网络编程(2)

server.sin_family=AF_INET; server.sin_port=htons(PORT);

server.sin_addr=*((struct in_addr *)he->h_addr);

if(connect(fd,(struct sockaddr *)&server,sizeof(struct sockaddr))==-1) { perror(\

exit(1);

}

if((numbytes=recv(fd,buf,MAXDATASIZE,0))==-1) { perror(\

exit(1);

}

buf[numbytes]='\\0';

printf(\ while(i){

printf(\ scanf(\ if(strlen(buf)<1) i=0 ;

if((numbytes=send(fd,buf,strlen(buf),0))==-1) { perror(\

exit(1);

}

if((numbytes=recv(fd,buf,MAXDATASIZE,0))==-1) { perror(\

exit(1);

}

buf[numbytes]='\\0';

printf(\ %s\\n\

6

printf(\ } close(fd); }

服务器端程序如下： #include #include #include #include #include #include #include #define PORT 1234 #define BACKLOG 2 #define MAXCHARSIZE 1000

void process_client(int connectfd,struct sockaddr_in client); int main(void) {

int listenfd,connectfd; struct sockaddr_in server,client; int sin_size;

int opt=SO_REUSEADDR; pid_t pid;

if((listenfd=socket(AF_INET,SOCK_STREAM,0))==-1) {

perror(\ exit(-1); }

setsockopt(listenfd,SOL_SOCKET,SO_REUSEADDR,&opt,sizeof(opt)); bzero(&server,sizeof(server));

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server.sin_family=AF_INET; server.sin_port=htons(PORT);

server.sin_addr.s_addr=htonl(INADDR_ANY);

if(bind(listenfd,(struct sockaddr *)&server,sizeof(struct sockaddr))==-1) { perror(\

exit(-1);

}

if(listen(listenfd,BACKLOG)==-1) { perror(\

exit(-1);

}

sin_size=sizeof(struct sockaddr_in); while(1){

if((connectfd=accept(listenfd,(struct sockaddr *) &client,&sin_size))==-1){ perror(\ exit(-1);

}

if((pid=fork())>0){ close(connectfd) ; continue; }

else if(pid==0){ close(listenfd);

process_client(connectfd,client); exit(1); } else {

perror(\ error.\\n\

exit(0);

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} }

close(listenfd); }

void process_client(int connectfd,struct sockaddr_in client){ char recvbuf[MAXCHARSIZE]; char sendbuf[MAXCHARSIZE]; int recvlen,i;

printf(\ send(connectfd,\ while(recvlen=recv(connectfd,recvbuf,MAXCHARSIZE,0)){ recvbuf[recvlen]='\\0';

printf(\ for(i=0;i

sendbuf[i] = recvbuf[recvlen - i -1] ; sendbuf[recvlen]='\\0';

send(connectfd,sendbuf,strlen(sendbuf),0);

}

close(connectfd); }

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实验三 多进程服务器设计

参考源代码： 客户端程序如下： #include #include #include #include #define PORT 1234

#define MAXDATASIZE 1000

int main(int argc,char * argv[]) {

int fd,numbytes;

char buf[MAXDATASIZE]; struct hostent * he; struct sockaddr_in server; int i=1; if(argc!=2) {

printf(\ \\n\ exit(-1); }

if((he=gethostbyname(argv[1]))==NULL){ perror(\

exit(-1);

}

if((fd=socket(AF_INET,SOCK_STREAM,0))==-1){ perror(\

exit(1);

}

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