Sockets - How to find out what port and address I'm assigned
If it's a server socket, you should call listen() on your socket, and then getsockname() to find the port number on which it is listening:
struct sockaddr_in sin;socklen_t len = sizeof(sin);if (getsockname(sock, (struct sockaddr *)&sin, &len) == -1) perror("getsockname");else printf("port number %d\n", ntohs(sin.sin_port));As for the IP address, if you use INADDR_ANY then the server socket can accept connections to any of the machine's IP addresses and the server socket itself does not have a specific IP address. For example if your machine has two IP addresses then you might get two incoming connections on this server socket, each with a different local IP address. You can use getsockname() on the socket for a specific connection (which you get from accept()) in order to find out which local IP address is being used on that connection.