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11.20.2017

How to Hide the Mouse Pointer (Cursor) to Create a Kiosk or Dashboard

Question sent in by K.G. from New Jersey

Q: I created a system that boots and loads a browser in kiosk mode to show a slideshow in my company office.  Is there a way I can hide the mouse pointer?  It shows up even if I disconnect the mouse.

A: Yes, the easiest way is to install the unclutter package.  Unclutter is a package that will hide the mouse pointer, but it's flexible because all you need to do is move the mouse to show the pointer again.  Another reason why it is so flexible is because it is available for Red Hat, CentOS, Fedora, Ubuntu, Debian, etc...

To install in Ubuntu:

sudo apt-get install unclutter

Once you have the package installed you just need to add one line to a configuration file.

For Ubuntu:

Add the following line to the ~/.config/lxsession/LXDE/autostart file:

unclutter -idle 0
or run the following command, which will add the line for you.

sudo echo "unclutter -idle 0" >> ~/.config/lxsession/LXDE/autostart

Good luck!

See the man pages for a complete list of options, it is a nifty little piece of software.

P.S. This package also comes in RPM flavor for people using Red Hat, CentOS, or Fedora.

11.19.2017

How Repeat Your Last Command in BASH

Question sent in by Olivia from New Jersey

Q: I am using an old Dell laptop that my Dad gave me and the arrow keys do not work.  Is there a way to execute the last command I ran since I can't use the up arrow.  Also is there a way to scroll through my history without the up arrow?

A: Yes, as with anything Linux there are multiple ways of doing it.  Let's explore a couple and talk about their downsides.

First and most simple is using the double bang (exclamation point). 

!!

The one major flaw with this is it will execute the command without letting you read it, which is different from the way scrolling up with the arrow would work. 

To get the same effect as using the up arrow once, which is showing the last command run without executing it, you can use CTRL+P.

Another option you have is using the history a little better.  You can run the following to run your last command:

!-1

Or change the number, and run any of your last commands.  For example changing the 1 to a 2 will run the second from last command.

[savona@bighat ~]$ cat /etc/redhat-release
Fedora release 25 (Twenty Five)
[savona@bighat ~]$ echo "ANOTHER COMMAND"
ANOTHER COMMAND
[savona@bighat ~]$ !-2
cat /etc/redhat-release
Fedora release 25 (Twenty Five)
[savona@bighat ~]$

Another option you have is to list out the history, then running the number of the command you want, like so:

[savona@bighat ~]$ history
    1  cat /etc/redhat-release 
    2  echo "ANOTHER COMMAND"
    3  echo "Putorius is Curious"
    4  uname -r
    5  date
    6  history
[savona@bighat ~]$ !4
uname -r
4.13.10-100.fc25.x86_64
[savona@bighat ~]$ 

For more basic information about using bash history, check out our "Basics of Using Bash History" post.

3.17.2017

Use DoD Smart Card PKI Authentication with FireFox on Linux

Here is a basic tutorial on how to get your Government or DoD Smart Card (Common Access Card or CAC) working with Firefox in Linux.  This will allow you to access Government and DoD website which require PKI authentication using your common access card.

This was tested on Red Hat 7, but should work on most Linux systems.  For Debian variants you will have to use a different package manager and the package names may vary.

1) Install the necessary packages.

yum -y install coolkey pcsc-lite*

2) Start the pscsd service/socket

systemctl status pcscd.service

3) Open Firefox and add coolkey module to security devices

Go to Preferences > Advanced then click the certificates tab

Click "Security Devices"

Click "Load"

Module Name: DoD PKI
Module Filename: /usr/lib64/pkcs11/libcoolkeypk11.so

4) Install DoD root certificates

Goto:

Iase.disa.mil/pki-pke/Pages/tools.aspx

Scroll to bottom of page under " PKI CA Certificate Bundles: PKCS#7"

Download " For DoD PKI Only - Version 5.0"

Extract the zip file and inside the uncompressed directory you will find 3 certificate files named similar to:

Certificates_PKCS7_v5.0u1_DoD_DoDRootCA2_withCAs_FirefoxChromeOS.der.p7b

5) Go back to Firefox, Preferences > Advanced and Click Certificates.

Click View Certificates to open the Certificate Manager

Click Import at the bottom of the screen and import the 3 files mentioned in step 4.  You will have to do one at a time.

That's it.  You CAC should now work without issue on Firefox.