gunzip --version (return code: 0)
gunzip (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.
gunzip --help (return code: 0)
Usage: /bin/gunzip [OPTION]... [FILE]...
Uncompress FILEs (by default, in-place).
Mandatory arguments to long options are mandatory for short options too.
-c, --stdout write on standard output, keep original files unchanged
-f, --force force overwrite of output file and compress links
-k, --keep keep (don't delete) input files
-l, --list list compressed file contents
-n, --no-name do not save or restore the original name and time stamp
-N, --name save or restore the original name and time stamp
-q, --quiet suppress all warnings
-r, --recursive operate recursively on directories
-S, --suffix=SUF use suffix SUF on compressed files
-t, --test test compressed file integrity
-v, --verbose verbose mode
--help display this help and exit
--version display version information and exit
With no FILE, or when FILE is -, read standard input.
Report bugs to <bug-gzip@gnu.org>.