Activity File: Useful Loops

In the previous activity we created for loops. Now we will take our loops a bit further and use them to do useful things in our scripts and in the command line.

We can use loops to do things like:

Loop through all the users in the system and take an action for each one.

Loop through the results of a find command and take action on each item found.

Loop through a list of packages and check if they are installed.

Loop through a list of files, check their permissions, and change them if needed.

Loop through a list of files and create a cryptographic hash of each file.

In this activity, we will take a look at a creating a few useful loops you can add to your sys$\_$info.sh script as well as loops you can use directly in the command line.

Instructions

Put the paths of the shadow and passwd files $($from the $/$etc directory$)$ in a list.

Create a for loop that prints out the permissions of each file in your file list.

Put the final touches on your script by adding comments for each action your script completes.

Bonus One

Create a for loop that checks the sudo abilities of each user that has a home folder on the system.

Run this for loop directly in the command line without putting it into a script.

Bonus Two

Create a list that contains the commands date, uname $-$a$,$ and hostname $-$s$.$

In your script, remove the lines that use these commands and replace them with a for loop that prints out "The results of the $\_\_\_\_\_\_\_$ command are:" along with the results of running the command.