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From:   "Randall S. Becker" <rsbecker@nexbridge.com>
To:     "'Jeff King'" <peff@peff.net>
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Subject: RE: [Breakage] Git v2.21.0-rc0 - t5318 (NonStop)
Date:   Fri, 8 Feb 2019 14:26:17 -0500
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On February 8, 2019 14:15, Jeff King wrote:
> On Fri, Feb 08, 2019 at 01:47:04PM -0500, Randall S. Becker wrote:
> 
> > > 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.
> >
> > For this, we could use truncate -s count file instead of dd to get a
> > fixed size file of nulls. This would remove the need for /dev/zero in
> > t5318 (the patch below probably will wrap badly in my mailer so I can
> > submit a real patch separately.
> 
> I don't think "truncate" is portable, though.

It is available AFAIK on Linux, POSIX, and Windows under Cygwin. That's more than /dev/zero has anyway. I have the patch ready if you want 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.
> >
> > What about reading from /dev/null?
> 
> That would yield zero bytes, not an infinite number of them.

So something like: yes | tr 'y' '\0' | stuff?