#include <stdio.h>

#include <sys/types.h>  
#include <sys/socket.h> 
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>  

#include <errno.h>  

#ifndef INADDR_NONE
#	define INADDR_NONE (in_addr_t)-1
#endif

int main(int argc, char *argv[])
{

	struct  hostent			*hp;
	u_long					add;
#if CUTRE
	int						ip[4];
#endif

	if ( (argc!=2) ||
		(INADDR_NONE  == (add = inet_addr(argv[1]))))
	{
		fprintf( stderr,"uso: %s ip\n", argv[0] );
		exit(1);
	}

#if CUTRE
	{
		fprintf( stderr,"uso: %s ip\n", argv[0] );
		exit(1);
	}

	add = (
			(( ip[0] & 0x00ff ) << 24 ) |
			(( ip[1] & 0x00ff ) << 16 ) |
			(( ip[2] & 0x00ff ) << 8 ) |
			( ip[3] & 0x00ff ) 
			);

	printf("%x\n", add);
#endif

	if ( NULL == ( hp = gethostbyaddr((void *)&add, sizeof(add),AF_INET)))
	{
		perror("gethostbyaddr: can't get host");
		exit(2);
	}
	else
	{
		puts(hp->h_name);
	}

	exit (0);
}