linux下socket編程之時間伺服器

為網路上的使用者提供時間服務，即為網路使用者返回伺服器的目前時間；

記錄發出請求的網路使用者的IP地址（儲存到檔案中）；

編寫時間服務用戶端timeclient，該用戶端能夠向伺服器發送時間服務要求，並把獲得的時間返回給使用者。

開發環境：fedora13，vim，gcc

timeserver.c檔案。

#include<stdio.h>#include<unistd.h>#include<sys/types.h>#include<sys/socket.h>#include<netinet/in.h>#include<arpa/inet.h>#include<time.h>#include<netdb.h>#include<stdlib.h>#include<string.h>#define PORT 1234#define BACKLOG 5int main(){int listenfd, connectfd;struct sockaddr_in server;struct sockaddr_in client;socklen_t addrlen;time_t t;t=time(NULL);FILE *fd=fopen("/root/saveIP","a");if((listenfd = socket(AF_INET, SOCK_STREAM, 0)) == -1){perror("socket() error.");return 0;}int opt = SO_REUSEADDR;setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));bzero(&server, sizeof(server));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(server)) == -1){perror("bind() error.");        return 0;}if(listen(listenfd, BACKLOG) == -1){perror("listen() error.");return 0;}addrlen = sizeof(client);if((connectfd = accept(listenfd, (struct sockaddr *)&client, &addrlen )) == -1)   {    perror("accept() error.");return 0;   }printf("Timeclient's IP is %s.  ",inet_ntoa(client.sin_addr));printf("Time is %s\n",ctime(&t));send(connectfd,(time_t *)&t,sizeof(time_t),0);fprintf(fd,"%s  %s\n",inet_ntoa(client.sin_addr),ctime(&t));fclose(fd);return 1;}

timeclient.c檔案

#include<stdio.h>#include<stdlib.h>#include<unistd.h>#include<strings.h>#include<sys/types.h>#include<sys/socket.h>#include<netinet/in.h>#include<netdb.h>#define PORT 1234   /*listen port*/int main ( int argc, char *argv[]){ int sockfd, num;struct hostent *he; struct sockaddr_in server;time_t t; if(argc!=2) {  printf("usage %s<ip address>\n",argv[0]); return 0;} /*get ip address*/ if((he = gethostbyname(argv[1])) == NULL) {  printf("gethostbyname error\n");                return 0; } if((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {  printf("socket() error \n");return 0; }  bzero(&server, sizeof(server)); server.sin_family = AF_INET; server.sin_port = htons(PORT); server.sin_addr = *((struct in_addr *)he->h_addr);   if(connect(sockfd, (struct sockaddr *)&server, sizeof(server)) == -1) {  printf("connetc() error\n");return 0; }recv(sockfd,(void *)&t,sizeof(time_t),0);printf("Time is %s\n",ctime(&t));}

運行結果：