I have this code: 
my $patterns = "/path/to/file.txt";
my $arg1 = shift;

open(PATTERNS, "<$patterns") || die("Cannot Open '$patterns'");
my @list_patterns = <PATTERNS>; 
close(PATTERNS);

open(FILE, "<$arg1") || die("Cannot Open $arg1");
my $file = join('',<FILE>);
close(FILE);

foreach my $list_patterns ( @list_patterns) {
    chomp ($list_patterns);
    if ($file =~ m/$list_patterns/is) {print "\n$arg1\n$list_patterns\
+n";}
    }

[download]
Comparing to other programs this scanner is very, very slow. I have also some troubles with some long patterns, but this is a small problem. Any idea how to improve to make it running faster? Thank you!!

In reply to Comparing pattern by mrc

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