Recently while trying to fix a printer I used lpr a bunch of times. It’s not exactly new to me, but never fails to surprise people when I use it.
The last command is a handy way to find out who has been connecting to a machine and when.
You can quickly kill everything running on a certain port with the following command.
Here’s how to install a package from a specific repository:
To get the MAC addresses of all your interfaces, grep the HWaddr from the ifconfig command: