compatibility notes -- look here if you have trouble getting another program running with 4DOS. README.DOC Last-minute revisions and bug reports. * Included only with diskette copies of 4DOS. Compatibility Compatibility information varies from release to release of both 4DOS and other products. See Appendix E - Troubleshooting 4DOS for general usage notes and troubleshooting tips. The file COMPAT.DOC (distributed with 4DOS) contains the latest compatibility information available to us, along with information on how to address known compatibility problems. If the information in Appendix E and COMPAT.DOC doesn't solve your problem, contact JP Software directly for technical support. 4DOS Reference Manual Copyright 1991, JP Software Inc. 10 Test Driving 4DOS While 4DOS is normally installed as your system's primary command processor, you can try it out by running it just like any other program. This allows you to explore the features and advantages of 4DOS before doing a full installation. To try 4DOS, copy the files 4DOS.COM and 4DOS88.EXE to your system disk. If the copy of 4DOS you received has these files compressed, use the following command to decompress them (this example assumes the files are stored in the compressed file A:\4DOS30.ZIP, and you are decompressing them with the PKUNZIP program onto the root directory of drive C) pkunzip a:\4dos30 c:\4dos.com c:\4dos88.exe You can put these files in any directory, including a separate 4DOS directory if you like. Change to that directory, and enter the command: 4dos You will see the 4DOS sign-on message and a prompt. You are now ready to try 4DOS! You can return to COMMAND.COM at any time by typing: exit Note that the 4DOS KEYSTACK command will be unavailable because it requires the KEYSTACK.SYS device driver to be installed. Installation of KEYSTACK.SYS is described in the Manual Installation section. The 4DOS HELP command will also be unavailable. To try it out, decompress and/or copy the files HELP.EXE and DOS.HLP to a directory included in your PATH statement. Then type HELP or press F1 at the 4DOS prompt to access the 4DOS online help facility. There are a few situations where you will need to make some changes in the method described above. If your system does not have a hard disk, EMS, or XMS memory, use the following command to start 4DOS: 4dos /s:n This will disable 4DOS swapping (floppy disk swapping is too slow to be useful). Under these conditions 4DOS will require about 70K of memory, instead of the under 4K required in swapping mode. If you are running network software, you can start 4DOS as above, but do so after your network is loaded. If you are running a multitasking or task switching environment such as DESQview or Microsoft Windows, load 4DOS as above within a partition or 4DOS Reference Manual Copyright 1991, JP Software Inc. 11 window, rather than attempting to load the operating environment after 4DOS has started. (These restrictions apply only to testing 4DOS. Once it is installed as the primary shell and configured properly for your system, they will not be necessary.) Quick Start If you are an experienced MS-DOS user, the following instructions will get you up and running with 4DOS. If you have trouble or if these instructions don't make sense, use the automatic or manual installation procedures described later in this section. These instructions assume you are booting from a hard disk which is drive C. 1) Be sure you have a bootable MS-DOS floppy. 2) Decompress and/or copy the files 4DOS.COM, KEYSTACK.SYS, and 4DOS286.EXE (for 8018x/286/386/486, V20, and V30 processors) or 4DOS88.EXE (for 808x processors) to the root directory of drive C:. 3) If you have a registered (non-shareware) copy of 4DOS, change to the root directory of drive C and run the BRAND program by entering "A:BRAND". Enter the serial number from the diskette label, and your EXE file will be branded as a fully registered copy. If you only copied one of the EXE files, ignore the error message about the missing EXE file. 4) Decompress and/or copy the files HELP.EXE and DOS.HLP to a directory included in your PATH statement. 5) Edit CONFIG.SYS so that it contains the following lines (delete any existing SHELL= line): device=c:\keystack.sys shell=c:\4dos.com /E:n /A:m /P where n is your desired environment size, and m is the desired alias list size (in bytes). The default values are /E:512 and /A:1024. 6) Reboot your system. The system will load 4DOS (swapping to XMS, EMS, or disk, depending on what is available), execute AUTOEXEC, and return to the 4DOS prompt when AUTOEXEC is done. 7) If you are using PROMPT commands in AUTOEXEC to transmit ANSI control sequences for key redefinitions, they will not work with 4DOS; you must use ECHO instead. See the PROMPT command in the Command Reference Guide for more information. ANSI control sequences for the prompt itself (to set colors etc.) will work properly. 4DOS Reference Manual Copyright 1991, JP Software Inc. 12 8) If you are explicitly setting COMSPEC in AUTOEXEC, you should delete this line or place a REM in front of it if you want to use 4DOS as your secondary shell. 4DOS will automatically set the COMSPEC to C:\4DOS.COM. Automatic Installation You must have a diskette version of 4DOS to use automatic installation. To install 4DOS automatically from a diskette in drive A to a hard disk configured as drive C, insert the 4DOS Shareware Disk in drive A and type: a:install If you need to install from a drive other than drive A: or to a drive other than drive C:, use the following command: x:install x y where x is the drive containing the 4DOS shareware disk, and y is the drive on which you want to place the installed copy of 4DOS. INSTALL will prompt you for your desired configuration, copy the necessary files to your boot disk, and create some new lines for CONFIG.SYS. These new lines, in the file CONFIG.4D, must be merged with your existing CONFIG.SYS file before rebooting your system to start 4DOS. NOTE: You may want to edit the new CONFIG.SYS lines if you have an unusual configuration, or if you want to modify the default values. If you have a registered copy of 4DOS, during the installation process INSTALL will prompt you to insert the registered disk in order to "brand" your copy of 4DOS with your name and serial number. 4DOS Reference Manual Copyright 1991, JP Software Inc. 13 DOS Shells Explained This section gives an overview of what "DOS shells" (as discussed in this manual) are, and of primary and secondary shells. This information is important in understanding how to install and configure 4DOS. If you already understand these concepts, go on to the next section. In the PC world the term shell has come to mean any program that gives you the capability to execute DOS commands and run programs. We will use it more precisely to mean the system command interpreter, the program which reads your keystrokes at the DOS prompt and interprets them, allowing you to execute internal commands and run external programs. Before 4DOS, virtually all PCs using DOS used COMMAND.COM as the shell. When your system is started, the last thing the system startup software does is to load a copy of the shell program into memory and give it control. This program is called the primary or root shell. It executes AUTOEXEC.BAT, displays the command line prompt and processes your commands. The primary shell is the program that executes most of the commands you enter, either as internal functions (e.g., the DIR command), or by loading and executing other programs (e.g., a word processing program). The text file CONFIG.SYS, stored in the root directory of your boot disk, tells MS-DOS how to start: what device drivers to load, how many open files to allow, etc. The SHELL statement in CONFIG.SYS determines what program is loaded as the primary shell. If you don't have a SHELL statement, MS-DOS will load COMMAND.COM as the primary shell. However, any properly written program can be loaded in place of COMMAND.COM. This is the normal method for loading 4DOS. Now, suppose from inside your word processor you invoke the "shell to DOS" option, to execute some commands without having to save your files and exit first. When the prompt comes up, you are running a secondary shell; the word processor has loaded a shell program into memory to perform commands. When you type the EXIT command, the secondary shell terminates and control is returned to the word processor. The same kind of sequence is used by many programs which run other programs or execute MS-DOS commands: the program loads a copy of the command processor (a secondary shell) and passes a command to it to execute a command or another program. For example, a hard disk manager which allows you to copy files may invoke a secondary shell and pass a COPY command to it to actually perform the copy. 4DOS Reference Manual Copyright 1991, JP Software Inc. 14 Multitasking or task switching systems may also use secondary shells to load and execute the programs you specify in each of the windows or partitions they support. For example, DESQview will load a secondary shell to execute your program under some conditions, and will execute the program directly under other conditions (see the DESQview manual for details). In all of these situations, the secondary shell need not be the same program as the primary shell. The two shells are completely independent, occupy different areas of memory, and generally have little interaction with each other. Both COMMAND.COM and 4DOS can work as primary and/or secondary shells. The COMSPEC Environment Variable A variable in the MS-DOS environment, COMSPEC, determines which program is loaded as the secondary shell, just as the SHELL command in CONFIG.SYS specifies the primary shell program. The COMSPEC variable is set at startup time to point to the primary shell program. It can be modified at any time with the SET command. If COMSPEC does not point to a valid command processor (including the correct drive and directory), programs attempting to shell to MS-DOS will fail. In 4DOS, COMSPEC is set at system startup to d:\4DOS.COM, where d: represents the drive the system was started from. In COMMAND.COM, COMSPEC is set to d:\COMMAND.COM. If 4DOS is your primary shell, and 4DOS.COM and 4DOS88.EXE (or 4DOS286.EXE) are not stored in the root directory of the boot drive, you MUST set COMSPEC yourself in AUTOEXEC.BAT with the proper drive and directory for 4DOS.COM and the 4DOS EXE files. If COMSPEC is not set correctly, you will not be able to shell out to 4DOS or execute external commands from within your application programs. For example, if your 4DOS.COM and 4DOS88.EXE or 4DOS286.EXE files are in D:\BIN\4DOS, put the following command in AUTOEXEC.BAT: set comspec=d:\bin\4dos\4dos.com Note that COMSPEC contains only the name of the shell program. Any options to be passed to secondary 4DOS shells must be set separately in 4DSHELL (see below). NOTE: A few ill-behaved programs ignore COMSPEC, and explicitly load COMMAND.COM as a secondary shell. Although it is possible to rename 4DOS.COM to COMMAND.COM to handle most of these cases, we recommend you keep a copy of COMMAND.COM on your system as it may be needed for other purposes. 4DOS Reference Manual Copyright 1991, JP Software Inc. 15 Some versions of COMMAND.COM permit specification of an alternate path for COMMAND.COM as an argument on the SHELL= line in CONFIG.SYS, and this path is used to set the COMSPEC. This is not a documented feature of COMMAND.COM, and is not supported by 4DOS. 4DOS Reference Manual Copyright 1991, JP Software Inc. 16 Manual Installation and Configuration Options These instructions assume that you are installing 4DOS on a hard disk with drive letter C, and that you will be placing the 4DOS system files in the root directory of that disk. If you need to place the files on another drive or directory (for example, on a floppy disk system), you will need to adjust the parameters. The first step in installing 4DOS is to copy the files from the 4DOS disk or compressed file to your boot disk. If you have a diskette copy of 4DOS, see the README.DOC file on the diskette for information on exactly how the files are stored. Copy (or decompress) the following 4DOS system files to the root directory of your boot disk: KEYSTACK.SYS 4DOS.COM 4DOS88.EXE, if your system has an 8086 or 8088 CPU (this applies to most PC and XT systems) 4DOS286.EXE, if your system has an 80186, 80188, 80286, 80386, 80486, or NEC V20 or V30 CPU (this applies to all AT and 386/486 systems, and some other systems with accelerator boards or replacement CPU chips) If you are in doubt about your CPU type, use 4DOS88.EXE until you can determine the CPU type definitively (see the _CPU variable in Environment Variables). 4DOS88.EXE will work with all PCs. Copy (or decompress) the files HELP.EXE and DOS.HLP to a directory included in your path (i.e. one listed in the PATH statement in AUTOEXEC.BAT). Copy (or decompress) the files 4DOS.DOC, README.DOC, COMPAT.DOC, and ALIASES to any directory you choose, if you wish to have them available on-line permanently, or temporarily in order to print them. 4DOS Reference Manual Copyright 1991, JP Software Inc. 17 4DOS Memory Usage When installing 4DOS you must decide whether you want to run in swapping mode or memory-resident mode. Swapping mode is recommended for most users. In this mode a small part of 4DOS (the resident portion, less than 4K in size, from the file 4DOS.COM) resides permanently in low memory. The remainder of 4DOS (the transient portion, about 70K in size, from the file 4DOS88.EXE or 4DOS286.EXE), resides at the end of normal MS-DOS memory, and is swapped out to XMS, EMS, or disk while your applications are running. This swapping is very fast, especially if XMS or EMS memory or a RAM disk is available, and it allows you to have the power of 4DOS, yet keep most of your memory available for applications. COMMAND.COM uses a similar approach to keep its resident portion in low memory and its transient portion at the end of DOS memory. It does not retain information while applications are running, so it does not use a swap area. The resident portion of COMMAND.COM is slightly larger than that of 4DOS. The transient portion is smaller (about 35K) as COMMAND.COM has far fewer features and capabilities than 4DOS. The resident portion of 4DOS takes about 10K of memory to load (later reduced to less than 4K), and the transient portion 70K, so you must have about 80K of free memory to load 4DOS in swapping mode (82K for 4DOS88). COMMAND.COM requires about 40K of free memory to load. If you find you are able to load COMMAND.COM as the secondary shell from a particular program, but are unable to load 4DOS, it is probably because you have more than 40K but less than 80K of free memory, or because COMSPEC and/or 4DSHELL (see below) are set incorrectly. Memory resident mode is recommended only on systems (older PCs and some laptops) which have no hard disk, XMS or EMS memory, or RAM disk. On such systems the only swap area available is a floppy disk, which is unacceptably slow. In memory-resident mode, all of 4DOS is loaded permanently into low memory; the memory required is about 70K for 4DOS286.EXE, or 72K for 4DOS88.EXE. 4DOS Reference Manual Copyright 1991, JP Software Inc. 18 Setting up CONFIG.SYS In order to install 4DOS you must modify the CONFIG.SYS file. First, create a SHELL command to tell MS-DOS to load 4DOS as the command processor. The format of the command is: SHELL=d:\path\filename [options] where d:\path is the drive and directory where the primary shell program is stored, filename is the full name of that program, and [options] is any option or parameter values for 4DOS. (See 4DOS Startup Options.) The options are passed to the program just as if they had been typed on the command line. When loading 4DOS, the filename part of the command should be 4DOS.COM. For example, the simplest SHELL command which will load 4DOS properly is: SHELL=C:\4DOS.COM /P This loads 4DOS in swapping mode (4DOS determines the optimal swapping method), with default sizes for the environment, alias list, and history list. The /P tells 4DOS it is the primary shell. Use an editor to edit or create your CONFIG.SYS file, and set up your SHELL command as shown above, along with any additional options you need (see next section). If you already have a SHELL command for COMMAND.COM, remove it. Examples of SHELL commands for different systems are given in 4DOS Startup Options. CAUTION: Due to a bug in all versions of MS-DOS and PC-DOS, the SHELL command in CONFIG.SYS may not contain more than 33 characters following the name of the shell program (i.e., beginning with the first character of the [options] in the example above). If the line is too long, the options will not be passed properly to 4DOS, and a variety of errors can occur. You can usually set all of the 4DOS options without exceeding this limit, provided you keep 4DOS88.EXE / 4DOS286.EXE in the root directory of your boot disk. If you need a longer SHELL command line, 4DOS provides the @filename option (see 4DOS Startup Options). In addition to the shell command, if you want to use the 4DOS KEYSTACK command (see Command Reference), you must place a line in CONFIG.SYS to load the 4DOS KEYSTACK device driver. This line should read: device=c:\keystack.sys 4DOS Reference Manual Copyright 1991, JP Software Inc. 19 Loading 4DOS Under DOS 2 While we recommend the use of MS-DOS 3.1 or above, 4DOS can be used with MS-DOS 2. In MS-DOS 2, certain functions require COMMAND.COM to be loaded as the primary command processor, so you must load COMMAND.COM first, then load 4DOS. Assuming all files are in the root directory of drive C, the SHELL command to do this is: shell=c:\command.com /c 4DOS [options] The [options] are defined in 4DOS Startup Options, and should include /P even though 4DOS is not (technically) the primary shell. If /P is left off, AUTOEXEC.BAT will not be run. Note that due to the /C 4DOS on the SHELL line, fewer options can be used before running into the 33-character limit discussed earlier. For this reason the "@filename" option may be necessary when loading 4DOS under DOS 2. Loading 4DOS in the OS/2 DOS Compatibility Box 4DOS can be loaded in the OS/2 MS-DOS compatibility box, but you will be limited to either disk swapping or memory resident modes. (The compatibility box does not support EMS or XMS.) 4DOS Reference Manual Copyright 1991, JP Software Inc. 20 4DOS Startup Options This section describes the options that can be included on the SHELL command in CONFIG.SYS, and/or used for secondary shells (see 4DSHELL). The same options can also be used when you start 4DOS in a window of a multitasking or task switching environment such as DESQview or Windows, or from the command line or a batch file. @d:\path\filename Stop processing input from the command line, and switch to the specified file. Any characters on the line after this option will be ignored. The file may contain any number of lines specifying additional 4DOS options, and may be up to a total of 255 characters long. This option allows you to get around the 33-character limit on options in the SHELL command by placing 4DOS options in a separate file. /A:n Set the alias list size. The range of allowable alias list sizes for all shells is 256 - 32000 bytes. The default value for all shells is /A:1024. The incremental syntax shown with /E below (/E+n) may also be used with /A. /C cmd Load a transient copy of 4DOS, execute cmd, and then return to the parent command processor. This option is used by some application programs to start the command processor, execute a command, and automatically return to the program. It should never be used in the SHELL statement. /E Set the environment size. The range of allowable environment sizes for all shells is 256 - 32000 bytes. There are two formats for this option: /E:n n is the size of the environment in bytes. The default for the primary shell is /E:512. /E+n Set the environment size to the amount of space previously used, plus n bytes. This allows you to guarantee a certain amount of free space in a secondary shell environment. The default for secondary shells is /E+128; the minimum increment allowed is 128 bytes. With either format, appending a U after the size (for example, /E:512U) will cause 4DOS to load the master environment into an XMS UMB. (See the /U option below for more information on UMBs.) This reduces low-memory requirements, but may not be compatible with some programs which access the master environment. If no UMB is 4DOS Reference Manual Copyright 1991, JP Software Inc. 21 available, 4DOS displays an error message, and the environment is put into low memory. Appending an S after the size will swap the master copy of the environment. This will save a small amount of DOS memory, but will not work with any application that attempts to modify the master environment (for example, Novell Netware). 4DOS will always ensure there is at least 128 bytes free in a secondary shell environment, and will override your /E parameter if necessary. /H:n Set the history size, where n is the size of the history list. (The default is 1024 bytes; the range is 512-8192 bytes.) /L:d:\path Tells 4DOS where to find 4DOS88.EXE (or 4DOS286.EXE). The default is the root directory of the boot drive for the primary shell, and the path specified by COMSPEC for secondary shells. You must use this switch if the EXE file is not in the default location. /P Load 4DOS permanently, and run AUTOEXEC.BAT. 4DOS will NOT run AUTOEXEC.BAT without a /P. This option may be placed anywhere on the SHELL= line, but normally appears as the last option. Do NOT use this option for secondary shells, or you will be unable to return to the primary shell. /S Set the 4DOS swapping mode, as follows: /S:B[d:\path] Best guess swapping (default mode). 4DOS first tries XMS memory swapping (on an 80286 or 80386), then EMS, then disk swapping to the specified drive and directory. Disk swapping filenames and defaults are as described for /S:D below. /S:D[d:\path] Swap to disk. Creates a file 4DOSSWAP.xxx where xxx is the current shell nesting level (000 for the primary shell). If the drive and path are not specified, disk swapping will default to the root directory of the boot drive for the primary shell, and the root directory of the drive specified in COMSPEC for secondary shells. /S:E Swap to EMS memory. EMS swapping requires a minimum of 80K free EMS memory for the primary shell, and 32K for 4DOS Reference Manual Copyright 1991, JP Software Inc. 22 most secondary shells; very large environment, alias list, and history sizes will require more. /S:N Load 4DOS in memory-resident mode (no swapping). /S:X Swap to XMS (extended) memory. XMS swapping requires an XMS device driver and a minimum of 70K of free XMS memory; large environment, alias list, and history sizes will require more. If 4DOS can't access EMS or XMS memory or create the disk swap file, it will load with swapping disabled (memory- resident mode). 4DOS displays the type of swapping (XMS, EMS, or disk) and the amount of swapping space used when it starts. If possible, 4DOS will reduce the space used to swap a secondary shell from 68K or more to about 20K by retrieving static information from the primary shell's swap area. This feature will not work if the total of alias, history, and environment sizes in the secondary shell is larger than the total for the primary shell, or if the size of DOS memory has been reduced when the secondary shell is started (e.g. by a program like DESQView that reserves some space at the top end of DOS memory). /U Move the resident portion of 4DOS to an XMS Upper Memory Block (UMB). This reduces the size of the resident portion in low memory from about 3K to 256 bytes, plus the environment size. This option can only be used on 286 and 386 systems with software which can map memory into the 640K to 1MB area and have 3K or more of free space in that area, and which include an XMS driver. XMS swapping may be used for the rest of 4DOS via /S:X, but is not required for /U to work. If the UMB load fails, the load will continue with the resident portion of 4DOS remaining in low memory. See COMPAT.DOC for up to date information on the memory management software needed to enable /U to work. Any text on the 4DOS command line (including the SHELL= line) following the final option will be interpreted as a startup program command. This allows you to directly load a program without running AUTOEXEC.BAT (and giving the user the opportunity to break out to the MS-DOS prompt with a ^C). For example, to load 4DOS in EMS swapping mode with a 2048 character alias list and a 2048 character command history: shell=c:\4dos.com /s:e /a:2048 /h:2048 /p 4DOS Reference Manual Copyright 1991, JP Software Inc. 23 To load 4DOS with a 2048 character environment in disk swapping mode, swapping to a RAM disk defined as F: shell=c:\4dos.com /s:df:\ /e:2048 /p To load 4DOS in "best available" swapping mode, using drive G for disk swapping if necessary, loading the .COM and .EXE files from the directory D:\BIN\4DOS, with a 1024 character environment, a 4096 character alias list, and a 2048 character history, and the low-memory code moved to a UMB if possible: shell=d:\bin\4dos\4dos.com @d:\bin\4dos\4dos.opt The file D:\BIN\4DOS\4DOS.OPT: would contain: /s:bg:\ /l:d:\bin\4dos /e:1024 /a:4096 /h:2048 /u /p To load 4DOS in XMS swapping mode, with default history and environment, and run a program called C:\UTIL\MYSHELL automatically after the AUTOEXEC file (if any) is completed: shell=c:\4dos.com /s:x /p c:\util\myshell The 4DOS EXE file (4DOS88 or 4DOS286) can be loaded directly as the primary shell, by using it as the filename in the SHELL command; or as the secondary shell, by using it as the filename in COMSPEC. For example: shell=c:\4dos286.exe /e:2048 /p When the EXE file is loaded directly, rather than via 4DOS.COM, 4DOS will be in memory-resident mode. The only options permitted are /A:n, /E:n, /H:n, /C, and /P. Aliases will not be inherited from a previous shell. We do not recommend this method of loading 4DOS in most circumstances; to load in memory-resident mode, use the /S:N option instead. However, you may wish to use it to conserve disk space (for example, on a laptop with no hard disk), as it does not require 4DOS.COM to be on your disk. 4DOS Reference Manual Copyright 1991, JP Software Inc. 24 The 4DSHELL Environment Variable When loading the primary shell, the shell name and options are both specified by the SHELL command in CONFIG.SYS. For secondary shells, COMSPEC specifies the shell name, but not the options. 