document updated 13 years ago, on Jun 27, 2011

How do you find the "backlinks" to a given module? Ie. For a given module, how do you find all modules that use it?

websites that do it
- http://deps.cpantesters.org/
  - a greasemonkey script for this
- CPANTS had offered a used_by feature. However, it seems to be broken.
The entire CPAN archive is currently 3.9gb? 1gb?. So you can download a local mirror, and do your own processing on it.
- you can just grep for the module name you're looking for
- but there are specific tools for dependency-tracking:
- cpangraph
- Module-Dependency
  - yes, it can generate its own index
- CPAN::Dependency
  - it can load the CPANTS database
  - however, it notes that CPANTS support is currently broken
- CPANDB::Dependency
- CPAN::FindDependencies
- places where the dependency information is actually stored
  - each module's META.yml file
  - Makefile.PL's call to WriteMakeFile( ... PREREQ_PM