From your everyday talking cows to upside-down, rainbow-colored, ASCII art made from ridiculously large prime numbers, these Linux commands range from mildly humorous to outright bizarre. Just because these commands are useless doesn’t mean you shouldn’t use them!
1
sl – The Typo Train is Coming
Let’s first clarify that this command is lowercase “S” and “L”, sl. The intent of this command is to provide a somewhat comical indication that you’ve mistyped the common Linux directory listing command, “ls”.
sudo apt install sl sudo dnf install sl
Once installed, simply enter “sl” at the terminal prompt to make the train run. To make it a bit more interesting, sl also shows different variants of the typo train if some of the more common ls command line switches are used.
sl -lsl -a
sl -la
man sl
If you know somebody who makes this mistake often, the typo train will help them break their bad habit fast!
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2
cowsay – Talking Cows (and More!)
Linux has always had a somewhat strange and ongoing relationship with a few specific animals—cows being one of them. (No offense to the penguins or the llamas.) In the spirit of creating absolutely useless yet entertaining programs, cowsay was released to the world.
sudo apt install cowsaysudo dnf install cowsay
To make the cow speak, enter any phrase after the cowsay command.
cowsay Moo I say to you! Now get back to work.
Bored with the cow and want to make Tux talk? You can do that too.
cowsay -f tux Never trust an animal with four stomachs.
There are also plenty more characters who will let you put words in their mouths. To see what else you can do with cowsay, try entering the following commands.
cowsay -l cowsay --help
3
fortune – Random (and Sometimes Profound) Wisdom
Fortune is one of the more self-explanatory items on this list. Think of it like being able to crack open a fortune cookie any time you want, right in your terminal (minus the preliminary delicious meal—and the tasty, crunchy cookie).
sudo apt install fortunesudo dnf install fortune
Asking for a new fortune is as simple as typing “fortune” at the command line. If you’re creative, you can even pass the output of fortune to other programs—for example, cowsay. Try the following commands.
fortunefortune | cowsay
fortune | cowsay -f bud-frogs
If you’re a bit creative with shell scripts, you can also set things up so that you are greeted with a new fortune each time you open (or exit) a terminal.
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4
yes – Print Yes (or Anything Else) Into Infinity
This one might just be truly useless at this stage of Linux evolution. By default, “yes” will simply print the letter y infinitely. This could be useful to automatically answer yes to programs that ask lots of yes/no questions. You can also add your own arbitrary phrase and that will be printed repeatedly and infinitely until you stop it.
This should be available on Ubuntu by default. For rpm based distributions, you may need to install it with the following command.
sudo dnf install core-utils
Once installed, typing “yes” by itself at a command prompt will output an endless stream of lowercase Y’s. You’ll need to hit Ctrl+C to stop the output. You can also give it a custom phrase to repeat.
yes "I never say no!"
To use it to answer questions coming from a program you don’t have enough patience for, run it through a pipe like this:
yes | program-wanting-answers
yes "no" | program-wanting-answers
Yes "prefer not to answer" | program-wanting-answers
Using the “yes” command can potentially cause CPU-intensive or memory-filling loops requiring a hard reset of your computer to escape. You should not experiment with it while you have any important tasks running or unfinished work of any kind.
5
rev – Print Anything in Reverse
The rev command will take any text input from you and spit it back out in reverse order. You can pass short snippets of text directly at the command line or feed it entire text files.
rev comes preinstalled on virtually all Linux distributions.
Pass text at the command line or have rev reverse an entire file with the following commands.
echo "Show me this text backwards!" | rev
cat biglongtextfile.txt | rev
cat input-rev-file.txt | rev > output-rev-file.txt
6
figlet – Generate ASCII Art in Your Terminal
Generate old school ASCII text banners right in your terminal with figlet.
sudo apt install figletsudo dnf install figlet
Once installed, simply type “figlet” followed by any text you want. Try the following commands to get an idea of what you can do with it.
figlet "I like big letters!"
figlet "Long text will wrap automatically"
figlet -w 120 "The W switch sets the column length of the banner!"
figlet
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7
toilet – ASCII Art with Colors and Fonts
If figlet wasn’t enough to blow your mind, check out toilet! (Yes, that really is the name. No, we don’t know why.)
sudo apt install toiletsudo dnf install toilet
Toilet takes things to a higher level, allowing you to add color and fonts to your terminal text banners. There are plenty of options to explore if you are in the mood. Here are a few quick commands to get you started.
toilet "How-To Geek"
toilet -t -f mono12 -F metal "How-To Geek"
toilet -t -f mono12 -F metal -F 180 "How-To Geek"
toilet --help
8
cmatrix – Hello, Mister Anderson
Do you dream of being Neo? Recreate the famous dripping green screen from The Matrix in your own terminal.
