send() on non-blocking sockets

[AlannY]

Hi there. I'm developing a tool, which uses non-blocking sockets on Linux.

When I'm sending something to socket with send(), the return value is -1, which means error. But it's not an error. <errno> indicates that this is EWOULDBLOCK, which means that my request will be async ;-)

I want to get number of bytes really written to socket, but not -1 as I get now.

switch (errno)
  {
    case EWOULDBLOCK:
       while (1)
         {
            tv.tv_sec = timeout; /* my timeout */
            tv.tv_usec = 0; 
 
            /* here - wait for socket is ready to write*/
            FD_ZERO (&writefds); 
            FD_SET (priv->socket, &writefds); 
            rc = select (priv->socket+1, NULL, &writefds, NULL, &tv); 
 
             if (rc < 0)
                {
                  /* error on select() */
                  return 1;
                }
              else if (rc==0)
                  {
                     /* time out */
                     continue;
                  }
               else if (rc > 0)
                  {
                     /* data was sended */
                     /* HERE I want to get number of bytes really written */
                     break;
                  }
             }
 
          break;
 

[AlannY]

All right, I solved this problem.

Thanks to everyone ;-)