When posix_getgrgid() fails (e.g. an invalid/unknown group id), it returns false.
This is except for Mac OSX on which you get an array with name "nogroup" and gid of "-1".
When posix_getgrgid() fails (e.g. an invalid/unknown group id), it returns false.
This is except for Mac OSX on which you get an array with name "nogroup" and gid of "-1".