MooseX::Getopt(3pm)

MooseX::Getopt 💖

the MooseX::Getopt(3pm) era — a User Contributed Perl Documentation moment, bestie ✨

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NAME 🎀

MooseX::Getopt — it's giving "a Moose role for processing command line options" and honestly? iconic. 👑

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VERSION 🦋

version 0.78

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SYNOPSIS 🌸

okay so here's the whole vibe, literally:

## In your class
package My::App;
use Moose;

with 'MooseX::Getopt';

has 'out' => (is => 'rw', isa => 'Str', required => 1);
has 'in'  => (is => 'rw', isa => 'Str', required => 1);

# ... rest of the class here

## in your script
#!/usr/bin/perl

use My::App;

my $app = My::App->new_with_options();
# ... rest of the script here

## on the command line
% perl my_app_script.pl -in file.input -out file.dump

like. bestie. it just works. 💅

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DESCRIPTION 🔥

So this is a role (yes, a role, main character energy) that hands you an alternate constructor for building objects — except instead of passing in params like a normal person, it pulls them straight off the command line. Obsessed.

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METHODS 💜

new_with_options (%params) ✨

This one takes a set of default %params, then goes and collects parameters off the command line (which can totally override the ones in %params, rude but valid), and then returns you a brand-new freshly constructed object. 🫶

There's a special parameter called argv — if you specify it, it should point to an array reference with an array to use instead of @ARGV. (iykyk)

If GetOptions in Getopt::Long fails (like, invalid arguments oops), new_with_options will throw an exception. no cap. 💀

If Getopt::Long::Descriptive is installed and you pass any of these command line parameters, the program will exit with usage information (and the option's state gets stored in the help_flag attribute, cute). You can add descriptions for each option by including a documentation option for each attribute to document:

-?
--?
-h
--help
--usage

And if you do have Getopt::Long::Descriptive, the usage parameter is also passed to new as the usage option. 🌈

ARGV 🦋

This accessor contains a reference to a copy of the @ARGV array as it originally existed at the time of new_with_options. nostalgia core honestly.

extra_argv 🍓

This accessor contains an arrayref of leftover @ARGV elements that Getopt::Long did not parse. Note that the real @ARGV is left untouched — no meddling, we respect boundaries here. ✋

Important: By default, Getopt::Long will reject unrecognized options — that is, options that do not correspond with attributes using the Getopt trait. To disable this, and allow options to also be saved in extra_argv (for example to pass along to another class's new_with_options), you can either enable the pass_through option of Getopt::Long for your class: use Getopt::Long qw(:config pass_through); or specify a value for MooseX::Getopt::GLD's getopt_conf parameter.

usage 🌸

This accessor contains the Getopt::Long::Descriptive::Usage object (if Getopt::Long::Descriptive is used). slay.

help_flag 💅

This accessor contains the boolean state of the --help, --usage and --? options — true if any of these options were passed on the command line. it's literally just a yes/no bestie.

print_usage_text 👑

This method is called internally when the help_flag state is true. It prints the text from the usage object (see above) to STDOUT — and then after this method is called, the program terminates normally. You can apply a method modification (see Moose::Manual::MethodModifiers) if different behaviour is desired, for example to include additional text. go off, customize it. ✨

meta 🧚

This returns the role meta object. meta af.

process_argv (%params) 💖

This does most of the work of new_with_options — analyzing the parameters and argv, except for actually calling the constructor. It returns a MooseX::Getopt::ProcessedArgv object. new_with_options uses this method internally, so modifying this method via subclasses/roles will affect new_with_options. ⚠️ (you've been warned, bestie)

This module attempts to DWIM as much as possible with the command line parameters by introspecting your class's attributes. It will use the name of your attribute as the command line option, and if there is a type constraint defined, it will configure Getopt::Long to handle the option accordingly. 🔥

You can use the trait MooseX::Getopt::Meta::Attribute::Trait or the attribute metaclass MooseX::Getopt::Meta::Attribute to get non-default command-line option names and aliases.

