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

I choose to send before each send() if i have to continue or not.

so i first have 3 define

#define BUFFSIZE 1024
#define CONT "CONT"
#define DONE "DONE"

Then to send my data

int     send_to_socket(int sock, char *msg)
{
    size_t  len;
    int     ret[2];

    len = strlen(msg);
    ret[0] = send(sock, (len <= BUFFSIZE) ? DONE : CONT, 4, 0);
    ret[1] = send(sock, msg, BUFFSIZE, 0);
    if (ret[0] <= 0 || ret[1] <= 0)
    {
        perror("send_to_socket");
        return (-1);
    }
    if (len > BUFFSIZE)
        return (send_to_socket(sock, msg + BUFFSIZE));
    return (1);
}

And to receive it :

char    *recv_from_socket(int cs)
{
    char    state[5];
    char    buff[BUFFSIZE+1];
    char    *msg;
    int     ret[2];

    msg = NULL;
    while (42)
    {
        bzero(state, 5);
        bzero(buff, BUFFSIZE+1);
        ret[0] = recv(cs, state, 4, 0);
        ret[1] = recv(cs, buff, BUFFSIZE, 0);
        if (ret[0] <= 0 || ret[1] <= 0)
        {
            perror("recv_from_socket");
            return (NULL);
        }
        // strfljoin() is selfmade
        // join the string and free the left argument to prevent memory leaks.
        // return fresh new string
        msg = (msg) ? ft_strfljoin(msg, buff) : strdup(buff);
        if (strncmp(state, DONE, 4) == 0)
            break ;
        i++;
    }
    return (msg);
}