Linux下的Socket基礎編程（來自Unix網路編程）

1.伺服器端：

/* * server.c * *  Created on: Nov 20, 2012 *      Author: gentoo */#include <stdio.h>#include <stdlib.h>#include <string.h>#include <unistd.h>#include <sys/types.h>#include <sys/socket.h>#include <sys/wait.h>#include <netinet/in.h>#include <arpa/inet.h>#include <time.h>#define SERVER_PORT 8999#define BUFFER 1024int main(int argc, char * argv[]) {int listenfd; //用於監聽int connfd;   //用於串連struct sockaddr_in seraddr; //socket的地址資訊結構體char buff[BUFFER];   //字串緩衝區time_t ticks;//時間//建立一個監聽的socketif ( (listenfd=socket(AF_INET, SOCK_STREAM, 0)) < 0 ){perror("create sock error!\n");exit(1);}//清空地址結構體並設定相應的資訊bzero(&seraddr, sizeof(seraddr));seraddr.sin_family = AF_INET;  //使用的協議：TCP/IPseraddr.sin_port = htons(SERVER_PORT); //用於監聽的連接埠seraddr.sin_addr.s_addr = htonl(INADDR_ANY); //伺服器端的IP地址，INADDR_ANY表示由系統自動擷取//進行綁定if ( bind(listenfd, (struct sockaddr *)&seraddr, sizeof(seraddr))< 0 ){perror("bind sock error!\n");exit(1);}//進行監聽if ( (listen(listenfd, 4)) < 0 ){perror("listen error!\n");exit(1);}//等待用戶端的請求for( ; ; ){//進行阻塞，直到有一個用戶端發起請求connfd = accept(listenfd, NULL, NULL);ticks = time(NULL);snprintf(buff, sizeof(buff), "%.24s\r\n", ctime(&ticks));//向串連中的socket通道寫一些字串write(connfd, buff, strlen(buff));//關閉該次的串連close(connfd);}return EXIT_SUCCESS;}

2.用戶端：

/* * Client.c * *  Created on: Nov 20, 2012 *      Author: gentoo */#include <stdio.h>#include <stdlib.h>#include <string.h>#include <unistd.h>#include <sys/types.h>#include <sys/socket.h>#include <sys/wait.h>#include <netinet/in.h>#include <arpa/inet.h>#define BUFFER 1024#define SERVER_PORT 8999int main(int argc, char * argv[]) {//用於串連的socketint sockfd;//讀取了多少個位元組int readBytes;//資訊的接收char recieve[BUFFER+1];//伺服器端的地址結構體資訊struct sockaddr_in servaddr;if ( argc != 2 ){perror("IP is required!\n");exit(1);}//建立一個socketif ( (sockfd=socket(AF_INET, SOCK_STREAM, 0)) < 0 ){perror("crate socket error!\n");}//清空地址資訊結構體並設定相應的資訊bzero(&servaddr, sizeof(servaddr));;servaddr.sin_family = AF_INET; //所用的協議servaddr.sin_port = htons(SERVER_PORT); //所要串連到伺服器的連接埠號碼//將參數argv[1]的字串轉化為IP地址if ( (inet_pton(AF_INET, argv[1], &servaddr.sin_addr)) <= 0 ){perror("IP transform error!\n");exit(1);}//進行串連if ( (connect(sockfd, (struct sockaddr *)&servaddr, sizeof(servaddr))) < 0 ){perror("connected error!\n");exit(1);}//讀取伺服器端發送的資訊並將其輸出到stdout中while ( (readBytes=read(sockfd, recieve, BUFFER)) > 0 ){recieve[readBytes] = 0;if ( fputs(recieve, stdout) == EOF ){fprintf(stdout, "fputs error!\n");}}if ( readBytes < 0 ){perror("read error!\n");}return EXIT_SUCCESS;}