VDataLength

Get length of variable-length data record.

Short Name

GTVLEN()

Type

Low-level variable-length data file function

Declaration

VRLEN VDataLength(COUNT datno, LONG recbyt)

Description

VDataLength() returns the total length of the variable-length data record beginning at byte offset recbyt in file datno.

Return

If no error occurs, VDataLength() returns the total record length for the specified offset. When VDataLength() returns a zero, check uerr_cod. If uerr_cod is zero, the record length is zero. Otherwise, an error occurred as follows:

Value	Symbolic Constant	Explanation
0	NO_ERROR	Successful operation.
29	ZREC_ERR	Data file routine called with recbyt = 0.
48	FMOD_ERR	A function has been called for the wrong type of file: e.g., a variable-length function is called for a fixed-length data file.
149	VRLN_ERR	Variable-length passed to AddVRecord() is less than minimum record length established at file creation.
154	VRCL_ERR	Attempt to read (R) a zero length record from a variable-length data file.
158	VFLG_ERR	ReReadVRecord() record not marked active.

See c-tree Plus Error Codes for a complete listing of valid c-tree Plus error values.

Example

LONG      pntr;

VRLEN     vreclen;

COUNT     datno,keyno;

TEXT      key_buffer[64];


if ((pntr = FirstKey(keyno,key_buffer)) != 0L) {

    vreclen = VDataLength(datno,pntr);

    if (uerr_cod == 0) {

        if (vreclen)

            printf(

            "\nFirst variable record by key requires %d bytes",

            vreclen);

        else

            printf("\nRecord length is zero.");

    else

        printf("\nError %d getting length.", uerr_cod);