(SYSLIB) Programming Reference Manual - Public Support Login ...

CASE * :
BEGIN
PROCESS_READ_ERROR;
RETURN;
END;
ENDCASE;
END;
.
.
.
SAR_CLOSE_INPUT(LOC(READ_PKT));
IF READ_PKT.CALL_STATUS NE S ‘Normal’
THEN BEGIN
PROCESS_READ_ERROR;
RETURN;
END;
SAR$ READ
In this example, the COPY statement obtains the SAR$ definitions for the buffers and
tables, READ packet, READ procedures, and file information packet. The SAR$ data
structures are declared by using the definitions contained in elements SAR$DEFN,
SAR$RPKTD, and SAR$FILEPKTD.
The READ packet is initialized by assigning appropriate values to all necessary fields.
All other packet fields take the default values if the READ packet is zero-filled.
The SAR_READ_PACKET_CURRENT_VERSION constant is defined in the SAR$RPKTD
element. The buffer length constants are defined in the SAR$DEFN element.
The READ function is initialized by the calling SAR_OPEN_INPUT procedure, passing the
READ packet address as a parameter. If the CALL STATUS field of the READ packet
(returned by SAR$) is not status ‘Normal', the error is processed.
The SAR_READ procedure reads one SDF image at a time until an end-of-file condition or
an error occurs. When all images are read, the READ function is closed by calling the
SAR_CLOSE_INPUT procedure.
17.1.4. Status Lists for PLUS READ Procedures
The READ procedure call status codes listed in Table 17–3 may be returned to the caller
in the CALL_STATUS field of the READ packet. These CALL_STATUS codes are for
SAR_READ_PACKET_CURRENT_VERSION = 3 and above. A list of all call status codes
is available as READ_CALL_STATUS_LIST, an 18-bit status data entity defined in the
element SAR$RPKTD.
Table 17–3. SAR$: READ Procedure CALL_STATUS Codes
Octal Code Status
0 Normal return from SAR$.
01 End-of-file condition reached by SAR_READ.
7833 1733–004 17–17