4DSHELL is an environment variable, used by 4DOS to set the options for secondary shells. If 4DSHELL is not defined, secondary shells will use default values for their options. If options are set on the command line, they will override those in 4DSHELL. 4DSHELL should normally be set in AUTOEXEC.BAT. It can contain any of the options listed in 4DOS Startup Options, except /C and /P. If the 4DOS EXE file is not in the directory specified by COMSPEC, you MUST use the /L option in 4DSHELL, or secondary shells will not start properly. The following examples show the use of both COMSPEC and 4DSHELL to configure your system properly for secondary shell operation. To load 4DOS.COM and the EXE file from C:\, use EMS swapping in secondary shells, and guarantee 512 bytes of free environment space: [no COMSPEC setting necessary] set 4dshell=/s:e /e+512 To load 4DOS.COM from C:\BIN and the 4DOS EXE file from D:\BIN, use best guess swapping (default), and move the resident portion of secondary shells to an XMS UMB if possible: set comspec=c:\bin\4dos.com set 4dshell=/l:d:\bin /u AUTOEXEC and 4START The AUTOEXEC.BAT file contains DOS commands to be AUTOmatically EXECuted by the primary shell when it starts. It is executed before you are given control at the prompt. The /P switch MUST be on the SHELL= line in CONFIG.SYS for AUTOEXEC.BAT to be executed. AUTOEXEC cannot be a .BTM file. If you do not have an AUTOEXEC.BAT file, COMMAND.COM will prompt you for the current date and time. 4DOS will not; it will simply transfer you immediately to the 4DOS prompt. 4START is an optional batch (.BAT or .BTM) file of 4DOS commands to be executed whenever 4DOS is started, whether as a primary or secondary shell. This makes it a convenient place to put configuration commands such as SETDOS, to make 4DOS operate in the mode you want regardless of whether you are in a primary or secondary shell. In the primary shell, 4START is executed before AUTOEXEC.BAT. 4DOS Reference Manual Copyright 1991, JP Software Inc. 25 You should not load any memory-resident programs (TSRs) from the 4START file, because 4DOS will attempt to load them every time it starts a new shell. You shouldn't load aliases from 4START, since 4DOS will pass them automatically to secondary shells. 4DOS and COMMAND.COM In virtually all circumstances you will want to load 4DOS as your primary and secondary shell. However, there are a handful of ill-behaved programs which dynamically modify COMMAND.COM, or otherwise interact with COMMAND.COM in a non-standard way, which may require you to load COMMAND.COM in order to work properly. In some circumstances, to run a particular program you may need to load a copy of COMMAND.COM from within 4DOS, then run the program. In very rare circumstances, you may need to load COMMAND.COM as the primary shell and then load 4DOS. An explanation of both techniques is included in Appendix E and the file COMPAT.DOC, along with a list of the programs known to require them. You may also find that in some cases, when there is a need to shell to DOS with very little memory available, you wish to use COMMAND.COM as your secondary shell, while 4DOS is the primary shell. To do so, simply set your COMSPEC to point to COMMAND.COM. If you wish to run a copy of COMMAND.COM from the 4DOS prompt for testing or other purposes, be sure to set the COMSPEC to point to COMMAND.COM first. If you don't, and an application overwrites the COMMAND.COM transient portion, COMMAND.COM may be unable to reload itself, and will give an error message and return to 4DOS. 4DOS Reference Manual Copyright 1991, JP Software Inc. 26 Using 4DOS This section briefly reviews 4DOS features, and provides some examples of how 4DOS can help improve your productivity, and make your computer easier to use. It also documents the features of 4DOS which are not related to specific commands, such as command line editing, command history, command syntax, and batch files. Starting 4DOS Whenever 4DOS is loaded, it searches the boot directory for the file 4START.BTM or 4START.BAT, and executes it if found. If 4DOS is started with the /P option, it will then execute AUTOEXEC.BAT. Because 4START is always executed when 4DOS starts, it provides a convenient place to put the 4DOS configuration commands (for example, SETDOS parameters) that would otherwise not be set when executing a secondary copy of 4DOS. (For example, when shelling out to MS-DOS from within a program.) See the Command Reference Guide for more information on SETDOS. When setting up 4START and AUTOEXEC.BAT, we recommend you break up the work to be done into smaller batch files. In particular, if you put the aliases and environment variables into separate batch files and use CALL to invoke them, you can edit and reinvoke them later without having to reboot the system. 4DOS Reference Manual Copyright 1991, JP Software Inc. 27 Command Line Editing The following keys have special meanings when editing command lines (the caret ^ means press the Control key together with the specified key): Left Arrow Move the cursor left one character. Right Arrow Move the cursor right one character. Up Arrow Recall the previous command from the history list, or match a partial command entry with a history list entry. Down Arrow Recall the next command from the history list, or match a partial command entry with a history list entry. ^Left Arrow Move the cursor left one word. ^Right Arrow Move the cursor right one word. Home Move the cursor to the beginning of the line. ^Home Delete from the beginning of the line to the character preceding the cursor. End Move the cursor to the end of the line. ^End Delete from the cursor to the end of the line. Ins Toggle between insert and overstrike mode. Del Delete the character at the cursor. Backspace Delete the character to the left of the cursor. CR or LF Execute the command. Esc Erase the entire line. ^L Delete the word to the left of the cursor. ^R or ^Bksp Delete the word to the right of the cursor. ^C Cancel the command. ^D Delete the history list entry, erase the line, and display the previous history entry. ^E Go to the end of the history list and display the entry. ^K Save the command to the history list, and erase the line. F1 Call the on-line help (HELP.EXE). F3 Repeat or complete the previous line from the history list (as in COMMAND.COM) F8, F9 & F10 F9 scans the filename (including the wildcard (TAB=F9, characters * and ?) at or immediately to the left shift-TAB=F8) of the cursor position, and replaces it with the first matching filename. Pressing F9 again substitutes the next filename; pressing F10 appends the next filename at the current cursor position. Pressing F8 gets the previous filename. If you don't enter an extension, F9 will append *.* to the filename; otherwise, F9 will append *. See Command History and Recall for more information on filename completion. Alt-255 You can enter characters that would normally be interpreted by the line editor as a command (for example, ^D) by preceding them with an Alt-255. (Hold down the Alt key and enter 255 on the numeric keypad.) Anything else Enter that character at the cursor position. 4DOS Reference Manual Copyright 1991, JP Software Inc. 28 Command History and Recall 4DOS saves each command into the command history list as it is entered (except when executing a batch file), allowing you to display, recall, search, and modify previous commands. The history list size is determined by the /H parameter at startup time (see Installation). The history is a circular list; when the history list is full, 4DOS discards the oldest command(s) before adding the newest. The command history list can be displayed or cleared with the HISTORY command. The /H option in SETDOS allows you to enable or disable the history saves, and to specify a minimum length to save. (See the Command Reference Guide for more information on HISTORY and SETDOS.) You can prevent a command line from being saved in the history list by beginning it with an @. The simplest use of the command history is to repeat commands exactly. For example, you might enter the command: dir /2p b:*.wks b:*.doc and then move some files to or from drive B. When you're through, you want to repeat the DIR command. Just press the up- arrow repeatedly to scan back through the history list; when the DIR command appears, press ENTER to reexecute it. After you've found the command, you can also edit it before pressing ENTER. This provides a simple means of executing a series of commands that differ only slightly from each other. Another powerful feature is command completion, which searches the command history for the last command that begins with the characters you entered. In the above example, you can quickly recall the DIR command by typing DI, and pressing the up arrow. 4DOS will display the most recent command in the history list that begins with DI. Pressing the up arrow again will display the next most recent match. Typing DI and pressing the down arrow key instead would search for the oldest matching command in the history list. 4DOS will beep if there are no matching commands. 4DOS Reference Manual Copyright 1991, JP Software Inc. 29 4DOS also offers filename completion. For example, suppose you want to copy a file. You remember that the name starts with AU, but you can't remember the rest. Enter: copy au and press the F9 key. The first filename that starts with AU will be inserted in the command line. If it's the right file, simply complete your command. If it's not, press F9 again to substitute the next matching filename. If you go past the filename(s) you wanted, pressing the F8 key will return the previous matching filename. The F10 key saves the current filename, and then appends the next matching filename to the command line. You can use the wildcard characters (* and ?) in the filename. 4DOS will beep when there are no more matching filenames. Multiple Commands You may enter multiple commands on a single line. The default command separator is a caret (^). For example, the following command displays a directory and then copies files to the root directory on drive A: dir *.bat ^ copy *.bat a:\ The command separator character can be changed by setting the COMPOUND variable (see the SETDOS command in the Command Reference Guide). Conditional Commands When an internal or external command finishes, it returns a result, called the exit code. The conditional commands allow you to perform tasks based upon the previous command's exit code. (See also the IF ERRORLEVEL and IFF ERRORLEVEL commands in the Command Reference Guide.) If two commands are separated by && (AND), the second command will be executed only if the first returns an exit code of 0. If two commands are separated by || (OR), the second command will be executed only if the first returns a non-zero exit code. NOTE: All 4DOS internal commands return an exit code (0 if successful, or non-zero for an error return), but not all external programs do. Conditional command behavior will be unpredictable for programs that don't explicitly return an exit code. 4DOS Reference Manual Copyright 1991, JP Software Inc. 30 For example, if the BACKUP operation fails, the files will not be erased: backup c:\ a: /s && global erase *.bak *.lst If the BACKUP operation fails, then ECHO will display a message: backup c:\ a: /s || echo Error in the backup! Escape Character 4DOS has a user-definable escape character (a character which gives the following character a non-standard meaning, not the same as the ASCII ESC). The default is ^X (control-X, which will be displayed as an up arrow ), but another character can be used by setting the ESCAPE variable (see the SETDOS command in the Command Reference Guide). 4DOS assumes special meanings when these characters follow the escape character on the command line: b backspace e the ASCII ESC character (27 decimal) f formfeed n linefeed r carriage return t tab Any other character following the escape character is copied directly to the command line and the escape character is removed. This allows you to suppress the normal interpretation of special characters (such as ? * / \ | ` > < and &). For example, to send a form feed followed by the sequence ESC Y to the printer: echo feY > prn 4DOS Reference Manual Copyright 1991, JP Software Inc. 31 Command Echoing Like COMMAND.COM, 4DOS defaults to ECHO ON in batch files. To prevent a line from being echoed, preface it with the @ symbol. You can tell 4DOS to default to ECHO OFF by setting the variable VERBOSE to 0 (see the SETDOS command in the Command Reference Guide). 4DOS also offers command echoing during keyboard input. If ECHO is set ON from the command line, the fully parsed and expanded command (including alias and variable expansion) will be displayed before it is executed. If the command line contains multiple commands, each command is echoed separately just before it is executed. Note that the command line echo state and batch file echo state are independent. Turning echo on or off inside a batch file will not affect command line echoing, and vice versa. Argument Quoting 4DOS normally parses command line arguments by searching for white space (blanks, tabs, and commas). Command line arguments enclosed in back quotes (`) or double quotes (") may contain white space. No special processing (alias or variable expansion, and I/O redirection) will be performed on expressions enclosed in quotes, except variable expansion WILL be performed inside double quotes. 4DOS will strip back quotes from the command line before executing the command. Double quotes will be passed through to the command. For 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 as: set %forvar=for Entering the command: quotes `Now is the time %forvar` all good produces the following output: Arg1 = Now is the time %forvar Arg2 = all Arg3 = good 4DOS Reference Manual Copyright 1991, JP Software Inc. 32 and entering the command: quotes "now is the time %forvar" all good produces the following output: Arg1 = "Now is the time for" Arg2 = all Arg3 = good When an alias is defined in a batch file or from the command line (see Aliases), its argument should be enclosed in back-quotes to prevent the expansion of parameters, variables, and multiple commands until the alias is invoked. Back quotes should NOT be used when defining aliases to be read in an ALIAS /R file. Batch Files COMMAND.COM executes batch files by opening the file, reading one line, saving the position, closing the file, executing the line, opening the file, moving to the saved position, reading the next line, etc. This scheme has two advantages: batch files can modify themselves dynamically, and they can extend across multiple disks. It also has one disadvantage: batch files run very slowly. For the sake of compatibility, 4DOS processes .BAT files the same way. But 4DOS also offers a much faster approach, called Batch to Memory (.BTM). Since a .BTM file is loaded entirely into RAM before it is executed (requiring only one disk access), .BTM files run two to five times faster than .BAT files (even faster on floppy disks). For very small batch files the difference between .BAT and .BTM files will be negligible, but for large files or ones with loops, a .BTM will run nearly as fast as an alias. Most .BAT files can be renamed to a .BTM extension and immediately realize a significant performance improvement. The maximum size of a .BTM file is 64K bytes. You should not use a .BTM file (or a .BAT file which is CALLed from a .BTM file) to load memory-resident (TSR) programs. If you do, the memory used for the .BTM file will be located below the TSR. When the .BTM file exits, this memory will be freed and you will be left with a "hole" in memory. This is not harmful, but wastes memory. 4DOS also offers an additional "Cancel ALL" option for ^C handling in batch files. If you press ^C or ^BREAK while in a batch file, 4DOS will prompt: Cancel batch job ? (Y/N/A) : 4DOS Reference Manual Copyright 1991, JP Software Inc. 33 Pressing N will continue batch processing at the next line. Pressing Y will end the current batch file and return to the calling batch file (if any). Pressing A will cancel all batch file processing, regardless of the nesting level (see CALL and CANCEL in the Command Reference Guide) and return to the command prompt. Batch files may be "nested" (batch file A CALLs batch file B which CALLS batch file C, etc.) up to 8 levels deep. Batch File Variables Batch file variables are only active inside a batch file. They are referenced as %0 to %127, and expand to the matching argument on the command line that started the batch file. The parameter %n& is a special case, and expands to all arguments in the command line tail, starting at argument number n. If n is not specified, it defaults to 1 (so %& expands to all arguments in the command line tail). The batch variable %# expands to the number of command line arguments, not including %0 (the batch file name). Note that the SHIFT command will shift both the numbered variables (%0, %1, etc.) and the %n& and %# variables. 4DOS Reference Manual Copyright 1991, JP Software Inc. 34 Aliases Much of the power of 4DOS comes together when using aliases. An alias is a new name for a command or combination of commands. Aliases are defined with the ALIAS command, and removed with the UNALIAS command. Aliases are expanded before the command line is broken up for multiple commands, redirection, and conditional commands. Aliases may be nested; i.e., an alias can refer to another alias, but they cannot refer back to themselves. The alias name is limited to no more than 80 characters, and the alias argument to no more than 255 characters. The simplest type of alias is to give a new name to an existing command. For example: alias up cd .. defines the alias UP to mean "change to the parent directory". Aliases can also create a customized version of a command. For example, the 4DOS DIR command allows a directory to be sorted in various ways. The alias: alias de dir /oe /p defines the alias DE to mean "sort the directory by extension, pausing after each page." Aliases can also be used to execute multiple commands; when used this way they act like very fast, in-memory batch files. For example, entering the command: alias w `pushd c:\wp ^ wp %& ^ popd` defines the alias W to mean "save the current directory, change to the WP directory on C, run the WP program passing it all of the arguments on the command line following the alias name, and when finished, restore the original directory." The back quotes are required to tell 4DOS this is a single alias with three commands, rather than three commands on a single line (see Multiple Commands). You can stop alias expansion by prefacing the alias with an asterisk (*). This allows you to use aliases to define commands as variations of themselves, or to rename internal commands to avoid conflicts with external programs. For example, the alias definition: alias global global /I will fail with an "alias loop" error message, but the alias: alias global *global /I 4DOS Reference Manual Copyright 1991, JP Software Inc. 35 will work properly. You can also use this feature to rename a 4DOS internal command (for example, if you have an external program of the same name). The following alias definitions rename the LIST command to DISPLAY, and call an external program for LIST: alias display *list alias list c:\util\list.com Alias names can be truncated by including an asterisk (*) in the alias name. For example, if you have an alias defined as: alias wher*eis dir /dp you can refer to it as wher, where, wherei, or whereis. Alias definitions can include replaceable parameters, like those in batch files. Alias parameters are referenced as %1 to %127, and expand to the matching command line argument. The parameter %n& is a special case, and expands to all arguments in the command line tail, starting at argument number n. If n is not specified, it defaults to 1 (so %& expands to all arguments in the command line tail). If an alias has replaceable parameters, 4DOS will delete command line arguments up to and including the highest referenced argument. For example, if you have an alias which refers only to %1 and %4, then the first and fourth arguments passed to the alias will be used, the second and third arguments will be discarded, and any additional arguments beyond the fourth will be appended to the end of the alias. If an alias has no replaceable parameters, all of the command line arguments will be appended to the alias. For example, the following alias will change directories, perform a command, and return to the original directory: alias in `pushd %1 ^ %2& ^ popd` When this alias is invoked with: in c:\comm mycomm /xmodem /2400 it is expanded into the following three commands: pushd c:\comm mycomm /xmodem /2400 popd 4DOS Reference Manual Copyright 1991, JP Software Inc. 36 The distribution disk includes a sample alias file (ALIASES) which demonstrates a number of useful predefined aliases. See the ALIAS and UNALIAS commands in the Command Reference Guide for more information and examples. Executable Extensions 4DOS provides a means to specify a program to be invoked when a filename which does not have a .COM, .EXE, .BTM, or .BAT extension is entered as the first argument on the command line. For example, you could start your text editor when a text file is specified, or your spreadsheet program when a worksheet file is specified. 4DOS uses environment variables to define what program or batch file to run for a particular extension. The syntax of the SET command to define an executable extension is: SET .ext=d:\path\program [options] where .EXT is the file extension, D:\PATH\PROGRAM is the full name of the program or batch file to be called, and [options] are any startup options you want to specify for the program. The file to be executed must be a .COM, .EXE, .BTM, or .BAT file; it cannot be an alias or internal command. For example, the following command would define BASICA.COM as the processor for .BAS files: set .bas=c:\dos\basica.com The following command would define B.EXE (the Brief text editor) as the processor for .C files: set .C=c:\brief\b.exe -Mxyz If you have a file HELLO.C, and enter the command: hello -i30 4DOS expands the command line to: c:\brief\b.exe -Mxyz hello.c -i30 4DOS Reference Manual Copyright 1991, JP Software Inc. 37 Note that 4DOS inserts the value of the environment variable at the beginning of the line, including any options, then appends the original command name (i.e., the file name, with extension added if necessary), and the remainder of the original command line. 4DOS searches for external commands in the following order: .COM, .EXE, .BTM, .BAT, and executable extensions (in the order they appear in the environment) in the current directory, and then in each subdirectory specified by the PATH environment variable. 4DOS Reference Manual Copyright 1991, JP Software Inc. 38 Keystack The KEYSTACK command can be used in aliases and batch files to feed keystrokes to application programs. The most common use of KEYSTACK is to have a program take certain actions when it starts. For example, when the alias (this should be entered on one line): alias 321 `keystack 0 13 0 13 0 13 0 13 0 13 "/fr" 0 "%1" 13 ^ 123` is executed as: 321 February it loads Lotus 1-2-3, skips the startup screens, and loads the spreadsheet FEBRUARY.WK1. KEYSTACK can store up to 255 characters, enough keystrokes to cause a program to do an entire operation and exit. For example, the following alias DRPT will run a dBASE report called TIMEREP in the directory DATA (this should be entered on one line): alias drpt `pushd c:\data ^ keystack "use times index times" 13 "report form timerep to print" 13 "quit" 13 ^ dbase ^ popd` See the Command Reference Guide for more information on KEYSTACK. KEYSTACK.SYS is a small device driver invoked in your CONFIG.SYS file (see Installation) and used to support the KEYSTACK command. You must have KEYSTACK.SYS installed to use the KEYSTACK command. 4DOS Reference Manual Copyright 1991, JP Software Inc. 39 Environment Variables Environment variables are defined with the SET command. (See the Command Reference Guide for more information on SET.) Environment variables are expanded before the command line is broken up for multiple commands, redirection, and conditional commands, but after alias expansion has been done. Variables are referenced in a command by starting the variable name with a percent sign (%). Two percent signs in a row (%%) signify a percent sign character. An environment variable name is terminated by either another percent sign, or by an invalid character (see below). To pass a variable name (instead of the value) to a command (for example, in INKEY or INPUT), you must precede it with two percent signs. Environment variable names may be composed of any alphanumeric character, plus the underscore (_) and $ characters. For example: c:\> set start=c:\wordproc\myfiles\memos c:\> dir /w %start In addition to the standard variable name characters, you can force 4DOS to accept any sequence of characters as a valid variable name by enclosing it in square brackets. For example: %[AB##1] refers to an environment variable named AB##1. There are some variable names that have special meanings in 4DOS. Only PATH, CMDLINE and TMP are actually stored in the environment; the remainder are internal to 4DOS, and cannot be viewed or modified with SET or ESET. The internal variable names are checked after variable expansion, so they can be overridden by creating an environment variable of the same name. ? returns the exit code of the last external program (see ERRORLEVEL). This allows you to save an exit code into another variable and then process it later, or to see what a program is actually returning. PATH tells 4DOS where to search for executable files (.COM, .EXE, .BTM and .BAT) not in the current directory. Some applications also use the PATH variable to find their files. CMDLINE is the fully expanded 255-character command line. You can access it from an external program by searching the environment. 4DOS Reference Manual Copyright 1991, JP Software Inc. 40 TMP specifies where 4DOS should put the temporary pipe files (see Redirection). _BG is the screen background color at the current cursor position. _COLUMNS is the width of the screen _CPU is the cpu type, returned as a string: 86 8086 and 8088 186 80186 and 80188 200 NEC V20 and V30 286 80286 386 80386 and 80486 _CWD is the current directory in the format d:\pathname. _CWDS has the same value as CWD, except it ensures the pathname ends in a backslash (\). _CWP is the current directory in the format \pathname. _CWPS has the same value as CWP, except it ensures the pathname ends in 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). _DISK is the current disk (for example, C). _DOSVER is the current MS-DOS version (for example, 3.3). _DOW is the day of the week as a string (Mon, Tue, etc.) _FG is the screen foreground color at the current cursor position. _NDP is the numeric data processor (coprocessor) type, returned as a string: 0 no coprocessor is installed 87 8087 287 80287 387 80387 _ROWS is the height of the screen _SHELL is the current shell nesting level (in swapping mode). The root shell is 0. If you are not in swapping mode, _SHELL returns 99. 