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From: rembo@unisoft.UUCP (Tony Rems)
Newsgroups: comp.unix.questions
Subject: Re: Periodic execution of a program
Message-ID: <3327@unisoft.UUCP>
Date: 30 Jan 91 01:23:33 GMT
References: <5830@rex.cs.tulane.edu> <1991Jan28.153105.2996@mcs.drexel.edu>
Reply-To: rembo@unisoft.UUCP (Tony Rems)
Organization: UniSoft Corporation -- UNIX R Us.
Lines: 30

In article <1991Jan28.153105.2996@mcs.drexel.edu> udparmet@mcs.drexel.edu (Daniel J. Parmet) writes:
>In article <5830@rex.cs.tulane.edu> rawdon@rex.cs.tulane.edu (Michael Rawdon) writes:
>>
>>I was wondering if it would be possible to execute at recursively, that is,
>>have the file that at executes call at again to execute the same file at
>>the same time the next day.  I'm not sure if this would be possible.
>
>I haven't worked with crons in a while, but I believe that what you are trying
>to do should work.  When the runstream goes off, your file gets taken out of
>cron.  But you can simply have an at command in your run to put the file back
>into cron.  I'd be interested in finding out what happens, since my shell
>programming is a little rusty, and I may start up with it again soon.  Let me
>know.  Thanks.
>

Just about every man page I've seen for the at command has the following
in it:

   BUGS
        Due to the granularity of the execution of /usr/lib/atrun,
        there may be bugs in scheduling things almost exactly 24
        hours into the future.
   

This includes SunOS, Pyramid, Vax, and a number of others.  You 
may run into this problem.

-Tony