On Thursday 14 September 2006 15:01 Andreas Schwab wrote:
> Philipp Marek <philipp@xxxxxxxxxxxxx> writes:
> > If I'm doing
> > ino_t ino;
> > char *name;
> > sprintf("%Lu %s", ino, name);
> Note that "L" is not a valid length modifier for integer formats.
For gnu libc it is:
http://www.gnu.org/software/libc/manual/html_node/Integer-Conversions.html#Integer-Conversions
> > that works fine for 64bit systems, but writes trash for sizeof(ino_t) ==
> > 4.
> >
> > Is there an easy way to find the format strings (sprintf, printf, sscanf)
> > for various system types, or something like that?
>
> Assuming you meant %llu instead of %Lu you can always add a cast to
> unsigned long long to match the format.
Yes. But that's a bit unclean, and doing that unnecessarily in a loop for
~300000 iterations is something I'd like to avoid.
> > Or has somebody some already defined preprocessor magic to get this for
> > some variable?
> > I'm thinking of something along the lines
> > #define FORMAT(x)
> > #if sizeof(x) == 4
> > "%l"
> > #else
> > #if sizeof(x) == 8
> > "%L"
> > #else
> > #error "Don't know size"
> > #endif
> > #endif
>
> You can't use sizeof in preprocessor directives.
Yes, that was meant as some kind of pseudo-code.
> Besides that, the size
> of an integer says nothing about its type. For example, a 4 byte integer
> can be either int or long on an ILP32 system, and an 8 byte integer can be
> long or long long on an LP64 system.
But that main problem arises if the printf() format doesn't match the size
pushed on the stack - then the remaining arguments are read in the wrong
order.
If I know that some variable is 32bit, and %lu takes a 32bit integer from the
stack, I'm saved.
Thank you for your answer - I think I'll have to go with casting everything.
Regards,
Phil
--
Versioning your /etc, /home or even your whole installation?
Try fsvs (fsvs.tigris.org)!
_______________________________________________
Autoconf mailing list
Autoconf@xxxxxxx
http://lists.gnu.org/mailman/listinfo/autoconf
