$RBA Function

The $RBA function accesses ESDS VSAM files by the relative byte address. The function returns the current relative byte address in numeric form. You can use the $RBA function in the WHERE clause of a FOR statement to select records, as the source operand in SET statements, and in expressions.

This function has the following format:

$RBA[(dataview‑name)]

dataview‑name: The name of a VSAM dataview that defines an ESDS file. The dataview name is required for this function except when it is used as the left‑hand operand in a WHERE clause. You cannot specify the dataview name for this function in the left‑hand operand of the WHERE clause.

You cannot use the $RBA function as the target of a SET or MOVE statement.
The $RBA function is accessible only when the dataview fields are accessible. This means that you cannot use the function before the execution of a FOR statement. If you try to reference this function before the FOR statement is executed, a run‑time error occurs.
The starting relative byte address must be exactly equal to the $RBA of a valid record.
You cannot use this function in a FOR NEW construct since a record does not have a relative byte address until it is written.
The first record in an ESDS file has a relative byte address of 0.

Examples

In the following example, the $RBA function is accessed after the FOR NEW processing is completed to determine the relative byte address of the last record added.

FOR NEW PSS‑MASTER

    statements
ENDFOR
SET NEW‑ADDRESS = $RBA(PSS‑MASTER)

In the next example, a table of relative byte addresses determines the starting address.

FOR FIRST PSS‑MASTER

    WHERE $RBA = RBA‑TABLE(REC‑NO)
       statements
ENDFOR