GetSockName () and Getpeername ()

For server side:

Bind with the port as a wildcard: for the server, bind (0,IP), after calling the bind function, you can call GetSockName to get the local port number of the server

With the IP address as the wildcard address bind, only after accept returns, call GetSockName (CONNFD, ...). ) will return the local IP address that the server received

For client side:

Since bind is not bound, when the Connect () function succeeds (three handshake is completed), you can call GetSockName to get the local port number and IP address

Getpeername ():

After the server calls accept (), call exec again to get the socket address structure on the client side, only by invoking theGetpeername (CONNFD, (struct sockaddr *) &peeraddr, &peerlen);

GetSockName () and getpeername ()