14.3 C Shell Features
14.3.3 The history command in the C shell
The history variable saves and prints the current command and history list number to the screen. The history list keeps a record of the exact command lines that you enter, in the order that you enter them. Unlike the Korn shell, the C shell does not automatically have the history variable set. You must set the history variable (history list) before the history command can be executed. You can set history to a specific number to display that number of previous commands to the screen.
Command Format:
set history=n

Activating the history Variable
In the first example in Figure , the last five command lines are displayed from the history list after setting history to 5 then typing the
history command. After you have set the history variable, the history list will then be created from that point on. Any commands entered before executing the set history command are not part of the history list. Any commands typed after setting the history variable are added to the history list, as shown in the second example, and are displayed each time you type the history command. To stop capturing history use the unset history command.