Appendix F. Standard Command-Line Options

Over time, there has evolved a loose standard for the meanings of command line option flags. The GNU utilities conform more closely to this "standard" than older UNIX utilities.

Traditionally, UNIX command-line options consist of a dash, followed by one or more lowercase letters. The GNU utilities added a double-dash, followed by a complete word or compound word.

The two most widely-accepted options are:

• -h

  --help

  Help : Give usage message and exit.

• -v

  --version

  Version : Show program version and exit.

Other common options are:

• -a

  --all

  All : show all information or operate on all arguments.

• -l

  --list

  List : list files or arguments without taking other action.

• -o

  Output filename

• -q

  --quiet

  Quiet : suppress stdout .

• -r

  -R

  --recursive

  Recursive : Operate recursively (down directory tree).

• -v

  --verbose

  Verbose : output additional information to stdout or stderr .

• -z

  --compress

  Compress : apply compression (usually gzip ).

However:

• In tar and gawk :

  -f

  --file

  File : filename follows.

• In cp , mv , rm :

  -f

  --force

  Force : force overwrite of target file(s).

A complete table of recommended options for the GNU utilities is available at http://www.gnu.org/prep/standards_19.html .