Perl in a Nutshell, 2nd Edition

Name

GetOptions

Synopsis

$result = GetOptions(option-descriptions)

Uses descriptions from option-descriptionsto retrieve and process the command-line options with which your Perl program was invoked. The options are taken from @ARGV. After GetOptions has processed the options, @ARGV contains only command-line arguments that were not options. Returns 0 if errors are detected. Each option description consists of two elements:

Option specifier

Defines the option name and optionally a value as an argument specifier.

Option linkage

A reference to a variable that is set when the option is present.

GetOptions can also take as a first argument a reference to a hash that describes the linkage for the options. The linkage specified in the argument list takes precedence over the one specified in the hash. Thus, the following are equivalent:

%optctl = (size => \$offset);
&GetOptions(\%optctl, "size=i");

and:

&GetOptions("size=i" => \$offset);

Option specifiers

Each option specifier consists of an option name and possibly an argument specifier. The name can be a name, or a list of names separated by |; the first name in the list is the true name of the option, and the others are treated as aliases. Option names may be invoked with the shortest unique abbreviation. Values for argument specifiers are:

<none>

Option takes no argument. The option variable is set to 1.

!

Option does not take an argument and may be negated, that is, prefixed by no.

=s

Option takes a mandatory argument that is a string that will be ...