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diff --git a/doc/zmq_recv.txt b/doc/zmq_recv.txt new file mode 100644 index 0000000..923badd --- /dev/null +++ b/doc/zmq_recv.txt @@ -0,0 +1,93 @@ +zmq_recv(3) +=========== + + +NAME +---- +zmq_recv - receive a message part from a socket + + +SYNOPSIS +-------- +*int zmq_recv (void '*socket', void '*buf', size_t 'len', int 'flags');* + + +DESCRIPTION +----------- +The _zmq_recv()_ function shall receive a message from the socket referenced +by the 'socket' argument and store it in the buffer referenced by the 'buf' +argument. Any bytes exceeding the length specified by the 'len' argument shall +be truncated. If there are no messages available on the specified 'socket' +the _zmq_recv()_ function shall block until the request can be satisfied. +The 'flags' argument is a combination of the flags defined below: + +*ZMQ_DONTWAIT*:: +Specifies that the operation should be performed in non-blocking mode. If there +are no messages available on the specified 'socket', the _zmq_recv()_ +function shall fail with 'errno' set to EAGAIN. + + +Multi-part messages +~~~~~~~~~~~~~~~~~~~ +A 0MQ message is composed of 1 or more message parts. 0MQ ensures atomic +delivery of messages: peers shall receive either all _message parts_ of a +message or none at all. The total number of message parts is unlimited except +by available memory. + +An application that processes multi-part messages must use the _ZMQ_RCVMORE_ +linkzmq:zmq_getsockopt[3] option after calling _zmq_recv()_ to determine if +there are further parts to receive. + +RETURN VALUE +------------ +The _zmq_recv()_ function shall return number of bytes in the message +if successful. Note that the value can exceed the value of the 'len' parameter +in case the message was truncated. If not successful the function shall return +`-1` and set 'errno' to one of the values defined below. + + +ERRORS +------ +*EAGAIN*:: +Non-blocking mode was requested and no messages are available at the moment. +*ENOTSUP*:: +The _zmq_recv()_ operation is not supported by this socket type. +*EFSM*:: +The _zmq_recv()_ 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. +*ETERM*:: +The 0MQ 'context' associated with the specified 'socket' was terminated. +*ENOTSOCK*:: +The provided 'socket' was invalid. +*EINTR*:: +The operation was interrupted by delivery of a signal before a message was +available. + + +EXAMPLE +------- +.Receiving a message from a socket +---- +char buf [256]; +nbytes = zmq_recv (socket, buf, 256, 0); +assert (nbytes != -1); +---- + + +SEE ALSO +-------- +linkzmq:zmq_recvmsg[3] +linkzmq:zmq_send[3] +linkzmq:zmq_sendmsg[3] +linkzmq:zmq_getsockopt[3] +linkzmq:zmq_socket[7] +linkzmq:zmq[7] + + +AUTHORS +------- +This 0MQ manual page was written by Martin Sustrik <sustrik@250bpm.com> and +Martin Lucina <mato@kotelna.sk>, and Pieter Hintjens <ph@imatix.com>. + |