libzmq/doc/zmq_send.txt
2010-02-10 16:18:46 +01:00

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zmq_send(3)
===========
NAME
----
zmq_send - sends a message
SYNOPSIS
--------
'int zmq_send (void *s, zmq_msg_t *msg, int flags);'
DESCRIPTION
-----------
Send the message 'msg' to the socket 's'. 'flags' argument can be combination
the flags described below.
*ZMQ_NOBLOCK*::
The flag specifies that the operation should be performed in non-blocking mode.
I.e. if it cannot be processed immediately, error should be returned with
'errno' set to EAGAIN.
*ZMQ_NOFLUSH*::
The flag specifies that 'zmq_send' should not flush the message downstream
immediately. Instead, it should batch ZMQ_NOFLUSH messages and send them
downstream only once 'zmq_flush' is invoked. This is an optimisation for cases
where several messages are sent in a single business transaction. However, the
effect is measurable only in extremely high-perf scenarios (million messages a
second or so). If that's not your case, use standard flushing send instead.
RETURN VALUE
------------
In case of success the function returns zero. Otherwise it returns -1 and
sets 'errno' to the appropriate value.
ERRORS
------
*EAGAIN*::
it's a non-blocking send and message cannot be sent at the moment.
*ENOTSUP*::
function isn't supported by particular socket type.
*EFSM*::
function cannot be called at the moment, because socket is not in the
appropriate state. This error may occur with sockets that switch between
several states (e.g. ZMQ_REQ).
EXAMPLE
-------
----
zmq_msg_t msg;
int rc = zmq_msg_init_size (&msg, 6);
assert (rc == 0);
memset (zmq_msg_data (&msg), 'A', 6);
rc = zmq_send (s, &msg, 0);
assert (rc == 0);
----
SEE ALSO
--------
linkzmq:zmq_flush[3]
linkzmq:zmq_recv[3]
linkzmq:zmq_msg_init[3]
linkzmq:zmq_msg_init_size[3]
linkzmq:zmq_msg_init_data[3]
linkzmq:zmq_msg_data[3]
linkzmq:zmq_msg_size[3]
AUTHOR
------
Martin Sustrik <sustrik at 250bpm dot com>