客户端
#define PORT 4321
#define BUFFER_SIZE 1024
int main(int argc, char *argv[])
{
int sockfd, sendbytes， res;
char buf[BUFFER_SIZE];
struct hostent *host;
struct sockaddr_in serv_addr;
/*地址解析函数*/
if ((host = gethostbyname(argv[1])) == NULL)
memset(buf, 0, sizeof(buf));
sprintf(buf, "%s", argv[2]);
/*创建socket*/
if ((sockfd = socket(AF_INET,SOCK_STREAM,0)) == -1)
/*设置sockaddr_in 结构体中相关参数*/
serv_addr.sin_family = AF_INET;
serv_addr.sin_port = htons(PORT);
serv_addr.sin_addr = *((struct in_addr *)host->h_addr);
bzero(&(serv_addr.sin_zero), 8);
/*调用connect函数主动发起对服务器端的连接*/
res = connect(sockfd,(struct sockaddr *)&serv_addr, sizeof(struct sockaddr));
//客户端将控制台输入的信息发送给服务器端，服务器原样返回信息,阻塞
while (fgets(sendbuf, sizeof(sendbuf), stdin) != NULL)
{
send(sockfd, sendbuf, strlen(sendbuf),0); ///发送
recv(sockfd, recvbuf, sizeof(recvbuf),0); ///接收
}
close(sockfd);
exit(0);
}
服务端
#define PORT 4321
#define MAX_QUE_CONN_NM 5
#define MAX_SOCK_FD 10
#define BUFFER_SIZE 1024
int main()
{
struct sockaddr_in server_sockaddr, client_sockaddr;
int sin_size, count;
fd_set inset, tmp_inset;
int sockfd, client_fd, fd;
char buf[BUFFER_SIZE];
if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
server_sockaddr.sin_family = AF_INET;
server_sockaddr.sin_port = htons(PORT);
server_sockaddr.sin_addr.s_addr = INADDR_ANY;
bzero(&(server_sockaddr.sin_zero), 8);
int i = 1;/* 使得重复使用本地地址与套接字进行绑定 */
setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &i, sizeof(i));
if (bind(sockfd, (struct sockaddr *)&server_sockaddr, sizeof(struct sockaddr)) == -1)
if(listen(sockfd, MAX_QUE_CONN_NM) == -1)
/*将调用socket函数的描述符作为文件描述符*/
FD_ZERO(&inset);
FD_SET(sockfd, &inset);
while(1)
{
tmp_inset = inset;
sin_size=sizeof(struct sockaddr_in);
memset(buf, 0, sizeof(buf));
/*调用select函数--阻塞*/
if (!(select(MAX_SOCK_FD, &tmp_inset, NULL, NULL, NULL) > 0))
for (fd = 0; fd < MAX_SOCK_FD; fd++)
{
if (FD_ISSET(fd, &tmp_inset) > 0)
{
if (fd == sockfd)
{ /* 服务端接收客户端的连接请求 */
if ((client_fd = accept(sockfd, (struct sockaddr *)&client_sockaddr, &sin_size))== -1)
FD_SET(client_fd, &inset);
}
else /* 处理从客户端发来的消息 */
{
if ((count = recv(fd, buf, BUFFER_SIZE, 0)) > 0)
{
send(fd, buf, count, 0);
}
else
{
close(fd);
FD_CLR(fd, &inset);
}
}
} /* end of if FD_ISSET*/
} /* end of for fd*/
} /* end if while while*/
close(sockfd);
exit(0);
}