1ZMQ_SEND(3) 0MQ Manual ZMQ_SEND(3)
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6 zmq_send - send a message on a socket
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9 int zmq_send (void *socket, zmq_msg_t *msg, int flags);
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12 The zmq_send() function shall queue the message referenced by the msg
13 argument to be sent to the socket referenced by the socket argument.
14 The flags argument is a combination of the flags defined below:
15 ZMQ_NOBLOCK
17 Specifies that the operation should be performed in non-blocking
18 mode. If the message cannot be queued on the socket, the zmq_send()
19 function shall fail with errno set to EAGAIN.
20 ZMQ_SNDMORE
22 Specifies that the message being sent is a multi-part message, and
23 that further message parts are to follow. Refer to the section
24 regarding multi-part messages below for a detailed description.
25 Note
27 A successful invocation of zmq_send() does not indicate that the
28 message has been transmitted to the network, only that it has been
29 queued on the socket and 0MQ has assumed responsibility for the
30 message.
31 Multi-part messages
33 A 0MQ message is composed of 1 or more message parts; each message part
34 is an independent zmq_msg_t in its own right. 0MQ ensures atomic
35 delivery of messages; peers shall receive either all message parts of a
36 message or none at all.
37 The total number of message parts is unlimited.
39 An application wishing to send a multi-part message does so by
41 specifying the ZMQ_SNDMORE flag to zmq_send(). The presence of this
42 flag indicates to 0MQ that the message being sent is a multi-part
43 message and that more message parts are to follow. When the application
44 wishes to send the final message part it does so by calling zmq_send()
45 without the ZMQ_SNDMORE flag; this indicates that no more message parts
46 are to follow.
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49 The zmq_send() function shall return zero if successful. Otherwise it
50 shall return -1 and set errno to one of the values defined below.
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53 EAGAIN
54 Non-blocking mode was requested and the message cannot be sent at
55 the moment.
56 ENOTSUP
58 The zmq_send() operation is not supported by this socket type.
59 EFSM
61 The zmq_send() operation cannot be performed on this socket at the
62 moment due to the socket not being in the appropriate state. This
63 error may occur with socket types that switch between several
64 states, such as ZMQ_REP. See the messaging patterns section of
65 zmq_socket(3) for more information.
66 ETERM
68 The 0MQ context associated with the specified socket was
69 terminated.
70 EFAULT
72 The provided socket was not valid (NULL).
73 EINTR
75 The operation was interrupted by delivery of a signal before the
76 message was sent.
77
79 Filling in a message and sending it to a socket.
80 /* Create a new message, allocating 6 bytes for message content */
82 zmq_msg_t msg;
83 int rc = zmq_msg_init_size (&msg, 6);
84 assert (rc == 0);
85 /* Fill in message content with 'AAAAAA' */
86 memset (zmq_msg_data (&msg), 'A', 6);
87 /* Send the message to the socket */
88 rc = zmq_send (socket, &msg, 0);
89 assert (rc == 0);
90 Sending a multi-part message.
92 /* Send a multi-part message consisting of three parts to socket */
94 rc = zmq_send (socket, &part1, ZMQ_SNDMORE);
95 rc = zmq_send (socket, &part2, ZMQ_SNDMORE);
96 /* Final part; no more parts to follow */
97 rc = zmq_send (socket, &part3, 0);
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101 zmq_recv(3) zmq_socket(7) zmq(7)
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104 This 0MQ manual page was written by Martin Sustrik
105 <sustrik@250bpm.com[1]> and Martin Lucina <mato@kotelna.sk[2]>.
106
108 1. sustrik@250bpm.com
109 mailto:sustrik@250bpm.com
110 2. mato@kotelna.sk
112 mailto:mato@kotelna.sk
1130MQ 2.1.4 03/30/2011 ZMQ_SEND(3)