Test whether a file exists anywhere in the include path

Question

I\'m writing an autoload function and in the inner logic of it would like to test whether a certain file exists somewhere in the path prior to including it.

This is the

Answer 1

As of PHP 5.3.2 there is the option to use the stream_resolve_include_path() function whose purpose is to

Resolve [a] filename against the include path according to the same rules as fopen()/include() does.

If the file exists on one of the include paths, then that path (including the file name) will be returned. Otherwise (i.e. the file was not on any of the include paths) it will return FALSE.

Relating this to your needs, your autoloader might look something like:

function my_autoloader($classname) {
    $found = stream_resolve_include_path($classname . '.specialversion.php');
    if ($found !== FALSE) {
        include $found;
    }
}