or download this
perl -MBenchmark -w
($s, $t) = qw/ foo xfoox /;
...
Benchmark: running oful, oless for at least 1 CPU seconds...
oful: 2 wallclock secs ( 1.08 usr + 0.00 sys = 1.08 CPU) @
+2427258.33/s (n=2621439)
oless: 2 wallclock secs ( 1.15 usr + 0.00 sys = 1.15 CPU) @
+1841144.35/s (n=2117316)