select.c

来自「《嵌入式Linux应用程序开发详解》源代码」· C语言 代码 · 共 69 行

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <sys/un.h>
#include <sys/time.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <netinet/in.h>
#define SERVPORT 3333
#define BACKLOG 10
#define MAX_CONNECTED_NO 10
#define MAXDATASIZE 100
int main()
{
	struct sockaddr_in server_sockaddr,client_sockaddr;
	int sin_size,recvbytes;
	fd_set readfd;
	fd_set writefd;
	int sockfd,client_fd;
	char buf[MAXDATASIZE];
	if((sockfd = socket(AF_INET,SOCK_STREAM,0))==-1){
		perror("socket");
		exit(1);
	}
	printf("socket success!,sockfd=%d\n",sockfd);
	server_sockaddr.sin_family=AF_INET;
	server_sockaddr.sin_port=htons(SERVPORT);
	server_sockaddr.sin_addr.s_addr=INADDR_ANY;
	bzero(&(server_sockaddr.sin_zero),8);
	if(bind(sockfd,(struct sockaddr *)&server_sockaddr,sizeof(struct sockaddr))==-1){
		perror("bind");
		exit(1);
	}
	printf("bind success!\n");
	if(listen(sockfd,BACKLOG)==-1){
		perror("listen");
		exit(1);
	}
	printf("listening....\n");
	FD_ZERO(&readfd);
	FD_SET(sockfd,&readfd);
	while(1){
	sin_size=sizeof(struct sockaddr_in);
	if(select(MAX_CONNECTED_NO,&readfd,NULL,NULL,(struct timeval *)0)>0){
		if(FD_ISSET(sockfd,&readfd)>0){
			if((client_fd=accept(sockfd,(struct sockaddr *)&client_sockaddr,&sin_size))==-1){
				perror("accept");
				exit(1);
			}
			if((recvbytes=recv(client_fd,buf,MAXDATASIZE,0))==-1){
				perror("recv");
				exit(1);
			}
			if(read(client_fd,buf,MAXDATASIZE)<0){
				perror("read");
				exit(1);
			}
			printf("received a connection :%s",buf);
		}/*if*/
		close(client_fd);
		}/*select*/
	}/*while*/
}