repeats.pl

#!/usr/bin/perl

# via http://perlmaven.com/count-words-in-text-using-perl
# $ cat fruit.txt
# apple
# pear
# banana
# pear
# pear
# banana
# grape
# $ ./repeats.pl fruit.txt
# .......
# pear       3
# banana     2
# grape      1
# apple      1

use strict;
use warnings;

my %repeat;
my $export = shift or die "\n \n Nope: $0 exportfilenamehere.txt \n \n";
open my $ef, '<', $export or die "\n \n I can't find a file named '$export'\n \n $!";
while (my $items = <$ef>) {
	chomp $items;
	foreach my $element ( split /\s+/, $items) {
		$repeat{$element}++;
		printf ".";
	}
}
printf "\n";
foreach my $element (reverse sort { $repeat{$a} <=> $repeat{$b} } keys %repeat) {
	printf "%-10s %s\n", $element, $repeat{$element};
}