$ wc words.english
 116246  116246  989075 words.english

$ time perl dict.pl words.english # first hack
1.38    user
0.05    system
0:01.43 elapsed
$ time perl dict2.pl words.english  # second hack
0.86     user
0.02     system
0:00.88 elapsed

##</code><code>##

push @{$Word{length$_}},$_ while (<>);
# ...
print OUT @{$Word{$_}};

##</code><code>##

$Word{length$_} .= $_ while (<>);
# ...
print OUT $Word{$_};

##</code><code>##

#!/usr/bin/perl -w
use strict;
my @words;
my $file;
$words[length$_] .= $_ while (<>);
for (0..$#words)
{
 next unless $words[$_];
 $file=$_-1 . ".mine";
 open OUT,">$file" or die "Cannot open $file.mine: $!\n";
 print OUT $words[$_];
 close OUT;
};