网络编程day5作业-编程知识

网络编程day5作业

1. 根据select TCP服务器流程图编写服务器（上交）

#include <myhead.h>
#define ERR_MSG(msg) do{\fprintf(stderr,"__%d__",__LINE__);\perror(msg);\
}while(0)
#define PORT 6666
#define IP "192.168.114.50"
int main(int argc, const char *argv[])
{//创建流式套接字int sfd=socket(AF_INET,SOCK_STREAM,0);if(sfd<0){ERR_MSG("socket");return -1;}printf("socket create success! sfd=%d\n",sfd);//允许端口快速被复用int reuse=1;if(setsockopt(sfd,SOL_SOCKET,SO_REUSEADDR,&reuse,sizeof(reuse))<0){ERR_MSG("setsockopt");return -1;}printf("允许端口快速被复用成功\n");struct sockaddr_in sin;sin.sin_family=AF_INET;sin.sin_port=htons(PORT);sin.sin_addr.s_addr=inet_addr(IP);if(bind(sfd,(struct sockaddr *)&sin,sizeof(sin))<0){ERR_MSG("bind");return -1;}printf("bind success\n");if(listen(sfd,128)<0){ERR_MSG("listen");return -1;}//创建一个读的集合fd_set readfds,tempfds;//清空集合FD_ZERO(&readfds);//将需要监测的文件描述符放入到集合中FD_SET(0,&readfds);FD_SET(sfd,&readfds);int maxfd=sfd;char buf[128]="";ssize_t res=-1;int newfd=-1;int s_res=-1;struct sockaddr_in savaCin[1024];struct sockaddr_in cin;socklen_t addrlen=sizeof(cin);while(1){tempfds=readfds;s_res=select(maxfd+1,&tempfds,NULL,NULL,NULL);if(s_res<0){ERR_MSG("select");return -1;}if(0==s_res){printf("time out..\n");break;}printf("__%d__\n",__LINE__);for(int i=0;i<=maxfd;i++){if(FD_ISSET(i,&tempfds)==0){continue;}if(0==i){printf("触发键盘输入事件\n");bzero(buf,sizeof(buf));fgets(buf,sizeof(buf),stdin);buf[strlen(buf)-1]=0;printf("输出：%s\n",buf);}else if(sfd==i){printf("触发客户端连接事件\n");newfd=accept(i,(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);FD_SET(newfd,&readfds);savaCin[newfd]=cin;maxfd=maxfd>newfd?maxfd:newfd;}else{printf("触发客户端交互事件\n");//清空字符串bzero(buf,sizeof(buf));//接收res=recv(i,buf,sizeof(buf),0);if(res<0){ERR_MSG("recv");return -1;}if(0==res){printf("[%s:%d]客户端下线newfd=%d\n",\inet_ntoa(savaCin[i].sin_addr),ntohs(savaCin[i].sin_port),i);close(i);FD_CLR(i,&readfds);for(;maxfd>=0;maxfd--){if(FD_ISSET(maxfd,&readfds)){break;}}continue;}printf("[%s:%d]newfd=%d:%s\n",\inet_ntoa(savaCin[i].sin_addr),ntohs(savaCin[i].sin_port),i,buf);//发送strcat(buf,"zyz");if(send(i,buf,sizeof(buf),0)<0){ERR_MSG("send");return -1;}printf("send success\n");}}}if(close(sfd)<0){ERR_MSG("close");return -1;}return 0;
}

思维导图：https://mubu.com/app/edit/home/4LfFX79g2CD#m