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INTRODUCTION: THE LIBRARY CONCEPT LU Command Conventions SUMMARY OF LU OPERATIONS Looking Over Existing Libraries: LDIR Unpacking Entire Libraries: LUNLOAD Selecting Libraries for Access: -O Accessing Individual Members in Libraries: -L -E Executing Programs in Libraries: LRUN Building and Maintaining Libraries: -D -N -A -R Finishing Up: -C -X HANDLING SPECIAL SITUATIONS Insuring Enough Memory Capacity: -B Changing Drives and Switching Disks -- Precautions: -U Staying Out of Trouble: Error Recovery HOW LIBRARIES ARE ORGANIZED :LU 3.00c NOTICE: Current Version Numbers dh: 84-01-15 =============================== This material applies to version 3.00 of LU.COM. Libraries created by LU 3.00 can be read by all previous versions, and vice versa, but version 3.00 provides additional protection against undetected damage in files that it creates and accesses. Copyright 1982, 1983 by Gary P. Novosielski All rights reserved. Permission is hereby granted to copy and distribute this work for any non-commercial purpose. Any use of this material for commercial advantage without prior written consent of the copyright owner is prohibited. Please report any problems and suggestions for enhancement to the author via CompuServe CP-MIG or EMAIL posting to user number 70160,120; or by voice phone to (201) 935-4087, evenings (eastern time) and weekends. LU.HLP #3.00a first derived by Dennis E. Hamilton on 83-10-30. next: What is a Library? INTRODUCTION: THE LIBRARY CONCEPT ================================= Library Utility (LU) is a system for storing several files as components of one larger file. The resulting library (.LBR) file has its own PRIVATE DIRECTORY. Library files provide an additional dimension for the collection, organization, and maintenance of your work. And because of CP/M disk-usage rules, libraries tend to require less space than the same files stored separately. In addition, libraries release CP/M disk-directory entries for other uses, especially when the library holds many tiny files. The maximum number of components -- library MEMBERS -- to be contained in a library must be specified in advance. But the limit can be changed later on when the library is re-organized. Because library members are tucked away within other, larger, CP/M files, they have to be extracted -- taken off the shelf -- in order to be worked on or used by typical programs. The modifed results are also restored to the library by using LU. next: How LU Utilities Help To make it easy to keep executable routines in libraries, the LRUN utility is provided. LRUN is a small program which will execute your .COM- file programs directly from the libraries which hold them. With LRUN, it is not necessary to extract a program into a separate disk file before execution. Also, when material is packed in a library for convenient distribution in one piece, there is another utility, LUNLOAD, which unpacks everything. The basic library utility, LU, lets you start new libraries and * Add new members to any specified library as long as there is room * Extract copies of any members for use outside of the library * Delete and rename members, as needed * Reorganize a library to change its capacity and recover deleted space. * Produce a directory to any library's current content. The utility LDIR allows inspection of a library's directory and there are variants, such as LRUNZ and LDIRZ, that support the extended conventions of ZCPR2. There is a trend to have newer CP/M utilities also accomodate .LBR files in their operation. next: Why (not) to LU WHY USE LIBRARIES? * Libraries make more compact use of disk capacity. * Libraries require fewer disk-directory entries, cutting down on clutter and releasing entries for other purposes. * Libraries aid the transfer of software from one system to another. Only one file is distributed, reducing the chance of omissions and oversights. * Libraries allow more flexible choice of file names, since uniqueness is important only within each separate library. WHAT IS THE PRICE? * Files within a library are unavailable to "normal" programs. A file will usually have to be extracted from the library before its data can be used. * When a library member is deleted, space is not automatically released for re-use. The library must be explicitly re-organized in order to recover the directory entry and space of a deleted member. On balance, LU lends tremendous support for disciplined organization and maintenance of your programs and data. ::LUCMD LU COMMAND CONVENTIONS ====================== LU is guided by a miniature language of COMMAND-STRING OPERATIONS. If you are unfamiliar with the notation and conventions of this tidy little language, you should locate the file LUCMD.HLP and review it using the command a>HELP LUCMD There you will find