NAME

CPAN::Unwind - Recursively determines dependencies of CPAN modules

SYNOPSIS

use CPAN::Unwind;

my $agent = CPAN::Unwind->new();

my $resp = $agent->lookup("Log::Log4perl");
die $resp->message() unless $resp->is_success();

my $deps = $resp->dependend_versions();

for my $module (keys %$deps) {
    printf "%30s: %s\n", $module, $deps->{$module};
}
    # Prints:
    #
    #  Test::Harness: 2.03
    #     Test::More: 0.45
    #     File::Spec: 0.82
    # File::Basename: 0
    #           Carp: 0

print "Installation schedule:\n";
for($resp->schedule()) {
    print "$_\n";
}
    # Installation schedule:
    # Carp
    # File::Basename
    # File::Spec
    # Test::Harness
    # Test::More
    # Log::Log4perl

DESCRIPTION

CPAN::Unwind recursively determines dependencies of CPAN modules. It fetches distribution tarballs from CPAN, unpacks them, and runs Module::Depends::Intrusive on them.

SECURITY NOTE: CPAN::Unwind runs all Makefile.PL files (via Module::Depends::Intrusive) of modules it finds dependencies on. If you are concerned that any module in the dependency tree on CPAN isn't trustworthy, don't use it.

METHODS

CPAN::Unwind supports the following methods:

my $agent = CPAN::Unwind->new();

Create a new dependency agent.

$resp = $agent->lookup_single($module_name)

Goes to CPAN and fetches the tarball containing the module specified in $module_name. After unpacking the tarball, it will use Module::Depends::Intrusive to determine the modules it depends on.

Returns a CPAN::Unwind::Response object.

$resp = $agent->lookup($module_name)

Calls lookup_single on $module_name recursively, builds a dependency tree and returns a CPAN::Unwind::Response object containing a consolidated dependency tree.

CPAN::Unwind::Response supports the following methods:

$resp->is_success()

Returns true if there's a valid response and no error occurred.

$resp->message()

Returns a response's error message in case is_success() returned a false value.

$resp->dependend_versions()

Returns a ref to a hash, containing a mapping between names of dependend modules and their version numbers:

{ "Test::More"  =>  0.51,
  "List::Utils" =>  0.38,
  ...
}

$resp->missing()

Similar to dependend_versions(), but only modules that are currently not installed are returned.

$resp->dependends()

Returns a ref to a hash, mapping module names to their dependencies.

{ "Net::Amazon"  =>  ["Log::Log4perl", "XML::Simple"],
  "List::Utils"  =>  [],
  ...
}

If an entry holds a ref to an empty array, the module doesn't have any dependencies.

$resp->schedule()

Returns an installation schedule, a list of module names in the correct order without dependency conflicts. Returns undef if no schedule can be made due to circular dependencies.

CPAN::Unwind requires a valid CPAN configuration.

LEGALESE

Copyright 2005 by Mike Schilli, all rights reserved. This program is free software, you can redistribute it and/or modify it under the same terms as Perl itself.

AUTHOR

2005, Mike Schilli <cpan@perlmeister.com>