API used to know IP of the Interface in VC++? - visual-c++

Question

I want to know the name of API which used to know current IP of the Interface.
I have two interface ethernet and WLAN.Both Interface are UP and i want to know IP of specific interface then Is there any API in VC++ that will give me interface IP ?
Thanks,
Neel

Answer 1

GetAdaptersInfo or GetAdaptersAddresses.

Answer 2

Use DnsQuery
/************************************************************\
THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF
ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO
THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A
PARTICULAR PURPOSE.
Copyright © 2000 Microsoft Corporation. All Rights Reserved.
/***************************************************************/
/*
FILE: Dnsquery.cpp
DESCRIPTION: This sample illustrates the use of DnsQuery() function to send query to
a DNS server to resolve the host name to an IP address and vice-versa.
PLATFORM: Windows 2000
WRITTEN BY: Rashmi Anoop
DATE: 3/22/2000
*/
/*
includes
*/
#include <windows.h> //windows
#include <windns.h> //DNS api's
#include <stdio.h> //standard i/o
#include <winsock.h> //winsock
#define BUFFER_LEN 255
//Usage of the program
void Usage(char *progname) {
fprintf(stderr,"Usage\n%s -n [OwnerName] -t [Type] -s [DnsServerIp]\n",
progname);
fprintf(stderr,"Where:\n\t\"OwnerName\" is name of the owner of the record set being queried\n");
fprintf(stderr,"\t\"Type\" is the type of record set to be queried A or PTR\n");
fprintf(stderr,"\t\"DnsServerIp\"is the IP address of DNS server (in dotted decimal notation)");
fprintf(stderr,"to which the query should be sent\n");
exit(1);
}
// the main function
void __cdecl main(int argc, char *argv[])
{
DNS_STATUS status; // return value of DnsQuery_A() function.
PDNS_RECORD pDnsRecord; //pointer to DNS_RECORD structure
PIP4_ARRAY pSrvList = NULL; //pinter to IP4_ARRAY structure
LPTSTR pOwnerName = NULL; //owner name to be queried
WORD wType; //Type of the record to be queried
char DnsServIp[BUFFER_LEN]; //DNS server ip address
DNS_FREE_TYPE freetype ;
freetype = DnsFreeRecordListDeep;
IN_ADDR ipaddr;
if (argc > 4) {
for (int i = 1; i < argc ; i++) {
if ( (argv[i][0] == '-') || (argv[i][0] == '/') ) {
switch (tolower(argv[i][1])) {
case 'n':
pOwnerName = argv[++i];
break;
case 't':
if (!_stricmp(argv[i+1], "A") )
wType = DNS_TYPE_A; //Query host records to resolve a name
else if (!_stricmp(argv[i+1], "PTR") )
wType = DNS_TYPE_PTR; //Query PTR records to resovle an IP address
else
Usage(argv[0]);
i++;
break;
case 's':
// Allocate memory for IP4_ARRAY structure
pSrvList = (PIP4_ARRAY) LocalAlloc(LPTR,sizeof(IP4_ARRAY));
if (!pSrvList) {
printf("Memory allocation failed \n");
exit(1);
}
if (argv[++i]) {
strncpy(DnsServIp, argv[i], sizeof(DnsServIp)-1 );
DnsServIp[sizeof(DnsServIp)-1] = '\0';
pSrvList->AddrCount = 1;
pSrvList->AddrArray[0] = inet_addr(DnsServIp); //DNS server IP address
if ( pSrvList->AddrArray[0] == INADDR_NONE ) {
printf("Invalid DNS server IP address \n");
Usage( argv[0] );
}
break;
}
default:
Usage(argv[0]);
break;
}
}
else
Usage(argv[0]);
}
}
else
Usage(argv[0]);
// Calling function DnsQuery_A() to query Host or PTR records
status = DnsQuery_A(pOwnerName, //pointer to OwnerName
wType, //Type of the record to be queried
DNS_QUERY_BYPASS_CACHE, // Bypasses the resolver cache on the lookup.
pSrvList, //contains DNS server IP address
&pDnsRecord, //Resource record comprising the response
NULL); //reserved for future use
if (status) {
if (wType == DNS_TYPE_A)
printf("Failed to query the host record for %s and the error is %d \n", pOwnerName, status);
else
printf("Failed to query the PTR record and the error is %d \n", status);
}
else {
if (wType == DNS_TYPE_A) {
//convert the Internet network address into a string
//in Internet standard dotted format.
ipaddr.S_un.S_addr = (pDnsRecord->Data.A.IpAddress);
printf("The IP address of the host %s is %s \n", pOwnerName,inet_ntoa(ipaddr));
// Free memory allocated for DNS records
DnsRecordListFree(pDnsRecord, freetype);
}
else {
printf("The host name is %s \n",(pDnsRecord->Data.PTR.pNameHost));
// Free memory allocated for DNS records
DnsRecordListFree(pDnsRecord, freetype);
}
}
LocalFree(pSrvList);
}
Output :
DNSQuery.exe -n localhost -t A
The IP address of the host localhost is 127.0.0.1