PacNOG 6, Nadi, Fiji

EDITING

Notes:
------
* Commands preceded with "$" imply that you should execute the command as a 
  general user - not as root.
* Commands preceded with "#" imply that you should be working as root
* Commands with more specific command lines (e.g. "RTR-GW>" 
  or "mysql>") imply that you are executing commands on remote equipment, or 
  within another program.

vi Cheat Sheet

Open:  

vi filename             (fn=filename)
vi -r filename          Recover a file from a crashed session
vi + filename           Place the cursor on last line of file.
vi +n filename          Place the cursor on line "n" of file.
vi +/pat filename       Place cursor on line with first occurrence of "pat"tern

Close:

:w                      Write the file to disk. Don't exit.
:w!                     Write the file to disk even if read/only.
:wq                     Write the file to disk and exit.
:wq!                    Write the file to disk even if read/only and quit.
:q                      Quit the file (only if no changes).
:q!                     Quite the file even if changes.

Movement:

A                       Move to end of line, change to insert mode.
h                       Move 1 space backwards (back/left arrow).
j                       Move down 1 line (down arrow).
k                       Move up 1 line (up arrow).
l                       Move 1 space forwards (forward/right arrow)
w                       Move cursor to start of next word.
W                       Same as "w".
b                       Move cursor to start of previous word.
B                       Same as "b".
:n                      Go to line number "n" in the file.

Editing:

i                       Enter in to input mode.
o                       Add a line below cursor and enter in to input mode.
x                       Delete character (del key in some cases).
D                       Delete line from right of cursor to end of line.
dd                      Delete entire line.
u                       Undo last edit or restore current line.
p                       Put yanked text before the cursor.
yy                      Yank current line.

Searching:

/pattern               Search for "pattern" in the file going forwards.
?pattern               Search for "pattern" in the file going backwards.
n                      Find the next occurrence of pattern found forwards.
N                      Find next occurrence of pattern found backwards.

Copy/Cut and Paste
nyyp                   Copy n lines to buffer, paste below cursor
nyyP                   Copy n lines to buffer, paste above cursor
nddp                   Cut n lines and copy to buffer, paste below cursor
nddP                   Cut n lines and copy to buffer, paste above cursor

Exercises
---------

1. Practice Using vi
   -----------------
Remember The vi editor uses "modes".

The easiest thing to do if you get confused in vi is to press the ESCape key a 
couple of times and start over. With what you were doing.

To begin log in or use a terminal with your inst user already logged in and 
do:

	$ cd
	$ touch temp.txt
	$ vi temp.txt

	- Press the "i" key to switch to input mode. 
	- Type something like, "VI is great! I think I'll be using vi from now 
          on instead of Word
	- Press <ENTER> to add lines.
	- Type some more text

Save the file that you are in. To do this do: 

	- Press the ESCape key for command mode
	- Type ":wq" to save and quite the file 

Copy a large file to your home directory so that you can play around with 
some more vi commands. We'll copy over your /etc/defaults/rc.conf file for this 
exercise. To do this do: 

	$ cd 
	$ cp /etc/syslog.conf syslog.conf.bak

Edit the file, but let's start at the bottom of the file:

	$ vi + syslog.conf.bak 

Go to the first line of the file:

	:1

Go to line 10, add a new line, and add in some text:

	:10
	Press the "o" key
	
Add the following text:

	## 
	## A sample comment
	##

Delete the three lines you just created:

	Move to the first line of new text
	Press the ESCape key
	Press "dd" to delete a line, repeat until the text is gone

Practice copying and pasting text. 

Go to line 10, copy 10 lines of text, go to the bottom of the file, place the 
text there:
	
	ESC
	:10
	10yy
	G
	p

Undo (reverse) what we just did:

	u

Go to the top of the file, replace all occurrences of "mail" with "smtp", but 
prompt for each change:

	ESC
	:%s/mail/smtp/gc

Say "yes" or "no" to a few prompts then escape from this mode by pressing ctrl-cmd <ENTER>

Go to line 1, search for "daemon", move to the end of the line, add some text:

	ESC
	:1
	/daemon
	$
	i
	"text here"
	ESC


2. Practice, practice, practice
   ----------------------------

As you should be able to see vi is extremely powerful as an editor, but not 
necessarily intuitive. The best way to get good at using vi is to practice. 

Make sure you are logged in as sysadmin on whatever virtual terminal you wish 
to use. Then do the following:

	$ cd
	$ vi syslog.conf.bak
	
In this file practice some of the following items:

	Moving around:
		By word
		End of line
		Start of line
		Top of file
		Bottom of file							
		To an absolute line number
	Copying and pasting multiple lines (use vi commands)
	Copying and pasting single lines (use vi commands)
	Copying and pasting multiple lines (use your mouse buffer)
	Copying and pasting single lines (use your mouse buffer)
	Search for items backwards and forwards
	Replacing text

And, anything else you wish to practice.

3. Repeat exercises 1 and 2 using another editor, like emacs, pico, etc.
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