Either of these will typically show you your running terminal: ps -p $$ echo $0 (command name that was used to invoke the shell) Not reliable: echo $SHELL

Either of these will typically show you your running terminal: ps -p $$ echo $0 (command name that was used to invoke the shell) Not reliable: echo $SHELL (preferred shell for the user, not necessarily what is running) Also note that you may want to remove/fix bash to make sure it doesn't get run by something else. A CGI script may run it despite you changing your default shell to something else.