#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <stdio.h>
main(argc, argv)
int argc;
char **argv;
{
struct hostent *hp;
long addr;
if (argc != 2) {
fprintf(stderr, "usage: %s i.p.addres\n", argv[0]);
exit(1);
}
addr = inet_addr(argv[1]);
if (hp = gethostbyaddr((char *) &addr, sizeof(addr), AF_INET)) {
printf("Hostname:\t%s\n", hp->h_name);
printf("Aliases:\t");
while (hp->h_aliases[0])
printf("%s ", *hp->h_aliases++);
printf("\n");
printf("Addresses:\t");
while (hp->h_addr_list[0])
printf("%s ", inet_ntoa(*(struct in_addr *) * hp->h_addr_list++));
printf("\n");
exit(0);
}
fprintf(stderr, "host %s not found\n", argv[1]);
exit(1);
}