Show which shell is running

Here are some examples of how you can find out which shell is running from the terminal:

1. Using the $SHELL environment variable:

   echo $SHELL

2. Using the ps command:

   ps -p $$

3. Using the echo command with the $0 parameter:

   echo $0

4. Using the ps command with the -o option:

   ps -o comm= -p $$

These commands will help you identify the current shell you are using in your terminal.