Re: about struct in_addr

["Lan Qing" <efiish () gmail com>]

So,never mind it is a structure or a typedef,it point to the same memory
address,to use a structure only for it's historical reason like Guy Harris
said?

On 5/7/06, Sebastien Raveau <sebastien.raveau () epita fr> wrote:
> On Saturday 06 May 2006 06:18, Lan Qing wrote:
> > the struct in_addr have only one variable in it, is there any necessary
> to
> > define a struct like that?
> > why not use "typedef in_addr_t in_addr;" directly?
>
> POSIX (the standard for UNIX software) states that: "The <netinet/in.h>
> header
> shall define the in_addr structure that includes at least the following
> member: in_addr_t  s_addr", as you can see for youself at:
> http://www.opengroup.org/onlinepubs/009695399/basedefs/netinet/in.h.html
>
> So it's a structure because it has to contain AT LEAST that one member :-)
>
> But as Hannes Gredler pointed out, the result will be exactly the same
> wether
> it's a typedef or a structure: the former will be transformed by the
> compiler
> into a reference to some memory address containing 4 bytes, and the latter
> into a reference to some memory address containing a structure with an
> offset
> of 0 to access its first 4 bytes...
>
> --
> Sébastien Raveau
> computer and network security student
> head of the hawKeye network monitor project
> http://hawkeye.sourceforge.net/
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