SFINX software tree - File compression

UNIX compress (.Z)

GNU zip (.z or .gz)

In general, GNU zip produces smaller files than compress, and it provides the user with more options to comtrol the compression. It uses the Lempel-Ziv coding (LZ77).

There are more utilities to handle gnu-zipped files:

• zcat:
  This will send the uncompressed version of the file to standard output. This is equivalent to gunzip -c. This leaves the original compressed file unchanged.
  [warning: there is also a zcat that comes with compress which can only handle .Z files]
• zmore
  This will show the uncompressed version of the file though a pager (more by default, or set in the environment variable PAGER).
• zdiff
  Compares two files which may be compressed, or it compares a compressed file with the uncompressed file with the same base name.
• zcmp
  As zdiff, but using cmp to compare the files.
• zgrep (and zegrep, zfgrep)
  Searches for text strings or regular expressions in a compressed file (as with grep, egrep or fgrep). You can also specify the environment variable GREP to select a different grep-like utility (such as agrep).
• znew
  Recompress .Z files to .gz files.
• zforce
  Force a .gz extension on all gzip'd files.
• gzexe
  Compress executable files in such a way that they get unzip'd when executed.
• gtar
  GNU tar can be invoked with a z option to use compression, either when reading or writing a archive. See tar for more information. On Linux systems, tar is actually gtar.

zip

The program to unpack such an archive is unzip.

• zipsplit
  Split a .zip archive into smaller archives
• zipinfo
  This utility can be used to get information about a .zip archive.
• zipnote
  Read or write notes included in an archive.
• zipgrep
  Search for regular expression in a .zip archive (Linux only)

arj

pack

Sun only