Description

   This routine builds a command string and passes it to TPU$TPU. If
   the length of the output descriptor is nonzero, then the /OUTPUT
   qualifier is added to the command string. The /OUTPUT qualifier
   causes a file to be written to the specified file even if no
   modifications are made to the input file. If the QUIT built-
   in procedure is called, it prompts the user as if changes had
   been made to the buffer. This allows applications to check for
   the existence of the output file to see if the editing session
   was terminated, which is consistent with other OpenVMS callable
   editors.

   If your application parses information that is not related to the
   operation of TPU, make sure the application obtains and uses
   all non-TPU parse information before the application calls
   TPU$EDIT. Your application must do this because TPU$EDIT destroys
   all parse information obtained and stored before TPU$EDIT is
   called.