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5.7 Deleting Vgroups and Data Objects within a Vgroup

The Vgroup interface includes two routines for deletion: one deletes a vgroup from a file and the other deletes a data object from a vgroup. These routines are discussed in the following subsections.

5.7.1 Deleting a Vgroup from a File: Vdelete

Vdelete removes the vgroup identified by the parameter vgroup_id from the file identified by the parameter file_id. The syntax of Vdelete is as follows:

C:		status = Vdelete(file_id, vgroup_id);
FORTRAN:	status = vdelete(file_id, vgroup_id)
This routine will remove the vgroup from the internal data structures and from the file.

Vdelete returns either SUCCEED (or 0) or FAIL (or -1). The parameters of Vdelete are further described in Table 5K on page 203.

5.7.2 Deleting a Data Object from a Vgroup: Vdeletetagref

Vdeletetagref deletes the data object, specified by the parameters obj_tag and obj_ref, from the vgroup, identified by the parameter vgroup_id. The syntax of Vdeletetagref is as follows:

C:		status = Vdeletetagref(vgroup_id, obj_tag, obj_ref);
FORTRAN:	status = vfdtr(vgroup_id, obj_tag, obj_ref)
Vinqtagref should be used to determine whether the tag/reference number pair exists before calling Vdeletetagref. If duplicate tag/reference number pairs are found in the vgroup, Vdeletetagref deletes the first occurrence. Vinqtagref should also be used to determine whether duplicate tag/reference number pairs exist in the vgroup.

Vdeletetagref returns either SUCCEED (or 0) or FAIL (or -1). The parameters of this routine are further described in Table 5K.

TABLE 5K - Vdelete and Vdeletetagref Parameter Lists

Routine Name

[Return Type]

(FORTRAN-77)
Parameter
Parameter Type
Description
C
FORTRAN-77
Vdelete

[int32]

(vdelete)
file_id
int32
integer
File identifier

vgroup_id
int32
integer
Vgroup identifier

Vdeletetagref

[int32]

(vfdtr)
vgroup_id
int32
integer
Vgroup identifier

obj_tag
int32
integer
Tag of the data object to be deleted

obj_ref
int32
integer
Reference number of the data object to be deleted



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HDF User's Guide - 05/19/99, NCSA HDF Development Group.