@b0rk I've only ever used bash and zsh, so I don't know if this works on other shells, but `echo $SHELL` also works!
@scubbo the reason i didn't do that is that in my life sometimes I've had my system shell set to bash, but I've had `fish` in my .bash_profile so that I'm actually using fish as my shell. so in that case `echo $SHELL` wouldn't have worked for me
to be fair that's a kind of weird thing to do, but “what's your user's default shell set to” is not quite the same thing as "what shell are you currently using”
@robryk @b0rk @scubbo MacOS has no proc system. See e.g. https://superuser.com/a/631696