Re: cron on Win9x works

[Igor Pechtchanski <pechtcha at cs dot nyu dot edu>]

BB,

I applaud the effort.  I think it would be terrific to have a cygrunsrv
equivalent on Win9x systems.  I don't know how far you've gotten in terms
of design, but here are a few suggestions:

- instead of creating yet another program, we should probably change
  cygrunsrv to do something different on Win9x.  That way, the READMEs
  (and some scripts) will apply

- if you need help hiding that command window, I have code
  that's been tested on Win9x (I think the command interpreter on Win9x
  is actually "command.com", not "cmd.exe", though)

- utime() is unimplemented for directories at all...  I don't know that it
  even works on WinNT/2k/XP...  Corinna?
	Igor

On Thu, 10 Apr 2003, BB wrote:

> I've notice some discussion about problems running cron on Win9x. I'm
> currently running cron and init on Win95.  Win98 works too.  I'm not running
> anything complex with cron yet though.  Unfortunately, I'm stuck in Win9x
> mode, but at least I'm being paid for it.
>
> One thing that is required is the addition of "SYSTEM:*:18:544:,S-1-5-18::"
> to the /etc/passwd file.
> The ",S-1-5-18" part probably isn't required, but I just simply copied the
> entry from an XP machine.  I also added "SYSTEM:S-1-5-18:18:" to /etc/group
> but I don't think it matters.
>
> -----------from cron.h----------------
> #ifdef __CYGWIN__
> #define ROOT_UID 18
> #define ROOT_USER "SYSTEM"
> #else
> -------------------------------------
>
> Try adding the SYSTEM user as mentioned above and then run
> /usr/sbin/cron -D.  In this case, the window it is running in will remain
> open.  If you run it without the -D and then try to exit from the cmd
> window, the window will not close until you kill cron.
>
> I am in the process of writing a cygwin /windows gui app (cygruncmd) modeled
> around the service_main() of cygrunsrv.  It will fork and exec a cmd (i.e.
> cron or init) redirecting stdout output the to a log such as
> /var/log/cron.log as cygrunsrvdoes.  I also plan to use it to run init on
> Win9x for agetty.  It needs to be a windows gui app so I can monitor system
> shutdown and kill the cmd when the system shuts down.  An option to the app
> will be to run with the window hidden.  Another option might be to respawn
> when the cmd exits.  Which gets me to another option I might try, running
> cron from init.  Not sure about this one.
>
> A few additional notes:
> 1. cron doesn't seem monitor system clock changes as far as I can tell.  So
> if the time is adjusted backwards say from 11:00am - 10:00am, when cron
> wakes up and adds 60 seconds to its previous time of 11:00 to 11:01, it will
> wait an hour before it wakes again.  I guess this could be a problem in the
> fall if the change in time is automatic.  If manually changing the time,
> restarting cron is the solution as long as the use knows about the problem.
>
> 2. On Win9x, crontab cannot touch the time on "/var/cron/tabs", so cron
> doesn't notice a change.  You can get around this my runnning the following
> commands, but you MUST not remove the tabs directory close to the 0 second
> or cron might exit when it wakes up and cannot find tabs.  Maybe crontab
> could be enhanced to make sure the directory time is modified on Win9x
> systems.  This workaround is fine for me right now.  I plan to insert a call
> to a program that waits until 30 seconds after the minute so cron doesnt
> fail between the cp and mv.
> ------------------------------------------
> rm -R -f /var/cron/tabs.sav
> cp -R /var/cron/tabs /var/cron/tabs.sav
> rm -R -f /var/cron/tabs
> mv /var/cron/tabs.sav /var/cron/tabs
> ----------------------------------------
>
> Hope this helps.
> [snip]
> BB

-- 
				http://cs.nyu.edu/~pechtcha/
      |\      _,,,---,,_		pechtcha at cs dot nyu dot edu
ZZZzz /,`.-'`'    -.  ;-;;,_		igor at watson dot ibm dot com
     |,4-  ) )-,_. ,\ (  `'-'		Igor Pechtchanski
    '---''(_/--'  `-'\_) fL	a.k.a JaguaR-R-R-r-r-r-.-.-.  Meow!

Knowledge is an unending adventure at the edge of uncertainty.
  -- Leto II


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