Re: hostent address list dereferencing problem..

Jens.Toerring_at_physik.fu-berlin.de
Date: 01/28/05 

Date: 28 Jan 2005 01:02:18 GMT

BM <b.marsh@gmx.net> wrote:
> i'm having problems grabbing the IP out of the h_addr_list (or h_addr)
> sturct on a
> freshly gethostbyname'd hostent structure.

> struct in_addr **address;

> if((h=gethostbyname(node)) == NULL) {
> herror("gethostbyname");
> exit(1);
> }

> address=(struct in_addr **)h->h_addr;

You need

  address = ( struct in_addr ** ) h->h_addr_list;

h_addr is just defined to h_addr_list[ 0 ].

> for(; *address != NULL; address++);

Here you've got a semicolon at the end of the line that definitely
shouldn't be there...

> printf("addr: %s\n",*address);

Whats pointed to by address isn't a simple string so you need

  printf( "addr = %s\n", inet_ntoa( *address );

to convert it to a string in numbers-and-dots notation.

                                    Regards, Jens 

-- 
  \   Jens Thoms Toerring  ___  Jens.Toerring@physik.fu-berlin.de
   \__________________________  http://www.toerring.de

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