http://www.perlmonks.org?node_id=969003


in reply to Re^2: Skip a row of csv file.
in thread Skip a row of csv file.

You make a good point, but I found myself wondering how the combination of substr, length, and eq would compare to a single anchored regex, so I did a benchmark. I'm convinced!

bannor:~/work/perl/monks$ cat 968838.pl #!/usr/bin/env perl use Modern::Perl; use Benchmark qw(:all); my $str = 'A.SERIAL_NUMBER||abcdefghijklmnopqrstuvwxyz'; my $ss = 'A.SERIAL_NUMBER||'; my $yay; cmpthese( 10_000_000, { 'substr' => sub { if(substr($str,0,length($ss)) eq $ss ){ $yay = 1; } }, 'regex' => sub { if( $str =~ /^\Q$ss\E/ ){ $yay = 1; } }, }); bannor:~/work/perl/monks$ perl 968838.pl Rate regex substr regex 1312336/s -- -65% substr 3802281/s 190% --

Aaron B.
My Woefully Neglected Blog, where I occasionally mention Perl.