Socket通信中的多進(jìn)程編程課件

1、1. 需求描述 （1）Linux下編寫(xiě)。 （2）創(chuàng)建一個(gè)服務(wù)器、若干個(gè)客戶端。 （3）用戶可以通過(guò)客戶端輸入文字向服務(wù)器發(fā)送消息。 （4）服務(wù)器端接收到客戶端發(fā)送的數(shù)據(jù)，將用戶輸入的內(nèi)容在服務(wù)器上打印出來(lái)，并原樣返回。2. 相關(guān)基礎(chǔ)2.1 套接字Socket通信編程2.1.1 TCP/IP通信過(guò)程：  2.1.2 UDP通信過(guò)程：2.2 fork多進(jìn)程編程 fork，在英語(yǔ)中意思是分叉的意思。Linux函數(shù)fork(void)被定義在#include<sys/types.h>中，調(diào)用成功時(shí)，返回兩個(gè)值，子進(jìn)程返回0，父進(jìn)程返回子進(jìn)程的ID，出錯(cuò)返回-1。子進(jìn)程是

2、父進(jìn)程的副本，它將獲得父進(jìn)程的數(shù)據(jù)空間、堆、棧等資源的副本并且擁有自己獨(dú)立的地址空間。 以下是一個(gè)fork的簡(jiǎn)單例子。#include<sys/types.h>#include<unistd.h>#include<stdio.h> int main(int argc, char * argv ) int pid = fork(); if (-1 = pid) 8 printf("error!"); else if(0 = pid )printf("This is the child process!"); /子進(jìn)程el

3、seprintf("This is the parent process! child process id = %d", pid); return 0;20  3. 設(shè)計(jì)3.1 框架設(shè)計(jì)本文使用TCP進(jìn)行通信。3.2 代碼設(shè)計(jì) 套接口的通信一般使用read( )和write( )。這里使用send( )和recv( )，因?yàn)檫@一對(duì)函數(shù)可以更好地控制數(shù)據(jù)傳輸。4. 詳細(xì)代碼4.1 服務(wù)器端代碼 服務(wù)器端代碼#include <sys/types.h> #include <sys/socket.h> / 包含套接字函數(shù)庫(kù) #incl

4、ude <stdio.h> #include <netinet/in.h> / 包含AF_INET相關(guān)結(jié)構(gòu) #include <arpa/inet.h> / 包含AF_INET相關(guān)操作的函數(shù) #include <unistd.h> #include<string.h> #include<stdlib.h> #include<fcntl.h> #include<sys/shm.h> #define MYPORT 8887 #define MYKEY 12345 #define SIZE 10240 i

5、nt main() char buf100; memset(buf,0,100); int server_sockfd,client_sockfd; socklen_t server_len,client_len; struct sockaddr_in server_sockaddr,client_sockaddr; printf("/n=serverinitialization=/n"); server_sockfd = socket(AF_INET,SOCK_STREAM, 0); server_sockaddr.sin_family = AF_INET; server

6、_sockaddr.sin_port = htons(MYPORT); server_sockaddr.sin_addr.s_addr = htonl(INADDR_ANY); server_len = sizeof(server_sockaddr); int on = 1; setsockopt(server_sockfd,SOL_SOCKET,SO_REUSEADDR,&on,sizeof(on);if(bind(server_sockfd,(structsockaddr*)&server_sockaddr,server_len)=-1) perror("bind

7、");exit(1); if(listen(server_sockfd,5) = -1) perror("listen"); exit(1); client_len = sizeof(client_sockaddr); pid_t ppid,pid; while(1) if(client_sockfd=accept(server_sockfd,(structsockaddr*)&client_sockaddr,&client_len)=-1) perror("accept error"); exit(1); else send(

8、client_sockfd,"You have connectServer!",strlen("You have connect Server!"),0);printf("/n%s:%dLoginserver!/n/n",inet_ntoa(client_sockaddr.sin_addr), ntohs(client_sockaddr.sin_port); ppid = fork(); /創(chuàng)建子進(jìn)程 if(ppid = -1) printf("fork 1 failed:"); else if(ppid = 0)

9、 /子進(jìn)程用于接收客戶端信息并發(fā)送 int recvbytes; pid = fork(); /再次創(chuàng)建子進(jìn)程 if(pid = -1) printf("fork 2 failed:");exit(1); else if(pid = 0) /子進(jìn)程的子進(jìn)程用于接收消息 while(1) bzero(buf,100); if(recvbytes = recv(client_sockfd,buf,100,0)=-1) perror("read client_sockfd failed:"); else if(recvbytes != 0) bufrecvby

10、tes = '/0' usleep(10000); printf("%s:%dsaid:%s/n",inet_ntoa(client_sockaddr.sin_addr), ntohs(client_sockaddr.sin_port), buf) if(send(client_sockfd,buf,recvbytes,0)=-1) perror("send error");break;else if(pid>0) /此時(shí)的id為子進(jìn)程id else if(ppid>0) close(client_sockfd); retur

11、n 0; 4.2 客戶端代碼 客戶端代碼#include <stdio.h> #include <stdlib.h> #include <errno.h> #include <string.h> #include <sys/types.h> #include <netinet/in.h> #include <sys/socket.h> #include <sys/wait.h> #include<unistd.h> #include <arpa/inet.h&g

12、t; #define SERVER_PORT 8887 /* 客戶機(jī)連接遠(yuǎn)程主機(jī)的端口 */ #define MAXDATASIZE 100 /* 每次可以接收的最大字節(jié) */ #define SERVER_IP "192.168.11.8" /* 服務(wù)器的IP地址 */int main() int sockfd, numbytes; char bufMAXDATASIZE;struct sockaddr_in server_addr;printf("/n=clientinitialization=/n"); if (sockfd = socket(AF

13、_INET, SOCK_STREAM, 0) = -1) perror("socket"); exit(1); server_addr.sin_family = AF_INET; server_addr.sin_port = htons(SERVER_PORT); server_addr.sin_addr.s_addr = inet_addr(SERVER_IP);bzero(&(server_addr.sin_zero),sizeof(server_addr.sin_zero); if(connect(sockfd,(structsockaddr *)&s

14、erver_addr,sizeof(struct sockaddr_in) = -1) perror("connect");exit(1); while(1) bzero(buf,MAXDATASIZE);printf("/nBegin receive./n");if (numbytes=recv(sockfd, buf, MAXDATASIZE, 0) = -1) perror("recv");exit(1); else if (numbytes > 0) int len, bytes_sent;bufnumbytes = '/0'printf("Received: %s/n",buf);printf("Send:");char *msg;scanf("%s",msg); len = strlen(msg);if(send(sockfd,msg,len,0) = -1) perror("send error");elseprintf(&