sudo apt install cmatrixsudo dnf install cmatrix
But wait! There’s more! Use the following commands to create different variations of the original Matrix terminal. Press Ctrl+C to exit and return to “reality”.
cmatrixcmatrix -a
cmatrix -a -b
cmatrix -a -b -r
cmatrix -h
9
lolcat – It’s Like Rainbow Sprinkles for Your Terminal
Somewhat similar to figlet and toilet, lolcat takes your bland and lifeless input and creates hypnotizing, eye-dazzling output.
sudo apt install lolcatsudo dnf install lolcat
Using lolcat on a single line of text doesn’t really do it justice. This entry on our list of useless commands works best if you pass the output from another program into it. To get a quick idea of what lolcat will do, try some of the following commands.
top | lolcat
figlet "This is lolcat!" | lolcat
ls -la | lolcat
sl | lolcat
lolcat --help
10
espeak – Make Your Computer Talk in Creepy Voices
Your terminal can talk to you, though don’t expect it to sound anywhere as natural as the text-to-speech tools on your phone. Install espeak easily if it’s not already there.
sudo apt install espeaksudo dnf install espeak
I don’t have a screenshot since this useless command only generates audio. Try a few of the following commands and look through the help to find combinations to make your own unique voices.
espeak "Welcome to Linux, master!"espeak -ven+whisper "I am watching you..."
espeak -f text file to read>
espeak
espeak --help
Related
11
asciiquarium – Swimming and Fishing Prohibited
Get a different underwater view every time you load up the asciiquarium. Don’t worry, you can’t overfeed these fish!
sudo apt install asciiquariumsudo dnf install asciiquarium
There are no special startup options for asciiquarium. While it’s running, the following keys are active:
- R – Redraw animation (new scene)
- P – Pause animation
- Q – Quit asciiquarium
12
oneko – A Cat That Will Chase Your Mouse
Who wouldn’t like a cute, but useless, tiny cat running back and forth across their screen while they work?
sudo apt install onekosudo dnf install oneko
Once oneko is started, hover your mouse cursor over the cat and it will turn into a mouse. Click and hold the left button and the cat will follow wherever you drag the mouse. You can also leave the cat on its own and it will decide when it does or doesn’t want to chase your cursor.
When running, press Ctrl+C in the terminal window where you started oneko to stop it. Here are a few commands to show you some of the options you can set.
oneko oneko -dog
oneko -tofocus
oneko -h
13
factor – Prime Factors of Any Number Instantly
Don’t you just hate it when you’re deep into a project, focused and productive, laser-like precision and attention, totally killing it, and then suddenly you realize you can’t continue until you figure out the prime factors of some random 12 digit number?
Yeah, it bugs the hell out of us too. Thankfully—long, loud sigh of relief—there is a quick solution!
Enter “factor” followed by any number at a terminal prompt and get back that number’s prime factors instantly! Try some or all of the following commands to make amazing math tricks in your terminal.
factor 384746133factor 384746133 | figlet -w 120
factor 384746133 | figlet -w 120 | lolcat
factor 384746133 | toilet -f mono12 -F 180 | lolcat
14
xeyes – Strange Eyes Follow Your Cursor
Just because you’re paranoid doesn’t mean they aren’t watching you. And trust us, they are watching you.
sudo apt install xeyessudo dnf install xeyes
Results may vary with this one as the program is quite old. It may not work correctly, or at all, on some window managers or most recent desktop environments. But let’s try anyway.
Just enter “xeyes” at a terminal prompt and two big eyes will appear. Watch them move to follow your cursor. You are amazed! You’re welcome!
15
Watch “echo beep” – Ring the Terminal Bell Infinitely
The “echo beep” command is another that gives us no visual output to show. Go ahead and type the command below to see what it does. Whether or not it will work will depend on the terminal emulator that you are using. It should work with the default terminal for the most common Linux desktops.
watch "echo -e '\a'"
If your terminal app allows for the audible “beep”, you’ll hear it repeat every few seconds. This might not seem very amusing at first, but it makes for a great prank. Start this as a background process on someone else’s Linux terminal and they’ll go mad trying to figure out what is wrong with their system. But hey, you didn’t hear that from us!
None of these commands will ease your workload, make you more productive, or improve your efficiency. They will, however, serve quite nicely the next time you find yourself in the inevitable recurring position all Linux enthusiasts find themselves in from time to time—arguing over useless facts and unnecessary knowledge about Linux and everything it encompasses. This is all just a drop in the bucket, though. There are many hidden treasures to find below the surface of Linux. Keep exploring!
