The more commands you enter, the harder it will be to find it again in the command line history. In such cases, you will get ahead faster with the search built into the shell. Press the keyboard shortcut [Ctrl-R] and type in a sequence of letters that appears in this command. The shell then returns the last command containing this string of letters. Once you find what you are looking for, press [Return] to execute the command. Or you press the [Esc] key. After that, the command is displayed and you can edit it or scroll back and forth in the command line history from this command