Just a quick way to check if a module is in Perl's core

perlcore.pl

#!/usr/bin/perl
use warnings;
use strict;
use Module::CoreList;

die "Heh, specify a module?\n" unless @ARGV;

foreach my $module (@ARGV){
    my @modules = Module::CoreList->find_modules($module);
    if (@modules){
        foreach my $module (@modules){
            print $module,' (',Module::CoreList->first_release($module),")\n";
        }
    }
    else {
        warn "Could not find $module in Module::CoreList\n";
    }
}