h/t @tesla809 https://developer.mozilla.org/en-US/docs/Learn/Tools_and_testing/Understanding_client-side_tools/Command_line https://swcarpentry.github.io/shell-novice/reference.html Linux / Unix: https://caiorss.github.io/C-Cpp-Notes/Linux-unix-system-programming.html https://notes.shichao.io/apue/ch1/
