How to execute shell script via crontab?
Mia Lopez
I have a notify.sh script that looks like:
notify-send "hi welcome"My crontab notification for 2 PM:
0 14 * * * home/hacks/notify.shHowever, this doesn't work. What is the problem?
07 Answers
Your script is missing a #! line at the start, which is the magic interpreted by the kernel to say which command interpreter is to be used for the script.
Make it look like this:
#!/bin/sh
notify-send "hi welcome"and make sure the script is executable:
ls -l home/hacks/notify.sh
chmod +x home/hacks/notify.sh
ls -l home/hacks/notify.shAlso, since you're asking for this to happen just once a day, is the timezone of the crontab the same as your own timezone? You might find this happening at 2pm GMT.
2Making crontab running is easy only . Here I am going to say how to run crontab jobs. It is useful for anyone who is stuck on crontab.
*/1 * * * * cd /home/hacks && sh notify.shTo make the script executable, we have to do:
chmod +x home/hacks/notify.shHere i run this script for every one minute ... By doing below script, you can write it in a log file to find whether its working
write log
*/1 * * * * cd /home/hacks && sh notify.sh>>test.logsend mail
*/1 * * * * cd /home/hacks && sh notify.sh>>test.log | mail -s "Hi this is example" 1 4 hypothesis:
the cron daemon is not running (do a
ps axfww | grep cronand check)the notify-send is trying to send output to a terminal, or an X session -- but it is ran from within the
cronenvironment and it does not know "who to talk to", so to speak.your script is not executable
the
home/path in the crontab script is relative to the user the scripts gets executed as. Try using the full path
Add export DISPLAY=:0 above the notify-send line in your script. This addresses lornezog's second point.
You have to open crontab by the following command:
crontab -u username -e (to edit) -l(to list) -r(to remove) 10(minutes) 8-15(hours) *(Day of month) *(month) 1,3,5(days of week) /path/to/script/script_name.shThis will run your script once an hour from 8AM-3PM at 10 minutes past the hour every Monday, Wednesday and Friday.
First of All, we need to edit the crontab with Command crontab -eand than Inside this Crontab add the Path of Executable script and in your Case like this * 14 * * * home/hacks/notify.sh >/dev/null 2>&1 .
Start /Stop / restart cron service
/etc/init.d/crond start /stop / restartservice crond start /stop /restartsystemctl stop crond.service
systemctl stop crond.service
1quite simple, add following line at bottom of the crontab file via:sudo nano /etc/crontab
@reboot root cd /home/pi/node-sonos-http-api && npm start &