Various methods of installing modules create metadata on what modules are installed. Unfortunately, reading this metadata only tells you about modules installed in this way, and there are many ways to install modules -- rpm, deb, MakeMaker, qpkg, MSI, cp...

Don't attempt to read any of that metadata. Instead, just look and see what modules are there: 

use File::Find;
use ExtUtils::MakeMaker;

find(
  sub {
    next unless /.pm$/i;
    my $mod = $File::Find::name;
    $mod =~ s/^$File::Find::topdir\/?//;
    $mod =~ s/\.pm$//i;
    $mod=~s!/!::!g;
    my $ver=MM->parse_version($File::Find::name);
    print "$mod ($ver)\n"
  },
  @INC
)

[download]
(BTW, the ExtUtils::MakeMaker call there /does/ look in the actual file (and thus does not fall prey to my problem with metadata), and /does/ run code out of it -- but only one line. Also note that it returns the string 'undef' when there is no version, and not an actual undef.)

Warning: Unless otherwise stated, code is untested. Do not use without understanding. Code is posted in the hopes it is useful, but without warranty. All copyrights are relinquished into the public domain unless otherwise stated. I am not an angel. I am capable of error, and err on a fairly regular basis. If I made a mistake, please let me know (such as by replying to this node).

In reply to Re: Installed modules and their versions by theorbtwo
in thread Installed modules and their versions by cog

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