#!/usr/local/bin/perl -w
use strict;
$|++;

my @numlist;
push @numlist, int(rand 100000) for 1..10;

for(@numlist) {
	next if /^$/;
	/.*?([0-9]).*?\1/ ? print "$_\tmultiple $1\n" : print "$_\tsingle\n";
}

##</code><code>##

Use of uninitialized value in concatenation (.) or string at test_match1.pl line 10.
Nested quantifiers before HERE mark in regex m/.*?([0-9]).*?+ << HERE / at test_match1.pl line 10.