From: Jonathan Nieder <jrnieder@gmail.com>
To: Jeff King <peff@peff.net>
Cc: Eric Rannaud <eric.rannaud@gmail.com>,
git@vger.kernel.org,
Johannes Schindelin <johannes.schindelin@gmx.de>,
Jeremy Serror <jeremy.serror@gmail.com>,
Brandon Williams <bmwill@google.com>
Subject: Re: git rebase regression: cannot pass a shell expression directly to --exec
Date: Tue, 16 May 2017 09:41:24 -0700 [thread overview]
Message-ID: <20170516164124.GO27400@aiede.svl.corp.google.com> (raw)
In-Reply-To: <20170516033736.23cfkouus3p67vhc@sigill.intra.peff.net>
(+Brandon Williams, who may have more context for execvp-related things)
Hi,
Jeff King wrote:
> On Mon, May 15, 2017 at 11:25:03PM -0400, Jeff King wrote:
>> One hack would be to look for BASH_FUNC_* in the environment and disable
>> the optimization in that case. I think that would make your case Just
>> Work. It doesn't help other oddball cases, like:
>>
>> - you're trying to run a shell builtin that behaves differently than
>> its exec-able counterpart
>>
>> - your shell has some other mechanism for defining commands that we
>> would not find via exec. I don't know of one offhand. Obviously $ENV
>> could point to a file which defines some, but for most shells would
>> not read any startup files for a non-interactive "sh -c" invocation.
>
> So I was thinking something like the patch below, though I guess
> technically you could look for BASH_FUNC_$argv[0]%%, which seems to be
> bash's magic variable name. I hate to get too intimate with those
> details, though.
>
> Another option is to speculatively run "foo" without the shell, and if
> execve fails to find it, then fall back to running the shell. That would
> catch any number of cases where the shell "somehow" finds a command that
> we can't.
Hm. execvp explicitly does this when it hits ENOEXEC, but not for
ENOENT. Do you know why that is?
I think we want to behave consistently for shell builtins and for
exported functions --- they are different sides of the same problem,
and behaving differently between the two feels confusing.
Thanks,
Jonathan
next prev parent reply other threads:[~2017-05-16 16:41 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-15 18:08 git rebase regression: cannot pass a shell expression directly to --exec Eric Rannaud
2017-05-16 3:25 ` Jeff King
2017-05-16 3:37 ` Jeff King
2017-05-16 16:41 ` Jonathan Nieder [this message]
2017-05-16 16:47 ` Jeff King
2017-05-16 17:11 ` Eric Rannaud
2017-05-16 17:15 ` Brandon Williams
2017-05-16 17:23 ` Jeff King
2017-05-16 17:30 ` Brandon Williams
2017-05-16 19:14 ` Linus Torvalds
2017-05-16 19:35 ` [TANGENT] run-command: use vfork instead of fork Eric Wong
2017-05-16 20:47 ` Linus Torvalds
2017-05-16 21:11 ` Brandon Williams
2017-05-16 20:12 ` git rebase regression: cannot pass a shell expression directly to --exec Johannes Schindelin
2017-05-16 20:27 ` Linus Torvalds
2017-05-16 17:37 ` Jonathan Nieder
2017-05-16 3:40 ` Junio C Hamano
2017-05-16 3:53 ` Jeff King
2017-05-16 4:08 ` Jeff King
2017-05-16 16:45 ` Eric Rannaud
2017-05-16 10:46 ` Johannes Schindelin
2017-05-16 10:23 ` Johannes Schindelin
2017-05-16 16:18 ` Jeff King
2017-05-16 16:59 ` Eric Rannaud
2017-05-16 17:14 ` Kevin Daudt
2017-05-16 17:29 ` Eric Rannaud
2017-05-16 17:41 ` Jeff King
2017-05-16 17:21 ` Eric Rannaud
2017-05-16 17:37 ` Jeff King
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