How to use strpos to determine if a string exists in input string?

Question

$filename = \'my_upgrade(1).zip\';
$match = \'my_upgrade\';

if(!strpos($filename, $match))
    {
    die();
    }
else 
   {
   //proceed
   }

In

Answer 1

strpos in this case will return a zero, which is then interpretted as false when you do the logical negation. You should check explicitly for the boolean false.