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Date: Fri, 6 Jun 2008 09:16:41 +0100
From: "Blair Sutton" <blairuk AT googlemail DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: Patch to allow Cron to use non-POSIX shells like Powershell.exe and CMD.exe
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On further investigation, it appears powershell does alias "-c" for
"-command" hence no changes would be required for cron to support it.
However, the change would still be useful for other shells or perhaps
interpreters like Perl.

On Pierre's offered solution: I now do recall how exec works and it is
correct that it replaces the current process - although a there will
be some overhead. However, that begs the question why cron ever
supported the SHELL parameter in the first place; if Mr Vixie wanted
everyone to write a wrapper script using his preferred shell.

On Thu, Jun 5, 2008 at 11:28 PM, Blair Sutton <blairuk AT googlemail DOT com> wrote:
> I'm not sure if that's a very good solution. It spawns an unnecessary
> bourne shell process on each new cron job.
>
> Don't worry if you don't want to make the change. I will maintain my
> own separate branch and perhaps post the patch with some instructions
> somewhere online where other people may find it useful.
>
> Best regards
> Blair
>
> On 6/5/08, Pierre A. Humblet <Pierre DOT Humblet AT ieee DOT org> wrote:
>> ----- Original Message -----
>> From: "Blair Sutton" <>
>> To: <cygwin>
>> Sent: Wednesday, June 04, 2008 12:48 PM
>> Subject: Patch to allow Cron to use non-POSIX shells like Powershell.exe and
>> CMD.exe
>>
>>
>> | Hi
>> |
>> | This is a very simple patch for Cron to allow one to use a shell like
>> | powershell or cmd. I've done some testing and it appears to work well.
>> |
>> | I simply introduce a new environment variable called SHELLSWICTH that
>> | defaults to "-c" if not used. Otherwise, one can set it to "/c" or
>> | "-Command" for Windows shells.
>> |
>>
>> ************
>> Hi Blair,
>>
>> I maintain cron for cygwin, thanks for your contribution.
>> There are other simple ways to achieve your goals,
>> without changing cron.
>>
>> For example SHELL could be /some/path/sh2powershell
>> and sh2powershell be a sh script such as
>> #! /bin/sh
>> shift
>> exec powershell -Command "$*"
>>
>> Wouldn't that work as well for you?
>>
>> Pierre
>>

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