Several server accounts where I run some scripts to extract data from databases have very limited tools available and on some of them you are not allowed (even by formal request) to use cron, than been said, can you recommend any tool(s) I can use to schedule the execution of the scripts (just like cron does)?
Thanks in advance :)
Update 1: Yes, the servers I am referring to are Linux, HP-Ux and Solaris, Bash > 3.x is available.
If you are allowed to SSH from a server with Cron, you could launch periodic jobs remotely.
How about a backgrounded, no-hup'd script in an endless loop with a sleep at the end?
Example:
$ cat runme.sh
#!/bin/bash
while true; do
echo "Do useful stuff here"
sleep 86400
done
$ nohup ./runme.sh &
This would print "Do useful stuff here" once a day.
ktower's suggestion will work, and I can't think of a better way, but if you had a real choice it wouldn't be the solution you'd pick. The best suggestion I can make to to move it all over to a host that provides the tools and facilities you require. Workarounds will generally cause more problems than they solve. With such a large choice of hosting providers there really is no reason to settle for a makeshift solution.
Are you able to use the at scheduler?
at running something and rescheduling itself: stackoverflow.com/questions/645992/… and stackoverflow.com/questions/1522968/…
Mar 14, 2010 at 4:51
Adding to ktower answer. If you have to go that route and you need a more frequent interval (i.e. run something every 5 minutes) you will see some drift in time. To minimize that you can use a line like (assuming you are using linux)
sleep $((60 - `date +%s` % 60))
where '60' is the number of seconds you want to wait.
As John G. noted, the way to win this game is not to play; i.e. to run your jobs on servers that allow at/cron. Of the workarounds listed, the idea to run cron/Task Scheduler to fire SSH commands from a separate server is probably the best assuming you have SSH access. (I don't have enough rep to upvote yet). Of the others: at will typically be disabled with cron; and any admin restrictive enough to deny at/cron will be most unhappy with your attempts to circumvent policy by running your shell scripts in a loop...