4DOS Reference Manual Copyright 1991, JP Software Inc. 41 _TIME contains the current system time in the format hh:mm:ss . The separator character may vary depending depending upon your country information - see CHCP in the Command Reference Guide). Variable Functions 4DOS Version 3 introduces a new type of environment variable. Called Variable Functions, they take one or more arguments (which can be environment variables or variable functions themselves), and return a value. Like all environment variables, variable functions must be preceded or surrounded by % signs when used. The variable functions are: @eval[expression] - evaluate an arithmetic expression. It supports parentheses, addition, subtraction, multiplication, division, and modulo (%%). The expression can contain envi- ronment variables, including other variable functions. The elements of the expression and the result are integers between -2,147,483,640 and +2,147,483,647. For example, if the value of the variable "a" is 5, then %@eval[(%a*4)-2] returns 18. @ext[filename] - returns the file extension (without the leading period) @full[filename] - returns the fully qualified path name @index[string1,string2] - returns the position of string2 within string1. The first position in string1 is numbered 0. If there is no match, the function returns -1. @len[string] - returns the length of the string @line[filename,n] - returns line "n" of the specified file. (The first line is line 0.) @lower[string] - returns the string shifted to lower case @name[filename] - returns the filename only (no path or extension) @path[filename] - returns the path only (including the trailing backslash) @search[filename] - searches for the filename, using the PATH environment variable, and appends an extension (.COM, .EXE, .BAT, .BTM, or executable extension) if one wasn't specified. @substr[string,start,length] - returns a substring, starting at the position start and continuing for length characters. If length is negative, the start is relative to the right side. (The first character is 0.) For example, to get the current time and extract the hour use %@substr[%_time,0,2]. @upper[string] - returns the string shifted to upper case 4DOS Reference Manual Copyright 1991, JP Software Inc. 42 I/O Redirection MS-DOS assumes input comes from the keyboard and output goes to the display. The keyboard is referred to as the standard input, and the display is referred to as the standard output. You can change the default standard input and standard output by using the < and > symbols on the command line. 4DOS also allows you to redirect the standard error by appending the & character. Normally, when redirecting standard output, if the specified file doesn't exist, it is created; if it exists, it is overwritten, and the previous contents are lost. If the variable NOCLOBBER is set (see the SETDOS command in the Command Reference Guide), an error message will be displayed if the file already exists. For example, to get standard input from a file instead of the keyboard, append: < filename to the command line. To redirect standard output to a file: > filename To redirect standard output to a file, overriding the NOCLOBBER setting: >! filename To redirect standard output and standard error to a file: >& filename To redirect standard error only to a file: >&> filename To redirect standard output and standard error to a file, overriding the NOCLOBBER setting: >&! filename To append standard output or standard error to a file, use >> in place of the first >. If NOCLOBBER is set, the file must exist before it can be appended to (unless overridden by a !). Otherwise, 4DOS will create the file. Pipes allow you to send the output of one command to the input of another command by separating the commands with the vertical bar (|). 4DOS will perform the commands in order from left to right. 4DOS Reference Manual Copyright 1991, JP Software Inc. 43 For example, to use the standard output of command1 as the standard input of command2: command1 | command2 To use the standard output and standard error of command1 as the standard input of command2: command1 |& command2 4DOS creates temporary files to hold the output of the pipes. The default directory for these temporary files is the root directory on the boot drive, but this can be overridden with the TMP environment variable. This is useful when booting from a floppy disk or a read-only network drive, or to speed up piping operations by putting the temporary files on a RAM disk. For example, to put the pipe files on a RAM disk defined as drive E: set tmp=e:\ 4DOS also provides TEE and Y "pipe fittings" (see the Command Reference Guide for more information on TEE and Y). 4DOS Reference Manual Copyright 1991, JP Software Inc. 44 Command Parsing Because of the number of features in 4DOS, the command line parsing is somewhat complex. The following is a summary of the process 4DOS uses to interpret command line input: ∙ Read the command line (from console or batch file) and strip leading white space ∙ Check for a leading @ ∙ Save line to history list if no @ found, and if not in a batch file ∙ Set the "no echo" flag if @ found ∙ Perform alias expansion, including expansion of nested aliases, for the first command on the line. ∙ Perform environment variable expansion (except the EXCEPT, FOR, GLOBAL, and SELECT commands) for the first command on the line ∙ Scan the first command for pipes, compound commands or conditionals ∙ Perform redirection (except the EXCEPT, FOR, GLOBAL, and SELECT commands) ∙ Get the first argument and search for commands in the following order: 1. Internal commands 2. External commands - .COM, .EXE, .BTM, and .BAT in that order 3. Executable extensions (in the order they appear in the environment) ∙ Execute the command ∙ Get the remainder of the command line, if any, and test for conditionals ∙ Repeat the above steps for the next command on the line (if any) If you are having trouble getting aliases, batch files, multiple commands, environment variable substitution, or other features related to command parsing to work properly, you may want to step through the command to determine how 4DOS is parsing it. When doing this you may find it useful to run the command with ECHO set on so you can see the expanded command 4DOS is trying to execute. 4DOS Reference Manual Copyright 1991, JP Software Inc. 45 Command Reference Guide 4DOS has more than 70 internal commands. Some are the same as, or improvements of, those in COMMAND.COM. The remainder are new commands. These commands are equivalent to those in COMMAND.COM: BREAK CHCP CTTY DATE EXIT GOTO TIME VER VERIFY These commands are enhanced: CD CHDIR CLS COPY DEL DIR ECHO ERASE FOR IF MD MKDIR PATH PAUSE PROMPT RD REM REN RENAME RMDIR SET SHIFT TYPE VOL These commands are new: ? ALIAS ATTRIB BEEP CALL CANCEL CDD COLOR DESCRIBE DIRS DRAWBOX DRAWHLINE DRAWVLINE ENDLOCAL ESET EXCEPT FREE GLOBAL GOSUB HISTORY IFF INKEY INPUT KEYSTACK LIST LOG MEMORY MOVE POPD PUSHD QUIT RETURN SCREEN SCRPUT SELECT SETDOS SETLOCAL SWAPPING TEE TEXT TIMER UNALIAS UNSET Y 4DOS Reference Manual Copyright 1991, JP Software Inc. 46 Command Syntax Words in uppercase are keywords and must be entered. Words in lowercase are either options (e.g., "on", "off", "bright", "blink") or variables (e.g. "filename", "path"). The expression d: represents a disk drive specification. (This can be A:, B:, C:, etc.). Words or letters in brackets ([ ]) are optional and are not required to be entered. A vertical bar (|) separating words means enter one word or the other, but not both. A letter preceded by a forward slash (/) is a switch. Switches are used to enable or disable the various command options. Because 4DOS supports multiple arguments for most commands, switches affect specific arguments, and must be placed with those arguments. Pay careful attention to switch placement as it is described under the various commands. The effects occasionally vary between commands in order to retain compatibility with COMMAND.COM. An ellipsis (...) means additional arguments are allowed, but not required. In the examples in the printed manual, characters in bold type represent input from the user. Characters in normal type represent 4DOS prompts or responses. 4DOS Reference Manual Copyright 1991, JP Software Inc. 47 ? Syntax: ? Purpose: Display the 4DOS commands. Comments: ? will display the 4DOS internal commands. For help with the internal 4DOS and external DOS commands, see the HELP command. Example: Display the internal commands: c:\> ? ? ALIAS ATTRIB BEEP BREAK CALL CANCEL CD CDD CHCP CHDIR CLS COLOR COPY CTTY DATE DEL DESCRIBE DIR DIRS DRAWBOX DRAWHLINE DRAWVLINE ECHO ENDLOCAL ERASE ESET EXCEPT EXIT FOR FREE GLOBAL GOSUB GOTO HISTORY IF IFF INKEY INPUT KEYSTACK LIST LOG MD MEMORY MKDIR MOVE PATH PAUSE POPD PROMPT PUSHD QUIT RD REM REN RENAME RETURN RMDIR SCREEN SCRPUT SELECT SET SETDOS SETLOCAL SHIFT SWAPPING TEE TEXT TIME TIMER TYPE UNALIAS UNSET VER VERIFY VOL Y 4DOS Reference Manual Copyright 1991, JP Software Inc. 48 ALIAS Syntax: ALIAS [/P] [/R filename...] [name[=][value]] Purpose: Load or display the alias list, or define name as a substitute for value. Comments: Aliases are useful as a means of executing a complex series of commands with a few keystrokes. Aliases can also be used as "in memory batch files," and will run much faster than disk-based batch files. If you only specify name, ALIAS displays the current alias value for name. Otherwise, ALIAS assigns the command(s) in value to name. (Value may contain environment variables or additional aliases.) Name can now be used as if it were a built-in or external command. If you don't specify any arguments, ALIAS displays the current alias list. Name is limited to no more than 80 characters, and value to no more than 255 characters. The /P(ause) option will pause after displaying each page and wait for a key to be pressed. The /R(ead) option allows you to load an alias list from a file. This is much faster than loading aliases from a batch file. The file is in the same format as the ALIAS display, so ALIAS /R can accept as input a file generated by redirecting ALIAS output. You can add comments to an alias file by starting the comment line with a colon (:). You can load multiple files with one ALIAS /R command by placing the names one after another on the command line, separated by spaces. For example, the following commands will save the aliases to a file, and then reload them from that file: alias > alist alias /r alist When defining aliases at the command line, back quotes must be used around the alias arguments that contain multiple commands or variable references (%1, %&2, etc.) to prevent premature expansion. Back quotes should NOT be used when defining aliases in a file to be read with ALIAS /R. 4DOS Reference Manual Copyright 1991, JP Software Inc. 49 Aliases may be nested; i.e., an alias can refer to another alias, but they cannot refer back to themselves (a=b=a). You can stop further alias expansion by prefacing the alias argument with an asterisk (*). This also allows an alias to refer to a command of the same name (see below for an example). An alias name can be truncated by including an asterisk (*) in the alias name (see example). To remove an alias, use the UNALIAS command. For more information on aliases (including the use of variables), see the Aliases section in Using 4DOS, and the sample file ALIASES, distributed with 4DOS. Example: Define D as an alias for DIR /AP: c:\> alias d dir /ap Display the current alias(es): c:\> alias D=dir /ap The following example creates a new command WHEREIS that searches a disk for matching files and subdirectories: c:\> alias whereis dir /dp The same command using alias name truncation (this alias can be referenced as wher, where, wherei, or whereis): c:\> alias wher*eis dir /dp The following example erases the backup files, and then displays the directory (the back-quotes are necessary to prevent 4DOS from processing the command separator ^): c:\> alias zap `del *.bak ^ dir /w` 4DOS Reference Manual Copyright 1991, JP Software Inc. 50 Redefine the 4DOS DIR command as a variation of itself (wide display, including hidden and system files, pausing after each page): c:\> alias dir *dir /whp Rename the 4DOS LIST command to DISPLAY, and alias LIST to an external program: c:\> alias display *list c:\> alias list c:\util\list.com The following examples show the use of alias arguments: c:\> alias zap `erase %& ^ chkdsk ^ dir /w` c:\> zap *.bak *.lst This expands to: erase *.bak *.lst ^ chkdsk ^ dir /w c:\> alias reverse `echo %5 %4 %3 %2 %1` c:\> reverse one two three four five This expands to: echo five four three two one The following example shows the use of IFF inside an alias. The alias modifies the SET command so that if SET is entered with no arguments, it is replaced by a SET /P (pause after displaying each page). Note the use of asterisks (*set) to prevent alias loops (this should be entered on one line): c:\> alias set `iff "%1"=="" then *set /p^ else *set %&^endiff` 4DOS Reference Manual Copyright 1991, JP Software Inc. 51 ATTRIB Syntax: ATTRIB [/D] [-|+[AHRS]] [d:][path]filename... Purpose: Change the file or subdirectory attributes. Comments: ATTRIB normally only modifies file attributes. Specifying the /D(irectory) option will also modify subdirectory attributes. +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 file attribute -S Clear the system file attribute 4DOS will preserve the previous file attributes and change only the specified attributes. New attribute values are allowed between filenames; otherwise ATTRIB uses the same attributes specified for the previous file(s). You cannot modify the directory or volume label attributes. You can display the file and subdirectory attributes using the /A option in DIR. Example: Set the read-only and hidden attributes for the file MEMO: c:\> attrib +rh memo Set the archive attribute (file has been modified) for MEMO, and change TEST.COM to system and not modified: c:\> attrib +a memo +s -a test.com 4DOS Reference Manual Copyright 1991, JP Software Inc. 52 BEEP Syntax: BEEP [frequency duration ...] Purpose: Beep the speaker. Comments: BEEP is normally used in batch files to signal that an operation has been completed, or that the computer needs attention (for example, to change disks). Because BEEP allows you to specify the frequency and duration, you can use it to play simple music. You can specify multiple frequency/duration pairs on the command line. The frequency is specified in Hertz, and the duration in 1/18th second intervals. 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. The following table gives the frequency values for a five octave range (middle C is 523 Hz): _______________________________________________________ | | | | | | | | | C | 65 | 131 | 262 | 523 | 1040 | 2093 | |-------|-------|-------|-------|-------|-------|-------| | C#/Db | 69 | 139 | 277 | 554 | 1103 | 2217 | |-------|-------|-------|-------|-------|-------|-------| | D | 73 | 147 | 294 | 587 | 1176 | 2349 | |-------|-------|-------|-------|-------|-------|-------| | D#/Eb | 78 | 156 | 311 | 622 | 1241 | 2489 | |-------|-------|-------|-------|-------|-------|-------| | E | 82 | 165 | 330 | 659 | 1311 | 2637 | |-------|-------|-------|-------|-------|-------|-------| | F | 87 | 175 | 349 | 698 | 1391 | 2794 | |-------|-------|-------|-------|-------|-------|-------| | F#/Gb | 93 | 185 | 370 | 740 | 1488 | 2960 | |-------|-------|-------|-------|-------|-------|-------| | G | 98 | 196 | 392 | 784 | 1568 | 3136 | |-------|-------|-------|-------|-------|-------|-------| | G#/Ab | 104 | 208 | 415 | 831 | 1662 | 3322 | |-------|-------|-------|-------|-------|-------|-------| | A | 110 | 220 | 440 | 880 | 1760 | 3520 | |-------|-------|-------|-------|-------|-------|-------| | A#/Bb | 117 | 233 | 466 | 932 | 1866 | 3729 | |-------|-------|-------|-------|------ |-------|-------| | B | 123 | 248 | 494 | 988 | 1973 | 3951 | |_______|_______|_______|_______|_______|_______|_______| Example: The following batch file fragment runs the program DEMO, 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... 4DOS Reference Manual Copyright 1991, JP Software Inc. 53 BREAK Syntax: BREAK [on | off] Purpose: Display, enable, or disable ^C / ^BREAK checking. Comments: BREAK turns the ^C / ^BREAK checking on or off. If no argument is given, it displays the current BREAK status. If BREAK is off, MS-DOS will only check for a ^C during DOS character I/O (screen, keyboard, serial port, or printer operations). Many programs don't use these I/O functions, and it can be difficult to break out of the program with BREAK off. If BREAK is on, MS-DOS will check for a ^C or ^BREAK during any MS-DOS operation (including disk I/O). BREAK defaults to OFF. You can change the default BREAK setting by adding the following line to your CONFIG.SYS file: break=on Example: Check the current BREAK status: c:\> break BREAK is OFF Enable ^C checking in all MS-DOS calls: c:\> break on 4DOS Reference Manual Copyright 1991, JP Software Inc. 54 CALL Syntax: CALL [d:][path]filename Purpose: Call a secondary batch file. Comments: CALL allows batch files to call other batch files (batch file nesting) without invoking a secondary copy of the command processor. 4DOS supports batch file nesting up to four levels deep. The calling batch file is suspended while the called batch file runs. When the called batch file finishes, the calling batch file resumes execution at the next command. If you execute a batch file from another batch file without using CALL, the first batch file is terminated before the second one starts. The current ECHO state will be inherited by a called batch file. See also CANCEL and QUIT. Example: The following batch file fragment compares an input line to "wp" and calls a secondary batch file if it matches: input Enter your choice: %%option if "%option" == "wp" call wp.bat 4DOS Reference Manual Copyright 1991, JP Software Inc. 55 CANCEL Syntax: CANCEL Purpose: Terminate batch file processing. Comments: The CANCEL command will end all batch file processing, regardless of the batch 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. See also CALL and QUIT. Example: 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 4DOS Reference Manual Copyright 1991, JP Software Inc. 56 CD / CHDIR Syntax: CD [d:][pathname] or CHDIR [d:][pathname] Purpose: Display or change the current directory. Comments: Entering CD with no argument or only a disk drive name will display the current directory. Entering CD and a pathname will change the current directory. 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. Use CDD to change both the drive and directory. To start at the root directory, start the pathname with a backslash (\). To start at the parent directory, start the pathname with two periods (..). All other pathnames start at the current directory. MS-DOS will not accept directory names longer than 64 characters. See also CDD. Example: Change to the subdirectory C:\FINANCE\MYFILES: c:\> cd \finance\myfiles c:\finance\myfiles> Change the default directory on drive A: c:\> cd a:\utility 4DOS Reference Manual Copyright 1991, JP Software Inc. 57 CDD Syntax: CDD [d:]pathname Purpose: Change the current disk drive and directory. Comments: CDD is similar to CD, except it also changes the default disk drive. To start at the root directory, start the pathname with a backslash (\). To start at the parent directory, start the pathname with two periods (..). All other pathnames start at the current directory. MS-DOS will not accept directory names longer than 64 characters. See also CD. Example: Change from the root directory on drive A to the subdirectory C:\WP: a:\> cdd c:\wp c:\wp> 4DOS Reference Manual Copyright 1991, JP Software Inc. 58 CHCP Syntax: CHCP [n] Purpose: Display or change the current system code page. Comments: 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 MS-DOS 3.3 or above. Before using CHCP, 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 two prepared system code pages. An error message is displayed if a code page is selected that has not been prepared for the system. Entering CHCP with no arguments displays the active code page. See your MS-DOS manual for more information on CHCP. Example: Display the current code page: c:\> chcp Active code page: 437 Set the code page to multilingual: c:\> chcp 850 4DOS Reference Manual Copyright 1991, JP Software Inc. 59 CLS Syntax: CLS [[bright] [blink] fg ON bg] Purpose: Clear the video display, optionally to the specified colors. Comments: CLS clears the display and moves the cursor to the upper left corner. fg is the foreground color, bg the background color. Only the first three characters of the color name and attributes ("bright" and "blink") are required. You must have ANSI.SYS (or another ANSI compatible screen driver) loaded to set screen colors. The available colors are: Black Blue Green Red Magenta Cyan Yellow White CLS is normally used in batch files to clear the screen before displaying text. See also COLOR. Example: Clear the display: c:\> cls Clear the display to a blue background, and set white characters as the new default: c:\> cls white on blue 4DOS Reference Manual Copyright 1991, JP Software Inc. 60 COLOR Syntax: COLOR [bright] [blink] fg ON bg Purpose: Set the screen display colors. Comments: fg is the foreground color, bg the background color. Only the first three characters of the color name and attributes ("bright" and "blink") are required You must have ANSI.SYS (or another ANSI compatible screen driver) loaded to set screen colors. The available colors are: Black Blue Green Red Magenta Cyan Yellow White See also CLS and SCRPUT. Example: Set the default screen colors to bright white text on a blue background: c:\> color bright white on blue 4DOS Reference Manual Copyright 1991, JP Software Inc. 61 COPY Syntax: COPY [/MPQRUV] [d:][path]filename[+]...[/AB] [[d:][path]filename][/AB] Purpose: Copy or append one or more files. Comments: Unlike COMMAND.COM, 4DOS allows you to copy several unrelated files to a target directory with a single COPY command. If there are two or more arguments on the command line, COPY assumes the last argument is the target. If there is only one argument, the target is assumed to be the current directory. The plus (+) tells 4DOS to append two or more files to a single target file. If you don't specify a target, COPY will append each subsequent file to the first file. If you specify more than one source file, and the target is NOT a directory, COPY will automatically append the files to the target. The /A(SCII) and /B(inary) options apply to the preceding filename and to all subsequent filenames on the command line until another /A or /B is entered. The other options (/M, /P, /Q, /R, /U, /V) apply to all filenames on the command line. If you use the /A option with a source filename, 4DOS will copy the file up to, but not including, the first ^Z character in the file. If you use /A with a target filename, 4DOS will add a ^Z to the end of the file. 4DOS defaults to /A when appending files, or when the source or target is a device. If you use the /B option with a source filename, 4DOS will copy the entire file. Using /B with a target filename prevents 4DOS from adding a ^Z to the end of the target file. 4DOS defaults to /B for normal file copies. The /M(odified) option copies only those files with the archive bit set (see ATTRIB). The archive bit will NOT be cleared after copying. The /P(rompt) option prompts you to confirm each file copy (Y or N). An N response will skip that particular source file. 4DOS Reference Manual Copyright 1991, JP Software Inc. 62 The /Q(uiet) option turns off the display of the files copied. The /R(eplace) option prompts before overwriting an existing file. The /U(pdate) option copies only those source files that are newer than a matching target file, or where a matching target file doesn't exist. The /V(erify) option verifies each disk write. This is the same as executing the VERIFY ON command, but is only active during the COPY command. See also MOVE. Example: Copy the files MEMO1, PROJECT8.WKS, and UPDATE.BAT to the root directory on drive A: c:\> copy memo1 project8.wks update.bat a:\ Append the files MEMO1, MEMO2, and MEMO3, and store the result in BIGMEMO: c:\> copy memo1+memo2+memo3 bigmemo Copy only those files in the root directory on drive A that are newer than the matching files in the current directory, or which don't exist in the current directory: c:\> copy /u a:\*.* c:\*.* Copy files from the root directory on drive A to the current directory, but prompt before overwriting existing files: c:\> copy /r a:\*.* Copy a downloadable font file to the printer in binary mode: c:\> copy myfont.dat prn: /b 4DOS Reference Manual Copyright 1991, JP Software Inc. 63 CTTY Syntax: CTTY device Purpose: Change the default console device. Comments: At startup, 4DOS uses the keyboard as the standard input device and the display as the standard output device. CTTY allows you to change the console (CON:) to another device that can perform standard character I/O. CTTY works only for those programs that use the standard MS-DOS I/O functions (this includes all of the 4DOS internal commands with the exception of DRAWBOX, DRAWHLINE, DRAWVLINE, LIST, SCREEN, SCRPUT, and SELECT). Example: Change the console to the first serial port: c:\> ctty com1: Change the console back to the standard keyboard and display: c:\> ctty con: 4DOS Reference Manual Copyright 1991, JP Software Inc. 64 DATE Syntax: DATE [mm-dd-yy] Purpose: Display and (optionally) change the system date. Comments: If you don't enter any parameters, DATE will display the current system date and time, and prompt for the new date. Press ENTER if you don't wish to change the date, otherwise enter the new date. The parameters for the DATE command are: mm (month) = 1 - 12 dd (day) = 1 - 31 yy (year) = 00 - 99 or 1900 - 2099 You can use hyphens, slashes, or periods to separate the month, day, and year entries. If you enter only two digits for the year and it is below 80 4DOS will assume it is in the 21st century; if it is 80 or above 4DOS will assume it is in the 20th century. You can specify the year you want explicitly by using a 4-digit value. The format for the date entry depends on the country code defined in the CONFIG.SYS file or by the CHCP command. The default format is U.S. (mm-dd-yy). The European format is dd-mm-yy; the Japanese is yy-mm-dd. See also CHCP and TIME. Example: Enter the date from the command line: c:\> date 12/25/89 To be prompted for the date: c:\> date Mon Dec 25, 1989 9:30:06 Enter new date (mm-dd-yy): 4DOS Reference Manual Copyright 1991, JP Software Inc. 65 DEL / ERASE Syntax: DEL [/PQY] [d:][path]filename... or ERASE [/PQY] [d:][path]filename... Purpose: Erase the specified file(s) from the disk. Comments: If the /P(rompt) option is specified, 4DOS will prompt you to enter a Y or N to confirm file deletions for all filenames. The /Q(uiet) option turns off the display of the files deleted. The /Y(es) option is the reverse of /P - it assumes a Y response to everything, including deleting an entire subdirectory (*.