#! perl -slw
use strict;
use G;

$|=1;

chomp( my @words = do{ open my $fh, '<words.dat'; <$fh> } );
print "loaded: " . @words . ' words';

local $/;

my %index; @index{ @ARGV } = ('') x @ARGV;
while(  <> ) {
	chomp( my $file = lc );
	1+index( $file, $words[ $_ ] )
		and vec( $index{ $ARGV }, $_, 1 ) = 1
			for 0 .. $#words;
}

open INDEX, '>', 'index.dat' or die $!;
print INDEX "$_(@{[ unpack '%b*', $index{ $_ } ]}) : [@{[ unpack 'b*', $index{ $_ } ]}]" 
	for sort keys %index;
close INDEX;