#!/usr/bin/perl

use warnings;


while (<>)	# the diamond operator to easily read files from the command line
{
	# This is probably the hardest line in the program and yours will certainly vary
	# This one splits based on whitespace or " . , ( ) !
	# Note that other characters (like $ or %) will be counted as part of a word
	@new_words = split /\s+|[".,()!]/, $_;
	foreach (@new_words)
	{
		if ($_)		# recall that split returns empty fields if it finds
		{		# delimiters side-by-side so ignore empty fields
			s/(.*)/\L$1/g;		# convert the word to lowercase
			$word_count{$_}++;	# add to hash
		}
	}
}

# Here we build a new list from the hash, storing each key to sort later
# Notice that we ignore the value for the time being, we just care about the keys
while ($key = each %word_count)
{
	push @keys, $key;
}

# Sort the array of keys
@keys = sort @keys;

# Print the key-value pairs from the hash
# Ordering the output based on the sorted @keys array
foreach (@keys)
{
	printf "%-20s %3s\n", $_, $word_count{$_};
}