or download this
[keszler@tek perl]# cat test3.pl
#!/usr/bin/perl -w
...
Benchmark: timing 10000 iterations of a2, b2...
a2: 54 wallclock secs (34.37 usr + 0.93 sys = 35.30 CPU) @ 28
+3.29/s (n=10000)
b2: 54 wallclock secs (33.69 usr + 0.90 sys = 34.59 CPU) @ 28
+9.10/s (n=10000)