Subroutine:    GDSD_WRITE

Purpose:       Write descriptor item.

Category:      GDS

File:          gdsd_basic.c

Author:        J.P. Terlouw

Use:           CALL GDSD_WRITE( SET ,         Input    CHARACTER*(*)
                                KEY ,         Input    CHARACTER*20
                                LEVEL ,       Input    INTEGER
                                BUFFER ,      Output   any type except CHARACTER
                                NBYTES ,      Input    INTEGER
                                POSITION ,    Input    INTEGER
                                DONE ,        Output,  INTEGER
                                ERROR )       Output,  INTEGER
               
               SET      =  Name or handle of set.
               KEY      =  Name of descriptor item.
               LEVEL    =  Coordinate word specifying the substructure to
                           which the descriptor belongs.
               BUFFER   =  Variable or array of containing the data to be
                           written.
               NBYTES   =  Number of bytes to be written. Optional argument.
                           If it is omitted, the current length of the
                           descriptor item is used.
               POSITION =  Relative position, starting at 1, from which will
                           be read. If zero (0) is specified, writing is done
                           at the end of the descriptor item. Optional argument.
                           If it is omitted, the default 1 is assumed.
               DONE     =  The number of bytes which have actually been written.
                           Optional argument. If it is omitted and the number 
                           of bytes which have been transferred is not equal
                           to the requested length of the transfer, an error
                           condition exists.
               ERROR    =  Error return code. In case of success, it will 
                           contain the level where the item has been found.
                           Optional argument.

Note:         This routine does not allow buffers of the type CHARACTER.
              Buffers of this type can be handled by the special routine
              GDSD_WRITEC.

Updates:      25-May-87   original document
              14-Nov-89   rewritten in C
               3-Mar-94   rewritten for GDS server