zfgrep --version (return code: 0)
zgrep (gzip) 1.6
Copyright (C) 2010-2013 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 Jean-loup Gailly.
zfgrep --help (return code: 0)
Usage: /bin/zgrep [OPTION]... [-e] PATTERN [FILE]...
Look for instances of PATTERN in the input FILEs, using their
uncompressed contents if they are compressed.
OPTIONs are the same as for 'grep'.
Report bugs to <bug-gzip@gnu.org>.