Have you consider doing a line-by-line comparison, if you have large files you might end up consuming too much memory for storing an array with the contents. Here's an example

use strict;
use warnings;

open my $fh1, '<', 'file1';
open my $fh2, '<', 'file2';

while ( defined( my $line1 = <$fh1> ) and defined( my $line2 = <$fh2> 
+) ) {
    chomp($line1);
    chomp($line2);

    my @values1 = split( ',', $line1 );
    my @values2 = split( ',', $line2 );

    print "$values2[4]\n"
      if (  $values1[0] eq $values2[1]
        and $values1[1] eq $values2[2]
        and $values1[2] eq $values2[3] );

}

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In reply to Re: Matching columns between files by bluescreen
in thread Matching columns between files by gggg

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