Quercus (PHP on Google App Engine) is_file is_dir not Working

I have a PHP application running on Google App Engine, who has the ability to run PHP on GAE via Quercus. However, I notice that my scripts choke on GAE when they run an is_dir() or is_file() function. These functions work just fine on a "regular" PHP server.

According to the link I gave above above, I have configured my application correctly, as all else works just fine. What could be the ca开发者_开发百科use of this sticking point? Is it a GAE configuration, or does Quercus not support these functions?

Thank you for your time.

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The local disk limitations are part of the Google App Engine restrictions, see Why can't I read from this file?

It is possible to read from a file which is uploaded as part of your application provided that it is in the following locations:

• war/WEB-INF
• in a location matching the pattern in appengine-web.xml (which by default includes everything)