Re: [PATCH 2/2] travis-ci: record and skip successfully built trees

From: Junio C Hamano <gitster@pobox.com>
Date: Dec 28, 2017, 19:01 UTC
Message-ID: <xmqqlghmllrq.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <CAM0VKjmCodQgmTa8bjEc02N99cPjrFdp4rFGF3yQOA-VMer4hw@mail.gmail.com>

SZEDER Gábor <szeder.dev@gmail.com> writes:

Show 12 quoted lines

> I was aware that things like 'cmd file >file' don't work, because the
> shell opens and truncates 'file' before executing the command, so 'cmd'
> will open the already empty file, but I didn't know that 'echo "$(cmd
> file)" >file' works.  Thanks for letting me know.
>
> However, this is subject to the portability issues of the shell's
> 'echo', i.e. try
>
>   echo "$(cat git.c)" >git.c
>
> with Bash and Dash.  Bash produces the exact same contents, but Dash
> turns all '\n' in help and error strings to real newline characters.

Besides, that is a bad practice in general if you do not have a guarantee that 'git.c' (or whatever file in question) is small enough not to bust any platform's argv[] length limit.

> ...  Still, I think it'd be better
> to stick to using a good old temporary file:

Yes.