Windows Socket Basics

Originally wanted to write a chat system, temporary level is limited, do not waste time, then fill it up again

Server code:

#include <Winsock2.h> #include <stdio.h> #include <iostream> #pragma comment (lib, "Ws2_32.lib") using namespace Std;void Main () {//windows unique uses Wsastarup () to initialize the socket font. Equivalent to allocating network resources wsadata Wsadata;int err = WSAStartup (0x0101, &wsadata); if (err! = 0) {return;} Windows-specific settings for the version of the network library if (Lobyte (wsadata.wversion)! = 1 | | Hibyte (wsadata.wversion)! = 1) {//windows unique corresponding network resource release wsacleanup (); return;}  Create socket af_inet represents IPV4 sock_stream socket type 0 Specify protocol type 0 default IPPROTO_TCP TCP protocol Socket SOCKSERV = socket (af_inet, Sock_stream, 0) if (invalid_socket = = Sockserv) {wsacleanup ();/////////This time just set the SOCKET parameter and it is not created so closesocket (sock_id) is not required; return;} Above with Linux SOCKET_FD = socket (af_inet, sock_stream, 0)) = = -1sockaddr_in ADDRSERV;//IP address set to Inaddr_any, let system automatically get native address Addrs Erv.sin_addr. S_un. S_ADDR = htonl (Inaddr_any); HTONL convert IP address format function Addrserv.sin_port = htons (6000);//Set port number 6000addrserv.sin_family = Af_inet; ipv4//assign a specific address in the address group to the socket err = bind (Sockserv, (sockaddr*) &addrserv, sizeof (SOCKADDR)); if (0! = Err) {WSacleanup ();//This time there is no real creation of the socket is also set the necessary parameters return;} At this time really created a socket to listen to the socket set maximum number of connections listen (Sockserv, somaxconn);//Loop Listener client Request This will store information for each client such as IP port sockaddr_in Addrclient;int len = sizeof (SOCKADDR); while (1) {//Accept client request client information placed in Addrclient if you do not care that a parameter can be set to null//block until there is a client connection,  Otherwise, it wastes CPU resources more. SOCKET Sockconn = Accept (Sockserv, (sockaddr*) &addrclient, &len); char sendbuf[255];cin >> sendbuf;//send Send data to the client send (Sockconn, SendBuf, strlen (sendbuf) + 1, 0); Char recvbuf[255];//accept data from the client to accept data written to recvbuf int nrecv = recv (s Ockconn, Recvbuf, 255, 0); if (Nrecv > 0) {recvbuf[nrecv] = ' ';p rintf ("%s\n", Recvbuf);} if (strcmp (Recvbuf, "") = = 0) closesocket (sockconn);} Closesocket (Sockserv);}

Client code:

#include <Winsock2.h> #include <stdio.h> #include <iostream> #pragma comment (lib, "Ws2_32.lib") using namespace Std;void Main () {wsadata wsadata; WORD wversionrequested = Makeword (1, 1); Set the request socket 1.1 version int err = WSAStartup (wversionrequested, &wsadata); if (err! = 0) return;//Check whether the 1.1 version is not returned if (Lobyte ( wsadata.wversion)! = 1 | | Hibyte (wsadata.wversion)! = 1) {wsacleanup (); return;} Create socket IPV4 Socket Type Sock_stream 0 represents the default TCP protocol Socket SOCKCONN = socket (af_inet, sock_stream, 0); Sockaddr_in addrserv;addrserv.sin_addr. S_un. S_ADDR = inet_addr ("127.0.0.1");//Set the address of the connection addrserv.sin_family = Af_inet; Ipv4addrserv.sin_port = htons (6000); Set the port number of the connection while (1) {//Connection Settings server Connect (sockconn, (SOCKADDR *) &addrserv, sizeof (SOCKADDR)); char recvbuf[255] = "+" ;//Accept server-sent data recv (Sockconn, recvbuf, 255, 0); if (strcmp (Recvbuf, "")! = 0) cout << recvbuf << Endl;char sendbu F[255];cin >> sendbuf;//sending data to the server send (Sockconn, SendBuf, strlen (SENDBUF), 0); Sendbuf[strlen (sendbuf)] = ' \0 '; if (strcmp (SendBuf, "n") = = 0) break; Close socket closesocket (sockconn);//Release Assigned network resource WSACleanup ();}

Windows Socket Basics