Re: Compare 2 files and create a new one if it matches

[lamp]

How about using 'Tie::File' module??

use strict;
use warnings;
use Tie::File;

my %seen;
tie my @file1, 'Tie::File', 'file.txt' or die;
tie my @file2, 'Tie::File', 'file2.txt' or die;

foreach (@file1) 
 { chomp; $seen{$_}++; }
 
for(@file2) {
    my $key = (split /\|/,$_)[1];
    print "$_\n" if $seen{$key};
}

untie(@file1);
untie(@file2);

output:

E|123|r|some|56|78|90
D|678|r|some|56|78|90
F|345|r|y|98|0|0

[GrandFather]

Why complicate the problem by introducing tied files when you need make only one pass through the file in any case? You are simply adding overhead for no gain and obfuscating the the code into the bargain.