...
my @matches = <$match_in>;
...
while (my $lines = <$fh_in>) {
  for my $matches ( @matches ) {
...

##</code><code>##

#!/usr/bin/perl

use strict;

open my $fh1, '<', 'file_iterator1';
open my $fh2, '<', 'file_iterator2';


while ( my $line1 = <$fh1> ) {
    chomp $line1;
    while ( my $line2 = <$fh2> ) {
        chomp $line2;
        print "$line1:\t$line2\n";
    }
}

##</code><code>##

one
two
three

##</code><code>##

ay
bee
see

##</code><code>##

one: ay
one: bee
one: see