Re: Optimise file line by line parsing, substitute SPLIT


Do you know where your variables are?
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Re: Optimise file line by line parsing, substitute SPLIT

by nbtrap (Sexton)

on Jun 06, 2013 at 02:04 UTC ( [id://1037347]=note: print w/replies, xml )

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in reply to Optimise file line by line parsing, substitute SPLIT

If memory is not lacking, you can slurp the entire file and then process the lines, as in:

#!/usr/bin/perl
use warnings;
use strict;


my $file = "/Path/to/file/file_X.txt";

open(my $fh, '<', $file) or die("Can not open file $file to read!\n");

my @lines = <$fh>;
close($fh);

for (@lines) {
    chomp;
    ## process the rest here, including calls to split    
}

print "\n# of lines: " . scalar(@lines) . "\n";
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This has a good chance to speed things up, presumably because perl will make fewer calls to read(2).