Re: [PATCH v2 1/2] perl: redirect stderr to /dev/null instead of closing

From: Junio C Hamano <gitster@pobox.com>
Date: Apr 5, 2013, 18:57 UTC
Message-ID: <7vsj34byb4.fsf@alter.siamese.dyndns.org>
In-Reply-To: <20130405144828.GX6137@machine.or.cz>

Petr Baudis <pasky@ucw.cz> writes:

Show 14 quoted lines

>> >  		} elsif ($pid == 0) {
>> > -			if (defined $opts{STDERR}) {
>> > -				close STDERR;
>> > -			}
>> >  			if ($opts{STDERR}) {
>> >  				open (STDERR, '>&', $opts{STDERR})
>> >					or die "dup failed: $!";
>> 
>> Indeed.  Thanks for pointing that out.
>
>   I'm sorry, I don't follow. Doesn't this just break the STDERR option
> altogether as we will try to dup2() over an already open file
> descriptor? We do need to close STDERR if we are going to reopen it,
> I think.

When $opts{STDERR} is 2, what the three lines the proposed patch removes did is actively wrong, because you dup2 the fd you just closed.

When $opts{STDERR} is 1, it seems to do the right thing with or without the "close STDERR" in front. Isn't this because the usual "open($fd, <<<anything>>>) closes $fd as necessary" applies to this case as well?

So, I am not sure what you are viewing as a problem.  Puzzled...