NAME
          fd_move - renumber a descriptor

     SYNTAX
          #include <fd.h>

          int fd_move(to,from);

          int to;
          int from;

     DESCRIPTION
          fd_move moves descriptor from to descriptor to.  If to was
          already open, fd_move closes it.  If the move is successful,
          fd_move closes from.  Exception:  if to and from are the
          same number, fd_move does nothing.

          fd_move returns 0 on success, -1 on error.

     SEE ALSO
          dup(2), fd_copy(3)