Hi all -

Today I was trying to remember the syntax of the 'at' command so I could schedule a task that is typically scheduled by cron but needs to be run _sooner_ than the crontab specifies because of some server downtimes at my job (there was a power outage at one of our server locations over the weekend, due to a building being demolished nearby).

Embarrassingly, I couldn't remember the correct syntax, and the things it is doing on my local machine (Solaris 10) are kinda mystifying to me ... & I'd like to understand better so I can use this utility with some confidence.

I suspect my confusion may have to do with where stdout is going ...

My first stabs involved just trying to get something echo'd to the terminal:

art-16: at now + 1 minute
at> echo whee
at> <EOT>
commands will be executed using /bin/tcsh
job 1218471623.a at Mon Aug 11 12:20:23 2008

I expected to wait approximately 60 seconds and see "whee" echoed to the terminal, but this sequence echoes nothing ... I do, however, get emails from the system that look like this (the special chars do not quite carry over):

Your "at" job on art
"/var/spool/cron/atjobs/1218465682.a"

produced the following output:

]2;art:/home/skutch]1;skutch


If I redirect the output to a file, the file gets created and has the correct contents:

art-17: at now + 1 minute
at> echo whee > whee.txt
at> <EOT>
commands will be executed using /bin/tcsh
job 1218471815.a at Mon Aug 11 12:23:35 2008
art-18: ls whee.txt
whee.txt
art-19: cat !$
cat whee.txt
whee

I have found several suggestions online that this is the best way to fire off a timed command:

echo "/this/is/my/command" | at now + 1 hour

... with whatever time specification is desired. Perhaps I am worrying needlessly, when the usually cronned commands in question don't need to echo anything out to stdout anyway ... I was just a little mystified by this.

Thanks for any clarifications ... hope this isn't too silly a matter.

GB

The at command does have an attached terminal, so it cannot output to your terminal. Imagine all sorts of backgrounded jobs dumping output on your terminal while you were typing or editing a document.

And if you insist having your terminal as the target of these at commands, you can still do it that way:
and one minute later:

Thanks to Mr. C. and jlliagre for the responses. I believe I understand this much better now.