Counting words in a file

Counting_words.pl

#!perl

# perl script.pl < file.txt

use warnings;
use strict;


my %seen=();
while(<>) {
 while (/(\w[\w'-]*)/g){
  $seen{lc $1}++;
 }
}

 foreach my $word ( sort  { $seen{$b} <=> $seen{$a} } keys %seen) {
 printf "%d %s\n", $seen{$word}, $word;
}