Adding getaddrinfo() to my UDP client causes it to fail - c

Question

I'm a C newbie. I'm writing a simple UDP echo server and client using the code from http://www.binarytides.com/programming-udp-sockets-c-linux/
It works perfectly. However, I have decided to add code that dynamically resolves the server name and opens on that a user-specified port. My client seems to hang on the gets() request. What am I doing wrong? The original client works just fine except for hardcoded IP and port numbers.
Relevant code follows
int main(int argc, char *argv[]) {
int sockfd, rv, i;
char buf[BUFLEN];
char message[BUFLEN];
struct addrinfo hints, *servinfo, *p;
socklen_t fromlen;
if (argc != 3) {
fprintf(stderr, "usage: %s hostname port\n", argv[0]);
exit(1);
}
memset(&hints, 0, sizeof hints);
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_DGRAM;
if ((rv = getaddrinfo(argv[1], argv[2], &hints, &servinfo)) != 0) {
die("getaddrinfo");
}
// loop through all the results and connect to the first we can
for (p = servinfo; p != NULL; p = p->ai_next) {
if ((sockfd = socket(p->ai_family, p->ai_socktype, p->ai_protocol)) == -1) {
perror("client: socket");
continue;
}
break;
}
if (p == NULL)
die("client: failed to connect");
while (1) {
printf("Enter message : ");
gets(message);
//send the message
if (sendto(sockfd, message, strlen(message), 0, p->ai_addr, p->ai_addrlen) == -1)
die("sendto()");
//receive a reply and print it
//clear the buffer by filling null, it might have previously received data
memset(buf, '\0', BUFLEN);
fromlen = p->ai_addrlen;
printf("Size is %d", fromlen);
//try to receive some data, this is a blocking call
if (recvfrom(sockfd, buf, BUFLEN, 0, p->ai_addr, &fromlen) == -1)
die("recvfrom()");
puts(buf);
}
close(sockfd);
return 0;
The code that works is shown below. It uses an identical gets() call
int main(void)
{
struct sockaddr_in si_other;
int s, i, slen=sizeof(si_other);
char buf[BUFLEN];
char message[BUFLEN];
if ( (s=socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1)
{
die("socket");
}
memset((char *) &si_other, 0, sizeof(si_other));
si_other.sin_family = AF_INET;
si_other.sin_port = htons(PORT);
if (inet_aton(SERVER , &si_other.sin_addr) == 0)
{
fprintf(stderr, "inet_aton() failed\n");
exit(1);
}
while(1)
{
printf("Enter message : ");
gets(message);
//send the message
if (sendto(s, message, strlen(message) , 0 , (struct sockaddr *) &si_other, slen)==-1)
{
die("sendto()");
}
//receive a reply and print it
//clear the buffer by filling null, it might have previously received data
memset(buf,'\0', BUFLEN);
//try to receive some data, this is a blocking call
if (recvfrom(s, buf, BUFLEN, 0, (struct sockaddr *) &si_other, &slen) == -1)
{
die("recvfrom()");
}
puts(buf);
}
close(s);
return 0;
}