Re: [PATCH] test-lib.sh: use awk instead of expr for a POSIX non integer check

[Eric Sunshine <sunshine@sunshineco.com>]

On Wed, Mar 9, 2022 at 3:14 PM Ævar Arnfjörð Bjarmason <avarab@gmail.com> wrote:
> On Wed, Mar 09 2022, Junio C Hamano wrote:
> > Eric Sunshine <sunshine@sunshineco.com> writes:
> >> This seems to work, though it's getting a bit verbose:
> >>
> >>     awk '/^glibc / { split($2,v,"."); if (sprintf("%s.%s", v[1], v[2])
> >> - 2.34 < 0) exit 1 }'
> >
> > In general it is a good discipline to question a pipeline that
> > preprocesses input fed to a script written in a language with full
> > programming power like awk and perl (and to lessor extent, sed) to
> > see if we can come up with a simpler solution without pipeline
> > helping to solve what these languages are invented to solve, and I
> > very much appreciate your exploration ;-)
>
> I agree :) But the first language we've got here is C. Rather than
> fiddle around with getconf, awk/sed etc. why not just the rather
> trivial:
>
>         +#include "test-tool.h"
>         +#include "cache.h"
>         +
>         +int cmd__glibc_config(int argc, const char **argv)
>         +{
>         +#ifdef __GNU_LIBRARY__
>         +       printf("%d\n%d\n", __GLIBC__, __GLIBC_MINOR__);
>         +       return 0;
>         +#else
>         +       return 1;
>         +#endif
>         +}

It feels overkill to add this just for this one case which is
otherwise done easily enough with existing shell tools.

That said, perhaps I'm missing something, but I don't see how this
solution helps us get away from the need for `expr`, `awk`, or `perl`
since one of those languages would be needed to perform the arithmetic
comparison (checking if glibc is >= 2.34).