$ /opt/perl-5.20.3/bin/perl demo.pl duration memfh: 0.526 seconds 917504 lines duration regex: 0.448 seconds 917504 lines duration split: 0.110 seconds 917504 lines duration trim : 0.268 seconds 917504 lines duration walk1: 0.073 seconds 917504 lines duration walk2: 0.110 seconds 917504 lines