*). Use this option with caution! 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(es) option. If you respond with a Y, DEL will delete all the files in that subdirectory (except hidden, system, and read-only files). Example: Erase all the files in the current directory with a .BAK or .PRN extension: c:\> del *.bak *.prn Confirm the deletion of all files in the current directory with .WKS extensions: c:\> del /P *.wks Delete JAN89.WKS (Y/N)? n Delete FEB88.WKS (Y/N)? y Delete DEC88.WKS (Y/N)? y 4DOS Reference Manual Copyright 1991, JP Software Inc. 66 DELAY Syntax: DELAY [seconds] Purpose: Pause for a specified length of time. Comments: DELAY is useful in batch file loops while waiting for a condition to occur. The default value is one second. You can cancel a DELAY loop by pressing ^C. Example: Wait for 10 seconds: delay 10 4DOS Reference Manual Copyright 1991, JP Software Inc. 67 DESCRIBE Syntax: DESCRIBE [d:][path]filename ["description"] ... Purpose: Create, modify, or delete file and subdirectory descriptions. Comments: DESCRIBE adds descriptions (up to 40 characters) to MS- DOS filenames and subdirectories. The descriptions will be displayed when using DIR with the default single column option, or when using SELECT. File descriptions allow you to identify your files in much more meaningful ways than MS-DOS allows in an eight character filename. You can enter a description on the command line by entering the filename followed by the description enclosed in quotes. Using wildcards (* and ?) and/or multiple filenames with a description on the command line will give all matching files the same description. Descriptions are stored in each directory in a hidden file called DESCRIPT.ION. Use the ATTRIB command to "unhide" this file if you need to copy or delete it. The description file is modified appropriately whenever you perform an internal command (such as COPY, MOVE, DEL, or RENAME), but not if you use an external program (such as XCOPY or a shell program). Example: Create a description for the file MEMO.TXT: c:\> describe memo.txt Describe "memo.txt" : Memo to Bob about party Enter the same description from the command line: c:\> describe memo.txt "Memo to Bob about party" 4DOS Reference Manual Copyright 1991, JP Software Inc. 68 DIR Syntax: DIR [/124ACDFHJNOeirtuzPQSVWX] [[d:][path]filename[+]...] Purpose: Display information about files and subdirectories. Comments: DIR displays information about the files and subdirectories in the specified directory. Depending upon the options specified, DIR can show the filename, file attributes, size, date and time of the most recent change to the file, and the file description. DIR allows wildcard characters (* and ?) in the filename. If you don't specify a filename, DIR defaults to *.* (display all files and subdirectories in the current directory). If you append filenames with a +, 4DOS will display the matching filenames in a single directory listing. If a country code was defined in the CONFIG.SYS file or by the CHCP command, DIR will display the date in the format for that country. The default date format is U.S. (mm-dd-yy). DIR can handle directories of any size, limited only by the available memory. Each filename requires 32 bytes of DOS memory plus the size of the description (if any); a system with 128K of free DOS memory can display up to 4,000 files per directory. Options on the command line apply only to the filenames which follow the option, except that options at the end of the line apply to the preceding filename only. This allows you to specify several options for a group of files, and retains compatibility with COMMAND.COM when a single filename is specified. The DIR options are: 1 Single column display - display the filename, size, date, time, and description. This is the default. 2 Two column display - display the filename, size, date, and time. 4 Four column display - display the filename and size (in K(ilobytes) or M(egabytes). 4DOS Reference Manual Copyright 1991, JP Software Inc. 69 A Display filenames and attributes (see ATTRIB), in the format RHSA, where: R Read-only H Hidden S System A Archive When displaying attributes, DIR cannot also display file descriptions. C Display filenames in upper case (like COMMAND.COM). See also SETDOS /U. D Display contents of the current directory and all of its subdirectories. DIR will only display headers and summaries for those directories with matching filenames. F Display files only (no subdirectories). H Display all files, including hidden and system files. J Justify filenames (same format as COMMAND.COM). N Reset DIR options to the default values (useful when displaying some files in one format, and then changing back to the default format). O? Sort sequence, where ? can be any combination of the following options: e Sort by extension i Sort by the file description (see DESCRIBE) r Reverse the normal sort order t Sort by time (oldest first) u Unsorted (same as COMMAND.COM) z Sort by size The default sort is by filename. P Pause after each screen page and wait for a key to be pressed (useful for displaying long directory listings). Q Suppress header line and summaries, and display file or subdirectory names only, in a single column (useful when redirecting output to a file or another program). S Display summary only (number of files & bytes used). V Display filenames sorted vertically rather than horizontally (with the /2, /4, or /W option). W Wide display - display the filenames only, horizontally across the screen (5 columns on an 80-character display). X Display subdirectories only. See also DESCRIBE and SELECT. 4DOS Reference Manual Copyright 1991, JP Software Inc. 70 Example: Display the .WKS files, and then the .WK1 files in the current directory: c:\> dir *.wks *.wk1 Display the .WKS and .WK1 files together: c:\> dir *.wks+*.wk1 Display all the files on drive C, including hidden and system files, pausing after each page: c:\> dir /dhp c:\*.* 4DOS Reference Manual Copyright 1991, JP Software Inc. 71 DIRS Syntax: DIRS Purpose: Display the current directory stack. Comments: DIRS displays the directory stack used by PUSHD and POPD (most recent entries first). The directory stack holds up to 255 characters (about 10 to 20 entries). See also PUSHD and POPD. Example: 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:\ 4DOS Reference Manual Copyright 1991, JP Software Inc. 72 DRAWBOX Syntax: DRAWBOX ulrow ulcol lrrow lrcol style [bright] [blink] fg ON bg [FILL bgfill] Purpose: Draw a box on the screen. Comments: DRAWBOX is useful for creating attractive screen displays in batch files. DRAWBOX 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). 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. The parameters are: 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 - borderless 1 - single line 2 - double line 3 - single line on top and bottom, double on sides 4 - double line 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) Only the first three characters of the color name and attributes ("bright" and "blink") are required. The available colors are: Black Blue Green Red Magenta Cyan Yellow White See also DRAWHLINE and DRAWVLINE. Example: Draw a single line box around the entire screen with bright white lines on a blue background: drawbox 0 0 24 79 1 bright white on blue fill blue 4DOS Reference Manual Copyright 1991, JP Software Inc. 73 DRAWHLINE Syntax: DRAWHLINE row column len style [bright] [blink] fg ON bg Purpose: Draw a horizontal line on the screen. Comments: DRAWHLINE is useful for creating attractive screen displays in batch files. DRAWHLINE 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). 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. The parameters are: row Start row column Start column len Length of line style Line drawing style: 1 - single line 2 - double line fg Foreground character color bg Background character color Only the first three characters of the color name and attributes ("bright" and "blink") are required. The available colors are: Black Blue Green Red Magenta Cyan Yellow White See also DRAWBOX and DRAWVLINE. Example: Draw a double line along the top row of the display with green characters on a blue background: drawhline 0 0 79 2 green on blue 4DOS Reference Manual Copyright 1991, JP Software Inc. 74 DRAWVLINE Syntax: DRAWVLINE row column len style [bright][blink] fg ON bg Purpose: Draw a vertical line on the screen. Comments: DRAWVLINE is useful for creating attractive screen displays in batch files. DRAWVLINE 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). 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. The parameters are: row Start row column Start column len Length of line style Line drawing style: 1 - single line 2 - double line fg Foreground character color bg Background character color Only the first three characters of the color name and attributes ("bright" and "blink") are required. The available colors are: Black Blue Green Red Magenta Cyan Yellow White See also DRAWBOX and DRAWHLINE. Example: Draw a double width line along the left margin of the display with bright red characters on a black background: drawvline 0 0 24 2 bright red on black 4DOS Reference Manual Copyright 1991, JP Software Inc. 75 ECHO Syntax: ECHO [on | off | message] Purpose: Display the echo status, enable or disable batch file or command line echoing, or display a message. Comments: 4DOS defaults to ECHO ON in batch files. To prevent a line from being echoed, preface it with the @ symbol. You can default to ECHO OFF by setting the variable VERBOSE to 0 (see SETDOS). The current ECHO state is inherited by called batch files. 4DOS defaults to ECHO OFF during keyboard input. If you set ECHO ON from the command line, 4DOS will display the fully parsed and expanded commands (including aliases and variables) before they are executed. The keyboard 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. If no arguments are entered, ECHO displays the current echo status (ON or OFF). ECHO commands in a batch file will send messages to the screen while the batch file executes, even if ECHO is set OFF. You cannot use the command separator character or the 4DOS redirection symbols (| > <) in an ECHO message, unless you enclose them in quotes or precede them with the escape character. See also SCREEN, SCRPUT, SETDOS and TEXT. Example: Enable command line echoing: c:\> echo on Display a message in a batch file: echo Processing your print files... Turn off batch file echoing, without displaying ECHO itself: @echo off 4DOS Reference Manual Copyright 1991, JP Software Inc. 76 ENDLOCAL Syntax: ENDLOCAL Purpose: Restore the saved disk drive, directory, environment variables and aliases. Comment: ENDLOCAL restores the disk drive, directory, environment variables and aliases saved by the previous SETLOCAL command. SETLOCAL and ENDLOCAL can only be used in batch files, not in aliases. See also SETLOCAL. Example: This batch file fragment saves the drive, current working directory, environment variables and aliases, changes the drive and directory, modifies some environment variables, runs the program TEST1, and then restores the original values: setlocal cdd d:\test set path=c:\;c:\dos;c:\util set lib=d:\lib test1 endlocal 4DOS Reference Manual Copyright 1991, JP Software Inc. 77 ESET Syntax: ESET varname... Purpose: Edit environment variables and/or aliases. Comments: ESET allows you to edit your environment variables and aliases using the 4DOS line editing commands (see Command Line Editing in Using 4DOS). The cursor will be positioned at the first character of the variable or alias. ESET will search for environment variables first, and then aliases. If you have an environment variable and an alias with the same name (a bad idea!), ESET will only be able to edit the environment variable. 4DOS limits environment variable and alias names to 80 characters, and their arguments to 255 characters. See also ALIAS, UNALIAS, SET, and UNSET. Example: Edit the MS-DOS executable file search path: c:\> eset path path=c:\;c:\dos;c:\util Create and then edit an alias: c:\> alias d dir /djp c:\> eset d d=dir /djp 4DOS Reference Manual Copyright 1991, JP Software Inc. 78 EXCEPT Syntax: EXCEPT ([d:][path]filename...) command [args...] Purpose: Perform a command, except on the file(s) specified. Comments: EXCEPT provides a means of executing a command on a group of files and/or subdirectories, except those enclosed within the parentheses. The command can be a 4DOS internal command or alias, an external command, or a batch file. You may use the wildcard characters (? and *) in a filename. When using filename completion (see Command Line Editing in Using 4DOS) to get the filenames inside the parentheses, type a space after the open parenthesis before entering a partial filename or pressing F9. Otherwise the command line editor will treat the open parenthesis as the first character of the filename to be completed. EXCEPT prevents operations on the specified file(s) by setting the hidden attribute, performing the command, and then clearing the hidden attribute. If EXCEPT is aborted in an unusual way, you may need to use the ATTRIB command to "unhide" (-H) the file(s). EXCEPT will not work with programs or commands that ignore the hidden attribute. See also ATTRIB. Example: Erase all the files in the current directory, except those beginning with MEMO and those ending in .WKS: c:\> except (memo*.* *.wks) erase *.* Copy all the files and subdirectories except those in C:\MSC and C:\DOS on drive C to drive D: c:\> except (c:\msc c:\dos) xcopy c:\*.* d:\ /s 4DOS Reference Manual Copyright 1991, JP Software Inc. 79 EXIT Syntax: EXIT [n] Purpose: Return from a secondary command processor. Comments: Some application programs will start a secondary copy of the command processor to allow you to execute MS-DOS commands. To return to the application again, type EXIT. If you include a numeric value after the EXIT command, 4DOS will return this value to the calling program as the error level. If the value is not specified, the error level from the most recently executed external program is returned. If no external program has been executed, 0 is returned. You cannot EXIT from the primary command processor. Example: Return to the previous command processor or application: c:\> exit 4DOS Reference Manual Copyright 1991, JP Software Inc. 80 FOR Syntax: FOR %var IN (set) [DO] command ... Purpose: Repeat a command for several variables. Comments: 4DOS sets var sequentially to each member of (set), and then evaluates and executes command for every argument in (set). If one of the arguments in (set) contains MS-DOS wildcard characters (* and ?), var will be set sequentially to each matching filename on the disk. The command can be a 4DOS internal command or alias, an external command, or a batch file. In COMMAND.COM, you must use a single % for the variable name from the command line, and %% when in a batch file. 4DOS will accept either % or %% in either case. COMMAND.COM requires the variable name to be a single character; 4DOS supports variable names up to 80 characters. COMMAND.COM requires the word "DO" on the command line; it is optional in 4DOS. Note that 4DOS supports nested FOR statements; COMMAND.COM does not. Example: The following example compiles the C programs in the current directory that have a 2 or a 3 somewhere in their name: c:\msc> for %a in ( *2*.c *3*.c ) do cl %a ; The following example uses 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) if exist %@name[%file].bak del %@name[%file].bak 4DOS Reference Manual Copyright 1991, JP Software Inc. 81 FREE Syntax: FREE [d:]... Purpose: Display the total disk space, total bytes used, and total bytes free on the specified (or default) drive(s). Comments: FREE provides the same disk information as the external MS-DOS command CHKDSK, but without the wait. See also MEMORY. Example: Display the status of the current drive: c:\> free Volume in drive C: is DEVELOPMENT 42,496,000 bytes total disk space 36,851,712 bytes used 5,644,288 bytes free Display 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 4DOS Reference Manual Copyright 1991, JP Software Inc. 82 GLOBAL Syntax: GLOBAL [/IQ] command [args] Purpose: Execute a command in the current directory and its subdirectories. Comments: GLOBAL performs the command first in the current directory, and then in every subdirectory under the current directory. The command can be a 4DOS internal command or alias, an external command, or a batch file. GLOBAL will terminate if the command returns a non-zero exit code, unless you specify the /I(gnore result) switch. GLOBAL will display the current directory unless you specify the /Q(uiet) switch. Example: Erase all the files with a .BAK extension in every directory on C: c:\> global erase *.bak Copy the files in every directory on drive A to the directory C:\TEMP : a:\> global copy *.* c:\temp 4DOS Reference Manual Copyright 1991, JP Software Inc. 83 GOSUB Syntax: GOSUB label Purpose: Call a subroutine in a batch file. Comments: GOSUB calls the specified label as a subroutine. The subroutine must end with a RETURN statement. After the RETURN, 4DOS will continue processing with the command following the GOSUB command. If the label doesn't exist, the batch file is terminated with the error message "Label not found." The label must begin with a colon (:), and appear by itself on the line. 4DOS ignores case differences when matching labels. See also GOTO and RETURN. 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 /hw return 4DOS Reference Manual Copyright 1991, JP Software Inc. 84 GOTO Syntax: GOTO label Purpose: Continue batch file processing at the line following the label. Comments: GOTO changes the current position in the batch file to the line immediately following the label. If the label doesn't exist, the batch file is terminated with the error message "Label not found." The label must begin with a colon (:), and appear by itself on the line. 4DOS ignores case differences when matching labels. To avoid errors in the processing of nested IFF statements, GOTO cancels all active IFF statements. This means that to avoid errors GOTOs inside IFF statements must branch entirely outside all IFF blocks which are active at the time of the GOTO. See also GOSUB. Example: The following batch file fragment checks for the existence of the file CONFIG.SYS. If the file exists, 4DOS jumps to C_EXISTS and copies all the files from the current directory to the root directory on A. If CONFIG.SYS doesn't exist, 4DOS 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:\ 4DOS Reference Manual Copyright 1991, JP Software Inc. 85 HELP Syntax: HELP [/BW] [/R] [topic] Purpose: Provide help for 4DOS and MS-DOS commands. Comments: The HELP command displays the proper syntax and a brief description of 4DOS and MS-DOS commands. You can also call HELP by pressing F1 at the 4DOS prompt. If you enter HELP with no topic, HELP will display all the commands it can help you with. Select a topic using the cursor keys and press ENTER. For help on a specific command, enter HELP followed by the command name. The /BW switch forces HELP to monochrome mode on color systems. The /R switch turns off dynamic window resizing and forces all HELP screens to full screen size regardless of the amount of text they contain. HELP switches may be set permanently by setting the values in the 4HELPC environment variable (e.g. SET 4HELPC=/BW). Detailed information on how to use the HELP system is provided with HELP itself. Once you have started HELP, follow the instructions on the screen regarding the effects of various keys. HELP.EXE and DOS.HLP must be in the current directory or one of the directories specified in the PATH environment variable. If you change the name of HELP.EXE or keep the help files in a directory which is not on your PATH, you must store the full path and filename for the help program in the 4HELP environment variable. To specify a text file name other than DOS.HLP, store the full path and filename for the help text file in the 4HELPF environment variable. The HELPCFG program included with 4DOS allows you to customize HELP's colors to suit your own preferences. If you want to customize the help text (for example, to add HELP for your own commands or aliases), you will need the 4DOS Utility Disk (available from JP Software) which contains the source text and hypertext compiler. HELP is an external command. Example: Display and select from all the available help topics: c:\> help For help on COPY: c:\> help copy 4DOS Reference Manual Copyright 1991, JP Software Inc. 86 HISTORY Syntax: HISTORY [/F] [/R [d:][path]filename] Purpose: Display, clear, or read the history list. Comments: If no parameters are entered, HISTORY will display the current history list. The /F(ree) option clears the command history list. The /R(ead) option loads the command history from the specified file. You can save the history list by redirecting its output to 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 512 to 8192 characters (see Installation). The default size is 1024 characters. You can disable saving commands to the history list, or specify a minimum command line length to save, with the SETDOS /H command. See also SETDOS. Example: Display the history list: c:\> history Clear the history entries: c:\> history /f Save the history list to the file HISTFILE, and then read it in again: c:\> history > histfile c:\> history /r histfile 4DOS Reference Manual Copyright 1991, JP Software Inc. 87 IF Syntax: IF [NOT] condition command Purpose: Allow conditional execution of commands. Comments: 4DOS first tests the given condition. If the condition is true, 4DOS executes the specified command, otherwise the command will be ignored. If you use the NOT option, the command is executed only when the condition is false. IF statements can be nested. The command can be a 4DOS internal command or alias, an external command, or a batch file. For the string tests, case differences are ignored. When comparing strings, you should enclose the strings in double quotes (see examples). If both arguments to be compared begin with digits, IF will do a numeric comparison; otherwise IF does an ASCII comparison. The condition can be any of the following: string1 == string2 string1 EQ string2 If string1 is equal to string2, the condition is true. string1 NE string2 If string1 is not equal to string2, the condition is true. string1 LT string2 If string1 is < string2, the condition is true. string1 LE string2 If string1 is <= string2, the condition is true. string1 GE string2 If string1 is >= string2, the condition is true. string1 GT string2 If string1 is > string2, the condition is true. In the tests below, the term "condition" refers to one of the relational operators described above (==, NE, LT, etc.). 