libzmq/doc/zmq_send.txt

zmq_send(3)
===========


NAME
----
zmq_send - send a message on a socket


SYNOPSIS
--------
*int zmq_send (void '*socket', zmq_msg_t '*msg', int 'flags');*


DESCRIPTION
-----------
The _zmq_send()_ function shall queue the message referenced by the 'msg'
argument to be sent to the socket referenced by the 'socket' argument.  The
'flags' argument is a combination of the flags defined below:

*ZMQ_NOBLOCK*::
Specifies that the operation should be performed in non-blocking mode. If the
message cannot be queued on the underlying _message queue_ associated with
'socket', the _zmq_send()_ function shall fail with 'errno' set to EAGAIN.

*ZMQ_NOFLUSH*::
Specifies that the _zmq_send()_ function should not flush the underlying
_message queue_ associated with 'socket' to the network automatically.
Instead, it should batch all messages queued with the 'ZMQ_NOFLUSH' flag and
only flush the _message queue_ once either a message without the 'ZMQ_NOFLUSH'
flag is queued, or manually on invocation of the _zmq_flush()_ function.

NOTE: A successful invocation of _zmq_send()_ does not indicate that the
message has been transmitted to the network, only that it has been queued on
the _message queue_ associated with the socket and 0MQ has assumed
responsibility for the message.


RETURN VALUE
------------
The _zmq_send()_ function shall return zero if successful. Otherwise it shall
return -1 and set 'errno' to one of the values defined below.


ERRORS
------
*EAGAIN*::
Non-blocking mode was requested and the message cannot be queued at the moment.
*ENOTSUP*::
The _zmq_send()_ operation is not supported by this socket type.
*EFSM*::
The _zmq_send()_ operation cannot be performed on this socket at the moment due
to the socket not being in the appropriate state.  This error may occur with
socket types that switch between several states, such as ZMQ_REP.  See the
_messaging patterns_ section of linkzmq:zmq_socket[3] for more information.


EXAMPLE
-------
.Filling in a message and sending it to a socket
----
/* Create a new message, allocating 6 bytes for message content */
zmq_msg_t msg;
int rc = zmq_msg_init_size (&msg, 6);
assert (rc == 0);
/* Fill in message content with 'AAAAAA' */
memset (zmq_msg_data (&msg), 'A', 6);
/* Send the message to the socket */
rc = zmq_send (socket, &msg, 0);
assert (rc == 0);
----


SEE ALSO
--------
linkzmq:zmq_flush[3]
linkzmq:zmq_recv[3]
linkzmq:zmq_socket[7]
linkzmq:zmq[7]


AUTHORS
-------
The 0MQ documentation was written by Martin Sustrik <sustrik@250bpm.com> and
Martin Lucina <mato@kotelna.sk>.