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Yet another way to declare CPAN dependencies
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lib 1.1001
script update doc
t stop using subtest. Fixes #38
.gitignore Enable travis
.travis.yml Enable travis
Changes 1.1001
META.json 1.1001
Makefile.PL 1.1001 1.1000
cpanfile Massive refactor to eliminate Result intermediate class and add Featu…
dist.ini Switch to MakeMaker (partially due to RT #84171)


Module::CPANfile - Parse cpanfile


use Module::CPANfile;

my $file = Module::CPANfile->load("cpanfile");
my $prereqs = $file->prereqs; # CPAN::Meta::Prereqs object

my @features = $file->features; # CPAN::Meta::Feature objects
my $merged_prereqs = $file->prereqs_with(@identifiers); # CPAN::Meta::Prereqs



Module::CPANfile is a tool to handle cpanfile format to load application specific dependencies, not just for CPAN distributions.


  • load

    $file = Module::CPANfile->load;
    $file = Module::CPANfile->load('cpanfile');

    Load and parse a cpanfile. By default it tries to load cpanfile in the current directory, unless you pass the path to its argument.

  • from_prereqs

    $file = Module::CPANfile->from_prereqs({
      runtime => { requires => { DBI => '1.000' } },

    Creates a new Module::CPANfile object from prereqs hash you can get via CPAN::Meta's prereqs, or CPAN::Meta::Prereqs' as_string_hash.

    # read MYMETA, then feed the prereqs to create Module::CPANfile
    my $meta = CPAN::Meta->load_file('MYMETA.json');
    my $file = Module::CPANfile->from_prereqs($meta->prereqs);
    # load cpanfile, then recreate it with round-trip
    my $file = Module::CPANfile->load('cpanfile');
    $file = Module::CPANfile->from_prereqs($file->prereq_specs);
                                      # or $file->prereqs->as_string_hash
  • prereqs

    Returns CPAN::Meta::Prereqs object out of the parsed cpanfile.

  • prereq_specs

    Returns a hash reference that should be passed to CPAN::Meta::Prereqs->new.

  • features

    Returns a list of features available in the cpanfile as CPAN::Meta::Feature.

  • prereqs_with(@identifiers), effective_prereqs(\@identifiers)

    Returns CPAN::Meta::Prereqs object, with merged prereqs for features identified with the @identifiers.

  • to_string($include_empty)


    Returns a canonical string (code) representation for cpanfile. Useful if you want to convert CPAN::Meta::Prereqs to a new cpanfile.

    # read MYMETA's prereqs and print cpanfile representation of it
    my $meta = CPAN::Meta->load_file('MYMETA.json');
    my $file = Module::CPANfile->from_prereqs($meta->prereqs);
    print $file->to_string;

    By default, it omits the phase where there're no modules registered. If you pass the argument of a true value, it will print them as well.

  • save


    Saves the currently loaded prereqs as a new cpanfile by calling to_string. Beware this method will overwrite the existing cpanfile without any warning or backup. Taking a backup or giving warnings to users is a caller's responsibility.

    # Read MYMETA.json and creates a new cpanfile
    my $meta = CPAN::Meta->load_file('MYMETA.json');
    my $file = Module::CPANfile->from_prereqs($meta->prereqs);
  • merge_meta

    $file->merge_meta('MYMETA.json', '2.0');

    Merge the effective prereqs with Meta specification loaded from the given META file, using CPAN::Meta. You can specify the META spec version in the second argument, which defaults to 1.4 in case the given file is YAML, and 2 if it is JSON.


Tatsuhiko Miyagawa


cpanfile, CPAN::Meta, CPAN::Meta::Spec

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