NN_SEND(3) nanomsg manual NN_SEND(3)NAMEnn_send - send a message
SYNOPSIS
#include <nanomsg/nn.h>
int nn_send (int s, const void *buf, size_t len, int flags);
DESCRIPTION
The function will send a message containing the data from buffer
pointed to by buf parameter to the socket s. The message will be len
bytes long.
Alternatively, to send a buffer allocated by nn_allocmsg(3) function
set the buf parameter to point to the pointer to the buffer and len
parameter to NN_MSG constant. In this case a successful call to nn_send
will deallocate the buffer. Trying to deallocate it afterwards will
result in undefined behaviour.
Which of the peers the message will be sent to is determined by the
particular socket type.
The flags argument is a combination of the flags defined below:
NN_DONTWAIT
Specifies that the operation should be performed in non-blocking
mode. If the message cannot be sent straight away, the function
will fail with errno set to EAGAIN.
RETURN VALUE
If the function succeeds, the number of bytes in the message is
returned. Otherwise, -1 is returned and errno is set to to one of the
values defined below.
ERRORS
EFAULT
buf is NULL or len is NN_MSG and the message pointer (pointed to by
buf) is NULL.
EBADF
The provided socket is invalid.
ENOTSUP
The operation is not supported by this socket type.
EFSM
The operation cannot be performed on this socket at the moment
because the socket is not in the appropriate state. This error may
occur with socket types that switch between several states.
EAGAIN
Non-blocking mode was requested and the message cannot be sent at
the moment.
EINTR
The operation was interrupted by delivery of a signal before the
message was sent.
ETIMEDOUT
Individual socket types may define their own specific timeouts. If
such timeout is hit, this error will be returned.
ETERM
The library is terminating.
EXAMPLE
Using data directly:
nbytes = nn_send (s, "ABC", 3, 0);
assert (nbytes == 3);
Using a pre-allocated message buffer:
void *msg = nn_allocmsg(3, 0);
strncpy(msg, "ABC", 3);
nbytes = nn_send (s, &msg, NN_MSG, 0);
assert (nbytes == 3);
SEE ALSOnn_recv(3)nn_sendmsg(3)nn_socket(3)nanomsg(7)AUTHORS
Martin Sustrik <sustrik@250bpm.com[1]>
NOTES
1. sustrik@250bpm.com
mailto:sustrik@250bpm.com
nanomsg Unknown 12/23/2015 NN_SEND(3)
