How to get ip to hostname ?

[headshot]

Hello everybody . I have a text file , I want to compare ip with in line text
This is file text

codeguru.com

c++.com
C#.com

google.com



c+++.com

And this is my code

#include <iostream>
#include <fstream>
#include <string>
#include <conio.h>
using namespace std;


string getip(string hostname)
{
	//function get ip
}

void main ()
{
    string string_main="http://abc-xyz.com/www/~av.123.456.789.000?url.aspx/etc";
	
	int count=0;

	string string_sub;
	ifstream infile;
	infile.open ("E:\\test.txt");

        while(!infile.eof()) // To get you all the lines.
        {
	        getline(infile,string_sub); // Saves the line in string_sub.
	      //  cout<<string_sub<<"\n"; // Prints our string_sub.

			if (!string_sub.empty())
			{
				string temp=getip(string_sub); // get ip of string_sub on the text line by line 
				size_t result = string_main.find( temp ); //check string_sub on the text file line by line, comparable to string_main

				if( result != string::npos )  // if found
				{
					count+=1;
				}
			}
        }
	infile.close();
	//cout<< count <<"\n";
	if (count != 0)
	{
		cout << "Found\n";
	}
	else
	{
		cout << "Not found\n";
	}
getch();
}

Can you see it , How to create function get ip above ?
Thank you .

[S_M_A]

Here is an example http://msdn.microsoft.com/en-us/libr...(v=vs.85).aspx
See also this thread http://forums.codeguru.com/showthrea...ethostbyname()

[headshot]

Here is an example http://msdn.microsoft.com/en-us/libr...(v=vs.85).aspx
See also this thread http://forums.codeguru.com/showthrea...ethostbyname()

Hi S_M_A . I have read two topic at reference
In this case . can you build function in my code above ? . If possible , thank so much

string getip(string hostname)
{
	//function get ip
}

In addition , i try code of "OneEyeMan"

#include "stdafx.h"
#include <WinSock2.h>

int _tmain(int argc, _TCHAR* argv[])
{
	WSADATA data;
	struct hostent *host;
	int result;
	DWORD error;
	result = WSAStartup( MAKEWORD( 2, 2 ), &data );
	if( result )
	{
		printf( "Error initializing sockets!\n\r" );
		return 1;
	}
	host = gethostbyname( "www.google.com" );
	if( !host )
	{
		error = WSAGetLastError();
	}
	return 0;
}

And this is error

Thank

[S_M_A]

You obviously don't have a stdafx.h. How did you create the project and what MSVC version do you use?

[headshot]

You obviously don't have a stdafx.h. How did you create the project and what MSVC version do you use?

MVSC 2010 Pro v10.0.30319
I created project : New Project -> C++ ->WIn 32 console Aplication -> Empty Project . Then I add file .CPP to project.

[Ejaz]

1. Don't use conio.h/stdio.h. use iostream, which is more C++ oriented.

2. You have created an empty project, therefore there is no "stdafx.h" file, while copy/pasting the code, you've picked this one too, hence your compiler is complaining that it cannot find this file.

3. You also need to link with "ws2_32.lib", otherwise you'll started getting linking errors once you are done with compiler errors.

Following is the code for your reference.

#define WIN32_LEAN_AND_MEAN

#include <iostream>
#include <Windows.h>
#include <tchar.h>
#include <WinSock2.h>

#pragma comment(lib, "ws2_32.lib")	// Need to link with ws2_32.lib

int _tmain(int argc, _TCHAR* argv[])
{
	WSADATA data;
	struct hostent *host;
	int result;
	DWORD error;

	result = WSAStartup( MAKEWORD( 2, 2 ), &data );

	if( result )
	{
		std::cout << "Error initializing sockets!" << std::endl;
		return 1;
	}

	host = gethostbyname( "www.google.com" );

	if( !host )
	{
		error = WSAGetLastError();
	}
	return 0;
}

[headshot]

1. Don't use conio.h/stdio.h. use iostream, which is more C++ oriented.

2. You have created an empty project, therefore there is no "stdafx.h" file, while copy/pasting the code, you've picked this one too, hence your compiler is complaining that it cannot find this file.

3. You also need to link with "ws2_32.lib", otherwise you'll started getting linking errors once you are done with compiler errors.

Following is the code for your reference.

#define WIN32_LEAN_AND_MEAN

#include <iostream>
#include <Windows.h>
#include <tchar.h>
#include <WinSock2.h>

#pragma comment(lib, "ws2_32.lib")	// Need to link with ws2_32.lib

int _tmain(int argc, _TCHAR* argv[])
{
	WSADATA data;
	struct hostent *host;
	int result;
	DWORD error;

	result = WSAStartup( MAKEWORD( 2, 2 ), &data );

	if( result )
	{
		std::cout << "Error initializing sockets!" << std::endl;
		return 1;
	}

	host = gethostbyname( "www.google.com" );

	if( !host )
	{
		error = WSAGetLastError();
	}
	return 0;
}

Hi Ejaz . i try it and i get many error . All of error in file "ws2def.h" 127 Error and 16 Warning

[headshot]

Hi Ejaz . I think I have libaray ws2_32.lib link. I have links and build, no errors, but can not get the result of running the IP of google.com

[Ejaz]

Your question was to resolve the errors, which are done. Please start separate thread for different problems (i.e. do no start multiple question in a single thread). Anyway, for this specific case, you need to do little more. Following code is for your reference.

