[ipv6hackers] Definition of "struct ip6_opt" in Mac OS

Adrian Bool adrian.bool at revolution.net.eu
Thu Jul 19 21:27:42 CEST 2012

Hi Fernando,

On Thu, Jul 19, 2012 at 7:45 PM, Fernando Gont <fernando at gont.com.ar> wrote:
> Just double-cheking: So this "Xcode" thing is the package that includes
> the header files, etc.?

Well, Xcode is Apple's IDE which includes a GUI, C/C++/Objective-C
compilers - and in later OSX versions too if I recall correctly - the
standard header files.

Actually this may be a little simplified as the way I think it works is you
install the Xcode app - which includes the GUI and compilers - and then
from within Xcode->Preferences->Downloads->Components you can "Install
Command Line Tools" which includes the header files.

If that's the case, is there any compile-time constant that I could use
> to check the Xcode version?

Not that I know of for Xcode.  Here's a list of the defined constants
(unlikely to be exhaustive),


It includes GCC version (GCC_VERSION) and the OS version
 (MACOSX_DEPLOYMENT_TARGET)  - one of these may help?

Perhaps the system on which the issue was reported had an updated OS but
still had the old library files?

(Big pity Apple aren't shipping the library files by default - they can't
really take up much room on diskā€¦)

Kind regards,



Adrian Bool, Director, Network Revolution Limited

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