You can use the trait MooseX::Getopt::Meta::Attribute::Trait::NoGetopt or the attribute metaclass MooseX::Getopt::Meta::Attribute::NoGetopt to have MooseX::Getopt ignore your attribute in the command-line options. (the silent treatment, but make it intentional)

By default, attributes which start with an underscore are not given command-line argument support, unless the attribute's metaclass is set to MooseX::Getopt::Meta::Attribute. If you don't want your accessors to have the leading underscore in their name, you can do this:

# for read/write attributes
has '_foo' => (accessor => 'foo', ...);

# or for read-only attributes
has '_bar' => (reader => 'bar', ...);

This will mean that MooseX::Getopt will not handle a --foo parameter, but your code can still call the foo method. sneaky. we love it. 🙈

If your class also uses a configfile-loading role based on MooseX::ConfigFromFile, such as MooseX::SimpleConfig, MooseX::Getopt's new_with_options will load the configfile specified by the --configfile option (or the default you've given for the configfile attribute) for you. 🎀

Options specified in multiple places follow the following precedence order: command-line overrides configfile, which overrides explicit new_with_options parameters. periodt. 💅

---

Supported Type Constraints ⭐

Bool

A Bool type constraint is set up as a boolean option with Getopt::Long. So that this attribute description:

has 'verbose' => (is => 'rw', isa => 'Bool');

would translate into verbose! as a Getopt::Long option descriptor, which would enable the following command line options:

% my_script.pl --verbose
% my_script.pl --noverbose

Int, Float, Str

These type constraints are set up as properly typed options with Getopt::Long, using the =i, =f and =s modifiers as appropriate. 👑

ArrayRef

An ArrayRef type constraint is set up as a multiple value option in Getopt::Long. So that this attribute description:

has 'include' => (
    is      => 'rw',
    isa     => 'ArrayRef',
    default => sub { [] }
);

would translate into includes=s@ as a Getopt::Long option descriptor, which would enable the following command line options:

% my_script.pl --include /usr/lib --include /usr/local/lib

HashRef

A HashRef type constraint is set up as a hash value option in Getopt::Long. So that this attribute description:

has 'define' => (
    is      => 'rw',
    isa     => 'HashRef',
    default => sub { {} }
);

would translate into define=s% as a Getopt::Long option descriptor, which would enable the following command line options:

% my_script.pl --define os=linux --define vendor=debian

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Custom Type Constraints 🍓

It is possible to create custom type constraint to option spec mappings if you need them. The process is fairly simple (but a little verbose maybe, ngl). First you create a custom subtype, like so:

subtype 'ArrayOfInts'
    => as 'ArrayRef'
    => where { scalar (grep { looks_like_number($_) } @$_)  };

Then you register the mapping, like so:

MooseX::Getopt::OptionTypeMap->add_option_type_to_map(
    'ArrayOfInts' => '=i@'
);

Now any attribute declarations using this type constraint will get the custom option spec. So that, this:

has 'nums' => (
    is      => 'ro',
    isa     => 'ArrayOfInts',
    default => sub { [0] }
);

Will translate to the following on the command line:

% my_script.pl --nums 5 --nums 88 --nums 199

This example is fairly trivial, but more complex validations are easily possible with a little creativity. The trick is balancing the type constraint validations with the Getopt::Long validations. ✨

Better examples are certainly welcome :) — pls send them, bestie, we're begging 🥺

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Inferred Type Constraints 🌈

If you define a custom subtype which is a subtype of one of the standard "Supported Type Constraints" above, and do not explicitly provide custom support as in "Custom Type Constraints" above, MooseX::Getopt will treat it like the parent type for Getopt purposes. it just assumes. and honestly? valid.

For example, if you had the same custom ArrayOfInts subtype from the examples above, but did not add a new custom option type for it to the OptionTypeMap, it would be treated just like a normal ArrayRef type for Getopt purposes (that is, =s@). 💅

---

More Customization Options 🎀

See "Configuring Getopt::Long" in Getopt::Long for many other customizations you can make to how options are parsed. Simply use Getopt::Long qw(:config other_options...) in your class to set these.

