Information about which shell you are using is held in the SHELL environment variable. The command
displays the value of this variable.
You can identify which shell you are presently using from the last part of the pathname.
Pathname Shell ______________________________________________________________ /.../sh Bourne shell /.../csh C shell /.../tcsh TC shell /.../ksh Korn shell /.../zsh Z shell /.../bash Bourne Again SHell ______________________________________________________________