Re: [PATCH 3/3] mingw: document the experimental standard handle redirection

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Nov 3, 2017, 11:51 UTC
Message-ID: <alpine.DEB.2.21.1.1711031251060.6482@virtualbox>
In-Reply-To: <xmqqzi84p1ue.fsf@gitster.mtv.corp.google.com>

Hi Junio,

On Fri, 3 Nov 2017, Junio C Hamano wrote:

Show 10 quoted lines

> Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:
> 
> >> If I was correct in assuming that "2>&1" is just as foreign as
> >> ">/dev/null", then we should be shunning "2>&1" just like we shun
> >> ">/dev/null".  That was all I meant to say.
> >
> > Did you know that `2>&1` works in Powershell?
> 
> No.  And that makes me curious if ">&-" is also there to replace
> "off" ;-)

No, it does not:

-- snip --
PS C:\Users\me> echo 123 >&-
At line:1 char:11
+ echo 123 >&-
+           ~
Missing file specification after redirection operator.
At line:1 char:11
+ echo 123 >&-
+           ~
The ampersand (&) character is not allowed. The & operator is reserved for future use; wrap an ampersand in double
quotation marks ("&") to pass it as part of a string.
    + CategoryInfo          : ParserError: (:) [],
ParentContainsErrorRecordException
    + FullyQualifiedErrorId : MissingFileSpecification
-- snap --

Besides, we're really getting off-track here. I do not *like* `2>&1` as quite cryptic placeholder for `redirect stderr into the same handle as stdout was already redirected`. It is Perl-level obscurity.

Adding even more of those "let's string together non-alphanumerical characters together and declare that they have some special meaning that nobody would guess so they have to ask us and thereby make us feel smarter than we are" is definitely not anything I want.

In my opinion, `off` is kind of a compromise that is both easy to understand and hard to confuse.

If there was a short, succinct and easy-to-understand textual representation of `same as stdout` that would not be easily confused for a real file path, I would rather use that instead.

Please note, though, that I am again very reluctant to change things for less than really compelling reasons at this stage. I have just burned two days as a consequence of Peff's decision to take my --no-lock-index work and turn it into something different enough that I had to put in more work to adjust it, only to introduce a bug in something that worked without any problem for over one entire year.

It is quite a bit ridiculous just how much bug hunting time I have to spend lately on stuff that used to work and that got broken on transit into git.git. It adds a whole new stress level to my work.

Ciao, Dscho