osx man page for zdiff

ZDIFF(1)						    BSD General Commands Manual 						  ZDIFF(1)

NAME
     zcmp, zdiff -- compare compressed files

SYNOPSIS
     zcmp [options] file [file2]
     zdiff [options] file [file2]

DESCRIPTION
     zcmp and zdiff are filters that invoke cmp(1) or diff(1) respectively to compare compressed files.  Any options that are specified are passed
     to cmp(1) or diff(1).

     If only file1 is specified, it is compared against a file with the same name, but with the extension removed.  When both file1 or file2 are
     specified, either file may be compressed.

     Extensions handled by gzip(1):
     o	 z, Z,
     o	 gz,
     o	 taz,
     o	 tgz.

     Extensions handled by bzip2(1):
     o	 bz,
     o	 bz2,
     o	 tbz,
     o	 tbz2.

     Extensions handled by xz(1):
     o	 lzma,
     o	 xz,
     o	 tlz,
     o	 txz.

ENVIRONMENT
     TMPDIR  Directory in which to place temporary files.  If unset, /tmp is used.

FILES
     /tmp/zcmp.XXXXXXXXXX   Temporary file for zcmp.
     /tmp/zdiff.XXXXXXXXXX  Temporary file for zdiff.

SEE ALSO
     bzip2(1), cmp(1), diff(1), gzip(1), xz(1)

CAVEATS
     zcmp and zdiff rely solely on the file extension to determine what is, or is not, a compressed file.  Consequently, the following are not
     supported as arguments:

     -	 directories

     -	 device special files

     -	 filenames indicating the standard input (``-'')

BSD
								   May 23, 2011 							       BSD