Have you ever had any doubts about the meaning of the arguments of some command-line tools? https://explainshell.com is a tool where you write the command and it explains you in an easy way the meaning of each of the parameters. For example if you write: ssh -i keyfile -f -N -L 1234:www.google.com:80 host The output of the ths tool will be: Or maybe: cut -d ‘ ‘ -f 1 /var/log/apache2/access_logs