or download this
use Benchmark;
@arr=('file.html')x1024;
...
For: 3 secs (3.13 usr + 0.00 sys = 3.13 CPU) @ 707.72/s (n=2218)
Map: 3 secs (3.14 usr + 0.00 sys = 3.14 CPU) @ 96.98/s (n=305)
Slice: 4 secs (3.14 usr + 0.00 sys = 3.14 CPU) @ 1074.72/s (n=3380)