udp-server.c

uclinux下tcp和udp服务器的建立

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#define PORT 3300
#define MSG 1024
void udps_respon (int sockfd)
{
 struct sockaddr_in addr;
 int addrlen;
 char msg [MSG];
 int n;
 addrlen=sizeof (struct sockaddr);
 for (;;)
    {
	n=recvfrom (sockfd, msg, MSG, 0, (struct sockaddr *) &addr, &addrlen);
	sendto (sockfd, msg, n, 1, addr, addrlen);
    }
}
int main ()
{
 int sockfd;
 struct sockaddr_in addr;
 sockfd=socket (AF_INET, SOCK_DGRAM, 0);
 if (sockfd<0)
    {
	fprintf (stderr,"Create socket error\n");
	exit (1);
    }
 bzero (&addr,sizeof (addr));
 addr.sin_family=AF_INET;
 addr.sin_addr.s_addr=htonl (INADDR_ANY);
 addr.sin_port=htons (PORT);
 if (bind (sockfd, (struct sockaddr * ) &addr, sizeof (addr)) <0)
    {
	fprintf (stderr,"Error when bind\n");
	exit(1);
    } 
 upds_respon (sockfd);
 close (sockfd);
}