//
// Created by wangji on 19-8-6.
//
// socket编程 8 select模型
#include <iostream>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <signal.h>
#include <sys/wait.h>
using namespace std;
struct packet
{
int len;
char buf[1024];
};
#define ERR_EXIT(m) \
do \
{ \
perror(m); \
exit(EXIT_FAILURE); \
} while(0);
ssize_t readn(int fd, void *buf, size_t count)
{
size_t nleft = count; // 剩余字节数
ssize_t nread;
char *bufp = (char*) buf;
while (nleft > 0)
{
nread = read(fd, bufp, nleft);
if (nread < 0)
{
if (errno == EINTR)
{
continue;
}
return -1;
} else if (nread == 0)
{
return count - nleft;
}
bufp += nread;
nleft -= nread;
}
return count;
}
ssize_t writen(int fd, const void *buf, size_t count)
{
size_t nleft = count;
ssize_t nwritten;
char* bufp = (char*)buf;
while (nleft > 0)
{
if ((nwritten = write(fd, bufp, nleft)) < 0)
{
if (errno == EINTR)
{
continue;
}
return -1;
}
else if (nwritten == 0)
{
continue;
}
bufp += nwritten;
nleft -= nwritten;
}
return count;
}
ssize_t recv_peek(int sockfd, void *buf, size_t len)
{
while (1)
{
int ret = recv(sockfd, buf, len, MSG_PEEK); // 查看传入消息
if (ret == -1 && errno == EINTR)
{
continue;
}
return ret;
}
}
ssize_t readline(int sockfd, void *buf, size_t maxline)
{
int ret;
int nread;
char *bufp = (char*)buf; // 当前指针位置
int nleft = maxline;
while (1)
{
ret = recv_peek(sockfd, buf, nleft);
if (ret < 0)
{
return ret;
}
else if (ret == 0)
{
return ret;
}
nread = ret;
int i;
for (i = 0; i < nread; i++)
{
if (bufp[i] == '\n')
{
ret = readn(sockfd, bufp, i+1);
if (ret != i+1)
{
exit(EXIT_FAILURE);
}
return ret;
}
}
if (nread > nleft)
{
exit(EXIT_FAILURE);
}
nleft -= nread;
ret = readn(sockfd, bufp, nread);
if (ret != nread)
{
exit(EXIT_FAILURE);
}
bufp += nread;
}
return -1;
}
void ehco_cli(int sockfd)
{
// char recvbuf[1024];
// char sendbuf[1024];
// // struct packet recvbuf;
// // struct packet sendbuf;
// memset(recvbuf, 0, sizeof recvbuf);
// memset(sendbuf, 0, sizeof sendbuf);
// int n = 0;
// while (fgets(sendbuf, sizeof sendbuf, stdin) != NULL) // 键盘输入获取
// {
// writen(sockfd, sendbuf, strlen(sendbuf)); // 写入服务器
//
// int ret = readline(sockfd, recvbuf, sizeof recvbuf); // 服务器读取
// if (ret == -1)
// {
// ERR_EXIT("readline");
// }
// if (ret == 0)
// {
// printf("server close\n");
// break;
// }
//
// fputs(recvbuf, stdout); // 服务器返回数据输出
//
// // 清空
// memset(recvbuf, 0, sizeof recvbuf);
// memset(sendbuf, 0, sizeof sendbuf);
// }
fd_set rset;
FD_ZERO(&rset);
int nready;//检测到的事件个数
int maxfd;
int fd_stdin = fileno(stdin);//fileno：获取标准输入的文件描述符
if (fd_stdin > sockfd)
{
maxfd = fd_stdin;
} else {
maxfd = sockfd;
}
char sendbuf[1024] = {0};
char recvbuf[1024] = {0};
//标准输入IO和网络IO
while (1)//检测套接口是否有可读事件，检测标准输入是否有可读事件
{
FD_SET(fd_stdin, &rset);//将fd_stdin放到读的集合rset中，关心fd_stdin文件描述符的事件
FD_SET(sockfd, &rset);//将sockfd放到读的集合rset中
nready = select(maxfd+1, &rset, NULL, NULL, NULL);//读集合中最大文件描述+1
//到底是哪一个套接口检测到事件？rset集合是会改变的！！返回的是哪一些io或者套接口检测到了事件
//说明rset是输入输出参数
if (nready == -1)
{
ERR_EXIT("select");
}
if (nready == 0)
{
continue;
}
//判断标准输入产生的可读事件，还是套接口产生的可读事件？
if (FD_ISSET(sockfd, &rset)) // 套接口产生的可读事件
{
int ret = readline(sockfd, recvbuf, sizeof(recvbuf)); // 服务器读取
if (ret == -1)
{
ERR_EXIT("readline");
}
if (ret == 0)
{
printf("server close\n");
break;
}
fputs(recvbuf, stdout); // 服务器返回数据输出
memset(recvbuf, 0, sizeof(recvbuf));
}
if (FD_ISSET(fd_stdin, &rset))//判断标准输入产生的可读事件
{
if (fgets(sendbuf, sizeof(sendbuf), stdin) == NULL) //等于NULL，说明客户端已经得到一个EOF结束符
{
break;
}
writen(sockfd, sendbuf, strlen(sendbuf)); // 写入服务器
memset(sendbuf, 0, sizeof(sendbuf));
}
}
close(sockfd);
};
void handle_sigchld(int sig)
{
// wait(NULL);
while (waitpid(-1, NULL, WNOHANG) > 0);
}
int main(int argc, char** argv) {
// signal(SIGCHLD, SIG_IGN);
signal(SIGCHLD, handle_sigchld);
// 1. 创建套接字
int sockfd;
if ((sockfd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) {
ERR_EXIT("socket");
}
// 2. 分配套接字地址
struct sockaddr_in servaddr;
memset(&servaddr, 0, sizeof(servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_port = htons(6666);
// servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
servaddr.sin_addr.s_addr = inet_addr("127.0.0.1");
// inet_aton("127.0.0.1", &servaddr.sin_addr);
// 3. 请求链接
if (connect(sockfd, (struct sockaddr *) &servaddr, sizeof(servaddr)) < 0) {
ERR_EXIT("connect");
}
struct sockaddr_in localaddr;
socklen_t addrlen = sizeof localaddr;
if (getsockname(sockfd, (struct sockaddr*)&localaddr, &addrlen) < 0)
{
ERR_EXIT("getsockname");
}
printf("id = %s, ", inet_ntoa(localaddr.sin_addr));
printf("port = %d\n", ntohs(localaddr.sin_port));
// 4. 数据交换
ehco_cli(sockfd);
// 5. 断开连接
close(sockfd);
return 0;
}
