how-do-i-find-out-what-shell-im-using

ps -p $$

So what is $ argument passed to -p option? Remember $ returns the PID (process identification number) of the current process, and the current process is your shell. So running a ps on that number displays a process status listing of your shell. In that listing you will find the name of your shell (look for CMD column) .

$ ps -p $$