0 Indicates success. -1 Indicates failure. The function sets errno to one of the following values: The fchown function will fail if: o EBADF - The fildes argument is not an open file descriptor. o EPERM - The effective user ID does not match the owner of the file, or the process does not have appropriate privilege. o EROFS - The file referred to by fildes resides on a read-only file system. The fchown function may fail if: o EINVAL - The owner or group ID is not a value supported by the implementation. o EIO - A physical I/O error has occurred. o EINTR - The fchown function was interrupted by a signal that was intercepted.