out about * Different ways of initiating LU and supplying command string * General format of the command-string: use of spacing and line-breaks * Notation for specifying operations * Notation for selecting files * LU place-keeping and default assumptions : SUMMARY OF LU OPERATIONS ======================== OP OPERAND(S) OPERATION -A file-spec ... Add the selected files to the open library. -B s Set the buffer size to s (1 to 255) records. -C Close any library that is presently open. -D file-spec ... Delete selected files in the open library. -E file-spec ... Extract selected files from the open library. -L List a directory for the open library. -N new=old ... Rename selected files in the open library. -O file-spec Close any open library and open the specified one. If the library does not exist, one will be created. -R Re-organize the open library. -U [u/][d:] Close, change to the given defaults, and reset the disk -X Exit from LU after the current line is processed. An empty command-stream line implies -X. In a pinch, you can ABORT processing with ^C at the input prompt. This leaves the open library directory as it was at the end of the last -C, -O, -A, -R or -U operation. Do -L and cleanup as needed, following with -R. ::LDIR LOOKING OVER EXISTING LIBRARIES =============================== When all you want to do is find out, or remind yourself, what is IN a library, the LDIR utility (and LDIRZ, its ZCPR2 counterpart) are just the ticket. Typically, LDIR lets you examine a library via a specification of the form d>LDIR library ... where library identifies the library that you want to know about Command "d>LDIR COMMAND will, with this convention, show everything that is known about files in library COMMAND.LBR. For specific information about the version of LDIR available on this system, you should locate the file LDIR.HLP for review via d>HELP LDIR ::LUNLOAD UNPACKING ENTIRE LIBRARIES ========================== When a library file is used as a "carton" for a group of files being distributed together, there is an easy way to make separate copies of its entire content: a>b:LUNLOAD c:library will, for example, "unpack" the files of c:library onto the a: disk. Precise operation of the currently-supported LUNLOAD version is specified in the file LUNLOAD.HLP. Locate that file and review it via a>HELP LUNLOAD Note that the functions of LUNLOAD can be obtained with LU, but not so directly. Also, LUNLOAD may succeed where LU is unable to obtain enough storage for operation. : SELECTING THE LIBRARY TO ACCESS =============================== Unless you are willing to use a library of name LIBRARY.LBR, you need to specify the actual library to use with an OPEN command-string sequence: -O library * Any library file that is already open will be closed. * The default u/, d:, and file type .LBR are used to complete the library filespec, as necessary. * If the specified library exists, it is opened for use as the current library. * If the specified library does not exist, a NEW LIBRARY is created. LU will request information from the console in order to allocate a library with sufficient capacity for the intended members. (Refer to the information on "Building and Maintaining Libraries" for further treatment of this case.) : ACCESSING MATERIAL IN LIBRARIES =============================== In addition to using an LDIR utility, you can review the contents of the currently-open library using the LU command-string -L for "LISTING" the library directory while LU is operating. When you need to work with separate copies of members, the LU command- string -E filespec ... "EXTRACTS" copies of those members selected by each following filespec. Every library member that matches a single filespec is copied. The copy has the same filename as the original member. WHERE copies go is determined by the u/d: determined for each filespec. (Read-only files cannot be overwritten in this way, however.) next: Understanding the Library Directory LIBRARY DIRECTORY ENTRIES The information presented in response to the -L operation consists of the following: filename for each current member (and DIRECTORY for the library's own directory space) index of the library record where the member starts (needed by the library utilities in finding the data) size of the member in CP/M RECORDS (128-byte units). Divide by 8 for size in 1k units. CRC a special kind of check code carried for each member and used to help detect the presence of damage to the library In addition to this information about the "active" entries, LU indicates how many members can be added and how many deleted members and deleted records are cluttering the library. (The waste for deleted members is eliminated by reorganizing with -R.) ::LRUN EXECUTING PROGRAMS IN LIBRARIES =============================== Usually, library data that is going to be