or download this
C:\WINDOWS\Desktop>perl test_regex-o.pl
Benchmark: timing 100000 iterations of s_direct, s_witho, s_withouto..
+.
s_direct: 4 wallclock secs ( 3.02 usr + 0.00 sys = 3.02 CPU) @ 33
+112.58/s (n=100000)
s_witho: 4 wallclock secs ( 3.41 usr + 0.00 sys = 3.41 CPU) @ 29
+325.51/s (n=100000)
s_withouto: 5 wallclock secs ( 4.28 usr + 0.00 sys = 4.28 CPU) @ 23
+364.49/s (n=100000)