Tread Routine; Twrt Routine - IBM 5280 Programmer's Manual

TREAD Routine
TWRT Routine
The format of the statement to call the TCLOZ routine is:
CALL "AVCLCLOZ" USING return-code
return-code is a data-item you code as follows:
01 return-code PIC 9999.
return-code - contains a code posted by the TCLOZ routine upon
completion. The return-codes and their meanings are explained in the IBM
5280 Communications Reference Manual, SC34-0247.
The TREAD routine is called to instruct CAM to read a record from the host
into buffer-2 defined when TIN IT is called. TREAD must be repeatedly
called until an end-of-data or other appropriate return-code is returned.
The format of the statement to call the TREAD routine is:
CALL "AVCLREAD If USING parameter-l
parameter-l is a data-item you code as follows:
01 parameter-1
02 return-code PIC 9999.
02 record-length PIC 9999.
02 read-type PIC X.
02 read-status PIC X.
The contents of the parameter-l record is as follows:
return-code - contains a code posted by the TREAD routine upon
completion. The return-codes and their meanings are explained in the IBM
5280 Communications Reference Manual, SC34-0247.
record-length - the length of the data read as posted by CAM.
read-type - for BSC only. Minus sign (-) indicates to read the entire block.
Otherwise, a record will be read.
read-status - for BSC only. Specifies whether the read is conditional or not.
Minus sign (-) indicates to return control immediately with status if data is
not available for the read. Otherwise, the read will wait until data becomes
available.
This routine is called to write a record from buffer-2.
The format of the statement to call the TWRT routine is:
CALL IfAVCLWRT If USING parameter-i
pararneter-l is a data-item you code as follows:
01 parameter-1
02 return-code
02 record-length
02 write-final
PIC 9999.
PIC 9999.
PIC X.
The contents of the parameter-l record is as follows:
return-code - contains a code posted by the TWRT routine upon completion.
The return-codes and their meanings are explained in the IBM 5280
Communications Reference Manual, SC34-0247.
record-length -- Specify the length of record to be written.
A- 4 IBM 5280 COBOL Programmer's Guide