Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!ut-sally!husc6!bacchus!mit-eddie!ll-xn!ames!ptsfa!ihnp4!inuxc!pur-ee!j.cc.purdue.edu!doc From: doc@j.cc.purdue.edu.UUCP Newsgroups: comp.binaries.amiga Subject: Amiga Arc (uuencoded part 2 of 2) Message-ID: <3887@j.cc.purdue.edu> Date: Mon, 13-Apr-87 16:24:48 EST Article-I.D.: j.3887 Posted: Mon Apr 13 16:24:48 1987 Date-Received: Sun, 19-Apr-87 04:10:59 EST Reply-To: doc@j.cc.purdue.edu (Craig Norborg) Distribution: world Organization: Purdue University Computing Center Lines: 1161 Keywords: utility, compression, archival Approved: doc@j.cc.purdue.edu This is part two of two of arc on the amiga. This file contains documentation for arc and the second part of the uuencoded binaries. # This is a shell archive. # Remove everything above and including the cut line. # Then run the rest of the file through sh. #----cut here-----cut here-----cut here-----cut here----# #!/bin/sh # shar: Shell Archiver # Run the following text with /bin/sh to create: # arc.doc # arc.uue.2 # This archive created: Mon Apr 13 16:10:50 1987 # By: Craig Norborg (Purdue University Computing Center) cat << \SHAR_EOF > arc.doc ARC File Archive Utility (C) COPYRIGHT 1985 by System Enhancement Associates; ALL RIGHTS RESERVED This file describes the ARC file utility, version 4.3, which was created by System Enhancement Associates on 22 August 1985. ARC is the copyrighted property of System Enhancement Associates. You are granted a limited license to use ARC, and to copy it and distribute it, provided that the following conditions are met: 1) No fee may be charged for such copying and distribution. 2) ARC may ONLY be distributed in its original, unmodified state. Any voluntary contributions for the use of this program will be appreciated, and should be sent to: System Enhancement Associates 21 New Street Wayne, NJ 07470 If you are using ARC in a commercial environment, then the contribution is not voluntary. A word about user supported software: The user supported software concept (usually referred to as "freeware") is an attempt to provide software at low cost. The cost of offering a new product by conventional channels is staggering, and hence dissuades many independant authors and small companies from developing and promoting their ideas. User supported software is an attempt to develop a new marketing channel, where products can be introduced at low cost. If user supported software works, then everyone will benefit. The user will benefit by receiving quality products at low cost, and by being able to "test drive" software thoroughly before purchasing it. The author benefits by being able to enter the commercial software arena without first needing large sources of venture capital. But it can only work with your support. We're not just talking about ARC here, but about all user supported software. If you find that you are still using a program after a couple of weeks, then pretty obviously it is worth something to you, and you should send in a contribution. And now, back to ARC: ARC is used to create and maintain file archives. An archive is a group of files collected together into one file in such a way that the individual files may be recovered intact. ARC is different from other archive and library utilities in that it automatically compresses the files being archived, so that the resulting archive takes up a minimum amount of space. When ARC is used to add a file to an archive it analyzes the file to determine which of four storage methods will result in the greatest savings. These four methods are: 1) No compression; the file is stored intact. 2) Repeated-character compression; repeated sequences of the same byte value are collapsed into a three-byte code sequence. 3) Huffman squeezing; the file is compressed into variable length bit strings, similar to the method used by the SQ programs. 4) Lempel-Zev compression; the file is stored as a series of twelve bit codes which represent character strings, and which are created "on the fly". Note that since one of the four methods involves no compression at all, the resulting archive entry will never be larger than the original file. USING ARC ========= ARC is invoked with a command of the following format: ARC [