C socket: recv and send all data

Question

I would like to obtain a behavior similar to this:

1. Server run
2. Client run
3. Client type a command like \"help\" or other
4. Server respond

Answer 1

The recv() and send() functions do not guarantee to send/recv all data (see man recv, man send)

You need to implement your own send_all() and recv_all(), something like

bool send_all(int socket, void *buffer, size_t length)
{
    char *ptr = (char*) buffer;
    while (length > 0)
    {
        int i = send(socket, ptr, length);
        if (i < 1) return false;
        ptr += i;
        length -= i;
    }
    return true;
}

The following guide may help you Beej's Guide to Network Programming