imported>Unknown at 05:23, 7 February 2021

2021-02-07T05:23:38Z

New page

= sample code =
/**
request domain name thru ip address from DNS server

eternalbleu

2006 03 23

**/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <unistd.h>

void error_handling(const char* message);

int main(int argc, char ** argv)
{
struct hostent* host;
struct sockaddr_in addr;
int i;

if (argc != 2) {
printf("USAGE : %s <ip>\n", argv[0]);
exit(1);
}

memset(&addr, 0, sizeof(addr));
addr.sin_addr.s_addr=inet_addr(argv[1]);

host = gethostbyaddr((char*)&addr.sin_addr, 4, AF_INET);
if(!host)
error_handling("gethost... error");

printf("Officially name : %s \n\n", host->h_name);

puts("Aliases ------");
for(i=0; host->h_aliases[i]; i++) {
puts(host->h_aliases[i]);
}

printf("Address Type:$s\n", host->h_addrtype == AF_INET? "AF_INET":"AF_INET6");

puts("IP Address ------");
for(i=0; host->h_addr_list[i]; i++) {
puts(inet_ntoa( *(struct in_addr*)host->h_addr_list[i]));
}

return 0;
}

void error_handling(const char* message)
{
fputs(message, stderr);
fputc('\n', stderr);
exit(1);
}
표준 BSD socket 을 이용한 소스. 리눅스에서 컴파일해야함. 대충 바꾸면 윈도우에서도 할 수 잇음.

LinuxProgramming/QueryDomainname - Revision history

imported>Unknown at 05:23, 7 February 2021