UniXKCD

On April Fools' Day in 2010 Randall altered the website to mimic a Unix command line interface. This interface is still available on uni.xkcd.com and the source code is available on GitHub.

The comic 721: Flatland which was released on March 31, 2010 was still up on April 1st, 2010, but had in it self nothing to do with the Unix interface or the April Fools' Day joke of that interface.

This Unix interface is thus in itself not one of Randall's April fools' comics, but since also the not existing comic 404: Not Found is listed in that category, this stunt is none the less listed under these comics.

The terminal lists a few available commands:

• next shows the next comic. Shows the error "Time travel mode not enabled" on the last comic (see enable time travel).
• prev shows the previous comic.
• first shows the first comic.
• last shows the last comic.
• display [number] shows the comic with the specified number. (Trying to display comic 404 will result in an endless loading attempt.)
• random shows a random comic.
• ls shows the content of the current directory.
• cat [filename] shows the content of the file, or "You're a kitty!" if [filename] is left blank.
• cd [directory] changes to the specified directory.

But there are several undocumented commands as well:

• :(){:|:&};: This command, otherwise known as a shell fork bomb will make the terminal display the [. . .] loading text indefinitely, as though it crashed.
• a/s/l A/S/L is not a unix command, but an acronym of Age/Sex/Location. The following replies are possible:

2/AMD64/Server Rack answered as if the server replied.

328/M/Transylvania answered by Dracula.

6/M/Battle School answered by Ender Wiggin or another boy from battle school.

48/M/The White House answered by Barack Obama or another male of the same age in the White House.

7/F/Rapture answered by a Little Sister from BioShock.

Exactly your age/A gender you're attracted to/Far far away. Requests for a/s/l are often not answered truthfully, but crafted to suit the one asking the question.

7,831/F/Lothlórien answered by Galadriel or another elf.

42/M/FBI Field Office answered by an FBI agent (referencing the old trope that all girls on the internet are FBI agents impersonating them).

