Use CPAN?

use CPAN ();

for my $mod (CPAN::Shell->expand("Module","/./")){
  next unless $mod->inst_file;
  my $ver = $mod->inst_version
  print $mod->id, ":\t", defined $ver ? $ver : "UNDEF", "\n";
}
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Hmm. I've never played around with 'use CPAN'... but wouldn't that miss modules built locally?

Do what CPAN.pm does, and grep for the first line containing the string $VERSION, and eval that line. Or, if you eschew eval, there is a new module in the PPI namespace that tries to replicate the eval needed for CPAN.pm.

#!/usr/bin/perl

use ExtUtils::Installed;
   my $instmod = ExtUtils::Installed->new();
    foreach my $module ($instmod->modules()) {
      my $version = $instmod->version($module) || "???";
        print "$module -- $version\n";
     }
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It works, I like it. I'm going to use that Monday!

Bill / N1VUX

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
)
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