my $username = "kvale";
my @groups = ($username);
open GROUP, "</etc/group"
   or die "Could not find /etc/group: $!\n";
while (<GROUP>) {
  my ($group,$x,$gid,$list)=split(':',$_);
  push(@groups,$group) if ($list=~/$username/);
}
print "Groups: ", join " ", @groups, "\n";