+int main(int argc, char *argv[])
+{
+ int sock;
+ int i, nread;
+ struct sockaddr_in addr;
+ char buffer[MAXLINE];
+ ...
+ /* create socket */
+ if ( (sock = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
+ perror("Socket creation error");
+ return -1;
+ }
+ /* initialize address */
+ memset((void *) &addr, 0, sizeof(addr)); /* clear server address */
+ addr.sin_family = AF_INET; /* address type is INET */
+ addr.sin_port = htons(13); /* daytime port is 13 */
+ /* build address using inet_pton */
+ if ( (inet_pton(AF_INET, argv[optind], &addr.sin_addr)) <= 0) {
+ perror("Address creation error");
+ return -1;
+ }
+ /* send request packet */
+ nread = sendto(sock, NULL, 0, 0, (struct sockaddr *)&addr, sizeof(addr));
+ if (nread < 0) {
+ perror("Request error");
+ return -1;
+ }
+ nread = recvfrom(sock, buffer, MAXLINE, 0, NULL, NULL);
+ if (nread < 0) {
+ perror("Read error");
+ return -1;
+ }
+ /* print results */
+ if (nread > 0) {
+ buffer[nread]=0;
+ if (fputs(buffer, stdout) == EOF) { /* write daytime */
+ perror("fputs error");
+ return -1;
+ }
+ }
+ /* normal exit */
+ return 0;
+}