binding a port number to a TCP socket (outgoin) to send packets

Question

I know that it is not easy to bind a port number to TCP socket that you would use to send data (because systems usually bi

Answer 1

Bind it before connecting.

s = socket(AF_INET, SOCK_STREAM, 0);
/* ... */

memset(&client_addr, 0, sizeof(client_addr));
client_addr.sin_family = AF_INET;
client_addr.sin_port = htons(22222);

if (bind(s, (struct sockaddr *) &client_addr, sizeof(client_addr)) < 0) {
    perror("bind");
    exit(1);
}

connect(s, (struct sockaddr *) &server_addr, sizeof(server_addr));

Answer 2

Actually it is quite easy. Simply use the bind function as you would for a server.

Answer 3

You can simply call bind() before connect() in a client in the same way that you would call bind() before listen() in a server. There is nothing more complicated to it than that.