or download this
Benchmark: timing 10000000 iterations of comp, exist, regex...
comp: 56 wallclock secs (55.39 usr + 0.00 sys = 55.39 CPU)
exist: 50 wallclock secs (49.34 usr + 0.00 sys = 49.34 CPU)
regex: 79 wallclock secs (79.32 usr + 0.00 sys = 79.32 CPU)