On Wed, Dec 15, 2021 at 1:21 PM Rich Felker <dalias@libc.org> wrote:
>
> On Wed, Dec 15, 2021 at 01:37:43PM -0500, Andrew Snyder wrote:
> > That is probably true but I think on accident trying to replicate my
> > original issue which was using the native function
>
> With the program:
>
> #include <stdio.h>
> int main(int argc, char **argv)
> {
>         printf("%0*i\n", 2, argc);
> }
>
> (written using argc so it can't be collapsed to a constant string at
> compile time) I get output of "01\n" as expected. If you think there's
> a bug in musl for this or related functionality, can you provide a
> minimal C test case?
>
> > On Wed, Dec 15, 2021 at 1:09 PM Quentin Rameau <quinq@fifth.space> wrote:
> >
> > > Hi Andrew,
> > >
> > > > Sorry accidentally sent before attaching this
> > > >
> > > > ~# docker run -it --rm alpine /bin/ash
> > > > / # /lib/libc.musl-x86_64.so.1
> > > > musl libc (x86_64)
> > > > Version 1.2.2
> > > > Dynamic Program Loader
> > > > Usage: /lib/libc.musl-x86_64.so.1 [options] [--] pathname [args]
> > > > / # printf %0*i 2 1
> > > > ash: %0*i: invalid format
> > >
> > > This looks like you found a bug in Busybox printf implementation.
>
> FWIW I suspect the problem is that Busybox is not recognizing the 0
> character as a flag (which it is, in the printf grammar) and thinks
> it's the leading character of a width, making the * specifier for
> width invalid (since a width was already seen).

yeah, since i was curious whether toybox had an issue too, i tested
this (with bionic and glibc, but _not_ musl) and saw that coreutils
and toybox both produce the correct output, but busybox fails with
"invalid format" for glibc too.

> Rich