Linux网络编程实例

来源：互联网发布：sql case when用法编辑：程序博客网时间：2024/05/27 21:50

服务端：server.c

#include <stdlib.h>#include <stdio.h>#include <errno.h>#include <string.h>#include <unistd.h>#include <netdb.h>#include <sys/socket.h>#include <netinet/in.h>#include <sys/types.h>#include <arpa/inet.h>int main(int argc, char *argv[]){int sockfd,new_fd;struct sockaddr_in server_addr;struct sockaddr_in client_addr;int sin_size,portnumber;char hello[]="Hello! Are You Fine?\n";if(argc!=2){fprintf(stderr,"Usage:%s portnumber\a\n",argv[0]);exit(1);}if((portnumber=atoi(argv[1]))<0){fprintf(stderr,"Usage:%s portnumber\a\n",argv[0]);exit(1);}/* 服务器端开始建立socket描述符 */if((sockfd=socket(AF_INET,SOCK_STREAM,0))==-1){fprintf(stderr,"Socket error:%s\n\a",strerror(errno));exit(1);}/* 服务器端填充 sockaddr结构  */bzero(&server_addr,sizeof(struct sockaddr_in));server_addr.sin_family=AF_INET;server_addr.sin_addr.s_addr=htonl(INADDR_ANY);server_addr.sin_port=htons(portnumber);/* 捆绑sockfd描述符  */if(bind(sockfd,(struct sockaddr *)(&server_addr),sizeof(struct sockaddr))==-1){fprintf(stderr,"Bind error:%s\n\a",strerror(errno));exit(1);}/* 监听sockfd描述符  */if(listen(sockfd,5)==-1){fprintf(stderr,"Listen error:%s\n\a",strerror(errno));exit(1);}while(1){/* 服务器阻塞,直到客户程序建立连接  */sin_size=sizeof(struct sockaddr_in);if((new_fd=accept(sockfd,(struct sockaddr *)(&client_addr),&sin_size))==-1){fprintf(stderr,"Accept error:%s\n\a",strerror(errno));exit(1);}fprintf(stderr,"Server get connection from %s\n",        inet_ntoa(client_addr.sin_addr));if(write(new_fd,hello,strlen(hello))==-1){fprintf(stderr,"Write Error:%s\n",strerror(errno));exit(1);}/* 这个通讯已经结束     */close(new_fd);/* 循环下一个     */}close(sockfd);exit(0);}

客户端：client.c

#include <stdlib.h>#include <stdio.h>#include <errno.h>#include <string.h>#include <unistd.h>#include <netdb.h>#include <sys/socket.h>#include <netinet/in.h>#include <sys/types.h>#include <arpa/inet.h>int main(int argc, char *argv[]){int sockfd;char buffer[1024];struct sockaddr_in server_addr;struct hostent *host;int portnumber,nbytes;if(argc!=3){fprintf(stderr,"Usage:%s hostname portnumber\a\n",argv[0]);exit(1);}if((host=gethostbyname(argv[1]))==NULL){fprintf(stderr,"Gethostname error\n");exit(1);}if((portnumber=atoi(argv[2]))<0){fprintf(stderr,"Usage:%s hostname portnumber\a\n",argv[0]);exit(1);}/* 客户程序开始建立 sockfd描述符  */if((sockfd=socket(AF_INET,SOCK_STREAM,0))==-1){fprintf(stderr,"Socket Error:%s\a\n",strerror(errno));exit(1);}/* 客户程序填充服务端的资料       */bzero(&server_addr,sizeof(server_addr));server_addr.sin_family=AF_INET;server_addr.sin_port=htons(portnumber);server_addr.sin_addr=*((struct in_addr *)host->h_addr);/* 客户程序发起连接请求         */if(connect(sockfd,(struct sockaddr *)(&server_addr),sizeof(struct sockaddr))==-1){fprintf(stderr,"Connect Error:%s\a\n",strerror(errno));exit(1);}/* 连接成功了           */if((nbytes=read(sockfd,buffer,1024))==-1){fprintf(stderr,"Read Error:%s\n",strerror(errno));exit(1);}buffer[nbytes]='\0';printf("I have received:%s\n",buffer);/* 结束通讯     */close(sockfd);exit(0);}

使用：

服务端：

#sudo ./server 8888 &

客户端：

#sudo ./client 127.0.0.1 8888

若正确打印说明通信成功。

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