G.1. 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
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
The two most widely-accepted options are:
Other common options are:
All: show all
information or operate on all arguments.
List: list files or arguments without
taking other action.
Recursive: Operate recursively (down
Verbose: output additional information to
stdout or stderr.
Compress: apply compression (usually
Many UNIX and Linux utilities deviate from this
"standard," so it is dangerous to
assume that a given option will behave in a
standard way. Always check the man page for the command in question
when in doubt.
A complete table of recommended options for the GNU utilities
is available at the GNU standards page.