How to run cron job every 2 hours? [closed]

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Closed 10 m开发者_如何学Pythononths ago.

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How can I write a Crontab that will run my /home/username/test.sh script every 2 hours?

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Just do:

0 */2 * * *  /home/username/test.sh 

The 0 at the beginning means to run at the 0th minute. (If it were an *, the script would run every minute during every second hour.)

Don't forget, you can check syslog to see if it ever actually ran!

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The line should read either:

0 0-23/2 * * * /home/username/test.sh

or

0 0,2,4,6,8,10,12,14,16,18,20,22 * * * /home/username/test.sh

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0 */2 * * *

The answer is from https://crontab.guru/every-2-hours. It is interesting.

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0 */1 * * * “At minute 0 past every hour.”

0 */2 * * * “At minute 0 past every 2nd hour.”

This is the proper way to set cronjobs for every hr.

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To Enter into crontab :

crontab -e

write this into the file:

0 */2 * * * python/php/java yourfilepath

Example :0 */2 * * * python ec2-user/home/demo.py

and make sure you have keep one blank line after the last cron job in your crontab file

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first do crontab -l to see your existing crontab and jobs if you don't anything then do crontab -e

check you editor maybe VI or nano or anything like that.. go to insert mode by 'i', command should be like (cron expression)[space](program execution address from home)[space](your script address from home)

example (0 /2 * * * /conda///bin/python3 ///USERNAME/TEST_PYTHON_SCRIPT.py >> execution_log.txt)

execution_log.txt will have the execution log of your script.

once you have your command correctly placed exit the editor by saving the file for nano -> ctrl + x for vi -> :wq!

check your scripts with some email/print statement.