//-------------------------------------------------------------------
//	iplookup.cpp
//
//	This program shows how we can reimplement the functionality
//	of our earlier Python program ('iplookup.py') using the C++
//	programming language, which affords us a better view of the 
//	role the 'sockets' application programming interface plays. 
//
//		compile using:  $ g++ iplookup.cpp -o iplookup
//		execute using:  $ ./iplookup <hostname>
//
//	programmer: ALLAN CRUSE
//	written on: 28 JAN 2009
//-------------------------------------------------------------------

#include <netdb.h>	// for gethostbyname()
#include <string.h>	// for strncpy() 
#include <stdio.h>	// for printf()  
#include <arpa/inet.h>	// for inet_ntop()

#define BUFLEN	INET_ADDRSTRLEN

int main( int argc, char **argv )
{
	char	hostname[ 64 ] = { 0 };
	if ( argc == 1 ) strcpy( hostname, "localhost" );  
	else	strncpy( hostname, argv[ 1 ], 63 );

	char	hostip[ BUFLEN ] = { 0 };
	struct hostent	*hostinfo = gethostbyname( hostname );	
	if ( !hostinfo ) strcpy( hostip, "unknown" );
	else	inet_ntop( AF_INET, hostinfo->h_addr, hostip, BUFLEN );

	printf( "The IP-address for \'%s\' is %s \n", hostname, hostip );
}