How To Use Cron Jobs in linux

What is Cron Job

Cron is a job scheduler available in Unix-like operating systems. It is used to schedule jobs to run periodically at fixed times, dates, or intervals.

How to use Cron Jobs

1. Cron Job Syntax

Cron jobs are scheduled using a syntax that defines five fields. The fields are separated by spaces and represent:

• Minute (0-59)
• Hour (0-23)
• Day of the month (1-31)
• Month (1-12)
• Day of the week (0-6)

2. Cron Job Examples

2.1. Run a command every 5 minutes

*/5 * * * * command

2.2. Run a command every 5 minutes between 8am and 5pm

*/5 8-17 * * * command

2.3. Run a command every 5 minutes between 8am and 5pm on Monday to Friday

*/5 8-17 * * 1-5 command

2.4. Run a command every 5 minutes between 8am and 5pm on Monday to Friday in January

*/5 8-17 1 * 1-5 command

3. Cron Job Editor

Cron jobs can be edited using the crontab command. The crontab command is used to install, deinstall, and list the crontabs of the current user.

3.1. List Cron Jobs

crontab -l

3.2. Edit Cron Jobs

crontab -e

After running the above command, you will be prompted to select an editor. Select your preferred editor and add your cron jobs.

3.3. Remove Cron Jobs

crontab -r

Conclusion

In this article, we learned about how to use cron jobs to automate tasks. We also learned about the cron job syntax and how to use the cron job editor.