Find the process that opened a local internet port

Lists open files and the corresponding processes.
Note: Root privileges (or sudo) is required to list files opened by others.
More information: <https://manned.org/lsof>.
Trick copyright: tl;dr; <https://github.com/tldr-pages/tldr>

lsof -i :{{port}}

click the source code to copy install lsof on any operating system with command-not-found.com