1. Agenda Using vi Editor Starting vi Session Command / Input Modes
Entering Text
Editing Text
Saving Edited File
Aborting Editing Session

2. vi (Visual) Editor
vi is a powerful, interactive, visually-oriented text editor
Features:
flexibility in performing various tasks.
ability to view many lines of text as opposed to one line at a time.
possible to recover file edited by vi in the event of a “system crash”.
Custom-designed for programmers.

3. Starting vi Session
There are two ways to start an editing session with vi:
Enter vi filename (recommended since filename has already been assigned and changes will be saved to filename by enter ZZ while in vi).
Enter vi (filename is not assigned, therefore user has to type <ESC> :w filename <ENTER> in order to save file.

4. Modes There are two operational modes while using the vi editor:
Command Mode (default mode when starting!)
Mode to allow user to give commands such as to delete text, search for strings, search & replace, save changes, abort editing session without saving changes and exit the vi editor.
Input Mode
Input Mode allows user to enter or edit text.
This is what makes vi difficult for most people first learning vi!

5. Input Mode
While in command mode, you can issue the following commands to
input text:
i – insert to left of cursor I – insert at beginning of line
o – insert line below current line – insert line above current line
a - append to right of cursor A - append at end of current line
r - replace character R – overwrite text
NOTE:
To enter command mode while in input mode, press the <ESC> key.
While in input mode, the input mode indicator should appear as INPUT on the bottom of the vi screen.If this indicator does not appear when you press i then type:
<ESC>:set showmode <ENTER>

6. Input Mode
Type in your text, but it is recommended to press <ENTER> before the end of the line (i.e. do not use word-wrap). Also, do not use <SPACE> to end a line. Tilde “~” characters below text represent end of file.
Error Correction (As you type):
CTRL-h Delete a letter
CTRL-w Delete a word
CTRL-u Delete a line
Do these key-combinations look familiar?

7. Editing Text
You can move around to text in the screen with the arrow keys while you are in insert mode.
For more advanced editing, you can return to Command Mode and use appropriate editing commands.
While in command mode, you can move throughout file by using arrow keys and letters h (left), j (down), k (up), and l (right).

8. Editing Text Other movement keys within command mode:
w – move forwards by one word W – move forwards by space-delimited word
0 (zero) – move to beginning of line $ - move to end of line
) - move forwards to next sentence ( - move backwards to previous sentence
} - move forwards to next code block { - move backwards to previous code block
<CTRL><f> - move forwards one screen <CTRL><b> - move backwards one screen
G – move to bottom of the file # G – move to line number in file
H – move to top of current screen M – move to middle of current screen
L - move to bottom of current screen
TIP:
Placing a number before the movement key will repeat the movement by that number

9. Editing Commands (Within Command Mode)
The major Text Editing Commands are:
d – Delete
c – Change
y – Yank (copy)
When combined with movement keys, the vi editor becomes an effective editing tool. eg. d4W (Delete the next four space-delimited words)
c$ (Change from the cursor to the end of the line)
y$ (Copy from cursor to the end of the line)
d34d (Delete current line and following 33 lines)
Pressing the period “.” in command mode will repeat the most recent edit!

10. Saving Edited File
When you create a file using vi, all work performed during vi session is stored in a Work Buffer (temporary storage) until the user saves their work.
When saving, changes in the work buffer are placed in a new file if creating a new file, or changes in work buffer modify existing (previously created) file.

11. Saving Edited File
To save your vi session, you must make sure you are in command mode by pressing <ESC>
To save your changes and exit, enter ZZ (i.e. two capital z’s)
You can also save without exiting by entering :w

12. Aborting Editing Session
If you make a huge mistake in your editing session (that undo cannot solve), you can abort your session without modifying the contents of your file (dump the work buffer)
To abort the current editing session, press <ESC> :q! <ENTER>