4DOS Reference Manual Copyright 1991, JP Software Inc. 88 ATTRIB [d:][path]filename [RHSVDA] If the file has matching attributes, the condition is true. See also ATTRIB and DIR. The attributes are : R Read-only H Hidden S System V Volume D Directory A Archive N No attributes set For the volume name test the filename used must refer to the root directory. Volume names longer than 8 characters require a period after the eigth character (e.g. IF ATTRIB A:\MYFILES0.107 V ...). DISKFREE condition n[K | M] Test for the free disk space on the current drive. DOSMEM condition n[K] Test for the free DOS memory. EMS condition n[K | M] Test for the amount of free expanded memory. EXTENDED condition n[K | M] Test for the amount of extended memory (non-XMS). ERRORLEVEL [condition] n Test the exit code of the preceding external program. ERRORLEVEL supports the same conditions as the string comparisons (for example, ==, LE, etc.). If no condition is specified, the default is GE. NOTE: Not all programs return an explicit exit code. In those cases, the behavior of ERRORLEVEL is undefined. EXIST [d:][path]filename If the file exists, the condition is true. You can use wildcard characters (* and ?) in the filename, in which case the condition is true if any file matching the wildcards exists. FILESIZE filename condition n[K | M] Test for the size of the specified file. ISALIAS aliasname If the specified name is an alias, the condition is true. 4DOS Reference Manual Copyright 1991, JP Software Inc. 89 ISDIR [d:]path If the subdirectory exists, the condition is true. MONITOR condition [MONO | COLOR] Test for the monitor type (condition should be ==, EQ, or NE). VIDEO condition [MONO | CGA | EGA | VGA] Test for the video card type (condition should be ==, EQ, or NE). XMS condition n[K | M] Test for the amount of available XMS 2.0 extended memory. The DOSFREE, EMS, EXTENDED, and XMS tests allow testing either by bytes (default), kilobytes (by appending a K to the test value), or megabytes (by appending an M). See also IFF. Example: Test for the presence of A:\JAN.DOC, and copy it to the root directory on drive C if it exists: c:\> if exist a:\jan.doc copy a:\jan.doc c:\ This batch file fragment tests for a string value: input "Enter your selection : " %%cmd if "%cmd" == "WP" goto wordproc if "%cmd" NE "GRAPHICS" goto badentry Test for more than 500K of free DOS memory: c:\> if dosfree gt 500K echo More than 500K free Test for expanded memory greater than 2 Mb: c:\> if ems gt 2M echo More than 2 Mb EMS available Run a program ("MONOPROG") if the monitor type is monochrome: c:\> if monitor==mono monoprog This batch file fragment tests to see if the disk in drive A is labeled "INSTALL1": if attrib a:\install1 V goto INSTALL1 4DOS Reference Manual Copyright 1991, JP Software Inc. 90 IFF Syntax: IFF [NOT] condition THEN ^ ... ^ ELSE[[IFF] ... THEN] ^ ... ^ ENDIFF Purpose: Allow IF/THEN/ELSE conditional execution of commands. Comments: 4DOS first tests the given condition. If the condition is true, 4DOS executes the specified command(s) until the next ELSE, ELSEIFF, or ENDIFF, otherwise the command(s) will be ignored and 4DOS will continue parsing at the next ELSE, ELSEIFF, or ENDIFF. If you use the NOT option, commands are executed only when the condition is false. IFF statements can be nested up to 15 levels deep. The command can be a 4DOS internal command or alias, an external command, or a batch file. See the IF command for a list of the tests available. Example: The following batch file fragment tests the monitor type (monochrome or color), and sets the appropriate colors and prompt (the PROMPT commands should be entered on one line): 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 following alias 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 zap `iff isdir %1 then ^ del %1 ^ rd %1 ^ else ^ echo Not a directory! ^ endiff` 4DOS Reference Manual Copyright 1991, JP Software Inc. 91 INKEY Syntax: INKEY [/Wn] [text] %%varname Purpose: Get a single keystroke environment variable from standard input. Comments: You can optionally display prompt text before the variable name. The /W(ait) option allows you to specify a timeout period, where n is the number of 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 check if a key is already in the buffer, and return immediately. ASCII values from 1 to 255 are stored as a character. Extended characters (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). This is the same format used by the KEYSTACK command. See Appendix C for a list of the extended key codes. INKEY and INPUT are normally used in batch files, allowing you great flexibility in entering or changing batch variables. If you press ^C or ^BREAK while INKEY is waiting for a key, execution of an alias will be terminated, and execution of a batch file will be suspended while you are prompted whether to cancel the batch job (see Batch Files in Using 4DOS). See also INPUT. Example: 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 The following batch file fragment waits up to 10 seconds for a character, then tests to see if a "Y" was entered (the INKEY command should be entered on one line): set net=N inkey /w10 Do you want to load the network (Y/N)? %%net if "%net" == "Y" goto load_net 4DOS Reference Manual Copyright 1991, JP Software Inc. 92 INPUT Syntax: INPUT [/Wn] [text] %%varname Purpose: Enter an environment variable from the standard input. Comments: You can optionally display prompt text before the variable name. The /W(ait) option allows you to specify a timeout period, where n is the number of 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 check if a key is already in the buffer, and return immediately. All characters entered up to, but not including, the carriage return are stored in the variable. INPUT and INKEY are normally used in batch files, allowing you great flexibility in entering or changing batch variables. See also INKEY. Example: The following batch file fragment prompts for a string and stores it in the variable FNAME: input Enter the file name: %%fname 4DOS Reference Manual Copyright 1991, JP Software Inc. 93 KEYSTACK Syntax: KEYSTACK ["abc"] [nn] [@nn] [!] Purpose: Feed keystrokes to a program from a batch file or alias. Comments: Characters entered within double quotes ("abc") will be stored "as is" in the keyboard buffer. Numbers (nn) not enclosed in quotes are ASCII decimal codes (e.g., 13 (ENTER), or 27 (ESCAPE)). The number 0 is a special case; it is used with programs that flush the keyboard buffer (it tells the program the buffer is clear, so subsequent keystrokes will be accepted normally). Numbers preceded by @ are extended keyboard codes generated by the Alt key, cursor pad keys, and the Function keys (e.g., @59 is the F1 function key). See Appendix C for a list of the extended key codes. A ! will clear all pending keystrokes, both in the KEYSTACK buffer and in the keyboard buffer. Some programs require both the keyboard "scan code" and the ASCII code to be stacked. To stack both codes calculate the value ((256 * scan) + ASCII) and use that for KEYSTACK. For example for ENTER the scan code is 28 and the ASCII code is 13, so to stack both values use KEYSTACK 7181 (7181 is 256 * 28 + 13). Scan code tables are available in many PC reference books. You can store a maximum of 255 characters. Each time KEYSTACK is executed, it will clear any remaining keystrokes stored by a previous KEYSTACK. You may need to experiment a bit with your programs to find the proper sequence of keystrokes. Programs that bypass MS-DOS and the BIOS for keyboard input cannot read keystrokes entered with KEYSTACK. KEYSTACK requires the device driver KEYSTACK.SYS be loaded in the CONFIG.SYS file (see Installation). Example: The following batch file starts Lotus 1-2-3 and loads the file specified on the command line: pushd c:\123 keystack 0 13 0 13 0 13 0 13 0 13 "/FR" 0 "%1" 13 123 popd The same command defined as an alias (enter this on one line): alias 321 `pushd c:\123 ^ keystack 0 13 0 13 0 13 0 13 0 13 "/FR" 0 "%1" 13 ^ 123 ^ popd` 4DOS Reference Manual Copyright 1991, JP Software Inc. 94 LIST Syntax: LIST [/HSW] [d:][path]filename... Purpose: Display a file with forward and backward paging and scrolling. Comments: LIST provides a much faster and more flexible way to view a file than TYPE, without the overhead of using a text editor. The /H option strips the high bit from each character before displaying. This is useful when displaying files created by some word processors that turn on the high bit for formatting purposes. The /S option will read from the standard input rather than a file. This allows you to redirect command output and view it with LIST. The /W option will wrap the text at the right margin. This option is useful when displaying non-text files. LIST uses the cursor pad to scroll through the file. The following keys have special meanings (the caret ^ means press the Control key together with with the specified key): Home Display the first page of the file. End Display the last page of the file. Esc Exit the current file. ^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. ^Left Arrow Scroll left 40 columns. ^Right Arrow Scroll right 40 columns. F1 Call the on-line help (HELP.EXE). F Prompt and search for a string (case is ignored). N Find next matching string (case is ignored). LIST saves the search string, so you can LIST multiple files and search for the same string simply by pressing N in each file. P Print the file on LPT1. LIST is normally only useful for displaying ASCII text files; executable files (.COM and .EXE) and many data files will be unreadable due to the presence of non- alphanumeric characters. See also TYPE. 4DOS Reference Manual Copyright 1991, JP Software Inc. 95 Example: Display the file MEMO.DOC: c:\> list memo.doc Display the output from a DIR command: c:\> dir | list /s Redefine the DIR command to always display its output via LIST: c:\> alias dir `*dir %& | list /s` 4DOS Reference Manual Copyright 1991, JP Software Inc. 96 LOG Syntax: LOG [/W [d:][path]filename | ON | OFF | text] Purpose: Save a log of commands to a disk file. Comments: LOG defaults to saving to the file 4DOSLOG in the root directory of the boot drive. Entering LOG with no parameters displays the log status (ON or OFF). Entering LOG with text writes the text to the log file, even if LOG is set OFF. This allows you to enter headers in the log file. You can specify a different filename with the /W(rite) switch. The /W switch automatically enables command logging. The commands are stored in the log file as they were entered, before performing any alias or variable expansion. The LOG file format looks like: [mm/dd/yy hh:mm:ss] command Example: Display the LOG status: c:\> log LOG is OFF Enable command logging: c:\> log on Enable command logging to the file C:\LOG\LOGFILE and insert a header: c:\> log /w c:\log\logfile c:\> log "Started work on the database system" 4DOS Reference Manual Copyright 1991, JP Software Inc. 97 MD / MKDIR Syntax: MD [d:]pathname... or MKDIR [d:]pathname... Purpose: Create subdirectories. Comments: To start at the root directory, start the pathname with a backslash (\). To start at the parent directory, start the pathname with two periods (..). All other pathnames start at the current directory. The longest allowable path in MS-DOS from the root directory to any subdirectory is 64 characters (including backslashes). See also RD. Example: Create a subdirectory called MYDIR in the root directory: c:\> md \mydir Create a subdirectory called DIRTWO in the current directory: c:\mydir> md dirtwo 4DOS Reference Manual Copyright 1991, JP Software Inc. 98 MEMORY Syntax: MEMORY Purpose: Display the system RAM status. Comments: MEMORY displays the total RAM, the free RAM (available to applications programs after loading MS-DOS, device drivers, 4DOS itself, and RAM resident programs); the total and free expanded memory, extended memory and XMS memory (on an 80286 or 80386); the total and free environment space; the total and free alias list space; and the total command history space. 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. Example: Display your RAM totals: 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 512 bytes total environment 195 bytes free 1,024 bytes total alias 452 bytes free 1,024 bytes total history 4DOS Reference Manual Copyright 1991, JP Software Inc. 99 MOVE Syntax: MOVE [/PQR] [d:][path]filename... [d:][path]filename Purpose: Move files to other directories and drives. Comments: The MOVE command moves the specified file(s) to the last filename specified, which is designated as the target. If the target already exists, it is deleted when the file is moved. You cannot move a file to a character device or to itself. If there is more than one source file specification, the target must be a directory, and the files are moved to the directory with their original filenames. If the target is not a directory, MOVE will display an error message and exit. Use caution when using MOVE with commands like SELECT. If multiple files are SELECTed and the target is not a subdirectory, each file will be moved in turn to the target, overwriting the previous file. The net result is that all files but the last will be deleted. If SELECT is invoked using square brackets instead of parentheses, the MOVE will be done in a single command and MOVE will detect the error. The /P(rompt) option will prompt you for a Y or N response to confirm each move. The /Q(uiet) option turns off the display of the files moved. The /R(eplace) option will prompt you for a Y or N response before overwriting an existing file. MOVE first attempts to rename the file(s). If that fails (the target is on a different drive, or the target already exists), MOVE will copy the file(s) and then delete the originals. If MOVE cannot delete the original (for example, a read-only file), it will display an error message, but the target file is still created. See also COPY and RENAME. 4DOS Reference Manual Copyright 1991, JP Software Inc. 100 Example: Move some files to a different directory: c:\> move *.wks *.txt c:\finance\myfiles Move all the files in the current directory to A:\, prompting before overwriting any existing files: c:\> move /r *.* a:\ 4DOS Reference Manual Copyright 1991, JP Software Inc. 101 PATH Syntax: PATH [[d:]path;[d:]path...]] Purpose: Tells 4DOS where to search for executable and batch files not in the current directory. Comments: When searching for an external command (.COM, .EXE, .BTM, and .BAT), 4DOS searches the current directory first, then the directories you specify in the order you list them. The directory names are separated by semicolons (;). Like COMMAND.COM, 4DOS shifts the entire path to upper case before storing it in the environment. This maintains compatibility with programs which can only recognize an upper case path. If you enter PATH with no parameters, 4DOS displays the current search path. If you enter PATH and a semicolon, 4DOS clears the search path and will search only the current directory (this is the default at system startup). If you specify an invalid directory, 4DOS will skip that directory and continue searching with the next directory in the path. Some applications use the PATH variable to search for their files. You can edit the path with the ESET command. Example: The following PATH command directs 4DOS to search for an executable file in the following order: the current directory, the root directory on C, the DOS subdirectory on C, and the UTIL subdirectory on C: c:\> path c:\;c:\dos;c:\util Display the current search path: c:\> path PATH=C:\;C:\DOS;C:\UTIL 4DOS Reference Manual Copyright 1991, JP Software Inc. 102 PAUSE Syntax: PAUSE [message] Purpose: Suspend alias or batch file execution. Comments: A PAUSE command will suspend execution, giving you the opportunity to perform activities such as changing disks, turning on the printer, etc. PAUSE flushes the keyboard buffer, and then waits for any key (except ^C or ^BREAK) to be pressed and then continues executing. If a prompt message is specified, 4DOS will display the message and wait for a keystroke. Otherwise, 4DOS will prompt: Press a key when ready... If you press ^C or ^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 prompted whether to cancel the batch job (see Batch Files in Using 4DOS). Example: The following batch file fragment prompts the user before erasing files: pause ^C aborts, any other key erases the .LST files erase *.lst 4DOS Reference Manual Copyright 1991, JP Software Inc. 103 POPD Syntax: POPD [*] Purpose: Change to the disk drive and directory at the top of the directory stack. Comments: POPD restores the disk drive and directory saved using PUSHD (most recent first). The * option clears the directory stack, without changing the current drive and directory. Use the DIRS command to display the directory stack. See also DIRS and PUSHD. Example: Save and change your disk drive and directory with PUSHD, and then restore it: 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:\> Clear the directory stack: c:\> popd * 4DOS Reference Manual Copyright 1991, JP Software Inc. 104 PROMPT Syntax: PROMPT [text] Purpose: Change the 4DOS command line prompt. Comments: If you enter PROMPT with no arguments, 4DOS sets the prompt on drives A and B to $n$g, and on all other drives to $p$g (display current disk and directory). The prompt text can contain special strings of the form $?, where ? is one of the following characters. b The | character c The open parenthesis ( d Current date, in the format Tue Jan 1, 1991 (US and Japan) or Tue 1. Jan 1991 (Europe) e The ASCII ESC character (decimal 27) f The close parenthesis ) g The > character h BACKSPACE over the previous character l The < character n Default drive letter P Current disk and directory (upper case) p Current disk and directory (lower case) q The = character s The space character t Current time, in the format hh:mm:ss v MS-DOS version number, in the format 3.10 Xd: Current disk and directory (upper case) where d is the drive specification xd: Current disk and directory (lower case) where d is the drive specification z Display the current 4DOS shell nesting level (you must be running 4DOS as the primary shell in swapping mode). The primary command processor is 0. Resident copies of 4DOS return a 99 for the shell nesting level. $ The $ character _ CR/LF (go to beginning of new line) 4DOS Reference Manual Copyright 1991, JP Software Inc. 105 Under COMMAND.COM, it is possible to use the PROMPT command in a batch file to transmit ANSI.SYS control sequences to the screen (for example, to redefine function keys). This is because COMMAND.COM displays a prompt when echoing lines in a batch file. This technique will not work with 4DOS, because 4DOS doesn'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, use the ECHO command, substituting e (control-X followed by an e) for $e in the PROMPT string. Example: Set the prompt to the current date and time: c:\> prompt $d $t $g Mon Dec 25, 1989 18:29:19 > Set a prompt using ANSI escape sequences to display the shell level, date, time and path in color on the top line (enter 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 4DOS Reference Manual Copyright 1991, JP Software Inc. 106 PUSHD Syntax: PUSHD [[d:]pathname] Purpose: Save the current disk drive and directory. Comments: PUSHD saves the current disk and directory on the directory stack, and if a pathname is specified on the command line, changes the disk drive and directory. The directory stack can hold up to 255 characters (about 10 to 20 entries). If you exceed the directory stack size, the oldest directory is removed before adding the current directory. The saved directory is restored on a "last in, first out" basis by the POPD command. The directory stack can be displayed with the DIRS command. See also CDD, DIRS and POPD. Example: Save the current directory and change to C:\WORDP\MEMOS: c:\> pushd \wordp\memos c:\wordp\memos> Save the current drive and directory, without changing directories: c:\> pushd c:\> 4DOS Reference Manual Copyright 1991, JP Software Inc. 107 QUIT Syntax: QUIT Purpose: Terminate the current batch file. Comments: You can QUIT at any point in a batch file, not just at the end. 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. To end all batch file processing, use CANCEL. See also CANCEL. Example: This batch file fragment checks to see if the user entered "quit" and exits if true. input Enter your choice : %%option if "%option" == "quit" quit 4DOS Reference Manual Copyright 1991, JP Software Inc. 108 RD / RMDIR Syntax: RD [d:]path... or RMDIR [d:]path... Purpose: Remove one or more subdirectories. Comments: Before removing a subdirectory, you must delete all the files and subdirectories (and their files) in that directory (including any hidden or read-only files). You can use the MS-DOS wildcard characters (* and ?) in the directory names. You cannot remove the root directory (\), the current directory (.), or the parent directory (..). See also MD. Example: Remove the subdirectory MEMOS from the subdirectory WP: c:\> rmdir \wp\memos 4DOS Reference Manual Copyright 1991, JP Software Inc. 109 REM Syntax: REM [comment] Purpose: Put a comment in a batch file. Comments: If ECHO is ON, or the variable VERBOSE (see the SETDOS command) is set, 4DOS will echo the comment. Otherwise, 4DOS will ignore it. If you don't want to echo the line, preface REM with the @ character. Enter your comment following the REM, separated by a space or tab. Comments can be up to 255 characters. 4DOS will ignore everything following a REM, including quote characters, the redirection symbols (| > <), the command separator character, aliases, and environment variables. Batch file comments are useful for documenting the purpose for a batch file and the procedures used. Example: Enter comments in a batch file: rem This batch file provides a rem menu-based system for accessing rem the word processing utilities. rem Clear the screen and get selection cls 4DOS Reference Manual Copyright 1991, JP Software Inc. 110 REN / RENAME Syntax: REN [/PQ] [d:][path]filename... [d:][path]filename or RENAME [/PQ] [d:][path]filename... [d:][path]filename Purpose: Rename files or subdirectories. Comments: The last filename is the new name; preceding names are the files or directories to be renamed. You can use the wildcard characters (* and ?) in the filenames. The new filename must not already exist. You cannot rename a subdirectory to a new path! If the /P(rompt) option is specified, 4DOS will prompt you to enter Y or N to confirm each rename. The /Q(uiet) option turns off the display of the files renamed. RENAME in COMMAND.COM only allows a path to be specified with the first file name; the path for the target is always assumed to be the same as the source. 4DOS allows you to optionally select the target path, renaming the source file to a new directory on the same disk drive. If you don't specify a path for the target, 4DOS will assume a "COMMAND.COM compatible" RENAME, and will rename the source file to the new name without moving it to another directory. If you want to rename to a different drive, use MOVE. Example: Rename the file MEMO.TXT to OFFICE.TXT: c:\> rename memo.txt office.txt Rename the files MEMO.TXT and MEMO2.TXT to another directory: c:\> rename memo.txt memo2.txt c:\wp\memos Rename the directory \WORDPROC to \WP: c:\> rename \wordproc \wp 4DOS Reference Manual Copyright 1991, JP Software Inc. 111 RETURN Syntax: RETURN Purpose: Return from a GOSUB (subroutine) call in a batch file. Comments: The RETURN command returns from a GOSUB call to the command following the original GOSUB. See also GOSUB. Example: The following batch file fragment calls a subroutine which displays the current directory: echo Calling a subroutine gosub subr1 echo Returned from the subroutine quit :subr1 dir /hw return 4DOS Reference Manual Copyright 1991, JP Software Inc. 112 SCREEN Syntax: SCREEN row column [message] Purpose: Position the cursor on the screen, and optionally display a message. Comments: 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. SCREEN allows you to create attractive batch file screen displays. 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. SCREEN checks for a valid row and column, and displays an error message if either value is out of range. See also ECHO, SCRPUT and TEXT. Example: 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 4DOS Reference Manual Copyright 1991, JP Software Inc. 113 SCRPUT Syntax: SCRPUT row column [bright] [blink] fg ON bg text Purpose: Display text in color. Comments: 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. SCRPUT works like SCREEN, but allows you to specify the display colors, and writes directly to the screen. The parameters are: row Start row col Start column fg Foreground character color bg Background character color Only the first three characters of the color name and attributes ("bright" and "blink") are required. The available colors are: Black Blue Green Red Magenta Cyan Yellow White See also CLS, ECHO, SCREEN and TEXT. Example: The following batch file fragment displays a menu in color (all commands should be entered on one line): @echo off ^ cls white on blue scrput 3 10 bri white on blue Select a number from 1 to 4: scrput 6 20 bri red on blue 1 - Word Processing scrput 7 20 bri yellow on blue 2 - Spreadsheet scrput 8 20 bri green on blue 3 - Telecommunications scrput 9 20 bri magenta on blue 4 - Quit 4DOS Reference Manual Copyright 1991, JP Software Inc. 114 SELECT Syntax: SELECT [/Oeirtuz] [command] ([d:][path]filename...)... Purpose: Execute a command on the specified files. Comments: SELECT allows you to select command line file arguments by marking the directory entries using a full-screen "point-and-shoot" display. SELECT substitutes the selected files for the argument enclosed in parentheses, and executes the command for each marked file. The command can be an alias, internal or external command, or batch file. If you don't specify a command, the selected filename(s) will become the command (see example). The command can be a 4DOS internal command or alias, an external command, or a batch file. If you join filenames with a plus (+) sign, SELECT will display the files together (an "include list"). Only the first file in an include list can have a pathname; subsequent filenames default to the same path. If the filenames are enclosed in square brackets instead of parentheses, SELECT will substitute all of the selected filenames on one command line. If there are too many filenames to fit on the line, SELECT will display an error message and exit. All internal 4DOS commands support 255 character command lines, but MS-DOS only supports 127 character command lines for external programs. SELECT displays the approximate command line length in the upper left corner; it is your responsibility to ensure SELECT doesn't exceed the 127 character limit for external commands. SELECT uses the up arrow, down arrow, PgUp, and PgDn keys to scroll through the files matching the argument(s). 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 select all of the files (excluding subdirectories). 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 when no other files have been marked. 4DOS Reference Manual Copyright 1991, JP Software Inc. 115 The /O option determines the sort order for the directory display (the default sort is by filename): e Sort by extension i Sort by description (see DESCRIBE) r Reverse the sort order t Sort by time (oldest first) u Unsorted z Sort by size If you want to use filename completion (see Command Line Editing in Using 4DOS) to enter the filenames inside the parentheses, type a space after the "(". Otherwise the command line editor will treat "(" as the first character of the filename. To cancel the SELECT command, type an Escape, ^C, or ^BREAK. Example: Select from the files in the current directory with the extension .COM, and then from the files with the extension .EXE to copy to the root directory on drive A: c:\> select copy (*.com *.exe) a:\ Define an alias that selects from the executable files in the directory C:\UTIL, and then executes them in the order marked (the alias should be entered on one line): c:\> alias utils select (c:\util\*.com+*.exe+*.btm+*.bat) c:\> utils Select from all the files in the current directory to move to the root directory on A (since the argument list is enclosed in square brackets, this will be done by a single command): c:\> select move [*.*] a:\ 4DOS Reference Manual Copyright 1991, JP Software Inc. 116 SET Syntax: SET [/P] [/R filename...] [variable[=][value]] Purpose: Display, create, modify, or delete environment variables. Comments: Entering SET with no variable or value displays the environment. If you don't enter a value, SET will remove the variable from the environment. Otherwise, the variable and the value are placed in the environment. If the variable already exists, its old contents are replaced by the new value. 4DOS limits the variable name to a maximum of 80 characters, and the value to a maximum of 255 characters. The variable names are shifted to upper case before being stored in the environment; the value is stored exactly as entered. The /P option will pause after displaying a page of environment entries. Press ^C to quit, or any other key to display the next page. The /R(ead) option allows you to load environment variables from a file. This is much faster than loading variables from a batch file. 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. You can load multiple files with one SET /R command by placing the names one after another on the command line, separated by spaces. 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 add comments to a variable file by starting the comment line with a colon (:). SET only affects the environment of the current command processor. If you EXIT to a parent command processor, the original environment will be unchanged. The size of the environment is specified by the /E parameter at startup. The default size is 512 characters, the minimum size 256 characters, and the maximum size 32000 characters. 4DOS Reference Manual Copyright 1991, JP Software Inc. 117 You can remove multiple environment variables with the UNSET command. You can edit environment variables and aliases with the ESET command. To enter aliases, use ALIAS. See also UNSET and ESET. Example: Display the current environment: c:\> set COMSPEC=C:\4DOS.COM PATH=C:\;C:\DOS;C:\UTIL Add a variable to the environment: c:\> set mine=c:\finance\myfiles c:\> set COMSPEC=C:\4DOS.COM PATH=C:\;C:\DOS;C:\UTIL MINE=c:\finance\myfiles Remove a variable from the environment: c:\> set mine c:\> set COMSPEC=C:\4DOS.COM PATH=C:\;C:\DOS;C:\UTIL 4DOS Reference Manual Copyright 1991, JP Software Inc. 118 SETDOS Syntax: SETDOS [/A? /C? /E? /H? /I+|-command /L? /M? /N? /R? /S?:? /U? /V?] Purpose: Display or set 4DOS configuration variables. Comments: SETDOS allows you to customize 4DOS to your personal tastes. You would normally define the SETDOS variables in your AUTOEXEC.BAT or 4START file. The SETDOS options are: A The ANSI variable determines whether 4DOS will attempt to use an ANSI escape sequence for CLS. 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 whether an ANSI driver is installed; /A1 forces 4DOS to assume an ANSI driver is installed. C The COMPOUND variable is the character used for separating multiple commands on the same line. The default character is the caret (^). You cannot use any of the redirection characters (| > <), or any of the whitespace characters (=,;) as the command separator. E The ESCAPE variable is 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 line. The default escape character is ^X (Ctrl-X, displayed as an up arrow). You cannot use any of the redirection characters (| > <) or the whitespace characters (=,;) as the escape character. H The HISTORY variable determines the minimum command size to save. Any command line whose length is less than this value will not be saved to the history list. Setting /H to 256 will disable history saves; setting it to 0 will save everything. The default value is 0 (save all command lines). 4DOS Reference Manual Copyright 1991, JP Software Inc. 119 I The INTERNAL variable allows you to disable or enable internal 4DOS commands. To disable a command, precede the command name with a minus (-). To reenable a command, precede it with a plus (+). L The LINE variable controls how 4DOS gets its input from the command line. The default value is 0 (character input). If you set /L to 1, 4DOS uses the INT 21 0Ah "Get Line" call (like COMMAND.COM). Note that this will disable command line editing, history recall, and filename expansion. If you have an program that requires line input, you can define an alias or batch file: setdos /L1 ^ program %& ^ setdos /L0 See the file COMPAT.DOC for information on programs which require this option. M The MODE variable controls the line editing mode. 4DOS defaults to overstrike mode (/M0). If MODE is set to 1, the default is insert mode. N The NOCLOBBER variable controls output redirection. If NOCLOBBER is set to 1, then existing files may not be destroyed by output redirection, and when appending with >>, the output file must exist. NOCLOBBER can be overridden with the ! character (see the section on redirection in Using 4DOS). The default value is 0. R The ROWS variable sets the number of screen rows used by the video display. Normally 4DOS detects the screen size, but if you have a non-standard display you may need to set it explicitly. The ROWS variable does not affect screen scrolling (that is controlled by your video 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. 4DOS Reference Manual Copyright 1991, JP Software Inc. 120 S The SHAPE variable sets the 4DOS cursor shape. The format is /Ss:e where s is the starting scan line and e the ending. The default values are the last two lines of the cursor cell. The default editing mode (see /M above) uses the default cursor shape; the other mode sets the starting scan line to 0 and displays a block cursor. U The UPPER variable controls the way filenames are displayed for the internal commands (COPY, DIR, etc.). If UPPER is set to 1, filenames will be displayed in upper case (like COMMAND.COM). UPPER defaults to /U0 (filenames will be displayed in lower case). V The VERBOSE variable controls command echoing in batch files. If VERBOSE is set to 0, batch file commands will NOT be echoed unless ECHO is set ON. VERBOSE defaults to 1 (that is, batch file commands WILL be echoed). Example: Change the COMPOUND character to a ~ (tilde): c:\> setdos /c~ Change MODE to insert, VERBOSE to off, and set NOCLOBBER on: c:\> setdos /m1 /v0 /n1 Disable the internal LIST command to force 4DOS to use an external command: c:\> setdos /i-list 4DOS Reference Manual Copyright 1991, JP Software Inc. 121 SETLOCAL Syntax: SETLOCAL Purpose: Save a copy of the current disk drive, directory, environment variables, and aliases. Comments: SETLOCAL is used in batch files to save the disk drive, directory, environment variables and aliases to a reserved block of memory. You can then change their values, and later restore the original values with ENDLOCAL. You cannot use SETLOCAL in an alias. SETLOCAL and ENDLOCAL are not nestable within the same 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. 4DOS will automatically perform an ENDLOCAL at the end of a batch file. Note that if you invoke a batch file from another without using CALL, the first batch file is implicitly terminated, and an automatic ENDLOCAL performed. The second batch file will inherit the drive, directory, environment variables, and aliases as they were prior to the SETLOCAL. Do not load TSRs (memory-resident programs) from a batch file while a 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 harmful, but wastes memory. See also ENDLOCAL. Example: This batch file fragment saves the disk drive, directory, environment variables and aliases, changes the disk and directory, modifies some variables, runs a program, and then restores the original values: setlocal cdd d:\test ^ set path=c:\;c:\dos;c:\util set lib=d:\lib rem run some program here endlocal 4DOS Reference Manual Copyright 1991, JP Software Inc. 122 SHIFT Syntax: SHIFT [n] Purpose: Allow the use of more than 10 variables in a batch file. Comment: SHIFT is provided for compatibility with COMMAND.COM. COMMAND.COM supports only 10 parameters (%0 through %9); 4DOS supports 128 parameters (%0 to %127), so you may not need to use SHIFT for batch files running exclusively under 4DOS. SHIFT moves each of the batch file parameters n positions (i.e., %1 becomes %0, %2 becomes %1, etc.). The default value for n is 1. You can also reverse a SHIFT, by giving a negative value for n (i.e., if n is -1, the former value for %0 is restored, %0 becomes %1, %1 becomes %2, etc.). SHIFT also affects the %n& (command line tail) and %# (number of command arguments) batch variables. 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 zero one two three four five six zero one two three one two three four three four five six two three four five 4DOS Reference Manual Copyright 1991, JP Software Inc. 123 SWAPPING Syntax: SWAPPING [on | off] Purpose: Display, enable, or disable the 4DOS swapping state. Comments: SWAPPING will temporarily disable or enable the swapping of the 4DOS transient portion to EMS, XMS, or disk (see Installation). This is particularly useful when running batch files while swapping to disk. If swapping is enabled, 4DOS saves its transient portion before executing any external command. When the command finishes, 4DOS performs a checksum on the transient portion (when swapping to disk), and restores it if necessary. (When swapping to EMS or XMS, 4DOS always restores the transient portion.) When you are running several small programs from a batch file and using disk swapping, the swapping can sometimes cause a noticeable delay. Turning SWAPPING OFF can speed up such operations. If SWAPPING is OFF, available MS-DOS memory will be reduced by the size of the 4DOS transient portion (about 70K). Setting SWAPPING OFF does not close the disk swap file, or release any reserved EMS or XMS memory. Setting SWAPPING OFF can be useful in speeding up your AUTOEXEC.BAT file. Example: Check the current SWAPPING status: c:\> swapping SWAPPING is ON The following batch file fragment disables swapping, runs several programs, and then reenables swapping: swapping off c:\util\mouse c:\video\ansi.com cls bright white on blue c:\bin\cache.com swapping on 4DOS Reference Manual Copyright 1991, JP Software Inc. 124 TEE Syntax: TEE [/A] [d:][path]filename... Purpose: Copy standard input to standard output, and save a copy in the specified file(s). Comments: The /A option causes the output to be appended to the file(s) rather than overwriting it. If you are typing at the keyboard, you need to enter a ^Z to terminate the input. TEE is often used to save the intermediate output of a pipe. See also Y. Example: 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 4DOS.DAT: c:\> find "4DOS" doc | tee 4.dat | sort > 4dos.dat 4DOS Reference Manual Copyright 1991, JP Software Inc. 125 TEXT Syntax: TEXT . . . ENDTEXT Purpose: Display a block of text in a batch file. Comments: The TEXT command is useful for displaying menus or multiple line messages. TEXT will display subsequent lines in the batch file until terminated by ENDTEXT. Both TEXT and ENDTEXT must be entered as the only command on that line. If you have ANSI.SYS loaded, you can change screen colors by inserting ANSI escape sequences into the text block. See also ECHO, SCREEN and SCRPUT. Example: 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 4DOS Reference Manual Copyright 1991, JP Software Inc. 126 TIME Syntax: TIME [hh[:mm[:ss]][am | pm] Purpose: Display or set the current system time. Comments: 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. The parameters for the TIME command are: hh (hour) = 0 - 23 mm (minute) = 0 - 59 ss (second) = 0 - 59 TIME defaults to 24-hour format, but you can optionally enter the time in 12-hour format by appending an "am" or "pm". Whenever you create or modify a file, the system time is recorded in the directory entry. Example: Enter the time (9:30 am): c:\> time 9:30 To be prompted for the time: c:\> time Mon Dec 25, 1989 9:30:10 New time (hh:mm:ss): 4DOS Reference Manual Copyright 1991, JP Software Inc. 127 TIMER Syntax: TIMER [/S] Purpose: System stopwatch. Comments: The TIMER command turns the system stopwatch on and off. The first time you run TIMER, the stopwatch starts. When you run TIMER again, the stopwatch stops and the elapsed time is displayed. The /S option allows you to display a split time without stopping the timer. TIMER is particularly useful for timing events in batch files. The smallest interval TIMER can measure is .06 seconds; the largest interval is 23:59:59.99. Example: Start the timer: c:\> timer Timer on: 12:21:46 Display the current time, leaving the timer running: c:\> timer /s Elapsed time: 0:00:08.90 Stop the timer: c:\> timer Timer off: 12:21:58 Elapsed time: 0:00:12.06 4DOS Reference Manual Copyright 1991, JP Software Inc. 128 TYPE Syntax: TYPE [/LP] [d:][pathname]filename... Purpose: Display the contents of the specified file(s). Comments: The TYPE command displays a file. Press ^S to suspend the display, and any character key to continue the display. The /L option prints line numbers preceding each line of text. The /P option will pause after each page. Press ^C to quit, or any other key to display the next page. TYPE is normally only useful for displaying ASCII text files; executable files (.COM and .EXE) and many data files may be unreadable due to the presence of non- alphanumeric characters. You will probably find LIST to be more useful for displaying files. See also LIST. Example: Display the files MEMO1 and MEMO2, pausing at the end of each page: c:\> type /p memo1 memo2 4DOS Reference Manual Copyright 1991, JP Software Inc. 129 UNALIAS Syntax: UNALIAS alias... or UNALIAS * Purpose: Remove aliases from the alias list. Comments: UNALIAS also accepts the wildcard character * to delete all aliases. See also ALIAS and ESET. Example: Remove the alias DDIR: c:\> unalias ddir Remove the aliases DDIR and ZAP: c:\> unalias ddir zap Remove all the aliases: c:\> unalias * 4DOS Reference Manual Copyright 1991, JP Software Inc. 130 UNSET Syntax: UNSET name... or UNSET * Purpose: Remove variables from the environment. Comments: UNSET also accepts the wildcard character * to delete all of the environment variables. Use caution with UNSET *; many programs are dependent on environment variables, and 4DOS itself relies on PATH, COMSPEC, and 4DSHELL. See also SET and ESET. Example: Remove the variable CMDLINE: c:\> unset cmdline Remove the variables CMDLINE and PATH: c:\> unset cmdline path Remove all the environment variables: c:\> unset * 4DOS Reference Manual Copyright 1991, JP Software Inc. 131 VER Syntax: VER Purpose: Display the current 4DOS and MS-DOS versions. Comments: The 4DOS and MS-DOS versions consist of a one digit major version number, a period, and a one or two digit minor version number. Example: Get the current version of 4DOS and MS-DOS: c:\> ver 4DOS 3.03 DOS 3.31 4DOS Reference Manual Copyright 1991, JP Software Inc. 132 VERIFY Syntax: VERIFY [on | off] Purpose: Display, enable, or disable disk write verification. Comments: When VERIFY is ON, MS-DOS will verify that no error occurred during the disk write operation. It does NOT compare the data actually written to the disk. VERIFY will remain ON until you set it OFF. Entering VERIFY with no parameters will display the current VERIFY state. Verification will slow your disk write operations slightly. At system startup, VERIFY is OFF. Example: Check the current verify status: c:\> verify VERIFY is OFF Enable disk write verification: c:\> verify on 4DOS Reference Manual Copyright 1991, JP Software Inc. 133 VOL Syntax: VOL [d:]... Purpose: Display the disk volume label(s). Comments: If you don't enter a drive name, VOL displays the disk label for the current drive. If the disk doesn't have a volume name, VOL will report it as "unlabeled." Volume labels can be created, changed or deleted with the external MS-DOS LABEL command. Example: Display the label for the default disk: c:\> vol Volume in drive C: is MYHARDDISK 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 4DOS Reference Manual Copyright 1991, JP Software Inc. 134 Y Syntax: Y [d:][path]filename... Purpose: Copy standard input to standard output, and then copy the specified file(s) to standard output. Comments: Standard input from the console is terminated by a ^Z. See also TEE. Example: Get text from standard input, append the files MEMO1 and MEMO2 to it, and send the output to MEMOS: c:\> y memo1 memo2 > memos 4DOS Reference Manual Copyright 1991, JP Software Inc. 135 APPENDIX A - 4DOS and MS-DOS Error Messages 4DOS swapping failed, loading in memory-resident mode None of the swapping options worked. Check your swapping specification in SHELL or 4DSHELL, and/or free XMS or EMS memory or disk space. 4DOS unrecoverable error XX An error occurred in the resident portion of 4DOS. These errors will terminate secondary shells, and require a reboot if they occur during a primary shell. BI Bad server function code DI Same as Disk swap file corrupted DR Same as Swap file read error DS Same as Swap file seek error ES Same as EMS map save or restore failed EI Same as EMS mapping error NS No number for new shell PT Illegal process termination TS Terminated inactive shell XI Same as XMS move failed Access denied You tried to erase or write to a read-only protected file, to rename a file or directory to an existing name, or to remove a read-only directory or a directory with files or subdirectories still in it. Alias loop An alias refers back to itself (i.e., a = b = a), or aliases are nested more than 16 deep. Correct your alias list. Attempt to exit from root shell Another program has destroyed a portion of 4DOS' memory, or you forgot a /P on your SHELL line in CONFIG.SYS. Reboot the system and correct the error. Bad disk unit Generally caused by a disk drive hardware failure. 4DOS Reference Manual Copyright 1991, JP Software Inc. 136 Bad environment The MS-DOS environment has a bad structure. Reboot the system. Batch file missing 4DOS can't find the batch (.BAT) file it was running. It was either deleted, renamed, moved, or the disk was changed. Can't copy file to itself 4DOS will not permit you to COPY or MOVE a file to itself. Unlike COMMAND.COM, 4DOS does full path and filename expansion before copying to ensure that files aren't inadvertently destroyed. Can't create 4DOS can't create the specified file. The disk may be full or write protected, the file already exists and is read-only, or the root directory is full. Can't delete 4DOS can't delete the specified file or directory. The disk is probably write protected. Can't find EXE file The loader (4DOS.COM) can't locate either 4DOS88.EXE or 4DOS286.EXE. At boot time, one of these files must be in the current directory, or the path must be specified with the /L switch (see Installation). When starting a secondary shell, one of these files must be specified with the /L switch in the 4DSHELL environment variable, or must be in the directory specified by COMSPEC. Can't get directory 4DOS can't read the directory. The disk drive is probably not ready. Can't make directory entry 4DOS 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. 4DOS Reference Manual Copyright 1991, JP Software Inc. 137 Can't open 4DOS can't open the specified file; either it doesn't exist or the disk directory or File Allocation Table is damaged. Can't remove current directory MS-DOS can't delete your current directory. Change to the parent directory and try again. 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, MS-DOS is out of file handles, or there is a hardware problem. Check SHELL and 4DSHELL. Command line too long The command exceeded 255 characters during alias and variable expansion, or you or your program attempted to pass a command line exceeding 126 characters to a secondary 4DOS shell (including the necessary alias, environment, and history settings). Reduce the line length and/or use default alias, environment, and history sizes. 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 MS-DOS can't read or write properly to the device. 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 if necessary. 4DOS Reference Manual Copyright 1991, JP Software Inc. 138 Disk swap file corrupted The 4DOS disk swapping file (4DOSSWAP) has been moved, deleted, or damaged. Reboot the system. Drive not ready--close door The floppy disk drive door is open. Close the door and try again. EMS deallocation failed The loader (4DOS.COM) can't deallocate EMS memory when exiting from a secondary copy of 4DOS. The EMS map has been corrupted or the loader's memory area has been destroyed by a program. Reboot the system. EMS map save or restore failed 4DOS cannot save or restore the EMS page map. The EMS map has been corrupted, or memory has been destroyed by a program, or you have an incompatible EMS driver. Try another swapping method. EMS mapping failed The loader (4DOS.COM) can't map EMS pages when swapping 4DOS to or from EMS. The EMS map has been corrupted, or the loader's memory area has been destroyed by a program. Reboot the system. EMS not available for swapping You requested EMS swapping but no EMS memory was available. Change your swapping method or free some EMS memory. Environment already saved You have already saved the environment with a previous SETLOCAL command. You cannot nest SETLOCAL / ENDLOCAL pairs. Error reading MS-DOS 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. 4DOS Reference Manual Copyright 1991, JP Software Inc. 139 Error writing MS-DOS 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 4 levels deep. EXE file [seek | read | close] failed The loader (4DOS.COM) encountered an I/O error while attempting to access 4DOS88.EXE or 4DOS286.EXE. Either the disk directory or FAT is corrupted, or one of these files has been damaged. Run CHKDSK to verify the disk is OK, and reload 4DOS88 or 4DOS286 from your distribution disk. Fatal error -- please reboot 4DOS cannot continue due to the previous error. Reboot the system. File Allocation Table bad MS-DOS can't access the FAT on the specified disk. This can be caused by a bad disk or a hardware error. File exists The requested output file already exists, and 4DOS won't overwrite it. File not found 4DOS couldn't find the specified file. Check the spelling or path name. 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. Internal DOS error MS-DOS encountered an internal bug and failed. Reboot the system. 4DOS Reference Manual Copyright 1991, JP Software Inc. 140 Invalid date An invalid date was entered. Check the syntax and reenter. Invalid drive A bad or non-existent disk drive was specified. Invalid load path specified, ignored You specified an invalid path in the /L option in SHELL or 4DSHELL. Invalid MS-DOS version You need a newer version of MS-DOS to execute the specified command. Invalid parameter 4DOS didn't recognize the a parameter. Check the syntax and spelling. Invalid path The specified path does not exist. Check the disk specification and/or spelling. Invalid swap path specified, using current drive and directory You specified an invalid path in the /S:B or /S:D option in SHELL or 4DSHELL. Invalid swapping option You specified an invalid value for the /S option in SHELL or 4DSHELL. Invalid time An invalid time was entered. Check the syntax and reenter. KEYSTACK.SYS not loaded You attempted to execute a KEYSTACK command without loading KEYSTACK.SYS in your CONFIG.SYS file (see Installation). 4DOS Reference Manual Copyright 1991, JP Software Inc. 141 Label not found A GOTO or GOSUB referred to a non-existent label. Check your batch file. Memory deallocation error The loader (4DOS.COM) can't deallocate memory while loading 4DOS. The MS-DOS memory allocation has been corrupted. Reboot the system. Memory destroyed The DOS memory control blocks have been corrupted. Reboot the system. Missing ENDTEXT A TEXT command is missing a matching ENDTEXT. Check the batch file. Missing GOSUB 4DOS 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 4DOS encountered an ENDLOCAL without a matching SETLOCAL. No aliases defined No aliases were found in the environment. No closing quote 4DOS couldn't find a second matching quote (` or ") on the command line. No file handle available This is an internal 4DOS disk swapping error. Change to another swapping method if possible, and contact JP Software. No high memory available, environment will be placed in low memory You requested loading the environment in an XMS UMB via the /E:nnnU option in SHELL or 4DSHELL, but no UMB was available. Check your XMS driver. 4DOS Reference Manual Copyright 1991, JP Software Inc. 142 No high memory available, resident portion will remain in low memory You requested relocation of the 4DOS resident portion to an XMS UMB via the /U option in SHELL or 4DSHELL, but no UMB was available. Free some memory or check your XMS driver. Non-DOS disk MS-DOS can't read the disk. Either the disk is bad, or it has been formatted by a different operating system. Reformat it as an MS-DOS disk. Not an alias The specified argument is not in the 4DOS alias list. Not an EXE file 4DOS88.EXE and/or 4DOS286.EXE is not recognized as an EXE file. Reload the file from your distribution disk. Not in environment The specified argument is not in the environment. 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. Out of environment space 4DOS has run out of environment space. Edit the SHELL line in CONFIG.SYS file to increase the environment size. Change the /E parameter to read: /E:n where n is a number from 256 to 32000), and reboot the machine. 4DOS Reference Manual Copyright 1991, JP Software Inc. 143 Out of memory MS-DOS or 4DOS had insufficient free memory to execute the last command, or the DOS memory control blocks have been destroyed. If this error occurs in a secondary shell, return to the primary shell before running the command. Otherwise, try to free some memory by removing memory-resident programs. If the error persists, reboot the system. Out of paper MS-DOS detected an out-of-paper condition on one of the parallel printers (LPT1, LPT2, or LPT3). Check your printer and add paper if necessary. Read error MS-DOS disk read error; usually caused by a bad disk or a non-DOS disk. Sector not found BIOS disk error; usually caused by a bad disk or a non-DOS disk. Seek error MS-DOS can't seek to the proper location on the disk. This is generally caused by a bad disk or drive. SETLOCAL only valid in batch file The SETLOCAL command can only be used in a batch (.BAT or .BTM) file, not in an alias or from the command line. Swap file [seek | read | write] failed The 4DOS loader (4DOS.COM) encountered an I/O error while accessing the disk swap file (4DOSSWAP.nnn). Either the disk was changed, or the file or loader's memory area has been destroyed by a program. Reboot the system. Syntax error A command was entered with the improper format. 4DOS Reference Manual Copyright 1991, JP Software Inc. 144 Too many open files MS-DOS has run out of file handles. Try setting FILES=20 or more in the CONFIG.SYS file. Transient memory allocation error 4DOS couldn't reserve memory for its transient portion (probably in a SWAPPING OFF command). The memory control blocks have been destroyed, or a program has fragmented memory. Reboot the system. Transient memory deallocation error 4DOS couldn't release memory for its transient portion (probably in a SWAPPING ON command). The memory control blocks have been destroyed, or a program has fragmented memory. Reboot the system. Unknown command A command was entered that 4DOS didn't recognize and couldn't find in the current search path. Check the spelling or PATH specification. Write error MS-DOS disk error; usually caused by a bad disk or a non-DOS disk. XMS deallocation failed 4DOS could not deallocate XMS memory when exiting a secondary shell. XMS memory has been destroyed; reboot your system. XMS move failed 4DOS could not move data between DOS memory and XMS memory while swapping itself. XMS memory has been destroyed; reboot your system. XMS not available for swapping You requested XMS swapping but no XMS memory is available. Change your swapping method or free some XMS memory. 