#! perl -sw
use strict;

my ($oldfirst, $oldc2n3) = ( '', '' );

open WORDS, '<',  $ARGV[0] or die $ARGV[0] . $1 . $/;
while(<WORDS>) {
    chomp;
    $_ = lc;
    my ($first, $c2n3) = /^(.)(..?)?.*/;
    $first = './' . $first;
    $c2n3 = substr($c2n3.'__',0,2) if !defined $c2n3 or length($c2n3) 
+< 2;
    $c2n3  = $first . '/' . $c2n3;

    if ( ($first ne $oldfirst) or ($c2n3 ne $oldc2n3) ) {
        mkdir $first if not -e $first;
        open SUB, '>>', $c2n3 or die $c2n3 . $! . $/;
    }
    print SUB $_, $/;
    ($oldfirst, $oldc2n3) = ($first, $c2n3);
    print "\r$c2n3:$_              ";
}
[download]

#! perl -sw
use strict;
use Benchmark::Timer;

sub IsWord {
    return if not @_ or length == 1;
    my ($word, $first, $c2n3) = $_[0] =~ /^((.)(..?)?.*)$/;
    local $_ = do{ local (@ARGV,$/) = "./$first/$c2n3"; <> };
    return /^$word$/im;
}

my $timer = Benchmark::Timer->new(skip=>0);

for (@ARGV) {
    $timer->start;
    my $IsWord = IsWord( $_ );
    $timer->stop;
    print $_, $IsWord ? ' is ' : ' is not ', 'a word', $/;
}

$timer->report;
print "@{[$timer->data('_default')]}", $/;

__END__
[download]

C:\test\WORDS>../208899-2 Anonymous Baltic Confirm Delta Entity Font G
+regarious Hazzard Indigo Jalopy Kilo Lascivious Matter Notorious Ovul
+ation 
Prosthetic Quinine Reading Semaphore Transendental Uniform
Vivisection Weather Xenophobia Yesterday Zorro

Anonymous is a word
Baltic is a word
Confirm is a word
Delta is a word
Entity is a word
Font is a word
Gregarious is a word
Hazzard is a word
Indigo is a word
Jalopy is a word
Kilo is a word
Lascivious is a word
Matter is a word
Notorious is a word
Ovulation is a word
Prosthetic is a word
Quinine is a word
Reading is a word
Semaphore is a word
Transendental is not a word
Uniform is a word
Vivisection is a word
Weather is a word
Xenophobia is a word
Yesterday is a word
Zorro is a word
26 trials of _default (70ms total), 2.692ms/trial
0 0 0 0 0 0.01 0 0 0.01 0 0 0 0 0 0 0.01 0.01 0 0.01 0.01 0 0 0 0 0.01
+ 0

C:\test\WORDS>
[download]