Commnands: c <range>: change a range of lines l <range>: list a range of lines, or the whole file if no range is given. s <string>: search for <string> in the file S <string>: case sensitive search i <linenumber>: insert at <linenumber> a: append to the end of file d <range>: delete a range of lines w: write the file out q: quit the editor when you're in insert mode, typing '.' on a line by itself will get you back to command mode.