#!/usr/bin/perl -l

use strict;
use warnings;
use autodie;

my $dir = '.';

opendir(my $dh, $dir);
my @emptyfiles = grep { -f && /^\d+$/ && -z } readdir $dh;
closedir $dh;

print for @emptyfiles;

##</code><code>##

$ ls -l 1 12 123
-rw-r--r--  1 ken  staff  0  8 Jan 03:00 1
-rw-r--r--  1 ken  staff  7  8 Jan 03:00 12
-rw-r--r--  1 ken  staff  0  8 Jan 03:00 123

##</code><code>##

1
123