How can I de-install a Perl module installed via `cpan`?

Question

I am using Perl running in user space (not installed via root) and installing modules via the command-line cpan. I would like to know if there is a simple way to remove a module without having to do a lot of work deleting individual files.

I searched for this question on the internet and found some answers, but the answers I've found seem to either discuss using the Perl package manager (specific for Microsoft Windows), otherwise operating-system specific (BSDpan), suggesting using cpanplus (which I've had several bad experiences with), or ended by pointing to a dead link as follows: http://www.cpan.org/misc/cpan-faq.html#How_delete_Perl_modules.

My question is specifically whether there is a clean way to remove a module installed via cpan.

Answer 1

As a general rule, there is not a specific 'uninstall' mechanism that comes with CPAN modules. But you might try make uninstall in the original directory the module unpacked into (this is often under /root/.cpan or ~/.cpan), as some packages do contain this directive in their install script. (However, since you've installed modules into a local (non-root) library directory, you also have the option of blowing away this entire directory and reinstalling everything else that you want to keep.)

A lot of the time you can simply get away with removing the A/B.pm file (for the A::B module) from your perllib -- that will at least render the module unusable. Most modules also contain a list of files to be installed (called a "manifest"), so if you can find that, you'll know which files you can delete.

However, none of these approaches will address any modules that were installed as dependencies. There's no good (automated) way of knowing if something else is dependent on that module, so you'll have to uninstall it manually as well once you're sure.

The difficulty in uninstalling modules is one reason why many Perl developers are moving towards using a revision control system to keep track of installations -- e.g. see the article by brian d foy as a supplement to his upcoming book that discusses using git for package management.

Answer 2

You can't. There isn't a feature in my CPAN client to do such a thing. We were talking about how we might do something like that at this weekend's Perl QA Workshop, but it's generally hard for all the reasons that Ether mentioned.

Answer 3

I don't need to uninstall modules often, but the .packlist file based approach has never failed me so far.

use 5.010;
use ExtUtils::Installed qw();
use ExtUtils::Packlist qw();

die "Usage: $0 Module::Name Module::Name\n" unless @ARGV;

for my $mod (@ARGV) {
    my $inst = ExtUtils::Installed->new;

    foreach my $item (sort($inst->files($mod))) {
        say "removing $item";
        unlink $item or warn "could not remove $item: $!\n";
    }

    my $packfile = $inst->packlist($mod)->packlist_file;
    print "removing $packfile\n";
    unlink $packfile or warn "could not remove $packfile: $!\n";
}