Exchange/RJE Manual
WRITEREAD Procedure
Exchange/RJE System Procedure Calls
104698 Tandem Computers Incorporated 5–41
The following are the maximum record sizes that the line server can receive:
2780/3780-emulation mode: 1 through 146 bytes
Block mode with 2780 blocking: 1 through BLOCKSIZE
Block mode with 3780 blocking: 1 through BLOCKSIZE - 1
Block mode without blocking: 1 through BLOCKSIZE
(BLOCKSIZE is specified in the RJESV command.)
If the record is larger than
read-count
bytes, the record is truncated to
read-
count
bytes.
If you have specified RAWDATA in the call to SETMODE function 43, which
specifies the parameters for a receive operation, the record you receive in
buffer
will include BSC control characters as well as the data.
For a write operation,
read-count
must be 0.
count-read
INT:ref:1
For a wait read operation,
count-read
returns the number of bytes in the record
received from the remote system (and now in
buffer
).
For a nowait read operation,
count-read
is not used and can be omitted. The
size of the record received from the remote system is returned in the count
transferred parameter of the call to AWAITIO that completes the read operation.
For a write operation,
count-read
is not used and can be omitted.
tag
INT(32):value
identifies individual nowait I/O operations when a single file can have two or
more nowait I/O operations outstanding at the same time. The value of
tag
is a
unique, arbitrary value that your program defines for each nowait I/O operation.
A subsequent call to AWAITIO that completes this I/O operation returns this
value to your program, identifying this I/O operation as the nowait I/O operation
that just completed.
If your program has no more than one outstanding nowait I/O operation against a
single file at one time, you can omit this parameter. In this case, the file number
returned by AWAITIO uniquely identifies the I/O operation that was completed.
If you opened the line server for wait I/O operations, omit this parameter.
Line Activity The line activity of the WRITEREAD procedure depends on whether it is used for
write operations or for read operations. Each case is discussed below.
Write Operations
For write operations, WRITEREAD works exactly the same as WRITE. See the WRITE
procedure earlier in this section for the line activity associated with a write operation.