Someone

#!C:\strawberry-perl\perl\bin\perl.exe
use warnings;

$masterlist = "masterlist.txt";
$newlist = "newlist.txt";

open(MASTERLIST, $masterlist) || die("Could not open file!");
open(NEWLIST, $newlist) || die("Could not open file!");
@masterlist = <MASTERLIST>;
@newlist = <NEWLIST>;

$i = 0;
foreach $line (@masterlist)
{
	#print "$line\n";
	$masterlines[$i] = $line;
	$i++;
}

$i = 0;
foreach $line (@newlist)
{
	#print "$line\n";
	$newlines[$i] = $line;
	$i++;
}

foreach $line (@newlines)
{
	@dupes = grep(/$line/, @masterlines);
	print @dupes;
}

sleep();