Getopt::Long::Util - Utilities for Getopt::Long


This document describes version 0.899 of Getopt::Long::Util (from Perl distribution Getopt-Long-Util), released on 2022-11-14.




 array_getopt_long_spec_to_hash($spec) -> hash

Convert array form of Getopt::Long spec to hash.

Getopt::Long's GetOptions function accepts a list of arguments. The first optional argument is a hash for option storage. After that, a list of option specs (e.g. foo=s), each optionally followed by a reference to specify destination (e.g. a reference to scalar, or array, or code).

Die on failure (e.g. invalid option spec).

This routine converts that array into a hash of option specs as keys and destinations as values. If an option spec does not have a destination, its destination is set to undef. If hash storage is specified then the destination will fall back to the hash storage's appropriate key when a specific destination is not specified.

Note that by converting to hash, 1) duplicate option specs are merged; and 2) order of option specs is not preserved.

This function is not exported by default, but exportable.

Arguments ('*' denotes required arguments):

  • $spec* => array

    Getopt::Long spec.

Return value: (hash)



 detect_getopt_long_script(%args) -> [$status_code, $reason, $payload, \%result_meta]

Detect whether a file is a Getopt::Long-based CLI script.

The criteria are:

  • the file must exist and readable;

  • (optional, if include_noexec is false) file must have its executable mode bit set;

  • content must start with a shebang #!;

  • either: must be perl script (shebang line contains 'perl') and must contain something like use Getopt::Long;

This function is not exported by default, but exportable.

Arguments ('*' denotes required arguments):

  • filename => str

    Path to file to be checked.

  • include_noexec => bool (default: 1)

    Include scripts that do not have +x mode bit set.

  • string => buf

    String to be checked.

Returns an enveloped result (an array).

First element ($status_code) is an integer containing HTTP-like status code (200 means OK, 4xx caller error, 5xx function error). Second element ($reason) is a string containing error message, or something like "OK" if status is 200. Third element ($payload) is the actual result, but usually not present when enveloped result is an error response ($status_code is not 2xx). Fourth element (%result_meta) is called result metadata and is optional, a hash that contains extra information, much like how HTTP response headers provide additional metadata.

Return value: (any)



 gen_getopt_long_spec_from_getopt_std_spec(%args) -> hash

Generate Getopt::Long spec from Getopt::Std spec.

This function is not exported by default, but exportable.

Arguments ('*' denotes required arguments):

  • is_getopt => bool

    Whether to assume spec is for getopt() or getopts().

    By default spec is assumed to be for getopts() instead of getopt(). This means that for a spec like abc:, a and b don't take argument while c does. But if is_getopt is true, the meaning of : is reversed: a and b take arguments while c doesn't.

  • spec* => str

    Getopt::Std spec string.

Return value: (hash)



 humanize_getopt_long_opt_spec( [ \%optional_named_args ] , $optspec) -> str|hash

Convert Getopt::Long option specification into a more human-friendly notation that is suitable for including in help/usage text, for example:

 help|h|?       ->  "--help, -h, -?"
 help|h|?       ->  "--help | -h | -?"               # if you provide 'separator'
 --foo=s        ->  "--foo=s"
 --foo=s        ->  "--foo=somelabel"                # if you provide 'value_label'
 --foo:s        ->  "--foo[=s]"
 --foo=s@       ->  "(--foo=s)+"
 --foo=s%       ->  "(--foo key=value)+"
 --foo=s%       ->  "(--foo somelabel1=somelabel2)+" # if you provide 'key_label' and 'value_label'
 --debug!       ->  "--(no)debug"

It also produces POD-formatted string for use in POD documentation:

 --foo=s        ->  {plaintext=>"--foo=s", pod=>"B<--foo>=I<s>"}
                                                     # if you set 'extended' to true

Will die if can't parse the optspec string.

This function is not exported by default, but exportable.

Arguments ('*' denotes required arguments):

  • extended => bool

    If set to true, will return a hash of multiple formats instead of a single plaintext format.

  • key_label => str (default: "key")

    (No description)

  • opt_link => str

    (No description)

  • $optspec* => str

    (No description)

  • separator => str (default: ", ")

    (No description)

  • value_label => str

    (No description)

  • value_label_link => str

    (No description)

Return value: (str|hash)



 parse_getopt_long_opt_spec($optspec) -> hash

Parse a single Getopt::Long option specification.


  • Example #1:

     parse_getopt_long_opt_spec("help|h|?"); # -> { dash_prefix => "", opts => ["help", "h", "?"] }
  • Example #2:

     parse_getopt_long_opt_spec("--foo=s"); # -> { dash_prefix => "--", desttype => "", opts => ["foo"], type => "s" }

Will produce a hash with some keys:

  • is_arg (if true, then option specification is the special <> for argument callback)

  • opts (array of option names, in the order specified in the opt spec)

  • type (string, type name)

  • desttype (either '', or '@' or '%'),

  • is_neg (true for --opt!)

  • is_inc (true for --opt+)

  • min_vals (int, usually 0 or 1)

  • max_vals (int, usually 0 or 1 except for option that requires multiple values)

Will return undef if it can't parse the string.

This function is not exported by default, but exportable.

Arguments ('*' denotes required arguments):

  • $optspec* => str

    (No description)

Return value: (hash)


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Source repository is at



Getopt::Long::Spec, which can also parse Getopt::Long spec into hash as well as transform back the hash to Getopt::Long spec. OO interface. I should've found this module first before writing my own parse_getopt_long_opt_spec(). But at least currently parse_getopt_long_opt_spec() is at least about 30-100+% faster than Getopt::Long::Spec::Parser, has a much simpler implementation (a single regex match), and can handle valid Getopt::Long specs that Getopt::Long::Spec::Parser fails to parse, e.g. foo|f=s@.


perlancar <>


Steven Haryanto <>


To contribute, you can send patches by email/via RT, or send pull requests on GitHub.

Most of the time, you don't need to build the distribution yourself. You can simply modify the code, then test via:

 % prove -l

If you want to build the distribution (e.g. to try to install it locally on your system), you can install Dist::Zilla, Dist::Zilla::PluginBundle::Author::PERLANCAR, Pod::Weaver::PluginBundle::Author::PERLANCAR, and sometimes one or two other Dist::Zilla- and/or Pod::Weaver plugins. Any additional steps required beyond that are considered a bug and can be reported to me.


This software is copyright (c) 2022, 2021, 2020, 2016, 2015, 2014 by perlancar <>.

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


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