Return_Values

   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.