this one caches, to make future lookups faster...

{
    my %gid;

    sub gid($)
    {
        my $group = shift;
        defined $gid{$group} && return $gid{$group};
        my $t = getgrnam($group);
        $gid{$group} = ${ $t }[2];
        return $gid{$group};
    } 
}
[download]

~Particle ;Þ