Linux Terminal in Rainbow Effect : Lolcat

Linux Terminal in Rainbow Effect , Yes lets make Linux beautiful. If you are among those who think Linux is boring, let me tell you it’s not. The lolcat program is used for the above purpose. It basically functions by concatenating files, or standard input, to standard output in a similar way as the cat command, overrides the default screen output color of a particular command and adds rainbow coloring to it.

What is lolcat?

Lolcat is an utility for Linux, BSD and OSX which concatenates like similar to cat command and adds rainbow coloring to it. Lolcat is primarily used for rainbow coloring of text in Linux Terminal.

Installation of Lolcat in Linux

1. Lolcat utility is available in the repository of lots of Linux distributions, but the available version bit older. Alternatively you can download and install latest version of lolcat from git repository.

Lolcat is a ruby gem hence it is essential to have latest version of RUBY installed on your system.

# apt-get install ruby     [On APT based Systems]
# yum install ruby      [On Yum based Systems]
# dnf install ruby      [On DNF based Systems]

Once ruby package has been installed, make sure to verify the version of ruby installed.

# ruby --version
ruby 2.1.5p273 (2014-11-13) [x86_64-linux-gnu]

2. Next download and install the most recent version of lolcat from the git repository using following commands.

# wget https://github.com/busyloop/lolcat/archive/master.zip
# unzip master.zip
# cd lolcat-master/bin
# gem install lolcat

Once lolcat is installed, you can check the version.

# lolcat --version
lolcat 42.0.99 (c)2011 moe@busyloop.net

Usage of Lolcat

3. Before starting usage of lolcat, make sure to know the available options and help using following command.

# lolcat -h

4. Next, pipeline lolcat with commads say ps, date and cal as:

# ps | lolcat
# date | lolcat
# cal | lolcat

5. 3. Use lolcat to display codes of a script file as:

# lolcat test.sh

6. Pipeline lolcat with figlet command. Figlet is a utility which displays large characters made up of ordinary screen characters. We can pipeline the output of figlet with lolcat to make the output colorful as:

# echo I ❤ EthicalHackx | lolcat
# figlet I Love EthicalHackx| lolcat

Note: Not to mention that ❤ is an unicode character and to install figlet you have to yum and apt to get the required packages as:

# apt-get install figlet 
# yum install figlet 
# dnf install figlet

7. Animate a text in rainbow of colours, as:

$ echo I ❤ EthicalHackx | lolcat -a -d 500

Here the option -a is for Animation and -d is for duration. In the above example duration count is 500.

8. Read a man page (say man ls) in rainbow of colors as:

# man ls | lolcat

9. Pipeline lolcat with cowsay. cowsay is a configurable thinking and/or speaking cow, which supports a lot of other animals as well.

Install cowsay as:

# apt-get install cowsay
# yum install cowsay
# dnf install cowsay

After install, print the list of all the animals in cowsay as:

# cowsay -l

Sample Output

Cow files in /usr/share/cowsay/cows:
apt beavis.zen bong bud-frogs bunny calvin cheese cock cower daemon default
dragon dragon-and-cow duck elephant elephant-in-snake eyes flaming-sheep
ghostbusters gnu head-in hellokitty kiss kitty koala kosh luke-koala
mech-and-cow meow milk moofasa moose mutilated pony pony-smaller ren sheep
skeleton snowman sodomized-sheep stegosaurus stimpy suse three-eyes turkey
turtle tux unipony unipony-smaller vader vader-koala www

Output of cowsay pipelined with lolcat and ‘gnu‘ cowfile is used.

# cowsay -f gnu ☛ EthicalHackx.com ☚ Ethical Hacking Tutorials | lolcat

Note: You can use lolcat with any other command in pipeline and get colored output in terminal.

10. You may create alias for the most frequently used commands to get command output in rainbow of colors. You can alias ‘ls -l‘ command which is used for long list the contents of directory as below.

# alias lolls="ls -l | lolcat"
# lolls

You may create alias for any command as suggested above. To create permanent alias, you have to add the relevant code (above code for ls -l alias) to ~/.bashrc file and also make sure to logout and login back for the changes to be taken into effect.