bzip2 is a freely available, patent free [(see README in the distribution kit)], high-quality data compressor. It typically compresses files to within 10% to 165% of the best available techniques (the PPM family of statistical compressors), whilst being around twice as fast at compression and six times faster at decompression.
BZIP2 is a UNIX-oriented utility, and as such, it has little hope of dealing well with RMS files whose record format is anything other than Stream_LF.
For more versatile compressor-archiver programs with greater RMS capability, consider the Info-ZIP programs, Zip and UnZip.
- Source kits are available at: ftp://ftp.info-zip.org/pub/infozip/src/
- Pre-built VMS kits are available at: ftp://ftp.info-zip.org/pub/infozip/vms/
- A SourceForge Web page provides another path to Info-ZIP software.
Note that this bzip2 kit includes an object library which can be used to provide bzip2 compression in the Info-ZIP Zip and UnZip programs, and these programs can deal well with VMS/RMS file attributes. The Info-ZIP installation instructions explain how to build these programs with bzip2 compression support.
For another UNIX-oriented compression utility, see gzip.
Note that support for extended file names on ODS5 file systems depends on fairly recent C RTL features, as found in VMS V7.3-2 or VMS V7.3-1 with VMS731_ACRTL V3.0.
The Zip archive for this kit was created using the Zip "-V" option to preserve the VMS file attributes, but the source files in this Zip archive should be usable on a non-VMS system.
All versions of BZIP2 for VMS, including older and experimental ones, may be found at the archive: /ftp/bzip2/
FTP access is also available at: ftp://ftp.antinode.info/bzip2/