If you want to overwrite a file by redirecting the output of a command, you can use: If you want to move up a line in vi command mode, you can press the up arrow key or Which regular expression character matches zero or more of the previous character? Which of the following regular expression characters is an extended regular expression character? The head -n -1 readme.txt command will Number the lines of readme.txt Display all but the last line of readme.txt Show the first character of every line of readme.txt ? Display the first line of readme.txt