CPAN::FindDependencies - find dependencies for modules on the CPAN
use CPAN::FindDependencies; my @dependencies = CPAN::FindDependencies::finddeps("CPAN"); foreach my $dep (@dependencies) { print ' ' x $dep->depth(); print $dep->name().' ('.$dep->distribution().")\n"; }
The module uses the CPAN packages index to map modules to distributions and vice versa, and then fetches distributions' META.yml files from http://search.cpan.org/ to determine pre-requisites. This means that a working interwebnet connection is required.
http://search.cpan.org/
There is just one function, which is not exported by default although you can make that happen in the usual fashion.
Takes a single compulsory parameter, the name of a module (ie Some::Module); and the following optional named parameters:
Warnings about modules where we can't find their META.yml, and so can't divine their pre-requisites, will be suppressed;
Failure to get a module's dependencies will be a fatal error instead of merely emitting a warning;
Use this version of perl to figure out what's in core. If not specified, it defaults to 5.005. Three part version numbers (eg 5.8.8) are supported but discouraged.
The location of CPAN.pm's 02packages.details.txt.gz file as a local filename, with either a relative or an absolute path. If not specified, it is fetched from a CPAN mirror instead. The file is fetched just once.
02packages.details.txt.gz
A directory to use for caching. It defaults to no caching. Even if caching is turned on, this is only for META.yml files. 02packages is not cached - if you want to read that from a local disk, see the 02packages option.
02packages
Cuts off the dependency tree at the specified depth. Your specified module is at depth 0, your dependencies at depth 1, their dependencies at depth 2, and so on.
It returns a list of CPAN::FindDependencies::Dependency objects, whose useful methods are:
The module's name
The distribution containing this module
How deep in the dependency tree this module is
If any warning was generated (even if suppressed) for the module, it will be recorded here.
Any modules listed as dependencies but which are in the perl core distribution for the version of perl you specified are suppressed.
These objects are returned in a semi-defined order. You can be sure that a module will be immediately followed by one of its dependencies, then that dependency's dependencies, and so on, followed by the 'root' module's next dependency, and so on. You can reconstruct the tree by paying attention to the depth of each object.
The ordering of any particular module's immediate 'children' can be assumed to be random - it's actually hash key order.
You must have web access to http://search.cpan.org/ and (unless you tell it where else to look for the index) http://www.cpan.org/, or have all the data cached locally.. If any META.yml files are missing, the distribution's dependencies will not be found and a warning will be spat out.
Startup can be slow, especially if it needs to fetch the index from the interweb.
I welcome feedback about my code, including constructive criticism and bug reports. The best bug reports include files that I can add to the test suite, which fail with the current code in CVS and will pass once I've fixed the bug
Feature requests are far more likely to get implemented if you submit a patch yourself.
http://drhyde.cvs.sourceforge.net/drhyde/perlmodules/CPAN-FindDependencies/
CPAN
http://cpandeps.cantrell.org.uk/
http://search.cpan.org
Copyright 2007 David Cantrell <david@cantrell.org.uk>
This module is free-as-in-speech software, and may be used, distributed, and modified under the same terms as Perl itself.
This module is also free-as-in-mason software.
To install CPAN::FindDependencies, copy and paste the appropriate command in to your terminal.
cpanm
cpanm CPAN::FindDependencies
CPAN shell
perl -MCPAN -e shell install CPAN::FindDependencies
For more information on module installation, please visit the detailed CPAN module installation guide.