Re: off_t weirdness

On Mar 13, 2005, at 8:31 AM, Nikolai Weibull wrote:

> Try this on a Linux+glibc+GCC system:
>
> #include <assert.h>
> #include <ruby.h>
> #include <sys/types.h>
>
> int
> main(void)
> {
> 	return sizeof(off_t);
> }
>
> on my system the result is 4.  Now, if I write this as
>
In this case /usr/include/features.h is included (by assert.h) before 
the ruby source file 'defines.h'.

> #include <ruby.h>
> #include <assert.h>
> #include <sys/types.h>
>
> int
> main(void)
> {
> 	return sizeof(off_t);
> }
In this case features.h is included after defines.h.

defines.h defines a constant (I forget which one) which tells glibc to 
use 8 byte offsets.
(If this constant is not defined when features.h is included then 4 
byte offsets are used.)

>
> instead, the result is 8.  This "bug" set me back about an hour of
> work, which kind of sucked.

I had the same experience once... it also sucked.

-Charlie