CPAN::Unwind - Recursively determines dependencies of CPAN modules
use CPAN::Unwind;
my $agent = CPAN::Unwind->new();
my $resp = $agent->lookup("Log::Log4perl");
die $resp->message() unless $resp->is_success();
my $deps = $resp->dependent_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
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, only use it in a secured sandbox.
CPAN::Unwind supports the following methods:
my $agent = CPAN::Unwind->new();Create a new dependency agent. The following options are supported:
cacheProvide your own Cache::Cache object (see Caching).
addProvide additional dependencies that should be part of the result:
CPAN::Unwind->new(add =>
["Foo", "Bar" => 0.17,
...
]);
indicates that Foo has a dependency on Bar 0.17, even if it's not listed in Foo's Makefile.PL. This way, you can fix broken Makefile.PL files of some CPAN modules, not listing their dependencies correctly.
$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->dependent_versions()Returns a ref to a hash, containing a mapping between names of dependent modules and their version numbers:
{ "Test::More" => 0.51,
"List::Utils" => 0.38,
...
}
$resp->missing()Similar to dependent_versions(), but only modules that are currently not installed are returned.
$resp->dependents()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.
To avoid costly downloads, CPAN::Unwind will cache dependencies in a Cache::FileCache cache, where they are stored indefinitely. Running it the second time on a module will speed up processing significantly.
CPAN::Unwind comes with a ready-to-use script cpan-unwind, which gets installed in perl's bin path. It is ready to use, just call
$ cpan-unwind Log::Log4perl
to see which modules Log::Log4perl depends on.
CPAN::Unwind requires a valid CPAN configuration.
$ cpan-unwind Net::Amazon
Carp Compress::Zlib Data::Dumper Fcntl File::Basename File::Path
File::Spec HTML::Tagset IO::Socket MIME::Base64 Socket Test::Harness
Test::More Test::Simple Time::HiRes URI XML::NamespaceSupport
Digest::base File::Temp HTML::Parser Log::Log4perl Net::FTP
XML::SAX XML::Simple Digest::MD5 LWP::UserAgent Net::Amazon
Copyright 2005-2011 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.
2005, Mike Schilli <cpan@perlmeister.com>
