#include <sys/types.h>
#include <sys/socket.h>
#include <stdio.h>
#include <netinet/in.h>
#include <sys/time.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <stdlib.h>
int main()
{
int server_sockfd, client_sockfd;
int server_len, client_len;
struct sockaddr_in server_address;
struct sockaddr_in client_address;
int result;
fd_set readfds, testfds;
server_sockfd = socket(AF_INET, SOCK_STREAM, 0);//建立服务器端socket
server_address.sin_family = AF_INET;
server_address.sin_addr.s_addr = htonl(INADDR_ANY);
server_address.sin_port = htons(8888);
server_len = sizeof(server_address);
bind(server_sockfd, (struct sockaddr *)&server_address, server_len);
listen(server_sockfd, 5); //监听队列最多容纳5个
FD_ZERO(&readfds);
FD_SET(server_sockfd, &readfds);//将服务器端socket加入到集合中
while(1)
{
char ch;
int fd;
int nread;
testfds = readfds;//将需要监视的描述符集copy到select查询队列中，select会对其修改，所以一定要分开使用变量
printf("server waiting\n");
/*无限期阻塞，并测试文件描述符变动 */
result = select(FD_SETSIZE, &testfds, (fd_set *)0,(fd_set *)0, (struct timeval *) 0); //FD_SETSIZE：系统默认的最大文件描述符
if(result < 1)
{
perror("server5");
exit(1);
}
/*扫描所有的文件描述符*/
for(fd = 0; fd < FD_SETSIZE; fd++)
{
/*找到相关文件描述符*/
if(FD_ISSET(fd,&testfds))
{
/*判断是否为服务器套接字，是则表示为客户请求连接。*/
if(fd == server_sockfd)
{
client_len = sizeof(client_address);
client_sockfd = accept(server_sockfd, (struct sockaddr *)&client_address, (socklen_t*) &client_len);
FD_SET(client_sockfd, &readfds);//将客户端socket加入到集合中
printf("adding client on fd %d\n", client_sockfd);
}
/*客户端socket中有数据请求时*/
else
{
ioctl(fd, FIONREAD, &nread);//取得数据量交给nread
/*客户数据请求完毕，关闭套接字，从集合中清除相应描述符 */
if(nread == 0)
{
close(fd);
FD_CLR(fd, &readfds); //去掉关闭的fd
printf("removing client on fd %d\n", fd);
}
/*处理客户数据请求*/
else
{
read(fd, &ch, 1);
sleep(5);
printf("serving client on fd %d\n", fd);
ch++;
write(fd, &ch, 1);
}
}
}
}
}
return 0;
}
评论0