A task that comes up often enough that you need to memorize a command and it’s options is to find out what’s listening on a port. Sometimes it’s a result of seeing an error like Address already in use or Socket in use when you try to start a new network process. Or you might need to know what’s listening on what port to configure a firewall etc. There are other tools that will show you the open network sockets such as nestat and ss but I always find myself using lsof. The output is ni...
