send message using tcp

Rabbit
,
1

Hello, I would like send a message like this with my client (so my card rabbit) :


  char *hello = "Hello from client"; 
  char buffer[1024] = {0}; 

  //there are the arguments for socket too

 if (connect(sock, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) < 0) 
    { 
        printf("
Connection Failed 
"); 
        return -1; 
    } 
    send(sock , hello , strlen(hello) , 0 ); 
    printf("Hello message sent
"); 
    valread = read( sock , buffer, 1024); 
    printf("%s
",buffer ); 
    return 0; 
}

But I must to convert it with dynamic C, looking at the doc i didn’t see this function (execpted in udp but i need tcp)

I found this to start :


if(sock_tbleft(&my_socket,size)) {
   sock_write(&my_socket,buffer,size);

i tried to convert it little like it : (but it doesn’t really work ^^,)


if(sock_tbleft(&my_socket,size)) {
    sock_write(&my_socket,buffer,size);}

    sock_write(&my_sock , hello , strlen(hello) , 0 ); 
    printf("Hello message sent
"); 
    valread = read( sock , buffer, 1024); 
    printf("%s
",buffer ); 
    return 0;
}

So I suppose send = sock_write but some people advice to see ModBus_slave but i don’t really understand why.

I must create a communication between my server and my card in using TCP to receive a message if my led = 1 then my server write : “your led blinks” ofc to start I have created my socket and establish connection but I block for the transmission part of the message.

If you have example or idea tell me please.

2

Try using Samples/TCPIP/echo.c as a starting point for your program. It’s set up for the Rabbit to open a TCP socket and listen for connections, and demonstrates reading and writing the socket.

1 Like
3

Thank you TomCollins it works !