'at now' not working as expected

Peter Wemm peter at wemm.org
Thu Oct 9 01:17:41 UTC 2008

On Sat, Oct 4, 2008 at 5:04 AM, Guido Falsi <mad at madpilot.net> wrote:
> Jeff Richards wrote:
>> When I try to schedule something immediately with an 'at now' command it
>> appears to queue up but can wait multiple minutes before actually executing.
>> Is there something I have missed with FreeBSD's version of at?  I've used
>> 'at now' with AIX, Linux, and OpenBSD and it immediately executes for those
>> systems.
>> I am running FreeBSD 7.0 stable.
> atrun is launched from crontab with a 5 minute granularity. So I think that
> at now can launch command with at most a 5 minutes delay.
> If this is a problem you can make atrun be launched every minute
> reconfiguring the crontab and you will wait at mosta one minute.
> This is explained in the at(1) man page.
> I don't know about other systems at setup.

Having a stand-alone at/atrun like this is pretty antiquated.  System
V cron has had an integrated 'at' since the late 80's.  If somebody
wanted to update our vixie-cron to integrate atrun functionality it
would make my day.  It shouldn't be particularly hard.  The trick is
to leave the nasty at(1) code alone as much as possible and just do
something for atrun(8).

My tolerance for hacking at(1) code was exceeded when I added hacks
for 'at sunrise' and 'at sunset' support to a local version.  It
wasn't pretty, especially when handling things like '30 minutes before
sunrise' etc.  (I use this for home automation stuff)

Peter Wemm - peter at wemm.org; peter at FreeBSD.org; peter at yahoo-inc.com; KI6FJV
"All of this is for nothing if we don't go to the stars" - JMS/B5
"If Java had true garbage collection, most programs would delete
themselves upon execution." -- Robert Sewell

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