Socket Programming Learning for C + +

Preface

Have to admit that as a front-end development, there is still a background development dream. Start learning from socket communications, add learning points to your work, and document the learning process.

　　PS: Can a friend of the park recommend some related books?

Service Side

The server code is as follows, after setting listen, the corresponding socket connection is obtained through accept and the thread is created to communicate, and the corresponding thread is closed after the communication is completed.

//socket_service.cpp: Defines the entry point of the console application. //#include"stdafx.h"#include<stdio.h>#include<Winsock2.h>#pragmaComment (lib, "Ws2_32.lib")#defineListen_max_count 5DWORD WINAPI answerthread (LPVOID lparam) {printf ("Thread id:%4d create!\n", GetCurrentThreadID ()); intret; Charbuf[ -] = {0 }; Charsendbuf[ the] = {0 }; SOCKET Clientsocket=(SOCKET) (LPVOID) lparam;  while(true) {memset (buf,0,sizeof(BUF)); RET= Recv (Clientsocket, buf,sizeof(BUF),0); if(ret<=0)        {             Break; } printf ("REVC:%s\n", BUF); sprintf_s (SendBuf,"Thread id:%4d revced", GetCurrentThreadID ()); RET= Send (Clientsocket, SendBuf, strlen (SENDBUF) +sizeof(Char),0); if(Ret <=0)        {             Break; }} printf ("Thread id:%4d stop!\n", GetCurrentThreadID ());    Closesocket (Clientsocket); return 1;}int_tmain (intARGC, _tchar*argv[])    {WORD wversionrequested;    Wsadata Wsadata; Wversionrequested= Makeword (1,1); if(WSAStartup (wversionrequested, &wsadata) = =invalid_socket) {        return 0; }    if(Lobyte (wsadata.wversion)! =1||hibyte (wsadata.wversion)!=1) {wsacleanup (); return 0; } SOCKET socksrv= Socket (Af_inet, Sock_stream,0); intLen =sizeof(SOCKADDR);    Sockaddr_in clientaddr;    Sockaddr_in serviceaddr; Serviceaddr.sin_addr. S_un. S_addr=htonl (Inaddr_any); Serviceaddr.sin_family=af_inet; Serviceaddr.sin_port= Htons (27015); if(Bind (Socksrv, (sockaddr*) &serviceaddr, len) = =invalid_socket) {printf ("failed bind!\n");        Closesocket (SOCKSRV);        WSACleanup (); return 0; }    if(Listen (socksrv, listen_max_count) = =socket_error) {printf ("Listen failed with error:%ld\n", WSAGetLastError ());        Closesocket (SOCKSRV);        WSACleanup (); return 0;    } SOCKET sockclient; HANDLE Hthread=NULL;    DWORD dwThreadID;  while(1) {sockclient= Accept (Socksrv, (sockaddr*) &clientaddr, &Len); Sleep ( +); Hthread= CreateThread (null, NULL, Answerthread, (LPVOID) sockclient,0, &dwThreadID); if(Hthread = =NULL) {printf ("creatthread answerthread () failed.\n");    }} closesocket (SOCKSRV);    WSACleanup (); return 0;}

Client

The client code is as follows, and after the connection succeeds, the loop enters for the communication conversation.

//socket_client.cpp: Defines the entry point of the console application. //#include"stdafx.h"#include<stdio.h>#include<Winsock2.h>#pragmaComment (lib, "Ws2_32.lib")int_tmain (intARGC, _tchar*argv[])    {WORD wversionrequested;    Wsadata Wsadata; interr; Wversionrequested= Makeword (1,1); if(WSAStartup (wversionrequested, &wsadata) = =invalid_socket) {        return-1; }    if(Lobyte (wsadata.wversion)! =1||hibyte (wsadata.wversion)!=1) {wsacleanup (); return-1; } SOCKET sockclient= Socket (Af_inet, Sock_stream,0); intLen =sizeof(SOCKADDR);    Sockaddr_in Local; Local.sin_addr. S_un. S_addr= Inet_addr ("192.168.1.15"); Local.sin_family=af_inet; Local.sin_port= Htons (27015); if(Connect (sockclient, (sockaddr*) &local, len) = =invalid_socket) {printf ("Connect error/n"); return 0; }    Charinputbuf[ -]; Charrecvbuf[ -]; intret;//While (scanf_s ("%s", Inputbuf, sizeof (INPUTBUF))! = EOF)     while(gets_s (inputbuf)) {if(strcmp (Inputbuf,"Stop") ==0)        {             Break; } ret= Send (Sockclient, Inputbuf, strlen (INPUTBUF) +sizeof(Char),0); if(ret<=0) {printf ("Send failed!\n");  Break; } ret= Recv (Sockclient, Recvbuf,sizeof(RECVBUF),0); if(Ret <=0) {printf ("recv failed!\n");  Break; } printf ("My reply is:%s\n", RECVBUF); //printf ("%s\n", Inet_ntoa (LOCAL.SIN_ADDR));} closesocket (sockclient);    WSACleanup (); return 0;}

Test

Hello world!!

1, open more than one client, you can see the server as follows to output the creation of multiple threads.

　　

2, the client input Hello world!, can get the server reply, and tell which server thread received the message.

　　

3, close one of the clients, you can see the corresponding thread is also closed.

4, close the server, you can enter any content, you can see the client also received a prompt to send failed and shut down.

Socket Programming Learning for C + +