Ubuntu下实现回射服务器-处理客户端连接断开后服务器响应(四)
服务器端程序如下:
1 #include<stdio.h> 2 #include <sys/types.h> /* See NOTES */ 3 #include <sys/socket.h> 4 #include <netinet/ip.h> 5 #include <errno.h> 6 #include <stdlib.h> 7 #include <netinet/in.h> 8 #include <arpa/inet.h> 9 #include <unistd.h> 10 #include <string.h> 11 void do_service(int conn){ 12 13 char recvbuffer[1024]; 14 while(1){ 15 memset(recvbuffer,0,sizeof(recvbuffer)); 16 int readsize=read(conn,&recvbuffer,sizeof(recvbuffer)); 17 if (readsize==0){ 18 perror("client disconnect"); 19 break;//跳出循环 20 }else if (readsize==-1){ 21 perror("read"); 22 exit(EXIT_FAILURE); 23 } 24 fputs(recvbuffer,stdout); 25 write(conn,recvbuffer,strlen(recvbuffer)); 26 } 27 } 28 int main(){ 29 int socketfd; 30 socketfd=socket(PF_INET,SOCK_STREAM,0); 31 if(socketfd<0){ 32 perror("socket"); 33 exit(EXIT_FAILURE); 34 } 35 36 struct sockaddr_in sockaddress; 37 sockaddress.sin_family=AF_INET; 38 sockaddress.sin_port=htons(5188); 39 sockaddress.sin_addr.s_addr=htonl(INADDR_ANY);//INADDR_ANY接收任何地址的连接 40 //sockaddress.sin_addr.s_addr=inet_addr("127.0.0.1");//也可以是这种方式 41 42 int on=1; 43 if (setsockopt(socketfd,SOL_SOCKET,SO_REUSEADDR,&on,sizeof(on))<0){ 44 perror("setsockopt"); 45 exit(EXIT_FAILURE); 46 } 47 48 if(bind(socketfd,(struct sockaddr*)&sockaddress,sizeof(sockaddress))<0){ 49 perror("bind"); 50 exit(EXIT_FAILURE); 51 } 52 53 if ( listen(socketfd,SOMAXCONN)<0){ 54 perror("listen"); 55 exit(EXIT_FAILURE); 56 } 57 58 int conn; 59 struct sockaddr_in peeraddr; 60 socklen_t len=sizeof(struct sockaddr_in); 61 pid_t pid; 62 while(1){ 63 conn=accept(socketfd,(struct sockaddr*)&peeraddr,&len); 64 if (conn<0){ 65 perror("accept"); 66 exit(EXIT_FAILURE); 67 } 68 printf("client ip:%s port:%d\n",inet_ntoa(peeraddr.sin_addr),ntohs(peeraddr.sin_port)); 69 pid=fork(); 70 if (pid<0){//开启进程失败 71 perror("fork"); 72 exit(EXIT_FAILURE); 73 }else if(pid==0){//进入子进程处理过程 74 close(socketfd); 75 do_service(conn); 76 exit(EXIT_SUCCESS);//do_service被break后,子进程就没有存在的必要了,直接退出 77 }else{//主进程处理过程 78 close(conn);//主进程执行到这后就不需要连接套接字了,关闭它 79 } 80 } 81 return 0; 82 83 }
通过read返回0判断客户端连接断开还是不严谨,可以参考https://www.cnblogs.com/Dennis-mi/articles/6047032.html