gistfile1.pl

my $opt_parser = OptParser->new();

$opt_parser->add_option(
    name    => "foo"       # name used to refer to this option
    short   => "f"         # use as -f
    long    => "foo"       # use as --foo
    depends => "bar|baz"   # option only valid if bar or baz is specified. using
                           # an array to list depends may be simpler... or not
    conflicts => "buh"     # option conflicts with option buh.
    required  => "yes"     # option is required (if depends are specified, only
                           # check after depends passes)
    type    => "string"    # data type (string|flag)
    default => "wibble"    # default value if none specified
    help    => "..."       # text to show when -h is used to display help
    error   => "..."       # text to show if option does not validate
    multi   => "no"        # allow option to be specified multiple times
                           # (no|yes|group)
    group   => "fuh"       # When showing help, group this option with others
                           # who are assigned to group fuh
    validate => \&sub      # ref to a sub that can validate the option
    after    => [qw(baz)]  # only validate *after* baz
);

# Sometimes in the help, usage and docs you want certain options to be
# grouped together. You may also want to apply validation to all the
# options in a group together.
$opt_parser->add_group(
    name     => "fuh"         # name of the option group
    validate => \&sub         # ref to a sub that can validate all the
                              # options in the group
    help     => "..."         # text describing the group when displaying help
    members  => [qw(foo baz)] # options belonging to this group.
);