根据select TCP服务器流程图编写服务器
#include <myhead.h>
#define ERR_MSG(msg) do{\
fprintf(stderr, "__%d__\n", __LINE__);\
perror(msg);\
}while(0)
#define PORT 8888
#define IP "192.168.114.96"
int main(int argc, const char *argv[])
{
//创建套接字
int sfd = socket(AF_INET, SOCK_STREAM, 0);
if(sfd < 0)
{
ERR_MSG("socket");
return -1;
}
printf("socket create success sfd=%d\n", sfd);
//允许端口快速复用
int reuse = 1;
if(setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR, &reuse, sizeof(reuse)) < 0)
{
ERR_MSG("setsockopt");
return -1;
}
printf("允许端口快速复用成功\n");
//通用地址信息结构体
struct sockaddr_in sin;
sin.sin_family = AF_INET;
sin.sin_port = htons(PORT);
sin.sin_addr.s_addr = inet_addr(IP);
//绑定
if(bind(sfd, (struct sockaddr *)&sin, sizeof(sin)) < 0)
{
ERR_MSG("bind");
return -1;
}
printf("bind success\n");
//转换成监听套接字
if(listen(sfd, 128) < 0)
{
ERR_MSG("listen");
return -1;
}
printf("listen success\n");
//定义读集合和备份
fd_set readfds, tempfds;
//清空集合
FD_ZERO(&readfds);
//将0号和sfd添加到读集合中
FD_SET(0, &readfds);
FD_SET(sfd, &readfds);
int res1 = -1;
ssize_t res2 = -1;
char buf[128] = "";
struct sockaddr_in cin;
socklen_t addrlen = sizeof(cin);
struct sockaddr_in saveCin[1024]; //下标对应文件描述符
//定义最大的文件描述符
int maxfd = sfd;
int newfd = -1;
while(1)
{
//将readfds拷贝一份给tempfds
tempfds = readfds;
//执行IO多路复用函数
res1 = (select(maxfd+1, &tempfds, NULL, NULL, NULL));
if(res1 < 0)
{
ERR_MSG("select");
return -1;
}else if(0 == res1)
{
printf("time out\n"); //超时
break;
}
printf("__%d__\n", __LINE__);
for(int i=0; i<maxfd; i++)
{
if(FD_ISSET(i, &tempfds) == 0)
continue;
//说明i代表的文件描述符在集合中
if(0 == i)
{
//触发键盘输入事件
printf("触发键盘输入事件\n");
//清空字符串
bzero(buf, sizeof(buf));
fgets(buf, sizeof(buf), stdin);
buf[strlen(buf)-1] = 0;
printf("%s\n", buf);
}else if(sfd == i)
{
//触发客户端连接事件
printf("触发客户端连接事件\n");
newfd = accept(sfd, (struct sockaddr *)&cin, &addrlen);
if(newfd < 0)
{
ERR_MSG("accept");
return -1;
}
printf("[%s:%d] 客户端连接成功 newfd=%d\n", \
inet_ntoa(cin.sin_addr), ntohs(cin.sin_port), newfd);
saveCin[newfd] = cin;
FD_SET(newfd, &readfds);
maxfd = maxfd>newfd ? maxfd:newfd;
}else
{
//触发客户端交互事件
printf("触发客户端交互事件\n");
//清空字符串
bzero(buf, sizeof(buf));
//接收数据
res2 = recv(i, buf, sizeof(buf), 0);
if(res2 < 0)
{
ERR_MSG("recv");
return -1;
}
if(0 == res2)
{
printf("[%s:%d] 客户端下线 newfd=%d\n", \
inet_ntoa(saveCin[i].sin_addr), ntohs(saveCin[i].sin_port), i);
//关闭文件描述符
close(i);
//将文件描述符从集合中剔除
FD_CLR(i, &readfds);
while(FD_ISSET(maxfd, &readfds)==0 && maxfd-->=0);
}
printf("[%s:%d] newfd=%d : %s\n", \
inet_ntoa(saveCin[i].sin_addr), ntohs(saveCin[i].sin_port), i, buf);
//发送数据
strcat(buf, "O.o");
if(send(i, buf, sizeof(buf), 0) < 0)
{
ERR_MSG("send");
return -1;
}
printf("send success\n");
}
}
}
//关闭文件描述符
if(close(sfd) < 0)
{
ERR_MSG("close");
return -1;
}
printf("close success\n");
return 0;
}
思维导图