udps.c

入门程序

#include	"s_com.h"
#include	"s_sock.h"
#include	"s_tool.h"


#define MPORT 4950 
#define MAXSIZE 80 
#define STDIN 0



int main(int argc,char *argv[])
{
	int sockfd ;
	struct sockaddr_in saddr={10,AF_INET,MPORT,0} ;
	struct sockaddr_in r_addr ;	
	struct	sockaddr *addr ;
	int addr_len ;
	int	n=0;
	char	recvs[MAXSIZE];
	size_t	len ;
	fd_set	rset;	
	struct timeval tv ;
	

		tv.tv_sec = 2 ;
		
	if ((sockfd=init_udp())==-1)
	{
		perror("socket error!!");
		exit(-1);
	}
	init_udp_addr(&saddr,"0",MPORT);
	
	if (bind(sockfd,(struct sockaddr*)(&saddr),sizeof(struct sockaddr_in))==-1)
	{
		perror("bind error!!");	
		exit(-1);
	}	

	printf("Input string:\n");
/*
	set_fl(sockfd,O_NONBLOCK);
*/
	FD_ZERO(&rset);	
			
	while(1)
	{
		len=sizeof(struct sockaddr_in);	
		memset(recvs,0,sizeof(recvs));

/*	FD_SET(STDIN,&rset) ;	*/
	FD_SET(sockfd,&rset);
	select(sockfd+1,&rset,NULL,NULL,&tv);

/*	if (FD_ISSET(STDIN,&rset))
		printf("a key was press!!\n");
*/
	if (FD_ISSET(sockfd,&rset))
		if ((n=recvfrom(sockfd,recvs,MAXSIZE,0,addr,&len))==-1)
		{
			printf("receive none!!\n");	
		}
		else	printf("receive:%s \n",recvs);
	else printf(".............\n") ;

	FD_CLR(sockfd,&rset);
		sleep(2);
		if ((recvs=="exit")||(recvs=="exit\n"))  exit(1) ; 
	}
	
	close(sockfd);	
	exit(0);
}