zless --version (return code: 0)
zless (gzip) 1.6
Copyright (C) 2007, 2011-2013 Free Software Foundation, Inc.
This is free software. You may redistribute copies of it under the terms of
the GNU General Public License <http://www.gnu.org/licenses/gpl.html>.
There is NO WARRANTY, to the extent permitted by law.
Written by Paul Eggert.
zless --help (return code: 0)
Usage: /bin/zless [OPTION]... [FILE]...
Like 'less', but operate on the uncompressed contents of any compressed FILEs.
Options are the same as for 'less'.
Report bugs to <bug-gzip@gnu.org>.