ARCA Command Version 1.28 ------------ Oct 4, 1987 Purpose: To create or add files to an ARC archive file. Format: ARCA [drive:][path]arcname.ext [filespecs...] [/d] Remarks: The drive and path names are optional. If omitted, the current drive and path name are used. The 'arcname' file name must be supplied. The extension defaults to ARC. All files matching the supplied filespecs are processed. The input 'filespecs' may contain the * and ? wildcard characters. If an existing archive file is used, the specified input files are added to the end of it. There is no checking for duplicate filenames and existing archive member files are not replaced. ARCA is best used when creating a brand-new archive. The /D option specifies that all input files be deleted. The files are deleted after successful processing of all of the input files. Invoking ARCA with no arguments yields a terse summary of the needed parameters, along with a version header. ARCA uses only 2 compression techniques: a modified LZW compression algorithm and repeated-string compression ("packing"). The LZW algorithm is the same as the one used by ARC, but modifications have been made to improve its compression performance, especially when dealing with files containing more "random" data such as executable files, though compression performance for files containing less random data such as textual files suffers a bit, but not much. ARCA generally performs better than ARC does -- it's significantly faster than ARC while yielding smaller archives (hard to imagine getting the best of two worlds!) Experiments have shown that the modified LZW compression algorithm generally compresses binary files better than the Huffman algorithm ("squeezing") can, Huffman compression is not used at all. If the LZW compression fails to yield a smaller file, then packing is used instead. There are cases where a packed file is larger than the original file, but these cases don't happen often enough for ARCA to handle, for example, by copying the unchanged file to the archive. Though ARCA uses an improved LZW algorithm, its output is TOTALLY compatible with the one used by System Enhancements Associates' (21 New Street, Wayne NJ 07470) ARC program, which means that ARCs created by ARCA can be processed by ARC, or by ARCE and ARCV (companion extraction & table-of-contents lister programs also written by Vernon Buerg and Wayne Chin). ARCA 1.28, Copyright (c) 1986,1987, Wayne Chin and Vernon D. Buerg. ALL RIGHTS RESERVED. ARCA Command Version 1.28 ------------ Oct 4, 1987 Examples -------- o Create an archive file called TEST.ARC, and place all files from the current directory into it: ARCA TEST *.* o Create an archive called SOURCE.ARC in the subdirectory \SAVE on drive B, and place all files with an extension of ASM into to: ARCA B:\SAVE\SOURCE *.ASM o Add files to the archive on drive A called PROGA.ARC all files in subdirectory \TEST on drive C, all files with a filename beginning with NE, and all file from the subdirectory \OLD on drive B: ARCA A:PROGA.ARC C:\TEST\*.* NE*.* B:\OLD\*.* ARCA Command Version 1.28 ------------ Oct 4, 1987 Error Messages -------------- ARCA: filename, analyzing, compressed. This message is issued for each 'filename' added to the archive file using LZW data compression. The program continues. ARCA: filename, analyzing, packed. This message is issued for each 'filename' added to the archive file using repeated-string compression. The program continues. ARCA: No matching files! No files were found that matched one of the 'filespecs' in the command line. The program terminates. ARCA: You must use DOS version 2.0 or higher. DOS version 2.0 or higher is required. The program terminates. ARCA: Insufficient memory. A minimum of 34k is required. The program terminates. ARCA: Shrink failed. This error should not occur. If it does, there is a problem with DOS. The program terminates. ARCA: Can't create archive file. There is no room in the target directory to create the specified archive file, or the target disk has become full. ARCA: Write error -- no more disk space? Don't trust this archive! ARCA has encountered a problem writing to the target disk. Check if there's sufficient room on the target disk to contain the full archive or delete unneeded files to free up some space. ARCA terminates leaving behind an archive that may not be usable -- check it carefully if you still want to use it (check the archive by using ARCV or ARCE). ARCA Command Version 1.28 ------------ Oct 4, 1987 Version history --------------- 1.07 - 4/21/86, initial release 1.08 to 1.13, internal versions 1.14 - 08/07/86 add logic to sort input files using binary tree; modify filtering of ARC name when adding to ARC; modify processing of "/D" switch; do packing of file if LZW compression does no good; add optional code for 286 processor 1.15, August 08, 1986 more 286-specific instructions 1.16, August 09, 1986 more 286-specific instructions in compression code 1.17, August 10, 1986 speed improvements in compression code 1.17a, August 10, 1986 bug fix for the case of "arca x d:*.*", where d is not the current drive 1.18, August 11, 1986 further speed tweaking in compression code; save a few more nanoseconds 1.19 to 1.21 internal versions not released for general consumption 1.22, Sept 13, 1986 improve error handling improve speed performance roughly 9% very modest compression perfomance improvement modify this document accordingly 1.23, Feb 24, 1987 add start-up banner omit "deleted" messages add 'copying' method 1.27, May 30, 1987 correct problem reverting to pack method (file size wrong) revert to copying if packing results in a larger file | 1.28, Oct 4, 1987 | correction for zero-byte files ARCA Command Version 1.28 ------------ Oct 4, 1987 As mentioned, ARCA is intended to be used to create a NEW archive, not for appending or updating an existing archive, though ARCA does not prevent you from doing so -- ARCA simply appends new files to the named archive without deleting existing entries. To properly append or to update, you should use ARC instead. There may be two COM files. The ARCA286.COM file is for 80286 based systems only. License ------- ARCA 1.28, Copyright (c) Wayne Chin and Vernon Buerg 1986,1987. ALL RIGHTS RESERVED. ARCA is free, but it is a copyrighted work and may be distributed only pursuant to this license. Permission is hereby granted to reproduce and disseminate ARCA so long as: (1) No remuneration of any kind is received in exchange; and (2) Distribution is without ANY modification to the contents of ARCA.COM and all accompanying documentation and/or support files, including the copyright notice and this license. No copy of ARCA may be distributed without including a copy of this license. Any other use is prohibited without express, written permission in advance. Vernon D. Buerg 456 Lakeshire Drive Daly City, CA 94015 CompuServe: 70007,1212 Data/BBS: 415-994-2944