#!/usr/local/bin/perl
@results=`/usr/local/bin/top -n 0`;
($total, $free, $rest) = split /,/, $results[3], 3;
($blah, $total, $rest) = split / /, $total, 3;
$total =~ s/M//;
$free =~ s/ //;
($free, $blah) = split / /, $free, 2;
$free =~ s/M//;
$used=$total-$free;

if ($used > 3584) {
  print "system memory CRITICAL: $used MB\n";
  exit(2);
}
else {
  print "system memory OK: $used MB.\n";
  exit (0);
}