ong, the error 
      SPICE(SEGIDTOOLONG) is signaled. 
 
   5) If SEGID contains any nonprintable characters, the error 
      SPICE(NONPRINTABLECHARS) is signaled. 
 
   6) Any file I/O problems will be detected and diagnosed by one 
      of the DAF routines called by this routine. 
 
   7) The error SPICE(EMPTYSTRING) is signaled if either input
      string does not contain at least one character, since the
      input strings cannot be converted to a Fortran-style string
      in this case.
      
   