Description

   The TPU$FILE_PARSE routine returns a string containing the fields
   requested of the file specified. The file is not required to
   exist when the parse is done. The intention of the TPU$FILE_
   PARSE routine is to construct a valid file specification from the
   information passed in through the file specification, the default
   file specification, and the related file specification.

   The routine uses the $PARSE system service to return the
   requested information.

   The TPU$FILE_PARSE routine is also called by TPU when the
   TPU built-in procedure FILE_PARSE is executed from TPU code. The
   return value of the built-in procedure is the string returned in
   the result-string argument.