Return_Values

   0                  Indicates success.
   -1                 Indicates failure. The function sets errno to
                      one of the following values:

                      o  EISDIR - The new argument points to a
                         directory, and the old argument points
                         to a file that is not a directory.

                      o  EEXIST - The new argument points to a
                         directory that already exists.

                      o  ENOTDIR - The old argument names a
                         directory, and new argument names a non-
                         directory file.

                      o  ENOENT - The old argument points to a file,
                         directory, or device that does not exist.

                         Or the new argument points to a nonexisting
                         directory path or device.