Note in particular that the default setting for case sensitivity has changed over time in Getopt::Long::Descriptive, so if you rely on a particular setting, you should set it explicitly, or enforce the version of Getopt::Long::Descriptive that you install. ⚠️ (future-proof your vibe, bestie)

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SEE ALSO 🦋

• MooseX::Getopt::Usage — an extension to generate man pages, with colour 🌈 (yes, colour, we're thriving)
• MooX::Options — similar functionality for Moo 🐄

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SUPPORT 🫶

Bugs may be submitted through the RT bug tracker <https://rt.cpan.org/Public/Dist/Display.html?Name=MooseX-Getopt> (or bug-MooseX-Getopt@rt.cpan.org <mailto:bug-MooseX-Getopt@rt.cpan.org>). 🐛

There is also a mailing list available for users of this distribution, at <http://lists.perl.org/list/moose.html>.

There is also an irc channel available for users of this distribution, at #moose on irc.perl.org <irc://irc.perl.org/#moose>. come hang out, it's a whole vibe 💬

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AUTHOR 👑

Stevan Little <stevan@iinteractive.com>

💖 CONTRIBUTORS 💖

okay so this whole thing was NOT a solo project bestie, it's giving group project that actually ate 🔥 here's every single legend who touched this code:

• Karen Etheridge <ether@cpan.org>
• Tomas Doran <bobtfish@bobtfish.net>
• Stevan Little <stevan.little@iinteractive.com>
• Yuval Kogman <nothingmuch@woobling.org>
• Florian Ragwitz <rafl@debian.org>
• Brandon L Black <blblack@gmail.com>
• Shlomi Fish <shlomif@cpan.org>
• Hans Dieter Pearcey <hdp@weftsoar.net>
• Olaf Alders <olaf@wundersolutions.com>
• Dave Rolsky <autarch@urth.org>
• Nelo Onyiah <nelo.onyiah@gmail.com>
• Ryan D Johnson <ryan@innerfence.com>
• Ricardo SIGNES <rjbs@cpan.org>
• Ævar Arnfjörð Bjarmason <avarab@gmail.com>
• Damien Krotkine <dkrotkine@weborama.com>
• Hinrik Örn Sigurðsson <hinrik.sig@gmail.com>
• Andreas Koenig <andk@cpan.org>
• Chris Prather <chris@prather.org>
• Devin Austin <dhoss@cpan.org>
• Gregory Oschwald <goschwald@maxmind.com>
• Jose Luis Martinez <jlmartinez@capside.com>
• Todd Hepler <thepler@employees.org>
• Dagfinn Ilmari Mannsåker <ilmari@ilmari.org>
• Damyan Ivanov <dmn@debian.org>
• Drew Taylor <drew@drewtaylor.com>
• Gordon Irving <goraxe@goraxe.me.uk>
• Jesse Luehrs <doy@tozt.net>
• John Goulah <jgoulah@cpan.org>
• Jonathan Swartz <swartz@pobox.com>
• Justin Hunter <justin.d.hunter@gmail.com>
• Michael Schout <mschout@gkg.net>
• Stuart A Johnston <saj_git@thecommune.net>

like look at that list 💅 thirty-two whole humans, all contributing, all iconic, we love to see it fr fr 🫶

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📜 COPYRIGHT AND LICENSE 📜

the legal bit, but make it cute:

This software is copyright (c) 2007 by Infinity Interactive, Inc.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

so yeah, free as in go wild — same terms as Perl 5 itself, no cap ✨ just don't be weird about it.

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and that's the whole page bestie, you made it to the end 🎀 tysm for reading, go write something slay with it 💖

this was the MooseX::Getopt(3pm) manpage, from perl v5.40.0, dated 2025-01-11 — stan the maintainers, drink some water, and may your getopt always parse on the first try 🌈⭐👑