#include <stdio.h>
#include <unistd.h>
#include <netinet/in.h>                                                                   
#include <arpa/inet.h>
#include <netdb.h>    
#include <sys/wait.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>

#define MAXLINE 200
#define RIO_BUFSIZE 8192

typedef struct{
	   int rio_fd;
	   int rio_cnt;
	   char *rio_bufptr;
	   char rio_buf[RIO_BUFSIZE];

}rio_t;

typedef struct sockaddr SA;

typedef struct{
	int tm_sec;
	int tm_min;
	int tm_hour;
	int tm_mday;
	int tm_mon;
	int tm_year;
	int tm_wday;
	int tm_yday;
	int tm_isdst;
}tm;

void sigchld_handler(int sig){

	    pid_t pid;
	    int stat;

	    while((pid = waitpid(-1,&stat,WNOHANG))>0){
	        printf("child %d terminated\n",pid);
				        }
	    return;
}

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

	    int listenfd,connfd,port,clientlen;
	    struct sockaddr_in clientaddr;
	    struct hostent *hp;
	    char *haddrp;
	    char sbuf[MAXLINE];
	    char rbuf[MAXLINE];
	    rio_t rio;
	    time_t lt;
	    tm *local;
	    char str1[MAXLINE]="客户端IP:";
	    char str2[MAXLINE]="服务器实现者学号:";
	    char str3[MAXLINE]="当前时间:";

    if(argc != 2){
							        
            fprintf(stderr,"usage:%s <port>\n",argv[0]);
            exit(0);
								        }
      port = atoi(argv[1]);
    signal(SIGCHLD,sigchld_handler);
    listenfd = open_listenfd(port);
									    while(1){
								        
     clientlen = sizeof(clientaddr);
     connfd = accept(listenfd,(SA *)&clientaddr,&clientlen);
     hp = gethostbyaddr((const char*)&clientaddr.sin_addr.s_addr,
     sizeof(clientaddr.sin_addr.s_addr),AF_INET);
     haddrp = inet_ntoa(clientaddr.sin_addr);
     printf("server connected to %s (%s)\n",hp->h_name,haddrp);
     if(fork() == 0){
     close(listenfd);
     lt = time(NULL); 
     local = localtime(&lt);
     strftime(sbuf,64, %H:%M:%S",local);
     send(connfd,sbuf,MAXLINE,0);
     close(connfd);
     exit(0);
        }
    close(connfd);
																	        }
}