Arguments

 

context

   OpenVMS usage:context
   type:         longword (unsigned)
   access:       modify
   mechanism:    by reference
   Value that distinguishes between multiple, concurrent SORT/MERGE
   operations. The context argument is the address of a longword
   containing the context value. When your program makes its first
   call to a SORT/MERGE routine for a particular sort or merge
   operation, the context longword must equal zero. SORT/MERGE
   then stores a value in the longword to identify the operation
   just initiated. When you make subsequent routine calls for the
   same operation, you must pass the context value supplied by
   SORT/MERGE.
 

dtype_code

   OpenVMS usage:word_unsigned
   type:         word (unsigned)
   access:       write only
   mechanism:    by reference
   Returned key data type code. The dtype_code argument is the
   address of a word into which SORT/MERGE writes the key data type
   code that can be used in the key_buffer argument to SOR$BEGIN_
   SORT or SOR$BEGIN_MERGE.
 

usage

   OpenVMS usage:longword_unsigned
   type:         longword (unsigned)
   access:       read only
   mechanism:    by reference
   Address of a longword containing a code that indicates the
   interpretation of the p1 argument. The following table lists
   and describes the valid usage codes:

   Flag             Description

   SOR$K_ROUTINE    The p1 argument should be interpreted as the
                    address of the procedure value of a routine
                    that SORT/MERGE will call to compare keys
                    described by the dtype_code returned by the
                    call to SOR$DTYPE.
   SOR$K_NCS_TABLE  The p1 argument should be interpreted as the
                    address of a collating sequence identification
                    returned by a call to NCS$GET_CS. SORT/MERGE
                    will use this collating sequence to compare keys
                    described by the dtype_code returned by the call
                    to SOR$DTYPE.

   If SOR$K_ROUTINE is returned, SORT/MERGE will call this routine
   with five reference arguments-ADRS1, ADRS2, LENG1, LENG2, CNTX-
   corresponding to the addresses of the two keys to be compared,
   the lengths of the two keys, and the context longword.

   The comparison routine must return a 32-bit integer value:

   o  -1 if the first key collates before the second

   o  0 if the keys collate as equal

   o  +1 if the first key collates after the second
 

p1

   OpenVMS usage:longword_unsigned
   type:         longword (unsigned)
   access:       read only
   mechanism:    by reference
   Address of the procedure value of a routine or the address of
   a collating sequence identification, depending on the usage
   argument.