@param s directory read context. Pointer to a NULL pointer must be passed.
@param url directory to be listed.
@param options A dictionary filled with protocol-private options. On return
this parameter will be destroyed and replaced with a dictionary
containing options that were not found. May be NULL.
@return >=0 on success or negative on error.
Open directory for reading.
@param s directory read context. Pointer to a NULL pointer must be passed. @param url directory to be listed. @param options A dictionary filled with protocol-private options. On return this parameter will be destroyed and replaced with a dictionary containing options that were not found. May be NULL. @return >=0 on success or negative on error.