The module uses a PHP5 function

The called function is strripos(), which is used to find a dot in a string. I think that strrpos() is enough in such cases.

strripos() doesn't return a different value than the one returned from strrpos, when searching for '.'.
The use of strripos(), is therefore perfectly useless.

That function call causes the module to run only on PHP5 but the module doesn't declare this dependency from the specific version of PHP in its installation file. It would rather preferable to change the function called.