| nn_recv(3) |
| ========== |
| |
| NAME |
| ---- |
| nn_recv - receive a message |
| |
| |
| SYNOPSIS |
| -------- |
| *#include <nanomsg/nn.h>* |
| |
| *int nn_recv (int 's', void '*buf', size_t 'len', int 'flags');* |
| |
| |
| DESCRIPTION |
| ----------- |
| Receive a message from the socket 's' and store it in the buffer referenced by |
| the 'buf' argument. Any bytes exceeding the length specified by the 'len' |
| argument will be truncated. |
| |
| Alternatively, _nanomsg_ library can allocate the buffer for you. To do so, |
| let the 'buf' parameter point to void* variable to receive the buffer and set |
| 'len' parameter to _NN_MSG_. After successful completion user is responsible |
| for deallocating the message using linknanomsg:nn_freemsg[3] function. |
| |
| 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 received straight away, the function will fail with 'errno' |
| set to EAGAIN. |
| |
| |
| RETURN VALUE |
| ------------ |
| If the function succeeds number of bytes in the message is returned. Otherwise, |
| negative number is returned and 'errno' is set to to one of the values defined |
| below. |
| |
| |
| ERRORS |
| ------ |
| *EFAULT*:: |
| The library is not initialised. |
| *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 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 there's no message to receive at the moment. |
| *EINTR*:: |
| The operation was interrupted by delivery of a signal before the message was |
| received. |
| *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 |
| ------- |
| |
| ---- |
| char buf [100]; |
| nbytes = nn_recv (s, buf, sizeof (buf), 0); |
| ---- |
| |
| |
| SEE ALSO |
| -------- |
| linknanomsg:nn_send[3] |
| linknanomsg:nn_recvmsg[3] |
| linknanomsg:nn_socket[3] |
| linknanomsg:nanomsg[7] |
| |
| AUTHORS |
| ------- |
| Martin Sustrik <sustrik@250bpm.com> |
| |
