Clear The Terminal Command History

                               By default, up to the last 500 command lines a user types in the terminal window are saved into a hidden .bash_history file. The previously typed commands can be readily accessed by using the up and down arrow keys.

Viewing the complete terminal command

               To view the complete history of commands typed in the terminal "for the logged in user" 

        Open a terminal window and type   history

Clear the terminal command line history:

1. Login with the user account whose terminal history you plan to clear
2. Open a terminal window and type history -c