use strict;
use warnings;

sub check_strings {
    my ($file, $r_stringsNeeded, $r_stringsToAvoid) = @_;
    open my $fh, '<', $file or die "Can't open '$file': $!\n";
    my %foundNeeded = map { $_ => 0 } @{$r_stringsNeeded};
    my %foundToAvoid = map { $_ => 0 } @{$r_stringsToAvoid};
    while (<$fh>) {
	for my $string (@{$r_stringsNeeded}) {
	    ++$foundNeeded{$string} if /\Q$string/;
        }
	for my $string (@{$r_stringsToAvoid}) {
	    ++$foundToAvoid{$string} if /\Q$string/;
        }
    }
    my $foundAllNeeded     = 0 == scalar grep { $_ == 0 } values %foundNeeded;
    my $foundNoneOfAvoided = 0 == scalar grep { $_ != 0 } values %foundToAvoid;
    return $foundAllNeeded && $foundNoneOfAvoided;
}

if (!check_strings('search.txt', ['first_neededString', 'second_neededString'],
	       	['firstStringToAvoid', 'secondStringToAvoid'])) {
    die "file did not contain all needed Strings or contained forbidden strings\n";
}