toaruos/apps/nslookup.c

40 lines
959 B
C

/* vim: ts=4 sw=4 noexpandtab
* This file is part of ToaruOS and is released under the terms
* of the NCSA / University of Illinois License - see LICENSE.md
* Copyright (C) 2016-2018 K. Lange
*
* nslookup - perform nameserver lookups
*
*/
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <stdlib.h>
#include <getopt.h>
#include <sys/socket.h>
static void ip_ntoa(uint32_t src_addr, char * out) {
sprintf(out, "%d.%d.%d.%d",
(unsigned int)((src_addr & 0xFF000000) >> 24),
(unsigned int)((src_addr & 0xFF0000) >> 16),
(unsigned int)((src_addr & 0xFF00) >> 8),
(unsigned int)((src_addr & 0xFF)));
}
int main(int argc, char * argv[]) {
if (argc < 2) return 1;
struct hostent * host = gethostbyname(argv[1]);
if (!host) {
fprintf(stderr, "%s: not found\n", argv[1]);
return 1;
}
char addr[16] = {0};
ip_ntoa(*(uint32_t *)host->h_addr_list[0], addr);
fprintf(stderr, "%s: %s\n", host->h_name, addr);
return 0;
}