As a SysAdmin you are often typing fast and furious on the command line. This leads to a lot of mistyped commands. A very common mistake is typing sl why trying to list a directory with the "ls" command.
Well someone (still trying to find where it originated) created a small program called to run a Steam Locomotive across your terminal when you type sl by accident. It's a lot of fun, and I like to install it on my new hires systems without telling them and wait for the mistype to happen.
Install sl package
Ubuntu / Debian:
sudo apt-get install sl
Fedora 28/29:
sudo dnf install sl
Red Hat 6 / CentOS 6 (Must install epel first):
sudo yum install wget https://dl.fedoraproject.org/pub/epel/epel-release-latest-6.noarch.rpm -y
sudo yum install sl -y
Red Hat 7 / CentOS 7 (Must install epel first):
sudo yum install epel-release -y
sudo yum install sl -y
Now that you have the package installed, have some fun...
Options I found while playing around:
sl -l (Creates a small and long train)
sl -L (Will create a larger, although shorter train)
sl -F (Will make the train fly)
sl -la (Will add people screaming for help from the windows)
sl -la (Will add people screaming for help from the windows)
If you find any fun options, or other little Easter eggs let me know in the comments or send me a note!