Hi Jim,
> > On 07/20/2011 07:34 AM, Ralph Corderoy wrote:
> > > BTW, the code for the built-in printf has a bug. For negative
> > > field-widths it negates a negative integer without checking it
> > > will fit. E.g. on this 64-bit machine
> > >
> > > $ printf '%-9223372036854775808s.\n' foo
> > > foo.
> > > $
> >
> > Coreutils' printf shares this misfortune. Sadly, it might even be a
> > bug in the underlying glibc printf(), although I haven't tried to
> > write a test program to check that, yet.
>
> This is not about a negative field width.
Just to ensure there's no confusion, as far as bash's built-in printf is
concerned one aspect of it is about a negative field width since
$ printf '.%*q.\n' -10 foo
.foo .
is implemented by converting the "-10" into a number, spotting it's
negative, setting the left-justified flag, and then negating the number.
Coreutils' printf doesn't have that particular issue since it passes the
negative number to the C library as a negative and has it deal with the
justification change. For %b, which libc doesn't support, coreutils
says
/* FIXME: Field width and precision are not supported
for %b, even though POSIX requires it. */
so there's no code to go wrong. :-)
Cheers, Ralph.
