NetIPC 3000/XL Programmer's Reference Manual (5958-8600)

100 Chapter3
NetIPC Intrinsics
IPCRECV
completes. This flag has no effect if waited I/O is
used.
• flags [25] — discarded (output). (X.25 only.) This
flag indicates that the call user data, or the facility
field were present, but that some or all had to be
discarded. This can occur if no call user data receive
option was specified or if either field is too short to
hold all of the data.
•flags [26] — more data (output). This flag indicates
that there may be more data to be received after
completion of this IPCRECV.
For TCP, this bit will always be set when normal,
non-urgent data has been received because TCP
sends data in stream mode, with no end-of-data
indication. However, if urgent data has been
received, and no more is pending, this bit will be set
to 0.
For X.25, the “more data” flag indicates that the data
returned is not the complete message. This will only
occur if the user request was for a smaller message
than was sent. The amount of data specified in
dlen
has been moved into data. The following part of the
message will be returned in the next call to IPCRECV,
unless the
destroy data flag (29) was set.
• flags [29] — destroy data (input). If set, this flag
causes delivered data that exceeds the amount
allowed by the specified
dlen or byte count (for
vectored data) to be discarded. Use this flag to
remove data that may have arrived at your node
(and queued in the NetIPC buffer) that you do not
want the process to receive.
Note that in TCP stream mode, there is no
mechanism to verify that data left over has been
discarded.
• flags [30] — preview (input). This flag allows the
calling process to preview the data - that is, to read
the data without removing them from the queue of
data to the receiving socket.
• flags [31] — vectored (input). This flag indicates
that the received data are to be distributed to the
addresses (vectors) given in the data parameter.