$ /opt/perl-5.26.1/bin/perl demo.pl

duration memfh: 0.479 seconds
917504 lines

duration regex: 0.442 seconds
917504 lines

duration split: 0.066 seconds
917504 lines

duration trim : 0.259 seconds
917504 lines

duration walk1: 0.070 seconds
917504 lines

duration walk2: 0.084 seconds
917504 lines