Re: Test failures with GNU grep 2.23

> On Sun, Feb 07, 2016 at 04:25:40PM +0000, John Keeping wrote:
>> The following patch fixes the tests for me, but I wonder if "-a" is
>> supported on all target platforms (it's not in POSIX, which specifies
>> that the "input files shall be text files") or whether we should do
>> something more comprehensive to provide sane_{e,f,}grep which guarantee
>> to treat input as text.
>>
>> I also tried setting POSIXLY_CORRECT but that doesn't affect the
>> text/binary decision.
>
> Yeah, I'd worry that "-a" is not portable. OTOH, BSD grep seems to have
> it, so between that and GNU, I think most systems are covered.

> We could
> do:
>
>   test_lazy_prereq GREP_A '
>         echo foo | grep -a foo
>   '
>
> and mark these tests with it. I'd also be happy to skip that step and
> just do it if and when somebody actually complains about a system
> without it (I wouldn't be surprised if most people on antique systems
> end up installing GNU grep anyway).
>
> Another option might be using "sed -ne '/^author/p'" or similar. But
> that may very well just be trading one portability problem for another.
>
> I also wondered whether we could get away without grepping at all here.
> But the blame output has a bunch of cruft we don't care about; I think
> the readability of the tests would suffer if we tried to match the whole
> thing in a test_cmp.
>
> -Peff