Benchmark: timing 100000 iterations of split, substr, unpack...
     split: 20 secs (19.39 usr  0.00 sys = 19.39 cpu)
    substr:  0 secs ( 1.78 usr  0.00 sys =  1.78 cpu)
    unpack:  2 secs ( 2.89 usr  0.00 sys =  2.89 cpu)