here is:
# include <sys/types.h># include <sys/socket.h># include <arpa/inet.h># include <stdio.h>
int main(int argc, char **argv)
{
struct sockaddr_in peeraddr, /*IP and socke port*/
localaddr;/*local socket address*/
int sockfd;
char recmsg[BUFLEN+1];
int socklen, n;
if(argc!=5){
printf("%s <dest IP address> <dest port> <source IP address> <source port>\n", argv [0]);
exit(0);
}
sockfd = socket(AF_INET, SOCK_DGRAM, 0);
if(sockfd<0){
printf("socket creating err in udptalk\n");
exit(1);
}
socklen = sizeof(struct sockaddr_in);
memset(&peeraddr, 0, socklen);
peeraddr.sin_family=AF_INET;
peeraddr.sin_port=htons(atoi(argv[2]));
if(inet_pton(AF_INET, argv[1], &peeraddr.sin_addr)<=0){
printf("Wrong dest IP address!\n");
exit(0);
}
memset(&localaddr, 0, socklen);
localaddr.sin_family=AF_INET;
if(inet_pton(AF_INET, argv[3], &localaddr.sin_addr)<=0){
printf("Wrong source IP address!\n");
exit(0);
}
localaddr.sin_port=htons(atoi(argv[4]));
if(bind(sockfd, &localaddr, socklen)<0){
printf("bind local address err in udptalk!\n");
exit(2);
}
if(fgets(recmsg, BUFLEN, stdin) == NULL) exit(0);
if(sendto(sockfd, recmsg, strlen(recmsg), 0, &peeraddr, socklen)<0){
printf("sendto err in udptalk!\n");
exit(3);
}
for(;;){
/*recv&send message loop*/
n = recvfrom(sockfd, recmsg, BUFLEN, 0, &peeraddr, &socklen);
if(n<0){
printf("recvfrom err in udptalk!\n");
exit(4);
}else{
recmsg[n]=0;
printf("peer:%s", recmsg);
}
if(fgets(recmsg, BUFLEN, stdin) == NULL) exit(0);
if(sendto(sockfd, recmsg, strlen(recmsg), 0, &peeraddr, socklen)<0){
printf("sendto err in udptalk!\n");
exit(3);
}
}
}
os: uclinux ,
Honored Contributor
