#!/usr/bin/perl
use strict;
my $var;

my $rhel4au = qr/Red Hat Enterprise Linux AS release 4 \(Nahant Update ([[:digit:]])\)/;
my $rhel4eu = qr/Red Hat Enterprise Linux ES release 4 \(Nahant Update ([[:digit:]])\)/;
my $rhel5 = qr/Red Hat Enterprise Linux Server release 5 \(Tikanga\)/;
my $rhel5u = qr/Red Hat Enterprise Linux Server release 5\.([[:digit:]]) \(Tikanga\)/;

if (-x '/usr/bin/lsb_release') {
  # my $hash{LSBRELEASE} = `/usr/bin/lsb_release -rs`;
  $var = `/usr/bin/lsb_release -ds`;
}
elsif (-f '/etc/redhat-release') {
  $var = `cat /etc/redhat-release`;
}
MatchPrint($var);

sub MatchPrint($var) {
  if ($var =~ m/$rhel4au/ ) {
    print "RHEL4." . $1 . "_AS\n";
  } elsif ( $var =~ m/$rhel4eu/ ) {
    print "RHEL4." . $1 . "_ES\n";
  } elsif ( $var =~ m/$rhel5/ ) {
    print "RHEL5.0\n";
  } elsif ( $var =~ m/$rhel5u/ ) {
    print "RHEL5." . $1 . "\n";
  } else {
    print "unrecognized version\n";
  }
}