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From: Rich Felker <dalias@libc.org>
To: Markus Wichmann <nullplan@gmx.net>
Cc: musl@lists.openwall.com
Subject: Re: [musl] Feasibility of FD_CLOEXEC on all streams
Date: Sat, 18 Dec 2021 12:14:15 -0500	[thread overview]
Message-ID: <20211218171414.GO7074@brightrain.aerifal.cx> (raw)
In-Reply-To: <20211218163320.GA1950@voyager>

On Sat, Dec 18, 2021 at 05:33:20PM +0100, Markus Wichmann wrote:
> Hi all,
> 
> I was recently reading the source code of popen(), and noticed that it
> has to iterate over all open files to close all the open pipe FDs the
> child might inherit. And that made me wonder:
> 
> 1. Does POSIX allow for all FILE streams to have FD_CLOEXEC applied by
> default?

No. Accessing fileno(f) is permissible subject to following the rules
for active handle:

https://pubs.opengroup.org/onlinepubs/9699919799/functions/V2_chap02.html#tag_15_05_01

and that entails being able to use them according to the rules for how
fds are inherited across exec.

Rich

  reply	other threads:[~2021-12-18 17:14 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-12-18 16:33 Markus Wichmann
2021-12-18 17:14 ` Rich Felker [this message]
2021-12-18 17:26   ` Rich Felker
2021-12-19 14:54     ` Alex Xu (Hello71)
2021-12-19 15:22       ` Rich Felker

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