Question

Create a cronjob which does the following tasks

1.) create a file named <yourname>.txt

2.) in the 35th minute of the hour change the permission to 755

3.) Create a shell script named first.sh in which you print your name and redirect the output by 45th minute of the hour to the text file

Answer 1

We will try to complete the tasks one by one.

1. Create a file named <yourname>.txt. My name is Mohit so I will create mohit.txt. I will create this file in a new task folder in my home directory. You can choose the file location anywhere you want. Command for creating a new file - touch mohit.txt

2. Now we need to change the permission of this file by using corn job. Since permission can be changed by root users, we will edit the /etc/crontab file and add the cronjob there as a root user. We need to change the permission of first.sh so that it becomes executable.

The cron command to run the permission change is-

35 * * * * * root /usr/bin/chmod 755 /home/mohit/task/first.sh

After adding this line to /etc/crontab using - sudo nano /etc/crontab it looks like-

3. Create the shell script in the same task directory by using touch command.touch first.sh

The contents of the script will be-

echo "Mohit"

Either you can redirect the output of this file to text file here or in the cron job. I will do that in the cron job which is a better usage of cron job.

The cron script for this command to be executed at 45th minute will be-

45 * * * * * <username> /home/mohit/task/first.sh -> /home/mohit/task/mohit.txt

Replace <username> with your terminal username. In the screenshots you can see my username is 'mohit'

The updated rontab file will look like-

After this taks has run the contents of file mohit.txt will change and will look lke-

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