Module::FatPack - Generate source code that contains fatpacked modules


This document describes version 0.182 of Module::FatPack (from Perl distribution Module-FatPack), released on 2020-01-03.




 fatpack_modules(%args) -> [status, msg, payload, meta]

Generate source code that contains fatpacked modules.

This routine provides the same core technique employed by App::FatPacker (which is putting modules' source code inside Perl variables and loading them on-demand via require hook) without all the other stuffs. All you need is supply the names of modules (or the modules' source code themselves) and you'll get the output in a file or string.

This function is not exported by default, but exportable.

Arguments ('*' denotes required arguments):

  • add_begin_block => bool

    Surround the code inside BEGIN { }.

  • assume_strict => bool (default: 0)

    Assume code runs under stricture.

  • line_prefix => str

  • module_names => array[str]

    Module names to search.

  • module_srcs => hash

    Module source codes (a hash, keys are module names).

  • output => str

    Output filename.

  • overwrite => bool (default: 0)

    Whether to overwrite output if previously exists.

  • pm => bool

    Make code suitable to put inside .pm file instead of script.

    This setting adjusts the code so it is suitable to put one or several instances of the code inside one or more .pm files. Also sets default for --line-prefix '#' --no-add-begin-block --put-hook-at-the-end.

  • postamble => str

    Perl source code to add after the fatpack code.

  • preamble => str

    Perl source code to add before the fatpack code.

  • put_hook_at_the_end => bool

    Put the require hook at the end of @INC using "push" instead of at the front using "unshift".

  • stripper => bool (default: 0)

    Whether to strip included modules using Perl::Stripper.

  • stripper_comment => bool (default: 1)

    Set strip_comment=1 (strip comments) in Perl::Stripper.

  • stripper_log => bool (default: 0)

    Set strip_log=1 (strip log statements) in Perl::Stripper.

  • stripper_maintain_linum => bool (default: 0)

    Set maintain_linum=1 in Perl::Stripper.

  • stripper_pod => bool (default: 1)

    Set strip_pod=1 (strip POD) in Perl::Stripper.

  • stripper_ws => bool (default: 1)

    Set strip_ws=1 (strip whitespace) in Perl::Stripper.

Returns an enveloped result (an array).

First element (status) is an integer containing HTTP status code (200 means OK, 4xx caller error, 5xx function error). Second element (msg) is a string containing error message, or 'OK' if status is 200. Third element (payload) is optional, the actual result. Fourth element (meta) is called result metadata and is optional, a hash that contains extra information.

Return value: (any)


Please visit the project's homepage at


Source repository is at


Please report any bugs or feature requests on the bugtracker website

When submitting a bug or request, please include a test-file or a patch to an existing test-file that illustrates the bug or desired feature.


App::FatPacker, the original implementation.

App::depak for more options e.g. use various tracing methods, etc.

fatpack-modules, CLI for fatpack_modules

Module::DataPack, which implements an alternative technique to fatpacking called datapacking. The modules are embedded not in a variable in Perl code (which still needs to be parsed by perl), but instead in the __DATA__ section (whch does not need to be parsed by perl). A script with lots of modules to embed can benefit from datapacking technique and lower its startup overhead.


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