关于时间获取的C/S模型

/* wrapper.c */
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>          
#include <sys/socket.h>

void
perr_exit(const char * s) {
	perror(s);
	exit(1);
}


int
Socket(int domain, int type, int protocol) {
	int sockfd;
	sockfd = socket(domain, type, protocol);
	if (sockfd == -1) {
		perr_exit("socket error");
	}
	return sockfd;
}


void 
Connect(int sockfd, const struct sockaddr *addr, socklen_t addrlen) {
	int n;
	n = connect(sockfd, addr, addrlen);
	if (n == -1) {
		perr_exit("connect error");
	}
}


void
Bind(int sockfd, const struct sockaddr *addr, socklen_t addrlen) {
	int n;
	n = bind(sockfd, addr, addrlen);
	if (n == -1) {
		perr_exit("bind error");
	}
}


void
Listen(int sockfd, int backlog) {
	int n;
	n = listen(sockfd, backlog);
	if (n == -1) {
		perr_exit("listen error");
	}
}


int 
Accept(int sockfd, struct sockaddr *addr, socklen_t *addrlen) {
	int connfd;
	connfd = accept(sockfd, addr, addrlen);
	if (connfd == -1) {
		perr_exit("accept error");
	}
	return connfd; 
} 

ssize_t 
Write(int fd, const void *buf, size_t count) {
	ssize_t n;
	n = write(fd, buf, count);
	if (n == -1) {
		perr_exit("write error");
	}
	return n;
}


ssize_t 
Read(int fd, void * buf, size_t count) {
	ssize_t n;
	n = read(fd, buf, count);
	if (n == -1) {
		perr_exit("read error");
	}
	return n;
}

void
Close(int fd) {
	int n;
	n = close(fd);
	if (n == -1) {
		perr_exit("close error");
	}
}

// TCP服务器端
// server.c
#include "wrapper.c"
#include <string.h>
#include <time.h>
#include <arpa/inet.h>

#define LISTENQ	 128

int main(int argc, char **argv)
{
	int listenfd, connfd;
	struct sockaddr_in servaddr, clieaddr;
	socklen_t clieaddr_len;
	char buff[BUFSIZ];
	time_t ticks;

	// 创建socket
	listenfd = Socket(AF_INET, SOCK_STREAM, 0);

	// 绑定
	bzero(&servaddr, sizeof(servaddr));
	servaddr.sin_family = AF_INET;
	servaddr.sin_addr.s_addr = htonl(INADDR_ANY);// INADDR_ANY表示本地的任意IP地址
	servaddr.sin_port = htons(13);

	Bind(listenfd,(struct sockaddr *)&servaddr, sizeof(servaddr));

	// 设置listenfd处于监听状态
	Listen(listenfd, LISTENQ);

	printf("wait for client connect ...\n");

	// 服务器调用accept()接受连接
	while (1) {
		clieaddr_len = sizeof(clieaddr);
		connfd = Accept(listenfd, (struct sockaddr *)&clieaddr, &clieaddr_len);

		ticks = time(NULL);
		snprintf(buff, sizeof(buff), "%.24s\r\n", ctime(&ticks));
		Write(connfd, buff, strlen(buff));

		Close(connfd);
	}
	return 0;
}

// TCP客户端 
// client.c
#include "wrapper.c"
#include <arpa/inet.h>
#include <string.h>

int main(int argc, char **argv)
{
	int sockfd, n;
	char recvline[BUFSIZ];
	struct sockaddr_in servaddr;

	if (argc != 2) {
		perr_exit("usage: client <IPaddress>");
	}

	sockfd = Socket(AF_INET, SOCK_STREAM, 0);

	bzero(&servaddr, sizeof(servaddr));
	servaddr.sin_family = AF_INET;
	servaddr.sin_port = htons(13);
	if (inet_pton(AF_INET, argv[1], &servaddr.sin_addr) <= 0) {
		perr_exit("inet_pton error");
	}

	Connect(sockfd, (struct sockaddr *)&servaddr, sizeof(servaddr));

	while (1) {
		n = Read(sockfd, recvline, sizeof(recvline));
		recvline[n] = 0;
		if (fputs(recvline, stdout) == EOF) {
			perr_exit("fputs error");
		}
	}

	Close(sockfd);
	return 0;
}