( string filename )
Returns the user ID of the owner of the file, or FALSE in case of
an error. The user ID is returned in numerical format, use
posix_getpwuid() to resolve it to a username.
Note: The results of this
function are cached. See clearstatcache() for
Tip: As of PHP 5.0.0 this function
can also be used with some URL wrappers. Refer to
Appendix M for a listing of which wrappers support
stat() family of functionality.
See also stat()