• apt-get replies "This APT has Super Cow Powers.". The apt-get command is part of the Debian package manager APT. This reply is one of the build in Easter eggs.
• apt-get moo replies "Have you mooed today" with an ascii cow.
• asl same as a/s/l.
• bash replies "You bash your head against the wall. It's not very effective.". Bash is a shell for POSIX-based systems.
• buy stuff same as cd store.
• cat [number]/alt.txt displays the alt-text of the specified comic.
• cat (without a filename, or an invalid one) will show "You're a kitty!" referencing 231: Cat Proximity.
• cheat promotes the xkcd store.
• clear clears the screen.
• curl creates an iframe to the URL specified
• date replies "March 32nd".
• dir same as ls.
• echo replies "Echo ... echo ... echo ...". The echo command is used to print text to the terminal.
• ed replies "You are not a diety [sic].". ed is a very simple text editor. It is usually not considered very user friendly (see also vi and emacs).
• emacs replies "You should really use vim.". References 378: Real Programmers.
• enable time travel replies "TARDIS error: Time Lord missing.". A Doctor Who reference. See also the next command.
• exit will end the terminal session.
• find kitten showed the robotfindskitten game (the link to the Flash version no longer works, but an HTML version is available here).
• find replies "What do you want to find? Kitten would be nice.".
• finger replies "Mmmmmm...".
• fuck replies "I have a headache.".
• goto [any] shows comic 292: goto and asks if you meant display instead.
• halp same as help.
• hello joshua replies "How about a nice game of Global Thermonuclear War?". A reference to the WarGames movie.
• hello replies "Hello.". There is a second reply "Why hello there!" coded, but it is never used.
• help says "That would be cheating!".
• hi replies "Hi.".
• hint randomly replies "We offer some really nice polos.", "This terminal will remain available at xkcd.com/unixkcd/", "Use the source, Luke!" or "There are cheat codes.".
• i read the source code replies "<3".
• irc [nick] starts an IRC session on the xkcd channel on irc.foonetic.net.
• kill replies "Terminator deployed to 1984.". A reference to the Terminator movie. In Bash, kill is used to end a process.
• locate [filename] is normally used to locate a file in a directory. It will give humorous results when searching for ninja, keys, joke, problem and raptor.
• logout same as exit.
• lpr replies "PC LOAD LETTER". lpr is a command to print documents. PC_LOAD_LETTER is a printer error.
• make love replies "I put on my robe and wizard hat.". A reference to this roleplay chat transscript (NSFW), also mentioned in 442: xkcd Loves the Discovery Channel. make love is a standard unix joke, because the reply is "make: don't know how to make love.".
• make me a sandwich behaves like 149: Sandwich.
• man [command] show unhelpful information about the command (only last, help, next, cat or no command are supported).
• moo replies "moo".
• more replies "Oh, yes! More! More!". The more command is used to paginate output.
• nano replies "Seriously? Why don't you just use Notepad.exe? Or MS Paint?". Nano is another text editor for Unix systems (see vi and emacs).
• ping replies "There is another submarine three miles ahead, bearing 225, forty fathoms down.". The ping command used to measure round trip times to a destination. The name does indeed originate from sonar technology.
• pwd replies "You are in a maze of twisty passages, all alike.". The pwd command prints the current working directory (see look).
• quit same as exit.
• reddit [number] shows the Reddit voting bar for the specified comic (or xkcd when no number is specified).
• rm [filename] will "remove" a file, while rm -r will remove a directory. (sudo rm -rf / will break all commands until the page is reloaded.)
• serenity replies "You can't take the sky from me.". This is a line from the Balad of Serenity from the Firefly TV series.
• ssh replies "ssh, this is a library.". ssh is the command to start a secure shell, but it also resembles the "Shh" sound.
• su replies "God mode activated. Remember, with great power comes great ... aw, screw it, go have fun.". The su command is used to log in as super user, which gives you full and potentionally dangerous access to the system. On some systems, "with great power comes great responsibility" is also part of a message that is printed the first time sudo is used.
• sudo [command] executes the command with root privileges.
• sudo apt-get dist-upgrade Returns "You are already running [OS].".
• sudo apt-get moo replies "Have you mooed today?" (apt-get Easter egg).
• sudo apt-get update Refreshes the package list so the system knows which updates are available.
• sudo apt-get upgrade shows a link to A Better Browser on Internet Explorer and Firefox (< v3). On all other browsers it doesn't complain.
• sudo make me a sandwich behave like 149: Sandwich.
• sudo !! will sudo the last command.
• sudo poweroff will shutdown the system.
• sudo reboot will restart the system.
• sudo restart same as sudo reboot.
• sudo shutdown same as sudo poweroff.
• sudo sudo will print An internal error occured: RangeError: Maximum call stack size exceeded in red text.
• time travel displays 630: Time Travel.
• top replies "It's up there --^". The top command shows a table of processes. Here it is taken literally.
• uname replies "Illudium Q-36 Explosive Space Modulator". uname on Unix lists system information. The Illudium Q-36 Explosive Space Modulator is an explosive device created by Marvin the Martian in the Looney Tunes series.
• unixkcd opens a new terminal window.
• use the force luke replies "I believe you mean source.". A reference to the Force in the Star Wars franchise.
• use the source luke replies "I'm not luke, you're luke!", an old programmers' joke.
• vi reply "You should really use emacs.". References 378: Real Programmers.
• vim same as vi.
• wget [url] shows the content of the specified url. The wget command on unix will download the content and not show it.
• who replies "Doctor Who?". Another Doctor Who reference. The who command on Unix lists the logged-in users.
• whoami replies "You are Richard Stallman.". The whoami command lists the name of the current user.
• write [nick] same as irc.
• xkcd replies "Yes?".
• xyzzy replies "Nothing happens.". xyzzy is a magic word, originally used in the game Colossal Cave Adventure.
• your gay replies "Keep your hands off it!".

Other commands

• There are also some other commands borrowed from a Zork like text based adventure game.
• look describes your current surroundings.
• go [direction] moves you in the specified direction (down is also supported; however, it replies a different message).
• light lamp lights your lamp.
• sleep [seconds] sleeps for the specified time. Without specifying, the nap is 5 seconds.
  • You will be killed by a grue if you didn't light your lamp when going south.
  • Going west repeatedly will list the refrain from the song Go west.

Konami code:

• The terminal also responds to the Konami code Up, Up, Down, Down, Left, Right, Left, Right, B, A. Entering this code repeatedly will transform all characters to upper case, add a gray text shadow, add an orange text shadow, shake the screen and add a background image of Richard Stallman from 345: 1337: Part 5.