Tuesday, August 09, 2011

Hinky Hack - ipconv.c

This little program takes a dotted-quad IP and returns the 32 bit unsigned integer that is the "real" address.  Given a 32 bit "real" address, it will return the dotted-quad representation.

Given an FQDN it will return 0.

I already know there are a zillion different ways to do this, so spare me your Better Way.

#include <stdlib.h>
#include <stdio.h>
#include <arpa/inet.h>
#include <string.h>

void main( int argc, char **argv )
   struct in_addr x;

   if ( argc==1 || argc>2 ) return ;
   if ( (strchr(argv[1], '.'))!=NULL) {
      inet_aton( argv[1], &x );
      printf( "%u\n", ntohl(x.s_addr) );
   } else {
     printf("%s\n", inet_ntoa(x) );

Compiles fine under Cygwin or vanilla Linux.

Oh and screw you if you don't like my coding style.

And I mean that in the most positive way possible.