szip, sunzip: (c) 1997,1998 Michael Schindler, szip@compressconsult.com http://www.compressconsult.com/szip/ The program szip performs data compression/decompression, the current version is 1.11. There were several previous incompatible versions of szip; version 1.00 to 1.04 use one format, version 1.05X another one. version 1.10 was available as alpha test only but had a bug in encoding. If you have szip files from that versions you need to keep the old decompression program around; if you lost it you can still download them from the website. Usage: szip [options] [inputfile [outputfile]] option meaning default -d decompress -b blocksize in 100kB -b17 -o order of context -o6 -r recordsize -r1 -i incremental coding (differences to previous value) -v turn on messages -v0 options may be grouped like -b14o10r3 if outputfile is omitted output is written to standardoutput. if inputfile is omitted too input is read from standardinput. I recommend using .sz for szipped files and .tar.sz or .tsz for szipped tarfiles. Future versions will produce these extensions. option effects: decompress: tells the program to decompress; default operation mode is compression. If present all other options except v are ignored. blocksize: larger blocks usually give better compression, but if your system gets into paging it will be slow. No effect on speed if enough memory is available. 1-41 possible. order: higher order gives better compression (and increased time). 3-255 possible. There is special code for order 4; this will give a faster (even faster than order 3) compression. order 0 makes a BWT transform; the code used in this version for full sort is just a qsort; a very bad choice indeed. A speedup by a factor of 4-10 is no miracle but I have no time right now. Decompression is fastest, so use it for distribution. fast compression but larger: -o4 fast decompression and probably smaller: -o0 Some files compress better with a small order like 3 or 4. recordsize: tells what size (in bytes) the elementary datatype is. getting this one right will improve compression. 24-bit graphics: use -r3 2-channel 8-bit audio: use -r2 4-byte words: use -r4 1-byte chars: use -r1 (default) the recordsize need not be in sync with the real record; if you have a 4-byte header on an -r3 file still choose -r3. 1-127 possible incremental: use differences to the last value (after recordsize reordering) instead of the actual value. Good for sounds. verbosity level: output progress messages. OPERATING SYSTEMS SUPPORTED: The code is plain C; please check out the webpage for available compilations. Currently: Windows 32bit, DOS, linux, HPUX. It can be compiled for other platforms upon request, please ask. The produced files are platform independent. COPYING: This Program can be freely distributed as unchanged executeable, as long as this file accompanies them unchanged. The program itself may not be sold, however you may collect fees for copying, distribution or bundled items. It MUST be clear to your customer that he can get the same free of charge from other sources; mentioning the website http://www.compressconsult.com/szip/ and "Freeware" will fulfill this requirement. CAVEATS: DOS/Windows does NOT support binary pipes, so SPECIFY BOTH FILES. The intention is mainly demonstration; I do not consider them production versions. This free program comes with ABSOLUTELY NO WARRANTY OF ANY KIND. Ask me about compression for your data; see http://www.compressconsult.com for more information. Szip is a free program of > d a t a < / / / / compression consulting