Java™ Application Development on Linux - Dator

36Chapter 2An Embarrassment of Riches: EditorsThere are several ways to get into input mode, depending on where youwant to do the insert. When the file you’re editing is completely empty, allthese commands are equivalent, but for nonempty files, each command willbegin input mode in a different place in the file:• i inserts before the cursor.• I inserts at the beginning of the line.• a appends after the cursor.• A appends at the end of the line.• o “opens” a line for input after the line on which the cursor sits.• O “opens” a line for input before the line on which the cursor sits.Remember that this is character-based editing, before the days of mice andI-bars. So there is no meta-character for the cursor to show its position betweentwo characters in the file. Instead, the cursor sits on top of a character, and thusinserts or appends will happen before or after that character.Reminder: Get out of input mode by pressing the Escape key.Next, let’s move the cursor around. The simplest way to do that is onecharacter at a time. Using the (lowercase) h, j, k, and l keys—notice thatthey’re all in a row on QWERTY keyboards—you have the “arrow” keys forleft, down, up, and right. One of the common enhancements for vi clones isto include support for the arrow keys on standard PC keyboards. Even so, theconvenience of having the motion keys on the “home row” for touch typistscan be a great speedup.• h moves left one character.• j moves down one line.• k moves up one line.• l moves right one character; same as a space.Often, character- or line-at-a-time is too slow. Move to the beginning ofthe line that you are on with 0 (zero), or to the end of the line with $. Moveto the top and bottom of the window with H (think “High”) and L (think“Low”). So first type L then hold down j. To move back in a file, first type Hthen hold down k. That gets the display moving down or up respectively.• H (“high”) moves to the top line of the window.• M (“middle”) moves to the middle line of the window.