used by a program must be extracted first. But programs that are kept in libraries can be executed without having to be removed first. This is accomplished by use of the LRUN utility or one of its kin. For more information on the current release of LRUN, locate the file LRUN.HLP and review it by a>HELP LRUN ::LBRBUILD BUILDING AND MAINTAINING LIBRARIES ================================== With a set of well-organized libraries in hand, most access will be in order to USE the material that the library contains. LU supports this effort as do the more-specialized utilities such as LDIR and LRUN. But LU is also designed to be used in constructing and modifying new libraries of your own material. Once you are comfortable with the general concepts of LBR-usage and LU operation, the additional provisions for building libraries will be easy to grasp. The file LBRBUILD.HLP describes these additional, advanced features. You can review it with the command a>HELP LBRBUILD : FINISHING UP ============ When operations on a library have been finished, there are three ways to move on. Command-string -C will "CLOSE" any currently-open library, if there is one, making sure that all changes are reflected in its directory. There is now no current directory. -X has the same effect as -C, followed by termination of LU, UPON COMPLETION OF THE CURRENT COMMAND-STRING LINE The end of the command-string, or the occurence of an empty line within it, has the same effect as the -X operation. : HANDLING SPECIAL SITUATIONS =========================== There are three areas where operation of LU can become tricky. First, it is possible to exceed the capacity of your computer in trying to manipulate a library with allowance for a great number of members. The LU operation -B nn may be used to obtain relief in some cases. Also, when it is necessary to change disks in the course of working on a library, there are some special precautions involved. The LU operation -U [u/][d:] helps to reset things properly after changing disks, when possible at all. Finally, use of .LBR files puts a lot of eggs in one basket. There are some useful tips available for making sure that the .LBR does not go the way of Humpty Dumpty. ::LBRSIZE INSURING ENOUGH MEMORY CAPACITY =============================== Besides the space taken for program and housekeeping during LU opera- tion, there are two large data buffers: one for DISK ACCESS and one for LIBRARY DIRECTORY. If your CP/M system has a very large TPA (transient program area), there is not much to worry about. But you should still review the capacity rules to get a sense of the headroom available. Command string: -B nn changes the disk-access buffer allocation to nn records as a way to increase performance or to accomodate a larger directory instead. Complete details about this and related adjustments are found in the file LBRSIZE.HLP. You should review this file with command a>HELP LBRSIZE : CHANGING DRIVES AND SWITCHING DISKS NEVER REMOVE OR CHANGE ANY DISK ON WHICH THERE IS AN OPEN LIBRARY. LU carries information about the library in computer memory. This information is not recorded on the disk until the last possible moment. If you change a disk without giving LU a chance to bring the disk and memory copies of data into agreement, OPERATION WILL FAIL. THERE IS THE POSSIBILITY OF DAMAGE TO MATERIAL RECORDED ON ONE OR MORE DISKS. The way to guarantee that all disks are in a "clean" condition is to CLOSE THE CURRENT LIBRARY with the -C operation. (If you are all done, -X does this too.) You can now remove and replace disks as desired. To continue (when there is no CON: redirection), try operation -U filespec ... to "log" into the new u/ and d: defaults specified in the following filespec(s). The filespecs should have only the u/ and d: fields, as needed. IF CONDITIONS ARE SAFE for -U, LU will close any current library, reset the disk system, and change the default parameters. You can now (re)-open the library to use next. ::LUTIPS STAYING OUT OF TROUBLE: ERROR RECOVERY ====================================== When you are building, modifying, and re-organizing libraries, a n umber of problems can "spoil" an entire library's worth of work. Tips on protecting your investment in library-stored material have been compiled in the file LUTIPS.HLP. The file can be reviewed, once located, using command a>HELP LUTIPS ::LBR HOW LIBRARIES ARE ORGANIZED =========================== .LBR files are organized in a special format that is only intelligible to special-purpose utilities such as LU, LDIR, and LRUN. So that specialists can incorporate .LBR access into other utilities, the format rules have been compiled in the file LBR.HLP. If you have access to this file, you can review it with the command a>HELP LBR : : : : LU.HLP #3.00 was first created on 83-10-30 by Dennis E. Hamilton.