# perl bench_regexp 100000lines.92MB.file 
Benchmark: timing 1 iterations of one_string, two_string...
one_string:  2 wallclock secs ( 1.68 usr +  0.42 sys =  2.10 CPU) @  0.48/s (n=1)
            (warning: too few iterations for a reliable count)
two_string: 77 wallclock secs (76.13 usr +  0.59 sys = 76.72 CPU) @  0.01/s (n=1)
            (warning: too few iterations for a reliable count)