Hi Paul,
Paul Eggert <egg...@cs.ucla.edu> skribis:
> On 11/12/11 13:48, Ludovic Courtès wrote:
>> +#ifdef __GNU__
>> + if (euid == -1 && !use_real
>> + && !just_group && !just_group_list && !just_context)
>> + error (EXIT_FAILURE, errno, _("cannot get effective UID"));
>> +#endif
>
> I suggest removing the "#ifdef __GNU__" here and in its other
> three uses in the patch, as functions like as geteuid() can fail on
> a few non-GNU systems too. See:
>
> http://publib.boulder.ibm.com/infocenter/iseries/v5r3/index.jsp?topic=%2Fapis%2Fgeteuid.htm
>
> For this particular application (the 'id' program) I doubt whether
> it's worth our time to configure this stuff at compile-time,
> and that it's fine to do a run-time check on all platforms.
OTOH, on POSIX-conforming systems (which includes GNU/Linux, so it may
be the majority of systems in use), -1 may well be a valid UID/GID.
That’s why I was conservative and decided to ifdef that. This ifdef
also served as a documentation that this is a GNU extension to POSIX.
Perhaps it’d be safer to keep an ifdef and list all the OSes known to
have this behavior?
Thanks,
Ludo’.
