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Date: Wed, 19 Jun 2013 16:25:24 -0400
From: Charles Wilson <cygwin AT cwilson DOT fastmail DOT fm>
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To: The Cygwin Mailing List <cygwin AT cygwin DOT com>
Subject: Re: Adding MSYS functionality to Cygwin
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On 6/19/2013 1:45 PM, Christopher Faylor wrote:
> I'm talking about providing hooks so that an add-on MSYS dll could
> modify the windows command-line.  Then we wouldn't care what MSYS does
> with the command-line since it isn't a Cygwin DLL decision.  The goal is
> to allow a small DLL to hook into Cygwin and do whatever MSYS wants to
> do.
>
> Something like:
>
> callout (CO_EXEC, &command_line);
>
> Where it is expected that the command line could be modified.

Interesting. Obviously, there's more to a "complete" MSYS 
replacement/reimplementation, but cmd-line manipulation for exec'ing 
native apps is really the biggest MSYS-ism of the bunch.

I assume that, eventually and as-needed, a *small* number of additional 
"hooks" could be added to other code paths than exec/spawn/etc -- such 
as the aforementioned uname(3) thing. (One of the "deltas" between 
cygwin and msys was msys used a really stupid ownership/permission model 
-- pretend current user owns everything; check the DOS R/O bit for +w; 
check the file extension for +x; -- but this can be approximated with 
existing $CYGWIN entries or mount options. I think. So reimplementing 
that "feature" of MSYS would not require any additional hooks).

> The goal would be to collapse the fork back into Cygwin
> with minimal cost to the Cygwin DLL.

+1 <g>

--
Chuck



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