#!/usr/bin/perl -w
use strict;

my %count;

open (INPUT, '<', "some_input_file") or
   die "unable to open some_input_file");

while (<INPUT>)
{
   my ($number) =~ /(\d+)/; #maybe????
   next unless $number; #skip undef's
   $count{$number}++; #new key if $number not there
}
foreach my $number (sort{$a <=> $b} keys %count) #numeric sort
{
    print "$number occurs $count{$number} time(s)\n";
}