#include <stdio.h>   /* for perror */
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>

int main(int argc, char **argv)
{
	const int s = socket(AF_INET, SOCK_DGRAM, 0);
	int ttl;   /* time to live */
	socklen_t length = sizeof ttl;

	if (s < 0) {
		perror(argv[0]);   /* Print message starting with argv[0]. */
		return 1;
	}

	if (getsockopt(s, IPPROTO_IP, IP_TTL, &ttl, &length) != 0) {
		perror(argv[0]);
		return 2;
	}

	printf("The time to live is %d.\n", ttl);
	return EXIT_SUCCESS;
}