#! /usr/bin/perl
use strict;
use warnings;

my $data = lc "howdoesonehandlethissensibly";
#my $data ='thesuperuserwascalledderekuser';

my %foundwords;
my $position;
while (<>) {
	chomp;
	next unless length>2; # remove 1 and 2 letter words
	$position = 0;
	while (index($data,lc $_, $position) >= 0) {
		my $found = index($data, lc $_, $position);
		push @{$foundwords{$found}}, lc $_;
		$position = $found + 1;
	}
}

# Print the word combinations
printwords('', -1);
sub printwords
{
	my $string = shift;
	my $position = shift;
	
	while (++$position < length $data) {
		if (exists $foundwords{$position}) {
			foreach my $word (sort {length $a <=> length $b} @{$foundwords{$position}}) {
				printwords (join(' ', $string, $word), $position + length($word) -1);
			}
			last;
		}
	}
	print "$string\n" if $position == length $data;
}