socket编程---服务器端与客户端简单通信

 服务器端：/*
* File: main.cpp
* Author: xiaomo
*
* Created on 2011年6月22日, 下午8:07
*/
#include<stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <netdb.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include<unistd.h>
#include<arpa/inet.h>
#include <time.h>

#define SERVER_PORT 2222 // define the defualt connect port id
#define LENGTH_OF_LISTEN_QUEUE 10 //length of listen queue in server
#define BUFFER_SIZE 10485760
#define WELCOME_MESSAGE "welcome to connect the server. "

ssize_t Read(int sockfd, char* recv, size_t bytes)
{
size_t nleft;
ssize_t nread;

char *ptr = recv;
nleft = bytes;
while(nleft > 0)
{
if((nread = read(sockfd, ptr, nleft)) < 0)
{
if(errno == EINTR)
nread = 0;
else
return -1;
}
else if(nread == 0)
break;
nleft -= nread;
ptr += nread;
}
return(bytes - nleft);
}

ssize_t Write(int sockfd, char* send, size_t bytes)
{
size_t nleft;
ssize_t nwritten;
char* ptr = send;
nleft = bytes;
while(nleft > 0)
{
if((nwritten = write(sockfd, ptr, nleft)) <= 0)
{
if(nwritten < 0 && errno == EINTR)
nwritten = 0;
else
return -1;
}
nleft -= nwritten;
ptr += nwritten;
}
return bytes;
}

int main(int argc, char **argv)
{
int servfd,clifd;
struct sockaddr_in servaddr,cliaddr;
int recvbytes;

if ((servfd = socket(AF_INET,SOCK_STREAM,0)) < 0)
{//建立Socket，程序调用Socket函数，该函数返回一个类似于文件描述符的句柄
printf("create socket error!n");
exit(1);
}
//sin_zero用来将sockaddr_in结构填充到与struct sockaddr同样的长度，可以用bzero()或memset()函数将其置为零
bzero(&servaddr,sizeof(servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_port = htons(SERVER_PORT);
servaddr.sin_addr.s_addr = htons(INADDR_ANY);/*系统自动填入本机IP地址 */

if (bind(servfd,(struct sockaddr*)&servaddr,sizeof(servaddr))<0)
{//服务端通过调用 bind函数来配置本地信息。Bind函数将socket与本机上的一个端口相关联，随后你就可以在该端口监听服务请求。
printf("bind to port %d failure!n",SERVER_PORT);
exit(1);
}

if (listen(servfd,LENGTH_OF_LISTEN_QUEUE) < 0)
{//Listen函数使socket处于被动的监听模式，并为该socket建立一个输入数据队列，将到达的服务请求保存在此队列中，直到程序处理它们。
printf("call listen failure!n");
exit(1);
}
while (1)
{//server loop will nerver exit unless any body kill the proces
long timestamp;
socklen_t length = sizeof(cliaddr);
//accept()函数让服务器接收客户的连接请求
clifd = accept(servfd,(struct sockaddr*)&cliaddr,&length);
if (clifd < 0)
{
printf("error comes when call accept!n");
break;
}
char* buf = new char[BUFFER_SIZE];
strcpy(buf,WELCOME_MESSAGE);
//inet_ntop(INET_ADDRSTRLEN,cliaddr.sin_addr,buf,BUFFER_SIZE);

printf("from client,IP:%s,Port:%dn",inet_ntoa(cliaddr.sin_addr),ntohs(cliaddr.sin_port));
timestamp = time(NULL);
strcat(buf,"/ntimestamp in server:");
strcat(buf,ctime(×tamp));
//Send()函数返回实际上发送出的字节数，可能会少于你希望发送的数据
Write(clifd,buf,BUFFER_SIZE);

if ((recvbytes=Read(clifd, buf, BUFFER_SIZE)) ==-1) {
perror("recv出错！");
exit(1);
}
buf[recvbytes]='/0';
printf("/nReceived from Client: %s",buf);
delete []buf;
close(clifd);
}//exit
close(servfd);

return 0;

}
客户端：

/*
* File:   main.cpp
* Author: xiaomo
*
* Created on 2011年6月18日, 下午6:38
*/
#include<stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <netdb.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include<unistd.h>
#include<arpa/inet.h>
#define SERVPORT 2222
#define MAXDATASIZE 1024 /*每次最大数据传输量 */
#define BUFFER_SIZE 255
#define FROMCLIENT "Hi,I'm client./n"

int main(int argc, char *argv[]){
int sockfd, recvbytes;
char buf[MAXDATASIZE];
//    char server_ip[64];
struct sockaddr_in serv_addr;
//  fgets(server_ip,BUFSIZ,stdin);  //从键盘输入数据

if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1){
perror("error！");
exit(1);
}
serv_addr.sin_family=AF_INET;
serv_addr.sin_port=htons(SERVPORT);
serv_addr.sin_addr.s_addr = htons(INADDR_ANY);//inet_addr(server_ip)
bzero(&(serv_addr.sin_zero),8);
if (connect(sockfd, (struct sockaddr *)&serv_addr,
sizeof(struct sockaddr)) == -1) {
perror("connect出错！");
exit(1);
}
if ((recvbytes=recv(sockfd, buf, MAXDATASIZE, 0)) ==-1) {
perror("recv出错！");
exit(1);
}
buf[recvbytes] = '/0';
printf("/nReceived from Server: %s",buf);
strcpy(buf,FROMCLIENT);
send(sockfd,buf,BUFFER_SIZE,0);
close(sockfd);

return 0;
}