4DOS Reference Manual Copyright 1991, JP Software Inc. 145 Appendix B - ASP The authors and publisher of 4DOS are members of the Association of Shareware Professionals (ASP), an organization formed in April 1987 to strengthen the future of shareware as an alternative to commercial software. Its members, all of whom are programmers who subscribe to a code of ethics, are committed to the concept of shareware as a method of marketing. The ASP's Standards for its members and their shareware products are: Programming Standards The program meets the ASP's definition of "shareware" (i.e., it is not a commercial demo with a major feature disabled, nor a time-limited program). The program has been thoroughly tested by the author and should not be harmful to other files or hardware if used properly. Documentation Standards Sufficient documentation is provided to allow the average user to try all the major functions of the program. Any discussion of the shareware concept and of registration requirements is done in a professional and positive manner. Support Standards The member will respond to people who send registration payments, as promised in the program's documentation. At a minimum, the member will acknowledge receipt of all payments. The member will establish a procedure for users to report, and have acknowledged, matters such as bug reports, and will describe such means in the documentation accompanying all versions of the programs. The author will respond to written bug reports from registered users when the user provides a self-addressed, stamped envelope. Known incompatibilities with other software or hardware and major or unusual program limitations are noted in the documentation that comes with the shareware (evaluation) program. 4DOS Reference Manual Copyright 1991, JP Software Inc. 146 ASP Ombudsman Information This program is produced by members of the Association of Shareware Professionals (ASP). ASP wants to make sure that the shareware principle works for you. If you are unable to resolve a shareware-related problem with an ASP member by contacting the member directly, ASP may be able to help. The ASP ombudsman can help you resolve a dispute or problem with an ASP member, but does not provide technical support for members' products. Please write to the ASP Ombudsman at: ASP Ombudsman P.O. Box 5786 Bellevue, WA 98006 or send a Compuserve message via Easyplex electronic mail to the ASP Ombudsman, Compuserve ID number 70475,1071. 4DOS Reference Manual Copyright 1991, JP Software Inc. 147 Appendix C - Key Codes Here are some of the extended key codes used by the INKEY and KEYSTACK commands (see the Command Reference Guide): F1 - @59 Alt-F1 - @104 Ctl-F1 - @94 Shift-F1 - @84 F2 - @60 Alt-F2 - @105 Ctl-F2 - @95 Shift-F2 - @85 F3 - @61 Alt-F3 - @106 Ctl-F3 - @96 Shift-F3 - @86 F4 - @62 Alt-F4 - @107 Ctl-F4 - @97 Shift-F4 - @87 F5 - @63 Alt-F5 - @108 Ctl-F5 - @98 Shift-F5 - @88 F6 - @64 Alt-F6 - @109 Ctl-F6 - @99 Shift-F6 - @89 F7 - @65 Alt-F7 - @110 Ctl-F7 - @100 Shift-F7 - @90 F8 - @66 Alt-F8 - @111 Ctl-F8 - @101 Shift-F8 - @91 F9 - @67 Alt-F9 - @112 Ctl-F9 - @102 Shift-F9 - @92 F10 - @68 Alt-F10 - @113 Ctl-F10- @103 Shift-F10 - @93 Home @71 Up @72 PgUp @73 Left @75 Right @77 End @79 Down @80 PgDn @81 Insert @82 Del @83 Ctl-Home @119 Ctl-PgUp @132 Ctl-Left @115 Ctl-Right @116 Ctl-End @117 Ctl-PgDn @118 Alt-A -@30 Alt-N -@49 Alt-1 - @120 Alt-B -@48 Alt-O -@24 Alt-2 - @121 Alt-C -@46 Alt-P -@25 Alt-3 - @122 Alt-D -@32 Alt-Q -@16 Alt-4 - @123 Alt-E -@18 Alt-R -@19 Alt-5 - @124 Alt-F -@33 Alt-S -@31 Alt-6 - @125 Alt-G -@34 Alt-T -@20 Alt-7 - @126 Alt-H -@35 Alt-U -@22 Alt-8 - @127 Alt-I -@23 Alt-V -@47 Alt-9 - @128 Alt-J -@36 Alt-W -@17 Alt-0 - @129 Alt-K -@37 Alt-X -@45 Alt-L -@38 Alt-Y -@21 Alt-M -@50 Alt-Z -@44 4DOS Reference Manual Copyright 1991, JP Software Inc. 148 Appendix D - Programming for 4DOS From a batch file, you can test if 4DOS is loaded with the variable function @EVAL (see Environment Variables): if "%@eval[2+2]" == "4" echo 4DOS is loaded! A program can test for the presence of 4DOS by making an INT 2Fh call. On entry: AX = D44Dh BX = 0 If 4DOS is loaded it will return: AX = 44DDh BX = Version number (BL = major version, BH = minor version) CX = 4DOS PSP segment address DL = 4DOS shell number (0 for the root shell, 1 for the second, etc.). The shell number is incremented each time a new copy of 4DOS is loaded, either in a different multitasker window (for example, DESQview), or via nested shells. This function is only available in swapping mode. It tells you if 4DOS is loaded in memory, but not whether it is the parent process of your program. You can determine if 4DOS is the parent process by comparing the PSP value returned in CX to the PSP chain pointer at offset 16h in your program's PSP. 4DOS also generates two different INT 2F calls to allow TSRs or other programs to tell when 4DOS is at the prompt. These calls have AX = D44Eh. The first occurs immediately before displaying the prompt, with BX = 0; the second occurs after displaying the prompt and immediately before accepting keyboard input, with BX =1. Any routine intercepting these calls should preserve at least the SI, DI, BP, SP, DS, ES, and SS registers. You can put keystrokes into the KEYSTACK driver via the MS-DOS IOCTL call. First, open the device 4DOSSTAK: MOV AX,3D01h DS:DX = pointer to the device name "4DOSSTAK" INT 21h The file handle will be returned in AX. Then send the string to the KEYSTACK device driver: MOV BX,AX MOV AX,4403h CX = string length DS:DX = pointer to string INT 21h 4DOS Reference Manual Copyright 1991, JP Software Inc. 149 Appendix E - Tips and Troubleshooting This appendix covers general usage notes and troubleshooting information about 4DOS. It will help you figure out what to do if you're having trouble with 4DOS, or compatibility problems with another software package. What isn't covered here is information on compatibility with specific hardware or individual software packages. Because this information is subject to change as 4DOS and other programs are modified, we have included it in the file COMPAT.DOC, which is distributed with 4DOS. This file is updated with every new release to reflect the latest compatibility information. It should be read in conjunction with this appendix. Installation and Boot Most 4DOS installation problems occur because the instructions in the manual have not been followed correctly. If you have trouble, re-read the instructions carefully and see if they cover the problem you're having. If not, try the information below. If you have questions about booting 4DOS on a system attached to a network, see the section in this appendix Using 4DOS on a Network. If you get a message such as "missing command interpreter" or "can't find EXE file", you probably have the 4DOS files in the wrong place. 4DOS is easiest to install when its system files (KEYSTACK.SYS, 4DOS.COM, and 4DOS88.EXE or 4DOS286.EXE) are stored in the root directory of your boot disk. If they aren't, be sure the SHELL command in CONFIG.SYS has the correct drive and path for 4DOS.COM, and that the /L: switch is set properly. Also be sure that you are setting COMSPEC properly in AUTOEXEC.BAT, or secondary shells won't load correctly. If the system hangs after 4DOS is loaded (i.e., while processing 4START.BAT or AUTOEXEC.BAT), edit AUTOEXEC to remove the program being loaded at the point where the hang occurs, and try again. If problems are inconsistent or persist, edit CONFIG.SYS and AUTOEXEC.BAT to remove all of the device drivers and TSRs that you can reasonably remove and still have the system boot. Then put them back one at a time until you find out what program or combination of programs is causing the problem. If you have trouble with keyboard device drivers or TSRs (including those that use "hot keys"), try removing KEYSTACK.SYS to see if there is a conflict between it and the other program. If the KEYSTACK command fails to work, try loading it as late as possible in CONFIG.SYS; another device driver may be stealing the keyboard interrupt and failing to pass it along to KEYSTACK. 4DOS Reference Manual Copyright 1991, JP Software Inc. 150 If you have trouble booting 4DOS, or see garbage characters in your environment immediately after boot, check the length of your SHELL command. As discussed in Installation, the line may not have more than 33 characters beyond the name of the shell (including trailing spaces), due to a bug in all versions of MS- DOS and PC-DOS. AUTOEXEC and 4START Problems If you follow the instructions in the manual, both of these files should work with no trouble. Some common problems are: 1. AUTOEXEC.BAT is not executed when the primary shell is started. This occurs because you did not put a /P in the SHELL command, or the AUTOEXEC.BAT file is not in the root directory of the boot drive. 2. AUTOEXEC.BAT is executed when a secondary shell is started. You've put a call to AUTOEXEC.BAT into 4START, moved the contents of AUTOEXEC.BAT into 4START, or called 4DOS with a /P option on the command line. 4START should only be used for commands to be executed when any shell is started. Commands for the primary shell should go in AUTOEXEC.BAT. 3. 4START is not executed when a secondary shell is started. This is because 4DOS cannot find 4START. 4START must be a .BAT or .BTM file, located in the root directory of the drive COMSPEC points to. 4DOS Reference Manual Copyright 1991, JP Software Inc. 151 Booting from a Floppy Disk 4DOS will boot properly from a floppy disk, as long as cautions about file locations are observed carefully. 4DOS.COM, KEYSTACK.SYS, and 4DOSxx.EXE should be placed in the root directory of the floppy disk, and the SHELL and DEVICE commands should point to them. If your system has a hard disk, the files can be placed there instead; be sure to set the /L: switch so the 4DOS EXE file can be found. When you boot from a floppy disk, 4DOS sets COMSPEC to point to that disk (e.g. A:\4DOS.COM), regardless of where the 4DOS files are loaded from (it isn't possible for the primary shell to determine where it was loaded from and set COMSPEC accordingly). If you are booting from a floppy disk on a system with a hard disk, and you want secondary shells to load 4DOS from the hard disk, you MUST set the COMSPEC yourself in AUTOEXEC.BAT to point to the hard disk copy of 4DOS. When using a pipe the temporary files created are written to the root directory of the boot drive. If you are booting from a floppy disk and want pipe temporary files to be written elsewhere (e.g. to a hard disk), set the TMP environment variable to point to the correct path. See Redirection in Using 4DOS for details on pipes and TMP. The AUTOEXEC and 4START batch files are always loaded from the root directory of the boot drive when starting the primary shell, so they will have to be on the floppy disk. The 4START file for secondary shells is loaded from the root directory of the drive COMSPEC points to, so if you are using 4START and change COMSPEC be sure to make a copy of 4START on the new drive. Hardware Errors 4DOS is compatible with virtually all PC hardware, including a wide variety of systems, memory configurations, disk drives, keyboards, and so on. While compatibility problems between 4DOS and your hardware could occur, hardware problems which appear to be due to 4DOS are usually found to be due to the hardware itself, or to other software. 4DOS performs ALL disk I/O through standard MS-DOS calls. We have avoided including capabilities which require direct access to the disk , in order to maintain the maximum level of compatibility with your disk hardware. There are no known incompatibilities between 4DOS and disk drive hardware or partitioning software. 4DOS is compatible with the large (over 32 MB) disk volumes created by Compaq DOS 3.31 and MS-DOS / PC- DOS 4.0. 4DOS Reference Manual Copyright 1991, JP Software Inc. 152 If you find that you are having trouble with a disk drive while running under 4DOS, check carefully to see what the problem is and whether it can be reproduced under COMMAND.COM. There has never been a documented instance of damage to a directory or FAT due to a problem in 4DOS. When such problems occur it is understandable that a new part of the operating system is the first thing suspected of causing them, but in the few cases we have heard about the problem has always turned out to be due to hardware problems or errors in applications software. Memory 4DOS does its best to detect and properly access all the types of memory your PC can have: MS-DOS RAM, EMS, XMS, and extended memory. 4DOS' access to these areas is always through standard documented methods. If you want to know whether 4DOS sees your system's memory accurately, check the output of the MEMORY command. Note that the output of MEMORY will show slightly more free MS- DOS RAM than is shown by CHKDSK and some memory map programs. This is because these programs do not count their own environment space as free space. When 4DOS is running this space is not occupied by a program's environment, and hence appears to be free. MEMORY's report of free space includes the space occupied by the 4DOS transient portion, at the end of MS-DOS memory (this space is freed whenever an application is run). While 4DOS is running this space is reserved, and is not available to 4DOS itself for use by commands which allocate DOS memory (COPY, DIR, LIST, SELECT, SETLOCAL, and the processing of .BTM files). If you use one of these features and receive an "out of memory" error when running in relatively limited (under 90K) memory (e.g., when shelled to 4DOS from an application), the problem may be there is not enough room for both 4DOS itself, and the memory to perform the command, despite what appears to be a reasonable amount of free RAM when looking at the output of MEMORY. 4DOS EMS swapping sometimes has difficulty with EMS drivers which do not fully meet the EMS 3.2 specifications (4DOS supports, but does not require, EMS 4.0). If you have trouble accessing EMS for swapping, check COMPAT.DOC to see if there are any known problems with your EMS board or the associated driver software. 4DOS Reference Manual Copyright 1991, JP Software Inc. 153 Critical Errors A "critical" error is an error that gives you the "Abort, Retry, Fail" message. When running 4DOS, this message appears as follows: [Error message] R(etry), I(gnore), F(ail), or A(bort)? The error message on the first line explains the error that has occurred, and the device it occurred on. The second line prompts for your choice of action (the Fail choice will not be displayed under MS-DOS 2). A critical error usually indicates a hardware malfunction. The error may be that the device doesn't exist, there is no disk in the drive, the network has gone down, or a data error occurred. In most cases you will choose R to retry the operation, or A to abort the operation. Choose I(gnore) at your peril: this response will cause 4DOS to proceed as if the error had not occurred! F(ail) will tell 4DOS that the operation it was attempting has failed, which will generally produce another error message. For example, if you attempt to do a directory on drive A with no disk in the drive, and answer F to the resulting critical error, you will get an additional error message, "Invalid drive A". Many programs install their own critical error handlers. If you get a critical error message within an application and the second line does not read as shown above, the message probably did not come from 4DOS, and any problem in handling your response properly is due to the application, and not to 4DOS. Choosing A to abort within an application may abort the entire application, and not just the operation being performed, depending on which critical error handler is in use (4DOS' or the applications's), and how the application's critical error handler (if any) is designed. 4DOS Reference Manual Copyright 1991, JP Software Inc. 154 Video 4DOS is compatible with most display adapters and monitors. However as with any software package, you may have to configure 4DOS to run properly on your system. 4DOS uses two methods of displaying text on the screen: 1. Prompts and normal messages call DOS to write text to the screen. If you use an ANSI driver, it will process these calls. Otherwise, DOS will transmit the text to the BIOS (the I/O software which comes on your system or video board) to display it on your screen. This method for displaying text will work on all MS-DOS systems, regardless of video type. 2. The DRAWBOX, DRAWHLINE, DRAWVLINE, LIST, SELECT, and SCRPUT commands bypass MS-DOS, the BIOS, and ANSI, and write text directly to video memory. These commands will only work on systems with 100% PC-compatible video. On other systems, results will be unpredictable at best. If you have such a system, you probably know it already, as most PC applications will have similar problems. Video Cursor The video cursor shape is defined by "start" and "stop" line numbers within a character "cell" (the space occupied by one character on the screen). Typical cell sizes are 14 lines on a monochrome or EGA system, and 8 lines on a CGA system; other video cards will have varying cell sizes. 4DOS reads the cursor shape at boot, and defines that as the default shape. The shape used by 4DOS can be adjusted with SETDOS /Sb:e, where b is the beginning line and e is the ending line. To see what values 4DOS is using, run SETDOS with no parameters. The shape defined in SETDOS is used for the default editing mode (set by SETDOS /M). The "other" editing mode (e.g., if overstrike is the default then insert is the other mode) uses a cursor that starts at line 0 and ends on the same line as the default cursor. If you have trouble with the cursor, experiment with the SETDOS /S command until you find a setting that works for your system. Note that you will have to reduce the SETDOS cursor settings if you switch an EGA or VGA to 43-line or 50-line mode. The cursor lines in 25-line mode use a larger character cell, and lie outside the smaller 43-line or 50-line cell, making the cursor invisible. If you find the cursor has disappeared and the problem is not addressed by SETDOS /S, it is probably due to screen color problems. The cursor is shown in the color of the underlying 4DOS Reference Manual Copyright 1991, JP Software Inc. 155 character cell. If that cell has (for example) the color attributes of black on black, the cursor will be invisible. If you have an ANSI driver installed, you can test this out easily by clearing the screen to a known color (see CLS in the Command Reference Guide). The cursor should reappear. If the problem persists, you will need to determine what is setting your screen attributes to an invisible color. One common source of this problem is use of an ANSI driver for 43-line or 50-line mode on an EGA/VGA system when the ANSI driver does not support these modes. Screen Length The SETDOS /R command sets the 4DOS screen length. It will not cause 4DOS to attempt to change the video mode; it is an internal variable used to determine display length for LIST, SELECT, and those commands which have a "pause" option (TYPE /P, DIR /P, etc.). 4DOS normally determines the screen length from the BIOS. If you have a non-standard display and/or have trouble with the default screen length, try correcting it with SETDOS /R. SETDOS /R will NOT affect display scrolling at the command prompt. This scrolling is handled by ANSI and/or your system BIOS. If you have an EGA or VGA, and have put the screen in 43- line or 50-line mode, you may find that the display still scrolls at the 25th line. This is usually because your ANSI driver is not properly supporting the extended screen length; it is not a 4DOS problem. ANSI.SYS ANSI.SYS is a device driver, normally installed in your CONFIG.SYS file, which allows control of a variety of screen characteristics via strings of characters sent to the screen. Most versions of MS-DOS include a copy of ANSI.SYS, and there are a number of more powerful versions available as public-domain, shareware, or retail products. The only 4DOS commands requiring ANSI.SYS are CLS and COLOR. CLS will always clear the screen, but will ignore color specifications if ANSI.SYS is not installed. COLOR will work ONLY if you have an ANSI driver installed. 4DOS normally detects automatically whether an ANSI driver is installed. If you have ANSI installed and 4DOS doesn't seem to recognize it (e.g., CLS BRIGHT WHITE ON BLUE still leaves the screen in white on black), try SETDOS /A1, which forces 4DOS to use ANSI commands. 4DOS Reference Manual Copyright 1991, JP Software Inc. 156 4DOS and COMMAND.COM 4DOS is designed to be 99% compatible with the standard MS-DOS command interpreter, COMMAND.COM. In virtually all cases commands will work identically under 4DOS and COMMAND.COM. However, 4DOS has improved on COMMAND.COM in a number of areas, and on rare occasions these improvements produce a conflict. In some cases 4DOS command output differs from COMMAND.COM in order to provide enhancements. For example, the default DIR display is in alphabetical order, rather than physical order as in COMMAND.COM. The filenames are also in lower case, rather than upper case. With DIR, as in most such cases, command options allow you to specify output that is closer to or exactly the same as COMMAND.COM. COMMAND.COM also contains bugs or quirks which are not part of its documented behavior, and some programmers and users have chosen to rely on these bugs and quirks in writing their batch files and programs. 4DOS does not emulate some of these quirks - in some cases to do so would be wrong; in others it would hinder useful features of 4DOS. The only specific compatibility difference we are aware of between 4DOS and COMMAND.COM that is unrelated to undocumented "features" is in handling batch file variables. 4DOS allows 128 batch variables (%0 to %127), and COMMAND.COM only 10 (%0 to %9). COMMAND.COM therefore only considers the first digit after the "%" as part of the variable name. As a result, a string like "%10A" will be interpreted by 4DOS as "the value of batch variable 10, followed by the character A", and by COMMAND.COM as "the value of batch variable 1, followed by the characters 0A". However, you can force 4DOS to make the same interpretation as COMMAND.COM by using the "%[varname]" feature: the string "%[1]0A" will be interpreted the same way COMMAND.COM interprets "%10A". Some users have renamed 4DOS.COM to COMMAND.COM. This will work provided you set COMSPEC properly (see Installation), and may be necessary to deal with programs that ignore COMSPEC and call COMMAND.COM directly. However, we do NOT recommend this approach under most circumstances. It will cause the DOS FORMAT /S command to copy 4DOS.COM rather than COMMAND.COM when creating a bootable floppy disk. Such a disk will not in fact be bootable because the 4DOS EXE file will not be on it, and you may not want it to boot with 4DOS in any case. It may also lead to confusion when someone else looks at your disk and sees a file called COMMAND.COM that isn't really COMMAND.COM. 4DOS Reference Manual Copyright 1991, JP Software Inc. 157 Using 4DOS on a Network 4DOS is compatible with most MS-DOS-compatible networks. This section will give you some tips on using 4DOS properly on a network, and on the locations used for 4DOS files on a network. If you need to boot from a network drive (i.e., on a diskless workstation), you must have the network drive accessible at boot time. If this condition is satisfied (so 4DOS can find its files on the network drives), the standard options can be used to load 4DOS from the network drive. When using 4DOS on a network, you must pay careful attention to where files are stored in order to be sure that two 4DOS users do not attempt to access the same file at the same time. When swapping to disk (either explicitly with the /S:D option, or implicitly because best guess swapping is used and no EMS or XMS is available), you must be sure that no two users ever use the same directory for their disk swap files, since the filenames (4DOSSWAP.000, .001, etc.) will conflict. This includes swap files created by shelling to 4DOS from a program, or running secondary shells implicitly (e.g. with a MAKE utility). Set the swap file location explicitly with the /S option, assigning each user's swap files to a different directory on the network drive. The primary shell's swap file location is controlled by the /S option in CONFIG.SYS. For instance, the following command will boot 4DOS with best guess swapping and store any disk swap file created in directory F:\USERA: shell=c:\ /s:bf:\usera The swap file location for secondary shells is controlled by the 4DSHELL environment variable (see Installation). Using the above example, the appropriate setting for 4DSHELL would be: set 4dshell=/s:bf:\usera Both SHELL and 4DSHELL must be set properly to ensure that there are no problems with disk swap files on your network. Note that if you set up the SHELL command and 4DSHELL to force EMS or XMS swapping (/S:E or /S:X), there is no need to set up a separate directory for each user for this purpose as there will be no disk swap files. Pipes are methods of passing information from one program to another, and are invoked with the pipe symbol | on the command line (see I/O Redirection in Using 4DOS). Pipes work by taking the output from one program, storing it in a temporary file, then telling a second program to obtain its input from that file. The temporary files, named P.1$$ and P.2$$, are placed by default in the root directory of the boot drive, but can be placed on a different drive and directory by setting the TMP environment variable. 