Get the group ID of “test.txt”:
| <?php echo filegroup(“test.txt”); ?> | 
The filegroup() function returns the group ID of a file.
Tip: Use the posix_getgrgid() function to convert the group ID to a group name.
Note: The result is cached. Use clearstatcache() to clear the cache.
| filegroup(filename) | 
| Parameter | Description | 
| filename | Mandatory. Specifies the path to the file to check. | 
| Return Value: | Returns the group ID of the file on success, or  | 
| PHP Version: | 4.0+ |