note kiat Thanks, [Courage] :)<p> Did you mean the following? <code> use Benchmark; $start = new Benchmark; open(FH, "wrongs") or die $!; open(FH2, ">wrongs2") or die $!; undef $/; $lines = <FH>; $counted2 = $lines =~ s/wrongs/wrongs4/g; print FH2 "$lines"; $/ = "\n"; close (FH); close (FH2); $end = new Benchmark; # calculate difference $diff = timediff($end, $start); print "replaced: $counted2 The operation took: " , timestr($diff, 'all'); </code> 497648 497946