Message-Id: <m0yyyFa-000S4XC@inti.gov.ar>
Comments: Authenticated sender is <salvador AT natacha DOT inti DOT gov DOT ar>
From: "Salvador Eduardo Tropea (SET)" <salvador AT inti DOT gov DOT ar>
Organization: INTI
To: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>, djgpp-workers AT delorie DOT com
Date: Wed, 22 Jul 1998 09:53:15 +0000
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Subject: Re: Ispell and pipes
References: <m0yydcV-000S4XC AT inti DOT gov DOT ar>
In-reply-to: <Pine.SUN.3.91.980722111051.10941G-100000@is>
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Eli Zaretskii <eliz AT is DOT elta DOT co DOT il> wrote:
 
> Does this multi-programming have to be able to run on DOS?  Or can we
> live with it being available on Windows 9X only, at least as the first
> version?

Well you can do it but personally I use DOS for most of development.

> If the Windows-only version is a possibility, then some of the
> problems are already solved there.  For example, launching a child
> program asynchronously is easy:
> 
> 	system ("start foo.exe");
> 
> There still are some problems to be solved, notably the problem with
> communication between the two programs.  But that's solvable (in
> particular, there was a thread on c.o.m.d. a while ago which proposed
> a device driver for this).

I remmember I had some success using the Bill's driver that makes the 
transfer buffer shared. But that's slow and needs the driver loaded. 
So this methode have 2 limitations: Winblows and the need for a 
driver. Plus speed.
 
> Another problem with `start' that needs to be solved is that programs
> which are run by `start' don't inherit the environment variables and
> the file handles of the parent program.  This can be solved by using a
> proxy program, like this:
> 
>       write_environment_to_file ("envfile");
>       system ("start proxycmd -f envfile -o out -e err foo.exe ...");
> 
> Where `...' stands for the rest of the foo's arguments.  `proxycmd' is
> a special program which will read the environment variables from
> `envfile', redirect the handles as the -o and -e switches say, and
> then spawn foo.exe in the usual way.  (There might be some problems
> with handle redirection, due to file-sharing mechanism, but since most
> programs don't need to inherit more than the first 3 standard streams,
> I hope this will not pose any grave limitations.)

Yes I think that's fine for most of the programs.
 
> What do you-all think?

I think is ok, but I preffer a most general solution. After all djgpp 
is a DOS compiler. (I think CygWin support real pipes ;-).

SET
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