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Date: Tue, 17 Feb 2009 13:11:00 -0600 (CST)
From: Tim McDaniel <tmcd AT panix DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: subshell redirection (/dev/fd/x)
In-Reply-To: <Pine.CYG.4.58.0902171238530.2888@PC1163-8460A-XP.flightsafety.com>
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On Tue, 17 Feb 2009, Brian Ford <Brian DOT Ford AT FlightSafety DOT com> wrote:
> $ uname -a
> CYGWIN_NT-5.1 PC1163-8460A-XP 1.7.0(0.193/5/3) 2009-02-09 22:27 i686
> Cygwin
>
> Just curious if the following is known behavior?
>
> $ echo a | tee >(wc)
> a
> tee: /dev/fd/63: Bad file descriptor
>
> $       0       0       0

The bash term is "Process Substitution".

I had the dim impression that there was a Windows misfeature that
prevented >(...) from working.

Anyway, thanks for reminding me about what I got onto the list to
complain about.  I think that, out of the box, <(...) doesn't work
under Cygwin.  We had to do
     ln -s /proc/self/fd /dev/fd
(We got there after we deleted all of Cygwin's directories and
reinstalled.  Apparently we'd set up that symlink before: <(...)
worked before the reinstall, but didn't work afterwards until we did
the symlink above.)

The bash manual says, by the way,

      Process substitution is supported on systems that support named
      pipes (FIFOs) or the /dev/fd method of naming open files.

-- 
Tim McDaniel, tmcd AT panix DOT com

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