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Subject: Re: [Breakage] Git v2.21.0-rc0 - t5318 (NonStop)
To:     Jeff King <peff@peff.net>,
        "Randall S. Becker" <rsbecker@nexbridge.com>
Cc:     'Junio C Hamano' <gitster@pobox.com>, git@vger.kernel.org,
        'Linux Kernel' <linux-kernel@vger.kernel.org>,
        git-packagers@googlegroups.com
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From:   Johannes Sixt <j6t@kdbg.org>
Message-ID: <0694f2f1-040a-1d8c-cd01-2cf51cdbe426@kdbg.org>
Date:   Fri, 8 Feb 2019 19:29:33 +0100
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Am 08.02.19 um 19:03 schrieb Jeff King:
> On Fri, Feb 08, 2019 at 12:49:59PM -0500, Randall S. Becker wrote:
>> Would you object to something like this:
>>
>> if [ ! -e /dev/zero ]; then
>> 	# use shred or some other mechanism (still trying to figure out a solution)
>> else
>> 	# existing dd
>> fi
> 
> That's fine, as long as it's wrapped up in a function in order to keep
> the tests readable.
> 
> Though I suspect we may be able to just find a solution that works
> everywhere, without having two different implementations. If we know we
> need $count bytes for dd, we could probably just generate a file with
> that many NULs in it.
> 
> Other cases don't seem to actually care that they're getting NULs, and
> are just redirecting stdin from /dev/zero to get an infinite amount of
> input. They could probably use "yes" for that.

If the data does not have to be a sequence of zero bytes, the
alternatives are:

* `test-genrandom seed-string $size` for a sequence of reproducible
"random" bytes

* `printf "%0*d" $size 0` for a sequence of '0' characters.

In t5318, the zero bytes do matter, though.

-- Hannes