How do I run a script every 61 minutes?

jsjones85 · 05-15-2010, 09:59 AM

Hi, I have a script I need to run hourly. I've looked around the net and found crontab.

The problem is, my script runs some macros I made using xmacro, which does some web surfing. So because of potential lag and whatnot, I want the script to run every 61 minutes rather than every 60 minutes. As far as I can tell, this is not possible in crontab.

Can someone please point me in the right direction?

Thank you very much.

Jeremy

pixellany · 05-15-2010, 10:11 AM

Similar question here:
http://www.linuxquestions.org/questi...terval-806495/

Also, search here at LQ using "crontab". There are quite a few threads.

jsjones85 · 05-15-2010, 10:42 AM

Oops, I did do a search of "crontab" but it seems I didn't scroll down far enough. Thank you for the link.

Jeremy

colucix · 05-15-2010, 01:29 PM

Hi Jeremy and welcome to LinuxQuestions!

To run a script every 61 minutes, you're forced to set a cron job that runs every minute. In fact, if the first run is at midnight, only after 61 days it will run at midnight again. In this 61-days interval it happens to run at all possible hour and minute pairs. Said that, the crontab entry must be

Code:

* * * * * /path/to/script.sh

Following the discussion in the thread linked by pixellany, inside the script you can try to set-up a check to see if the difference between the current date and a reference date of your choice is a multiple of 61 minutes. For example (using BASH)

Code:

#!/bin/bash
reftime=$(date -u -d "20100515" +%s)
timenow=$(date -u -d "$(date -u +"%Y%m%d %H:%M")" +%s)
if [ $(( ($timenow - $reftime) % 3660 )) -ne 0 ]
then
  exit
fi
<your code here>

In this example the main code will run every 61 minutes starting on 15-May-2010 00:00 UTC. Calculations are made in UTC to avoid weird results at the passage from/to Daylight Saving Time.

catkin · 05-15-2010, 02:05 PM

If the computer is running all the time there could be a single cron job to run at, say, midnight and it could use the at command to schedule itself to be run again in 61 minutes.

MTK358 · 05-15-2010, 02:54 PM

Code:

while true
do
  # do stuff here every 61 minutes
  sleep 61m
done

The thing is that it won't really be run every 61 minutes, it will be run every 61 minutes + the time it takes to do what you wanted to do.

jsjones85 · 05-16-2010, 07:20 AM

Thank you everyone! Your replies have been very useful.