4DOS Reference Manual Copyright 1991, JP Software Inc. 158 If you choose to set TMP, or if you have a system where multiple users can boot from the same directory, the same cautions given for disk swapping must be followed for pipe temporary files; that is, you must ensure that each user's pipe temporary files go to a separate directory. For example, for the user in the examples for disk swapping above, the pipe temporary files can be set to go the same directory by placing this command in AUTOEXEC.BAT: set tmp=f:\usera Common Questions and Problems This section covers a variety of problems and questions which come up regularly in technical support calls and messages, and which are not covered by the sections above. If you have questions about compatibility with a specific software product, refer to COMPAT.DOC. When you find another piece of software that appears to be incompatible with 4DOS, there are several techniques you can try to determine where the problem lies. Even if these methods are not workable as a permanent solution, they will provide valuable information as to the nature of the problem. Try removing all of the device drivers and TSRs you can from CONFIG.SYS and AUTOEXEC.BAT (including KEYSTACK.SYS), and see if the problem persists. If it doesn't, put the drivers and TSRs back one at a time until you find the conflict. Many apparent two-way compatibility problems ("4DOS and package X don't work together") turn out to be three-way interactions between 4DOS, the problem program, and a device driver or TSR. If the program you are having trouble with uses EMS memory and you are using EMS swapping, you can try changing to disk swapping to see if the problem goes away. The same is true for XMS swapping and programs which use XMS. If you are using the /U option on a system with XMS memory, try removing it to see if the program cannot work when the command processor is loaded high. If the program is not a TSR, try running it under COMMAND.COM. For example, if COMMAND.COM is in C:\: c:\command /c myprog [parameters] If you need to continue to use this method, you can define an alias: alias myprog `c:\command /c myprog %&` If the program is large enough to overwrite the transient portion of COMMAND.COM, you will need to change COMSPEC temporarily to 4DOS Reference Manual Copyright 1991, JP Software Inc. 159 point to COMMAND.COM, to avoid an error message when exiting the program. Problems with Shelling to DOS Many application programs allow you to "shell to DOS" from inside the program. If you have trouble shelling to DOS, or running a program which uses an implicit shell (e.g., a hard disk manager which shells to DOS to perform file copies), check your COMSPEC and 4DSHELL settings. To shell to 4DOS, COMSPEC must point to 4DOS.COM, and the 4DOS EXE file must be in the same directory that COMSPEC points to, or if it is not, the /L: switch must be set in 4DSHELL. (See Installation for more details on COMSPEC and 4DSHELL.) You can view the settings of these variables with the command SET /P; this is a more reliable approach than looking at AUTOEXEC, since it tells you what the variables are really set to, instead of what you tried to set them to. You can test whether these variables are set up properly by changing to the directory you are in when the problem occurs, and entering %COMSPEC at the prompt. This will attempt to execute the program COMSPEC points to. If this works and 4DOS starts, type EXIT to return to the previous shell. If it fails, correct COMSPEC and/or 4DSHELL. If COMSPEC and 4DSHELL are set correctly and you still cannot shell to DOS, you may have too little memory. Try running a smaller application which also shells to DOS and verify that it works correctly; if so, see if the problem application can be adjusted to provide more free memory for a DOS shell. Finally, you may have trouble shelling to DOS because the application is trying to shell directly to COMMAND.COM, rather than looking at the COMSPEC setting. If you have moved COMMAND.COM or changed your PATH since you installed 4DOS, make sure there is a copy of COMMAND.COM accessible to the program and see if it will then shell properly. You may need to contact the program manufacturer to determine if a particular program shells directly to COMMAND.COM. 4DOS Reference Manual Copyright 1991, JP Software Inc. 160 Name Conflicts with 4DOS Commands You may have a program which has the same name as a 4DOS internal command. Many 4DOS users use Vern Buerg's excellent file viewer, LIST.COM, whose name conflicts with 4DOS' internal LIST command. Such conflicts can be solved in one of two ways. If you want to disable the 4DOS internal command entirely, use the SETDOS /I- command. For example: setdos /i-LIST The command can be re-enabled with SETDOS /I+ (see SETDOS in the Command Reference Guide). The other method is to set up an alias to redirect the command to the external program. For example: alias list c:\util\list.com This also disables the internal command. However you can then add another alias to invoke the internal command under a different name. For example: alias show *list Problems with Memory-Resident Programs (TSRs) Most TSRs will work properly with 4DOS. If you have trouble getting a TSR to pop up, you may need to use the SETDOS /L1 command to convince the TSR that it is at the DOS prompt, or because it traps the DOS line input interrupt to do some of its work. If you have trouble getting a TSR to unload, the problem may be due to the method used by the TSR to remove itself from memory. In most cases programs which cannot be unloaded directly can be removed using the MARK and RELEASE utilities available from TurboPower Software. These programs are part of a package called TSRCOM which also contains many other useful utilities, and is available free on many bulletin boards and on-line services, and is included on the 4DOS Utility Disk available from JP Software. 4DOS Reference Manual Copyright 1991, JP Software Inc. 161 Glossary 4DSHELL: An environment variable which defines the 4DOS switch values for secondary shells. 4START: A batch file which is executed whenever 4DOS is started, either as a primary shell or a secondary shell. Alias: A shorthand name for a command or series of commands. Alias Argument: A numeric variable included in an alias definition, allowing a different value to be used in the alias each time it is executed. ANSI.SYS: A device driver supplied with MS-DOS which provides enhanced screen display and keyboard macros, or one of the many similar programs available free or as shareware or retail products. Append: Concatenation of one file or string onto the end of another. (There is also an MS-DOS external command, APPEND, which has an entirely different meaning -- and should be used extreme with caution!) Application: A program run from the command prompt or a batch file. The term is 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 (presuming that the last backup cleared the archive attribute, as most backup programs do). Also sometimes used to refer to a single file which contains a number of other files in compressed form. Argument: A piece of additional information placed after a command or function name. For example in the command DIR XYZ, XYZ is an argument. Also used to refer to an alias argument or batch file argument. 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 codes, numbers, or other information that cannot be sensibly interpreted as text. 4DOS Reference Manual Copyright 1991, JP Software Inc. 162 Attribute: A characteristic of a file which can be set or cleared. The standard attributes are Read-Only, Hidden, System, and Archive. The special attributes Volume Label and Directory are also used for files of those types. AUTOEXEC.BAT: A batch file which is AUTOmatically EXECuted when the computer is started. BAT File: Same as a Batch File. Batch File: A text file containing a sequence of MS-DOS or 4DOS commands. 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 Argument: A numeric variable 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, and many networks. Boot: The process of starting the computer and loading MS-DOS and the command processor into memory. Boot Directory: The current directory at the time the system is booted, almost always 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 (including 4DOS) 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, dramatically speeding up execution. Buffer: An area of memory set aside for storage. Usually refers to disk buffers, used to save information as it is transferred between your program and the disk; or to the keyboard buffer. 4DOS Reference Manual Copyright 1991, JP Software Inc. 163 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. Code Page: A set of definitions which tells DOS how to get and display date, time, and other information in the format appropriate to a particular country. Command Completion: A 4DOS 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 feature which retains commands you have previously executed, so that they can be modified and re-executed later. Command Processor: A program, such as 4DOS or COMMAND.COM, which interprets commands and executes other programs. The command processor is the first program loaded when the system is booted. Command Recall: See Command History. 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 get the command processor for a secondary shell. Conditional Commands: A 4DOS feature allowing commands to be executed or skipped depending on the results of a previous command. See also Exit Code. CONFIG.SYS: A file which tells MS-DOS what device drivers to install, what command processor to use, and other information about what to do when your system boots. See your MS-DOS manual for more information. Console: A term describing the PC keyboard and display,. 4DOS Reference Manual Copyright 1991, JP Software Inc. 164 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. For example the control character called "BEL" is generated by pressing Ctrl-G, and will cause the computer to beep if pressed at the MS-DOS prompt. Country Code: See Code Page. 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 input, output, or network access, which prevents a program from continuing. When a critical error occurs a prompt such as "R(etry), I(gnore), F(ail), or A(bort)" is given and you must decide what action to take. Current Directory: The directory in which all file operations will take place unless otherwise specified. For example if the current directory is C:\MYFILES then the command "DEL XYZ" will delete the file XYZ in the directory C:\MYFILES, and will not affect other files with the same name which may be in other directories. Description: A string of up to 40 characters assigned to describe a file with the 4DOS DESCRIBE command. Device: A physical device for input or output such as the console, a communications port, or a printer. Sometimes the term "device" alone is used to refer to character devices such as those listed above, and excludes block devices. Device Driver: A program which allows DOS to communicate with a device, and which is loaded into memory when the system is booted, via a statement in CONFIG.SYS. Some device drivers are used to manage memory or for other similar internal functions, rather than to communicate with an external device. 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. Disk Swapping: A type of swapping where the transient portion of 4DOS is stored on disk while an application is running. 4DOS Reference Manual Copyright 1991, JP Software Inc. 165 DOS Memory: 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 bytes of the computer's memory (one K is 1024 bytes). Echo: See Command Echoing. EMS Memory: Memory which conforms to the Lotus - Intel - Microsoft Expanded Memory Specification (LIM EMS). This hardware/software standard allows programs to access large amounts of memory outside of standard DOS memory or extended memory. Most systems which have EMS memory have either a specific EMS board (on any PC or compatible system), EMS emulation software (on PC-AT compatible systems), or a 386 control program such as QEMM or 386MAX (on 386 systems). If you do not have one of these items, you probably do not have EMS memory. EMS Swapping: A type of swapping where 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". Each entry is called an environment variable, with the name "NAME". See also master environment and passed environment. Environment Variable: The name of a single entry in the environment. Environment variables are entered with the SET command, and used to associate the specified value with the specified name for any purpose desired by the user. Typically, their function is to set default switches for a program, specify a directory path where files can be found, and so on. When 4DOS encounters an environment variable name in a command in the form "%NAME" (or "%NAME%"), it substitutes the corresponding value in its place. Errorlevel: A numeric value returned from an external command to indicate its result (e.g. success, failure, response to a question), and accessible via the IF ERRORLEVEL command and the %? environment variable. The value is between 0 and 255, plus 256 if the program was interrupted by a break, 512 if it aborted due to a critical error, or 768 if it remained resident in memory as a TSR. See also Exit Code. Escape Character: This term has two meanings. In some contexts it means the 4DOS escape character, normally Ctrl-X, which is used to suppress the normal meaning of or give special meaning to the following character. In other cases it refers to the specific ASCII character ESC. The meaning must be determined from the context. 4DOS Reference Manual Copyright 1991, JP Software Inc. 166 Executable Extensions: A 4DOS 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 with the extension .COM or .EXE, which can be loaded into memory and run as a program. Exit Code: The error level returned by an external command, or a similar exit code returned by a 4DOS internal command. 4DOS internal commands return an exit code of 0 if successful, or non- zero if unsuccessful. Expansion: The process 4DOS goes through when it scans a command line and substitutes the appropriate actual values for aliases, alias arguments, batch file arguments, and environment variables. 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) or 386-based computer system which is above the 1 MB (one megabyte, or 1024*1024 bytes) of memory that DOS can address directly. Any PC-AT compatible or 386 system with more than 640K of memory has extended memory. This memory can be used for a variety of purposes depending on the software installed to utilize it. See also XMS. External Command: A program which resides in an executable file, as opposed to an internal command which is part of the command processor. For example, FORMAT and DISKCOPY are external commands; you can find them on your DOS disk under the names FORMAT.COM and DISKCOPY.COM. File Attribute: See Attribute. File Description: See Description. Filename Completion: A 4DOS feature which allows you to type part of a filename on the command line, and have 4DOS fill in the rest for you. Free Memory: Usually, the amount of DOS memory which is currently unoccupied and available for use by applications. 4DOS Reference Manual Copyright 1991, JP Software Inc. 167 Hidden: A file attribute indicating that the file should not be displayed with a normal DIR command, and should not be available for access by programs unless they specifically request use of hidden files. History: See Command History. 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. For example, DIR and COPY are internal commands. Keyboard Buffer: A buffer which holds keystrokes you have typed that have not yet been used by the currently executing program. Label: A marker in a batch file which allows GOTO or GOSUB commands elsewhere in the batch file to "jump" to the command on the line following the label. 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. The master environment is manipulated with the SET and UNSET commands. The size of the master environment is set by the /E: command line switch. Memory Resident Mode: A method of installing 4DOS where swapping is disabled, and all of 4DOS remains permanently resident in memory. Memory-resident mode requires much more memory than the normal swapping mode. Multiple Commands: A 4DOS feature which allows multiple commands to be placed on a line, separated by a caret (^) or other 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 DESQview. Option: See Switch. 4DOS Reference Manual Copyright 1991, JP Software Inc. 168 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: See Argument. Parsing: The process 4DOS performs when it analyzes the command line, performs alias and environment variable expansion, and finds 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. The size of the passed environment is determined by the amount of space actually used in the master environment when the application is started. Path: A specification of the directories a file resides in, including all parent directories. 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 when the system boots. RAM Disk: A pseudo "disk drive", created by software, which appears like a normal physical disk drive to programs. RAM disks can be stored in extended memory, XMS memory, EMS memory, or DOS memory, and provide a convenient way for programs to use this memory for temporary files. Read-Only: A file attribute indicating that the file can be read, but not written by MS-DOS and 4DOS. Reboot: The process of restarting the computer, usually by pressing the Ctrl, Alt, and Del keys simultaneously. 4DOS Reference Manual Copyright 1991, JP Software Inc. 169 Redirection: A method for collecting the standard output of a program in a file, and/or of providing the standard input for a program from a file, signified respectively by a greater than symbol ">" or less than symbol "<" on the command line. See also Pipe. Replaceable Parameter: See Alias Argument and Batch File Argument. Resident Portion: The small portion of 4DOS stored permanently in memory when swapping mode is in use, as opposed to the larger transient portion. The resident portion is stored as close as possible to the beginning of DOS memory. Root Directory: The first directory, from which all other directories are "descended." The root directory is referenced with a single backslash (\). When a disk is first formatted, it is the only directory. Secondary Shell: Any copy of any command processor which is loaded after the system boots. Secondary shells may be started from the command line; by executing a "shell to DOS" operation from within an application; implicitly by executing some MS-DOS- related functions within certain applications; or by starting a new partition in a multi-tasking or task switching system. Shell: A command processor. Also used to refer to a program which gives access to MS-DOS functions and commands through a menu- or mouse-driven system. Source: In the 4DOS file commands (COPY, MOVE, and RENAME), the original files before any copying or modification has taken place, i.e. those specified earlier on the command line. See also Target. Stack: An area of memory used by any program to store temporary data while the program is running; more generally, any such storage area where the last item stored is normally the first one removed. Standard Error: A file or character device where error messages from a program are displayed. Standard error output always goes to the console, unless redirection is used. Standard Input: A file or character device where a program obtains its normal input. Standard input always comes from the console, unless redirection is used. 4DOS Reference Manual Copyright 1991, JP Software Inc. 170 Standard Output: A file or character device where normal output from a program is displayed. Standard output always goes to the console, unless redirection is used. Subdirectory: Any directory other than the root directory. See also Root Directory. Swap File: A disk file created by 4DOS to store its transient portion when disk swapping is in use. Swapping: A 4DOS feature which removes the larger transient portion of 4DOS from DOS memory while an application is running, leaving the maximum possible amount of memory for the application, yet allowing 4DOS to retain information such as the command history after the application is finished. See also XMS Swapping, EMS Swapping, and Disk Swapping. Switch: An argument to an internal command or application which specifies a particular behavior or setting. For example, the command "DIR /P" might be referred to as "having the /P switch set". Also, a configuration value for 4DOS specified on the SHELL= line in CONFIG.SYS, or in 4DSHELL. System: A file attribute indicating that the file belongs to MS- DOS and should not be accessed by normal programs. Target: In the 4DOS file commands (COPY, MOVE, and RENAME), the final files after any copying or modification has taken place; generally those referred to by the last specification on the command line. See also Source. Transient Portion: The larger portion of 4DOS stored in memory temporarily when swapping mode is in use, as opposed to the smaller resident portion. The transient portion is stored as close as possible to the end of DOS memory, and is removed from memory whenever an application is executed. TSR: A Terminate and Stay Resident program, i.e. a program which "terminates" but remains resident in DOS memory, to provide capabilities such as network support, a pop-up notepad or telephone dialer, a disk cache, or mouse support. UMB: An XMS Upper Memory Block, whose address is above the end of normal DOS memory, but is within the 1 megabyte of memory that DOS can address directly. 4DOS Reference Manual Copyright 1991, JP Software Inc. 171 Variable: See Alias Argument, Batch File Argument, and Environment Variable. Volume Label: A special, hidden file placed on any disk whose name constitutes a "label" for the entire disk. White Space Character: Generally, a character used to separate arguments on the command line. The white space characters recognized by 4DOS are the space, tab, comma, semicolon, and equals sign. Wildcard: A character ("*" or "?") used in a filename to specify the possibility that any single character ("?") or sequence of characters ("*") can occur at that point in the actual name. XMS Memory: A software method for accessing extended memory on 286 and 386 systems (and some systems which support version 4.0 of the EMS memory specification). XMS memory is not additional memory, but is a software specification only. Its use generally requires Microsoft's HIMEM.SYS be installed as a device driver, or that another program such as 386MAX or MOVE-EM be used. XMS Swapping: A type of swapping where the transient portion of 4DOS is stored in XMS memory while an application is running. 4DOS Reference Manual Copyright 1991, JP Software Inc. 172 Index 4DOS Cancel batch job 34 Features 1 CD 57 Memory Usage 18 CDD 58 Startup Options 21 CHCP 59 Swapping mode 22 CHDIR 57 4DOS.COM 9 CLS 60 4DOS.DOC 10 CMDLINE 3, 40 4DOS286.EXE 9 Code page 59 4DOS88.EXE 9 COLOR 61 4DOSSTAK 149 Colors 60, 114 4DSHELL 15, 25, 160 Command 4START 25, 27, 119, 151 Completion 29 Echoing 32 ? 48 History and Recall 29 Line 3 ALIAS 35, 49 Line arguments 32 Alias Line editing 28 Expansion 35 Parsing 45 List 130 Processor 80 List size 21, 99 Reference Guide 46 Parameters 36 Separator 30, 119 Aliases 3, 10, 35, 37, 78, Syntax 47 130 COMMAND.COM 26, 157 AND 30 Comment 110 ANSI 60, 61, 119, 156 COMPAT.DOC 10 Append 62 Compatibility 10 Archive attribute 52, 62 COMPOUND 30, 119 Argument quoting 32 COMSPEC 15, 160 ASP 146 Conditional commands 3, 30 Association of Shareware Conditional execution 88, 91 Professionals 146 CONFIG.SYS 14, 19 ATTRIB 52, 89 Configuration 17 Attribute 52 Console 64 AUTOEXEC.BAT 14, 25, 27, 151 COPY 62 Automatic Installation 13 Country code 65 Create subdirectories 98 Batch Critical errors 154 File nesting 55 CTTY 64 File echoing 76 Current directory 57, 107, 109 File parameters 123 Cursor 113, 121, 155 File processing 56 File variables 34 DATE 65 Files 33 DEL 66 Processor 7 DELAY 67 Variables 157 DESCRIBE 68 BEEP 53 DESCRIPT.ION 68 Box 73 DIR 69 BREAK 54 Directory stack 72, 107 DIRS 72 CALL 55 Disk swapping 22 CANCEL 56, 108 Disk write verification 133 4DOS Reference Manual Copyright 1991, JP Software Inc. 173 DOS Shells 14 EXTENDED 89 DOS.HLP 10 Extended key codes 148 DOSMEM 89 Extended memory 99 DRAWBOX 73 External command 102 DRAWHLINE 74 DRAWVLINE 75 F1 28, 95 F8, F9 & F10 28, 30 ECHO 32, 76 File descriptions 2, 68 Edit 78 File attributes 52 EGA 156 Filename completion 30 ELSE[IFF] 91 Floppy disk 152 EMS 18, 89 FOR 81 Swapping 23, 153 FREE 82 ENDIFF 91 Frequency 53 ENDLOCAL 77, 122 ENDTEXT 126 GE 88 Environment 2, 131 GLOBAL 83 Size 2, 21 GOSUB 84, 112 Space 99 GOTO 85 Variables 2, 40, 78, 92, GT 88 93, 117, 122 @ext 42 Hardware errors 152 @full 42 HELP 10, 11, 86 @length[string] 42 Hidden attribute 52, 79 @name 42 HISTORY 87, 119 @path 42 History list 29, 87 @search 42 History size 22 @substr 42 Horizontal line 74 _BG 41 _CPU 41 I/O Redirection 43 _CWD 41 IF 88 _CWDS 41 IFF 91 _CWP 41 INKEY 92, 148 _CWPS 41 INPUT 93 _DATE 41 INSTALL 13 _DISK 41 INSTALL.BAT 9 _DOSVER 41 Installation 9, 150 _FG 41 INTERNAL 120 _SHELL 41 ISALIAS 89 _TIME 42 ISDIR 90 EQ 88 ERASE 66 Key Codes 148 Error messages 136 KEYSTACK 10, 11, 39, 94, ERRORLEVEL 30, 41, 89 148, 149 ESCAPE 31, 119 Escape character 31, 119 Label 85, 134 ESET 78 Language support 59 EXCEPT 79 LE 88 Executable extensions 37 LINE 120 EXIST 89 Line editing mode 120 EXIT 80 LIST 95 Exit code 30 LOG 97 Expanded memory 99 LT 88 4DOS Reference Manual Copyright 1991, JP Software Inc. 174 Manual Installation 17 SCREEN 113 MARK 161 Screen length 156 MD 98 SCRPUT 114 MEMORY 99, 153 SELECT 115 Memory resident mode 18,23 SET 40, 117 Memory-resident programs 161 SETDOS 29, 30, 31, 32, 43, MKDIR 98 76, 87, 110, 119, MODE 120 155, 156, 161 MONITOR 90 SETLOCAL 77, 122 MOVE 100 SHAPE 121 Multiple arguments 4 Shell 14, 19, 21 Multiple commands 2, 30 Shelling to DOS 160 SHIFT 34, 123 Name conflicts 161 Standard NE 88 Error 43 Network 3, 158 Input 43, 64, 125, 135 NOCLOBBER 43, 120 Output 43, 64, 125, 135 Starting 4DOS 27 OR 30 Stopwatch 128 OS/2 DOS box 1, 20 Subdirectory 98, 109 Subroutine 84, 112 Parent directory 109 SWAPPING 124 PATH 40, 98, 102 Swapping mode 18 PAUSE 103 System attribute 52 Pipes 44, 125,158 PKUNZIP 10, 11 TEE 125 POPD 104 TEXT 1 26 Primary shell 14 THEN 91 Programming for 4DOS 149 TIME 127 PROMPT 105 TIMER 128 PUSHD 107 Tips 150 TMP 41, 44, 159 Quick Start 12 Transient portion 18, 124 QUIT 108 Troubleshooting 150 Quotes 32 TSR 161 TSRCOM 161 RAM 99 TYPE 129 RD 109 Read-only attribute 52 UMB 23 README.DOC 10 UNALIAS 35, 50, 130 Redirection 3, 120 UNSET 131 RELEASE 161 UPPER 121 REM 110 Using 4DOS 27 REN 111 RENAME 111 Variable functions 42 Replaceable parameters 36 Variables 131 Resident portion 18 VER 132 RETURN 84, 112 VERBOSE 32, 76, 110, 121 RMDIR 109 VERIFY 63, 133 Root directory 98, 109 Version number 132 Root shell 14 Vertical line 75 ROWS 120 VGA 156 4DOS Reference Manual Copyright 1991, JP Software Inc. 175 VIDEO 90, 155 Video cursor 155 VOL 134 Volume label 134 Wildcards 2 XMS 18, 90 Memory 99 Swapping 23 Upper Memory Block 23 Y 135 4DOS Reference Manual Copyright 1991, JP Software Inc. 176