NAME

Getopt::Compact - getopt processing in a compact statement with both long and short options, and usage functionality.

SYNOPSIS

inside foobar.pl:

use Getopt::Compact;

# (1) simple usage:
my $opts = new Getopt::Compact
    (struct =>
     [[[qw(b baz)], qq(baz option)],  # -b or --baz
      ["foobar", qq(foobar option)],  # --foobar only
     ])->opts();

# (2) or, a more advanced usage:
my $go = new Getopt::Compact
    (name => 'foobar program', modes => [qw(verbose test debug)],
     struct =>
     [[[qw(w wibble)], qq(specify a wibble parameter), ':s'],
      [[qw(f foobar)], qq(apply foobar algorithm)],
      [[qw(j joobies)], qq(jooby integer list), '=i', \@joobs],
     ]
    );
my $opts = $go->opts;

print "applying foobar algorithm\n" if $opt->{foobar};
print "joobs: @joobs\n" if @joobs;
print $go->usage if MyModule::some_error_condition($opts);

using (2), running the command './foobar.pl -x' results in the following output:

Unknown option: x
foobar program v1.0
usage: foobar.pl [options]
options
-h, --help      This help message
-v, --verbose   Verbose mode
-n, --test      Test mode
-d, --debug     Debug mode
-w, --wibble    Specify a wibble parameter
-f, --foobar    Apply foobar algorithm
-j, --joobies   Jooby integer list
    --man       Display documentation

DESCRIPTION

This is yet another Getopt related module. Getopt::Compact is geared towards compactly and yet quite powerfully describing an option syntax. Options can be parsed, returned as a hashref of values, and/or displayed as a usage string or within the script POD.

PUBLIC METHODS

new()

my $go = new Getopt::Compact(%options)

Instantiates a Getopt::Compact object. This will parse the command line arguments and store them for later retrieval (via the opts() method). On error a usage string is printed and exit() is called, unless you have set the 'usage' option to false.

The following constructor options are recognised:

name

The name of the program. This is printed at the start of the usage string.

cmd

The command used to execute this program. Defaults to $0. This will be printed as part of the usage string.

version

Program version. Can be an RCS Version string, or any other string. Displayed in usage information. The default is ($main::VERSION || '1.0')

usage

'usage' is set to true by default. Set it to false (0) to disable the default behaviour of automatically printing a usage string and exiting when there are parse errors or the --help option is given.

args

A string describing mandatory arguments to display in the usage string. eg:

print new Getopt::Compact
    (args => 'foo', cmd => 'bar.pl')->usage;

displays:

usage: bar.pl [options] foo

modes

This is a shortcut for defining boolean mode options, such as verbose and test modes. Set it to an arrayref of mode names, eg [qw(verbose test)]. The following statements are equivalent:

# longhand version
my $go = new Getopt::Compact
    (struct => [[[qw(v verbose)], qw(verbose mode)],
                [[qw(n test)],    qw(test mode)],
                [[qw(d debug)],   qw(debug mode)],
                [[qw(f foobar)],  qw(activate foobar)],
               ]);

and

# shorthand version
my $go = new Getopt::Compact
    (modes => [qw(verbose test debug)],
     struct => [[[qw(f foobar)], qq(activate foobar)]]);

Mode options will be prepended to any options defined via the 'struct' option.

struct

This is where most of the option configuration is done. The format for a struct option is an arrayref of arrayrefs (see SYNOPSIS) in the following form (where [ ] denotes an array reference):

struct => [optarray, optarray, ...]

and each optarray is an array reference in the following form: (only 'name specification' is required)

[name spec, description, argument spec, destination]

name specification may be a scalar string, eg "length", or a reference to an array of alternate option names, eg [qw(l length)]. The option name specification is also used to determine the key to the option value in the hashref returned by opts(). See opts() for more information.

The argument specification is passed directly to Getopt::Long, so any syntax recognised by Getopt::Long should also work here. Some argument specifications are:

=s  Required string argument
:s  Optional string argument
=i  Required integer argument
+   Value incrementing
!   Negatable option

Refer to Getopt::Long documentation for more details on argument specifications.

The 'destination' is an optional reference to a variable that will hold the option value. If destination is not specified it will be stored internally by Getopt::Compact and can be retrieved via the opts() method. This is useful if you want options to accept multiple values. The only way to achieve this is to use a destination that is a reference to a list (see the joobies option in SYNOPSIS by way of example).

configure

Optional configure arguments to pass to Getopt::Long::Configure in the form of a hashref of key, boolean value pairs. By default, the following configuration is used:

{ no_auto_abbrev => 1, bundling => 1 }

To disable bundling and have case insensitive single-character options you would do the following:

new Getopt::Compact (configure => { ignorecase_always => 1, bundling => 0 });

see Getopt::Long documentation for more information on configuration options.

$go->usage()

print $go->usage();

Returns a usage string. Normally the usage string will be printed automatically and the program will exit if the user supplies an unrecognised argument or if the -h or --help option is given. Automatic usage and exiting can be disabled by setting 'usage' to false (0) in the constructor (see new()). This method uses Text::Table internally to format the usage output.

The following options may be automatically added by Getopt::Compact:

"This help message" (-h or --help)

A help option is automatically prepended to the list of available options if the usage constructor option is true (this is enabled by default). When invoked with -h or --help, Getopt::Compact automatically displays the usage string and exits.

"Display documentation" (--man)

This option is appended to the list of available options unless an alternative --man option has been defined. When invoked with --man, Getopt::Compact prints a modified version of its POD to stdout and exits.

$go->pod2usage()

Displays the POD for the script. The POD will be altered to include USAGE, NAME and VERSION sections unless they already exist. This is invoked automatically when the --man option is given.

$go->status()

print "getopt ".($go->status ? 'success' : 'error'),"\n";

The return value from Getopt::Long::Getoptions(). This is a true value if the command line was processed successfully. Otherwise it returns a false result.

$go->opts()

$opt = $go->opts;

Returns a hashref of options keyed by option name. If the constructor usage option is true (on by default), then a usage string will be printed and the program will exit if it encounters an unrecognised option or the -h or --help option is given.

The key in %$opt for each option is determined by the option names in the specification used in the struct definition. For example:

["foo", qw(foo option)]

The key will be "foo".

[[qw(f foo)], qw(foo option)]

[[qw(f foo foobar)], qw(foo option)]

In both cases the key will be "foo". If multiple option names are given, the first long option name (longer than one character) will be used as the key.

[[qw(a b)], qq(a or b option)]

The key here will be "a". If all alternatives are one character, the first option name in the list is used as the key

AUTHOR

Andrew Stewart Williams

SEE ALSO

Getopt::Long