Descriptionint filegroup ( string filename)
Returns the group ID of the file, or FALSE in case of an error. The group ID is returned in numerical format, use posix_getgrgid() to resolve it to a group name. Upon failure, FALSE is returned along with an error of level E_WARNING.
Note: The results of this function are cached. See clearstatcache() for more details.
Note: This function will not work on remote files as the file to be examined must be accessible via the servers filesystem.