sl

sl [-alFce]

sl (Steam Locomotive) displays an ASCII art animation of a steam locomotive crossing the terminal. It was created as a humorous punishment for users who accidentally type sl instead of ls (list directory contents).When executed, a detailed ASCII train animation scrolls across the screen from right to left. By default, the program ignores Ctrl+C, forcing users to watch the entire train pass—a gentle reminder to type more carefully.The default locomotive is the D51 (a Japanese steam locomotive). The -c option shows the alternative C51 model. Options can be combined for effects like a flying miniature locomotive with passengers in distress.

-a

An accident occurs; people appear crying for help

Display a smaller (little) locomotive

The locomotive flies across the screen

Show C51 locomotive instead of the default D51

Allow interrupt with Ctrl+C; normally you must wait

By default, Ctrl+C is ignored, and you must wait for the animation to complete. Use -e to allow early termination. The animation may not display correctly in terminals with very small dimensions.

sl was created by Toyoda Masashi in 1993 at the University of Tokyo. It was designed as a joke program to discourage the common typo of typing sl instead of ls. The program has become a beloved piece of Unix humor and is available in most Linux distribution repositories.

ls(1), cowsay(1), fortune(1), figlet(1)