# HDF Reference Manual

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> [VSQ Interface][Top]

> VSQuerycount/vsqfnelt

> intn VSQuerycount(int32 vdata_id, int32 *n_records)

> | vdata_id | IN: | Vdata access identifier returned by VSattach
> | n_records | OUT: | Number of records in the vdata

> | Purpose | Retrieves the number of records in a vdata.
> | Return value | Returns `SUCCEED` (or 0) if successful and FAIL (or -1) otherwise.
> | Description | VSQuerycount retrieves the number of records in the vdata identified by vdata_id in the parameter n_records.

> | FORTRAN | integer function vsqfnelt(vdata_id, n_records)
> |  | integer vdata_id, n_records

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> [VSQ Interface][Top]

> VSQueryfields/vsqfflds

> intn VSQueryfields(int32 vdata_id, char *field_name_list)

> | vdata_id | IN: | Vdata access identifier returned by VSattach
> | field_name_list | OUT: | List of field names

> | Purpose | Retrieves the names of the fields in a vdata.
> | Return value | Returns `SUCCEED` (or 0) if successful and FAIL (or -1) otherwise.
> | Description | VSQueryfields retrieves the names of the fields in the vdata identified by the parameter vdata_id into the parameter field_name_list.
> |  | The parameter field_name_list is a comma-separated list of the fields in the vdata. (i.e., "PX,PY,PZ" in C and 'PX,PY,PZ' in Fortran).

> | FORTRAN | integer function vsqfflds(vdata_id, field_name_list)
> |  | integer vdata_id
> |  | character*(*) field_name_list

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> [VSQ Interface][Top]

> VSQueryinterlace/vsqfintr

> intn VSQueryinterlace(int32 vdata_id, int32 *interlace_mode)

> | vdata_id | IN: | Vdata identifier returned by VSattach
> | interlace_mode | OUT: | Interlace mode

> | Purpose | Retrieves the interlace mode of the vdata.
> | Return value | Returns `SUCCEED` (or 0) if successful and FAIL (or -1) otherwise.
> | Description | VSQueryinterlace retrieves the interlace mode of the vdata identified by the parameter vdata_id into the parameter interlace_mode.
> |  | Valid values for interlace_mode are FULL_INTERLACE (or 0) and NO_INTERLACE (or 1).

> | FORTRAN | integer function vsqfintr(vdata_id, interlace_mode)
> |  | integer vdata_id, interlace_mode

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> [VSQ Interface][Top]

> VSQueryname/vsqfname

> intn VSQueryname(int32 vdata_id, char *vdata_name)

> | vdata_id | IN: | Vdata identifier returned by VSattach
> | vdata_name | OUT: | Name of the vdata

> | Purpose | Retrieves the name of a vdata.
> | Return value | Returns `SUCCEED` (or 0) if successful and FAIL (or -1) otherwise.
> | Description | VSQueryname retrieves the name of the vdata identified by the parameter vdata_id into the buffer vdata_name. The buffer vdata_name should be set to at least `VSNAMELENMAX` bytes. `VSNAMELENMAX` is defined by the HDF library.

> | FORTRAN | integer function vsqfname(vdata_id, vdata_name)
> |  | integer vdata_id
> |  | character*(*) vdata_name

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> [VSQ Interface][Top]

> VSQueryref/vsqref

> int32 VSQueryref(int32 vdata_id)

> | vdata_id | IN: | Vdata identifier returned by VSattach

> | Purpose | Returns the reference number of a vdata.
> | Return value | Returns the reference number of the vdata if successful and FAIL (or -1) otherwise.
> | Description | VSQueryref returns the reference number of the vdata identified by the parameter vdata_id.

> | FORTRAN | integer function vsqref(vdata_id)
> |  | integer vdata_id

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> [VSQ Interface][Top]

> VSQuerytag/vsqtag

> int32 VSQuerytag(int32 vdata_id)

> | vdata_id | IN: | Vdata identifier returned by VSattach

> | Purpose | Returns the tag of the specified vdata.
> | Return value | Returns the tag of the vdata if successful and FAIL (or -1) otherwise.
> | Description | Returns the tag of the vdata identified by the parameter vdata_id.

> | FORTRAN | integer function vsqtag(vdata_id)
> |  | integer vdata_id

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> [VSQ Interface][Top]

> VSQueryvsize/vsqfvsiz

> intn VSQueryvsize(int32 vdata_id, int32 *vdata_size)

> | vdata_id | IN: | Vdata identifier returned by VSattach
> | vdata_size | OUT: | Size of the vdata record

> | Purpose | Retrieves the size of a record in a vdata.
> | Return value | Returns `SUCCEED` (or 0) if successful and FAIL (or -1) otherwise.
> | Description | VSQueryvsize retrieves the size, in bytes, of a record in the vdata identified by the parameter vdata_id into the parameter vdata_size. The returned size value is machine dependent.

> | FORTRAN | integer function vsqfvsiz(vdata_id, vdata_size)
> |  | integer vdata_id, vdata_size

HDF4.2r4 - February 2009 Copyright | The HDF Group www.hdfgroup.org