simple text matching with index

gistfile1.pl

#!/usr/bin/perl

use v5.14;
use warnings;
use utf8::all;
use File::Slurp qw( read_file );

my $pattern_list = do 'fw.pl';
my @patterns = keys $pattern_list;
my $content = read_file( 'dracula.txt' );

foreach my $term (@patterns) {
    if ((index $content, $term) > -1) {
            #say $term;
        }
}