in Linux, Ubuntu

How to write a Cron Job in Linux?

What is a Cron Job?

Cron is a Linux utility where you can setup a task in your machine to run automatically, if required in a repetitive manner at a specific time and date.
Such a task that you schedule is called a Cron Job.

Here we’ll look into how we can setup a cron job in a Linux machine.

Follow the steps bellow.

Step 1 :

Place the script you want to schedule as a Cron Job to one of the following directories in your machine depending on how often you need to repeat the execution of the script.


For example, if you want to schedule your task daily, place the script in the /etc/cron.daily directory.

Step 2 :

Then give correct permissions to the script as follows. Assume is the script that you need to schedule.

cd /etc/cron.daily
chmod 755
Step 3:

Then you should add a new Cron Job to crontab.

crontab -e
Step 4 :

Then you will be prompted with your vi editor in the terminal. Type in the following into the editor and to save it hit ESC key, and then type :w followed by :q to exit.

0 0 * * * /etc/cron.daily/

This command will make the Cron Job run every night.
Note: Look at the following to identify the different ways of customizing the command given in Step 4.