The command-line.parser vocabulary can be used to parse command-line arguments.

A sequence of option instances is used to control how the arguments are parsed and is typically passed to the following words from a command-line program:

with-options ( ... options quot: ( ... -- ... ) -- ... )

parse-options ( options -- arguments )

Some variables control certain aspects of the parsing:

default-help?	A boolean value controlling if a --help option is added.
allow-abbrev?	A boolean value controlling if abbreviations are allowed for options.
program-name	An optional program name, or it will be inferred from the script or launched binary name.
program-prolog	Some text to include in the help display before the options.
program-epilog	Some text to include in the help display after the options.

Option values can follow the option as a separate argument, as in --host localhost, or be attached with an equals sign, as in --host=localhost. The attached form also accepts empty values and values starting with a dash. Options that take no arguments and negated options do not accept attached values.

In the case that you want to pass an option lookalike as a positional argument, for example --foo then you can pass it after -- to indicate that the remaining arguments should be interpreted as positional arguments.

Sub-commands are supported using the with-commands word.