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

my $dictfile = '/usr/share/dict/linux.words';

use vars qw/$regex1 $regex2 @list1 @list2 $word1 $word2 @array $match 
+$expr/;
my $cols  = 2;
my $max   = -1;

$regex1 = &build_regex( '1' );
$regex2 = &build_regex( '2' );

open ( FILE1, "< $dictfile")
  or die("Could not open FILE1, $dictfile\n");

while (<FILE1>) {
  chomp;
  push @list1, $_;
}
close FILE1;

@list2 = @list1;

$expr = &build_expr( $regex1, $regex2 );
print "\nPlease wait a moment...\n";
eval $expr;

unless ($array[0]) {
    print "\n\nNo matches!\n";
    exit;
}

print "\n\nThe results are,\n\n";
$_ > $max && ($max = $_) for map {length} @array;
while (@array) {
    print join " " => map {sprintf "%-${max}s" => $_}
                           splice @array => 0, $cols;
    print "\n";
}
exit;

### SUBS

sub build_regex {
    my $this = shift;
    my ($regex, $total, $other, $position);
    my $count = 1;
    if ($this == 1) {
        $other = 2;
    }
    else {
        $other = 1;
    }
    
    print "\nHow any letters does word $this have?\n";
    $total = <STDIN>;
    chomp $total;
    unless ($total =~ /^([0-9]+)$/) {
        die("Incorrect input! - $total\n");
    }
    $total = $1;
    
    print "What position does it meet word $other at?\n";
    $position = <STDIN>;
    chomp $position;
    unless ($position =~ /^([0-9]+)$/) {
        die("Incorrect Input! - $position\n");
    }
    $position = $1;
    print "\n";
    
    while ($count <= $total) {
        if (($this == 1) && ($position == $count)) {
            $regex .= '(\w)';
        }
        elsif (($this == 2) && ($position == $count)) {
            $regex .= '${match}';
        }
        else {
            my $suffix = &build_suffix( $count );
            
            print "What is the ${count}${suffix} letter?\n";
            if ($count == 1) {
                print "Hit <RETURN> if you don't know.\n";
            }
            my $input = <STDIN>;
            chomp $input;
            unless (($input =~ /^([a-zA-Z])$/) | ($input =~ /^()$/)) {
                die("Incorrect input! - $input\n");
            }
            $input = $1;
            
            if ($input eq '') {
                $regex .= '\w';
            }
            else {
                $regex .= $input;
            }
        }
        
        $count ++;
    }
    
    return $regex;
}

sub build_suffix {
    my $number = shift;
    if ($number =~ /([0-9])$/) {
        $number = $1;
    }
    else {
        die("Could not build number suffix!\n");
    }
    
    if ($number == 1) {
        return 'st';
    }
    elsif ($number == 2) {
        return 'nd';
    }
    elsif ($number == 3) {
        return 'rd';
    }
    else {
        return 'th';
    }
}

sub build_expr {
    my $string1 = shift;
    my $string2 = shift;
    
    my $build = "
foreach \$word1 (\@list1) {
  if (\$word1 =~ /^$string1\$/i) {
      \$match = \$1;
    foreach \$word2 (\@list2) {
        if (\$word2 =~ /^$string2\$/i) {
            push \@array, \$word1;
            push \@array, \$word2;
        }
    }
  }
}";

    return $build;
}