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Replacing resources

A resource block may be easily modified if the modification does not change it's length - one can simply get the pointer to a resource and overwrite the contents.

If the length of the resource has to be changed, then ids_get_res should be called to get the pointer to the resource and this is followed by a call to ids_rpl_res.

pnt = ids_rpl_res(pnt,nwords,data,ierr)

pnt

pointer to existing resource

nwords

Integer - new resource length in words. If this number is negative then the memory is allocated for ABS(nwords) but nothing is copied

data

Data to be copied (if nwords>0)

ierr

Returned error flag - should be 0

ids_rpl_res returns the new pointer to a resource. If nwords>0 then nwords words are copied from data, if nwords<0 then nothing is copied but the memory is allocated and the pointer is returned.

Access to resources - an example

subroutine ds_setcl(name,ivdsn,class,itype,ierr)
* 
*   ********************************************************************
*   *                                                                  *
*$$ *   subroutine ds_setcl  Set object class and type.                *
*   *   Object must be defined already.                                *
*   *   Input:                                                         *
*   *         name - character - object name                           *
*   *         ivdsn - integer - object handle                          *
*   *         class - character - class ident (may be with parentage)  *
*   *         itype - integer - object type (lt 32000)                 *
*   *         ierr - integer - error code:                             *
*   *            0 - OK                                                *
*   *   Output:                                                        *
*   *         ivdsn - integer - correct handle                         *
*   *                                                                  *
*   *   Ryszard Zybert    Apr 13 15:13:57 1994                         *
*   ********************************************************************
* 
      character*(*) name
      character*(*) class
      character*16 cls(10)

      structure /cl_typ/
        union
          map
            integer*2 class
            integer*2 type
          end map
          map
            integer cl_type
          end map
        end union
      end structure
      record /cl_typ/ ct
      structure /cl_res/
        integer class
        character*16 name
      end structure
      record /cl_res/ cl
      pointer ( cl_p,cl )

....
....
....
                                                        ! Now deal with ancestry

      call dsfldc(class,cls,n,'.')                      ! parse class into cls array
      if( n.gt.0 ) then
        isk = 0
        cl_p = ids_get_res(name,ivdsn,'PRTG',isk,nw,ierr)   ! is there parentage resource?
        if( cl_p.eq.0 ) then
          cl_p = ids_add_res(name,ivdsn,'PRTG',-n*5,0,ierr) ! if not - make one
        else
          cl_p = ids_rpl_res(cl_p,-n*5,0,ierr)              ! if yes - replace it
        endif
        if( cl_p.eq.0 ) go to 990
        do i=n,1,-1                                         ! write ancestry into resource
          cl.class = ids_nclass(cls(i))                     ! convert class to a number
          cl.name  = cls(i)                                 ! store the class name
          cl_p = cl_p + 20
        enddo
      endif

990   continue
      call ds_error('DS_SETCL',name,ierr,idum)

999   end