#include <iostream>
#include <string>
#include <winsock2.h>

#pragma comment(lib, "ws2_32.lib")	// Need to link with ws2_32.lib

std::string get_ip( const std::string& hostname )
{
	hostent * host_info;
	WSADATA wsa_data;
	SOCKADDR_IN sock_addr;

	if ( WSAStartup( MAKEWORD( 1 , 1 ) , &wsa_data ) != 0 ) 
	{
		throw std::exception("WSAStartup Failed.");
	}

	host_info = gethostbyname( hostname.c_str() );

	if ( host_info == NULL ) 
	{
		throw std::exception("Unable to resolve host.");
	}

	memcpy( &( sock_addr.sin_addr ) , 
			host_info->h_addr		, 
			host_info->h_length );

	std::string ip = inet_ntoa( sock_addr.sin_addr );

	WSACleanup();

	return ip;
}

int main()
{
	try
	{
		std::string url("www.google.com");
		std::cout << "IP of " << url << " : " << get_ip( url ) << std::endl;
	}
	catch ( std::exception& e )
	{
		std::cout << e.what() << std::endl;
	}
}

[headshot]

Hi Ejaz . can you see my code . I think www.google.com have six IP address as pic above

#include <stdlib.h>
#include <iostream>
#include <fstream>
#include <string>
#include <conio.h>
#include <stdio.h>
#include <WinSock2.h>  

#pragma comment(lib, "ws2_32") 

WSADATA wsaData; //golbal
//HOSTENT* list_ip;  golbal
IN_ADDR addr;  //golbal

using namespace std;

string getip(string hostname) 
{
	HOSTENT* list_ip; // not golbal, in this function
		/*
		// convert string to char 
		char c[1000];
		int so=hostname.size();
		for(int a=0;a<=so;a++)
		{
			c[a]=hostname[a];
		}
		*/
		if ( WSAStartup( MAKEWORD( 1 , 1 ) , &wsaData ) != 0 ) 
		{
				cout << "WSAStartup Failed.";
		}
		else
		{
			WSAStartup(MAKEWORD(2,0),&wsaData);
			//list_ip=gethostbyname(c);

			list_ip=gethostbyname(hostname.c_str()); //convert hostname from string to char

			if (list_ip ==NULL)
			{
				//ExitProcess(0);
				cout<<"Unable to resolve host.";
			}
			else
			{
				memcpy(&addr.S_un.S_addr , list_ip->h_addr, list_ip->h_length);
				return inet_ntoa(addr);
				WSACleanup();
			}
		}
}

void main ()
{
    //string string_main="http://abc-xyz.com/www/~av.64.71.33.95?url.aspx/etc";

	//int count=0;

	string string_sub;

	ifstream infile("E:\\test.txt");

	if (!infile)
	{
		cout << "Unable to open file\n";
        exit(1); // terminate with error
	}
    while(!infile.eof()) // To get you all the lines.
	{
	    getline(infile,string_sub); // Saves the line in string_sub.
	    cout<<string_sub<<"\n"; // Prints our string_sub.
			
		if (!string_sub.empty()) //check line have content 
		{
			string temp=getip(string_sub); //temp get ip from string_sub
			cout << temp <<"\n"; //prints IP of hostname

			//size_t result = string_main.find( string_sub ); //check string_sub on the text file line by line, comparable to string_main
			
			//if( result != string::npos )  // if found
			//{
			//	count+=1;
			//	//cout << "String is found at position"<< infile.tellg() << "\n"; 
			//}	
		}
    }
	infile.close();
	//cout<< count <<"\n";
	/*
	if (count != 0)
	{
		cout << "Found\n";
	}
	else
	{
		cout << "Not found\n";
	}*/
	//return 0;
getch();
}

And this is test.txt file

msdn.com

c++.com
C#.com

google.com



c+++.com

But I can get IP address form hostname ?
Thank you so much if you try it .

[Igor Vartanov]

Sample attached.

E:\Temp\660>660.exe www.google.com
HostName: www.l.google.com
Alias[0]: www.google.com
 Host[0]: 173.194.32.50
 Host[1]: 173.194.32.49
 Host[2]: 173.194.32.52
 Host[3]: 173.194.32.51
 Host[4]: 173.194.32.48

[headshot]

Hi . thank for your help
if you do not mind can see through my code, you can modify it slightly so that IP can print out. I think my jaw getip missing anything. Urge you to check out . I think in GetIP function

string getip(string hostname) 
{
	WSADATA wsaData; 
	IN_ADDR addr; 
	HOSTENT* list_ip; 
        //int i=0;
		if ( WSAStartup( MAKEWORD( 2 , 2 ) , &wsaData ) != 0 ) 
		{
				cout << "WSAStartup Failed.";
		}
		else
		{
			list_ip=gethostbyname(hostname.c_str()); //convert hostname from string to char
			if (list_ip ==NULL)
			{
				//ExitProcess(0);
				cout<<"Unable to resolve host.";
			}
			else
			{
//				while (list_ip->h_addr_list[i] != 0)
//				{
//					addr.S_un.S_addr=*(u_long *)list_ip->h_addr_list[i++];
//					return inet_ntoa(addr);
//				}
				memcpy(&addr.S_un.S_addr , list_ip->h_addr, list_ip->h_length);
				return inet_ntoa(addr);
				WSACleanup();
			}
		}
		WSACleanup();
}

[headshot]

Hi all
I have already edit function getip . I think it`s ok , but get one IP from hostname

[Ejaz]

Take a look at the sample attached here by Igor, step through it with the debugger and see how it works.