Command line option
<software> (Or "option", "flag", "switch", "option switch") An argument to a command that modifies its function rather than providing data.
Options generally start with "-" in
Unix or "/" in
MS-DOS.
This is usually followed by a single letter or occasionally a digit.
Some commands require each option to be a separate argument, introduced by a new "-" or "/", others allow multiple option letters to be concatenated into a single argument with a single "-" or "/", e.g. "ls -al".
A few Unix commands (e.g.
ar,
tar) allow the "-" to be omitted.
Some options may or must be followed by a value, e.g. "cc prog.c -o prog", sometimes with and sometimes without an intervening space.
getopt and getopts are commands for parsing command line options.
There is also a
C library routine called getopt for the same purpose.
