sub check_log_file{
   my ($dir,$name) = @_;
   open my $file, '<', "$dir/$name" or die $!;
   while (defined (my $line = <$file>)) {
       if($line =~ /kein (?:PDF|TIFF)/){
           print "Fehler gefunden\n";
           return 0;
       }
   }
   return 1;
}