This should do what you want:

#!/usr/bin/perl

# http://perlmonks.org/?node_id=1151834

use strict;
use warnings;

open my $FH1, '<', shift or die $!;

my %keys;
while (<$FH1>) {
    chomp;
    $keys{$_}++;
}

close $FH1;

open my $FH2, '<', shift or die $!;

while (<$FH2>) {
    chomp;
    my ($record, $key) = split ',', $_, 2;
    print "match: $key record: $record\n" if exists $keys{$key};
}

close $FH2;
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Your code looks like something you've copied from somewhere without really understanding it. I'd advise against doing that: cargo cult code like that might be inefficient, might not actually do what you want, or it might even do damage to your system or data without you knowing it.