Re: [PATCH] redir: savefd: use F_DUPFD_CLOEXEC instead of F_DUPFD+F_SETFD

[Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>]

Jilles Tjoelker <jilles@xxxxxxxx> wrote:
> On Sat, Dec 17, 2022 at 12:01:09AM +0100, наб wrote:
>> [use F_DUPFD_CLOEXEC instead of F_DUPFD+F_SETFD]
>> This saves a syscall on every source file open, &c.;
>> F_DUPFD_CLOEXEC is a mandatory part of POSIX since Issue 7
>> (Austin Group Interpretation 1003.1-2001 #171).
> 
> This is a small optimization and simplification if all target platforms
> support F_DUPFD_CLOEXEC, but it may not be worth it if this code is
> supposed to work on older platforms. In the mailing list archives, there
> are various patches (some applied) to make dash work on old platforms.
> 
> Often, the newer _CLOEXEC interfaces are used to avoid race conditions,
> but not here, which might confuse porters that the necessary changes are
> more complicated than they need to be.

Right.  I would accept this patch if you add the autoconf bits
to retain support for older platforms.

Thanks,
-- 
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
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