And perhaps a little faster with an RE instead of splits.

use strict;
use warnings;

my $name = '';
my %id_list;

open (STDIN,"perl first_program.pl|") || die "$!";
open (OUT, ">", "out.txt") || die "$!";

while( my $line_in = <STDIN> ) {
    line_in =~ m/^([^\t]*)(?:[^\|]*\|){3}([^\|]*)/;
    unless($name eq $1) {
        %id_list = ();
        $name = $1;
    }
    next if $id_list{$2}++;
    print OUT "$line_in";
}

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Although the parsing of the line is quicker with the RE, the difference may be very small compared to the I/O time. The benefit will depend very much on how often the loop prints.

use strict;
use warnings;
use Benchmark;

my $line_in = "mmenr\thh|gg|kk|3445|uu|zzz\t234\twwe\twe\tqw\t233\n";

Benchmark::cmpthese( 1000000, {
    'split' => sub {
      chomp($line_in);
      my @line_array = split(/\t/,$line_in);
      my @subline_array = split(/\|/, $line_array[1]);
    },
    're' => sub {
      my ($name, $id) = ($line_in =~ m/^([^\t]*)(?:[^\|]*\|){3}([^\|]*
+)/);
    }
});
__END__
          Rate split    re
split  84962/s    --  -68%
re    266667/s  214%    --

[download]

In reply to Re^2: slow parser how to make it faster by ig
in thread slow parser how to make it faster by baxy77bax

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