exit - terminates the shell
This command is a built-in command in the C shell and the Korn shell.
When the exit(1) command is called, the shell exits either with the value of the specified expr (an expression, as described in the tcsh(1) section on Expressions) or, without expr, with the value of the status variable.
When the exit(1) command is called, the shell exits with the specified exit status. If status is not specified, the exit status is the current value of the ? parameter.