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diff --git a/test/monniaux/ncompress/README.md b/test/monniaux/ncompress/README.md new file mode 100644 index 00000000..be0e0bc2 --- /dev/null +++ b/test/monniaux/ncompress/README.md @@ -0,0 +1,100 @@ +# About + +This is version 4.2 of (N)compress (an improved version of compress 4.1). + +Compress is a fast, simple LZW file compressor. Compress does not have +the highest compression rate, but it is one of the fastest programs to +compress data. Compress is the defacto standard in the UNIX community +for compressing files. + +(N)compress 4.2 has a special, fast compression hash algorithm. This +algorithm uses more memory than the old hash table. If you don't want +the faster hash table algorithm set 'Memory free for compress' below +800000. + +zcmp, zdiff, zmore were copied from version 4.1 without any changes. + +The output of (N)compress 4.2 is fully compatible with that of compress 3.0. +In other words, the output of (N)compress 4.2 may be fed into uncompress 3.0 or +the output of compress 3.0 may be fed into uncompress 4.2. + +The output of (N)compress 4.2 is not compatible with that of +compress 2.0. However, compress 4.2 still accepts the output of +compress 2.0. To generate output that is compatible with compress +2.0, use the undocumented "-C" flag. + +# Building + +For recent systems with GNU make, you can simply run `make` as the default +'GNUMakefile' will get picked up. + +'build' is a menu driven shell script for compiling, testing and +installing (N)compress. So to build and install (N)compress all you have to +do is run build. Build will first test your system for default +settings. The current compile settings are stored in a special file +called compress.def. + +For user with problems with build there is a default makefile included +called 'Makefile.def'. Also build is capable of generating a Makefile with +all options (option genmake). + +# Support + +[](https://travis-ci.org/vapier/ncompress) + +Send comments, complaints and especially patches relating to + https://github.com/vapier/ncompress/issues + +# Licensing + +The ncompress code is released into the public domain. See the +[UNLICENSE](UNLICENSE) file for more details. + +# Patents + +All existing patents on the LZW algorithm have +[expired world-wide](http://en.wikipedia.org/wiki/LZW#Patent_issues). +So LZW is now patent free. + +# Remarks + +- Build is a bourne shell script. On some system it is necessary to type + 'sh build'. + +- The build script usages tput for nice screen handling of the script. + If your system has no tput no problems. + +- For configuration testing build uses a lot of small C programs. During + those test stderr is redirected to /dev/null. + During the compilation of compress output is NOT redirected. + +- The /bin/sh under Ultrix can't handle ${var:-str} so use ksh for the + build script. + +- The output if (N)compress 4.2 is not exactly the same as compress 4.0 + because of different table reset point. The output of (N)compress 4.2 + is 100% compatible with compress 4.0 + +- Some systems has performance problems with reads bigger than BUFSIZ + (The read a head function is not working as expected). For those + system use the default BSIZE input buffer size. + +- (N)compress can by slower on small files (<10Kb) because of a great + table reset overhead. Use cpio or tar to make 1 bigger file if + possible, it is faster and also gives a better compression ratio most + of the time. + +- (N)compress is slower in vax systems because of removing some + undocumented inline assembler. + +- files compressed on a large machine with more bits than allowed by + a version of compress on a smaller machine cannot be decompressed! Use the + "-b12" flag to generate a file on a large machine that can be uncompressed + on a 16-bit machine. + +- compatibility with compress 3.0 has not been tested in the 4.2 release of + (N)compress. + +- There has been 1 problem report in relation to GCC 2.0 on a sparc + workstation. GCC 2.0 seems to generate a bad compress. Use the + standard c compiler 'cc'. |