Force users to change their linux passwords

Building on the previous post regarding tldr I decided to use the chage command to force a user to change his password. In this example, I'm forcing the user kingtux to change his password at his next login attempt:

Now I'm going to login as kingtux:

 

Now I'm going to force the user kingtux to change his password using the passwd command:

 

Now I'll log in kingtux again:

The nice thing about Linux is that there is usually more than one way to get a job done. Use either: chage or passwd to force users to change their passwords.

Installing tldr on CS8

I installed a nice little application called "tldr." You can think of it as  "man pages" lite. In order to install it I had to install nodeJS and npm first. I followed the procedures on this page:

nodeJS and npm

-----------------------------------

Then I installed tldr following these directions:

Tecmint tldr

----------------------------------

Here's a screen shot of using tldr to lookup help for the chage command:

Centos Stream 8

 I loaded Centos Stream 8 (CS8) today in order to learn RHEL using RHEL closest clone out there. Here's what I've done so far: 

1) I downloaded and installed CS8 in VirtualBox, 

2) I ran # dnf check-update and dnf update

3) installed VB Guest Additions using the procedure found on:

Tecmint How-Tos

Setting the "hostname" of the machine.

 Here's a good article by Red Hat that list seven ways to set a machine's hostname:

Update hostnames

When just using: hostnamectl with no arguments you get this print out:

Ret Hat Certification

I've decided that I need a new challenge, specifically, I want to achieve a Red Hat Linux certification. I want to achieve the Red Hat Certified System Administrator (RHCSA) credential. To that end, I've ordered a Red Hat Enterprise Linux 8 (UPDATED): Training and Exam Preparation Guide (EX200), Second Edition that should be here today. LinkedIn Learning also has a 5.5 hour course on RHCSA that I plan to take. I'm only doing this to keep my mind occupied and sharp.

The bash Shell

There is a lot of misunderstanding when it comes to what the bash shell is and is not.  The bash shell is not "Linux." The bash shell lets a user interact with Linux by typing Linux commands into bash and then bash executes the commands by handing them off to the Linux kernel. Over the next several post I will explorer the bash shell with the goal of being able to clearly explain how it operates.

Double quotes in a script

Using double quotes while referencing (using a value of a variable) helps to prevent word splitting (regarding white space) and unnecessary globbing (recognizing and expanding wildcards. Check out this script:

Pay close attention to the remarks embedded in the script as they tell you what is happening. After running the script, this is the results: