sl

Let a steam locomotive run through your terminal

$ sl

$ sl -a

$ sl -F

$ sl -l

$ sl -e

sl [options]

-a
    Shows people calling for help from the train cars. All cars are animated.

-l
    Displays a smaller, "long format" version of the locomotive, mimicking 'ls -l'.

-F
    Makes the train fly across the screen, adding a fantastical element.

-e
    Enables 'every error' mode, which often prevents immediate interruption with Ctrl+C, making the full animation play out. This is part of the command's humorous intent.

The sl command (Steam Locomotive) is a whimsical, non-functional program designed to provide a humorous response to a common typing mistake: accidentally entering "sl" instead of "ls". Instead of an error message, sl displays an ASCII art animation of a steam locomotive passing across your terminal screen. It serves no practical purpose in system administration or file management but is purely for entertainment. It's often installed as a joke or a fun addition to a Linux system, reminding users of the occasional beauty and playfulness hidden within the command-line interface. Its animation, sometimes accompanied by sound effects (depending on the installation), provides a brief, delightful distraction.

sl is purely for entertainment and should not be confused with any serious utility. It consumes terminal resources for its animation and offers no functional benefits. Repeatedly typing it can be distracting or mildly annoying if not intended.

While appearing to be a simple terminal animation, sl serves as a playful reminder of human error and the potential for humor even in technical interfaces. It's a testament to the creativity found within the open-source community, transforming a mundane typo into a moment of amusement.

Some versions or installations of sl might include sound effects or have slightly different animations, depending on the compiler options or specific distribution packages. Its simplicity often allows for easy porting and minor variations.

The sl command was created by Toyoda as a humorous response to the common typo of typing `sl` instead of `ls` (list directory contents). Its primary motivation was to give users a fun, unexpected output instead of a simple "command not found" error. It quickly gained popularity in the Unix/Linux community as a delightful example of the playful side of open-source development, becoming a staple "joke" command found in many distributions.

ls(1), cowsay(1), fortune(6), lolcat(1)