Another possibility is to use Math::Combinatorics: 
#! /usr/bin/perl
use warnings;
use strict;
use feature qw{ say };

use Math::Combinatorics;

my $count = 0;
my $comb = 'Math::Combinatorics'->new(count => 4, data => [ 0 .. 9 ]);
++$count, say @$_ while @$_ = $comb->next_combination;
say $count;

[download]
($q=q:Sq=~/;[c](.)(.)/;chr(-||-|5+lengthSq)`"S|oS2"`map{chr |+ord
}map{substrSq`S_+|`|}3E|-|`7**2-3:)=~y+S|`+$1,++print+eval$q,q,a,

[download]

In reply to Re: list of four digit lock combinations without repeated digits by choroba
in thread list of four digit lock combinations without repeated digits by Lotus1

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