DNS test program for HP

$ ./getaddrinfo localhost
Host: localhost
IPv4 address: 127.0.0.1 (localhost.oracle.com)

$ ./getaddrinfo CAKOA01
Host: CAKOA01
IPv4 address: 211.106.67.221 (CAKOA01)


============== =============
#include
#include
#include
#include
#include
#include
#include

int lookup_host (const char *host)
{
struct addrinfo hints, *res;
int errcode;
char addrstr[100];
void *ptr;

memset (&hints, 0, sizeof (hints));
hints.ai_family = PF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
hints.ai_flags |= AI_CANONNAME;

errcode = getaddrinfo (host, NULL, &hints, &res);
if (errcode != 0)
{
perror ("getaddrinfo");
return -1;
}

printf ("Host: %s\n", host);
while (res)
{
inet_ntop (res->ai_family, res->ai_addr->sa_data, addrstr, 100);

switch (res->ai_family)
{
case AF_INET:
ptr = &((struct sockaddr_in *) res->ai_addr)->sin_addr;
break;
case AF_INET6:
ptr = &((struct sockaddr_in6 *) res->ai_addr)->sin6_addr;
break;
}
inet_ntop (res->ai_family, ptr, addrstr, 100);
printf ("IPv%d address: %s (%s)\n", res->ai_family == PF_INET6 ? 6 : 4,
addrstr, res->ai_canonname);
res = res->ai_next;
}

return 0;
}

int
main (int argc, char *argv[])
{
if (argc < 2)
exit (1);
return lookup_host (argv[1]);
}