debian man page for zdiff

ZDIFF(1)						      General Commands Manual							  ZDIFF(1)

NAME
       zcmp, zdiff - compare compressed files

SYNOPSIS
       zcmp [ cmp_options ] file1 [ file2 ]
       zdiff [ diff_options ] file1 [ file2 ]

DESCRIPTION
       Zcmp  and  zdiff are used to invoke the cmp or the diff program on files compressed via gzip.  All options specified are passed directly to
       cmp or diff.  If only one file is specified, then it is compared to a file with the same name without the .gz extension. If two	files  are
       specified, then they are uncompressed if necessary and fed to cmp or diff.  The exit status from cmp or diff is preserved.

       When  both files must be uncompressed before comparison, the second is uncompressed to /tmp.  In all other cases, zdiff and zcmp use only a
       pipe.

SEE ALSO
       cmp(1), diff(1), zmore(1), zgrep(1), znew(1), zforce(1), gzip(1), gzexe(1)

BUGS
       Messages from the cmp or diff programs refer to temporary filenames instead of those specified.

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