Configuring .wgetrc file for Wget Proxy: running Wget behind your Proxy server

Like most of the applications wget has a configuration file too – i.e. “wgetrc”. You can locate the file in  /etc/wgetrc folder. Configuring the proxy is only applicable for local settings (i.e. user specific) only. Please follow the steps provided bellow to apply the proxy settings. Perform these in Super User mode (i.e. “sudo su” in ubuntu).
Open the file ~/.wgetrc file. If the file doesn't exist, then create it.  
cd   /etc/wgetrc
vim  .wgetrc

Now, add the following statement in the file  
http_proxy=http://SERVER_NAME:PORT_NUMBER

If your proxy requires authentication (i.e. Username & Password),  you have two methods to mention the username and password for proxy server. They are as follows:

Explicitly specify those arguments in the command directly

The arguments for username and password are “--proxy-user” and “--proxy-password”  respectively. The format for using them in the command line are:.

$ wget --proxy-user=USERNAME --proxy-password=PASSWORD FILE_NAME

Setting the values permanently in the “.wgetrc” configuration file

If your authentication information is static/fixed, then it’s always advised to change the configuration file (i.e. .wgetrc file) itself. To apply these changes, follow the steps listed below:

Open the .wgetrc file and append/add the following lines in it.

proxy_user=USERNAME

proxy_password=PASSWORD

Note: You can apply the ftp proxy along with the authentication credentials using the aforesaid method.

Once the proxy settings are successfully configured in the wgetrc file, each time you run wget, it will automatically connect to the proxy server. Sometimes for local/LAN based downloads, you may not need the proxy server. If you require to turn off the proxy settings, then use the “--no-proxy” argument in the command for getting the file. Refer following statement:

$ wget --no-proxy FILE_URL

More Wget Commands can be found here.

WGET Tips and Tricks Video for Curious Minds (Thank you GEEKBLOG.TV.. :) )

vi Editor Commands - A quick reference list

General Startup

To use vi: vi filename

To exit vi and save changes: ZZ   or  :wq

To exit vi without saving changes: :q!

To enter vi command mode: [esc]

Counts

A number preceding any vi command tells vi to repeat that command that many times.

Cursor Movement

Command	Purpose
h	move left (backspace)
j	move down
k	move up
l	move right (spacebar)
[return]	move to the beginning of the next line
$	last column on the current line
0	move cursor to the first column on the current line
^	move cursor to first nonblank column on the current line
w	move to the beginning of the next word or punctuation mark
W	move past the next space
b	move to the beginning of the previous word or punctuation mark
B	move to the beginning of the previous word, ignores punctuation
e	end of next word or punctuation mark
E	end of next word, ignoring punctuation
H	move cursor to the top of the screen
M	move cursor to the middle of the screen
L	move cursor to the bottom of the screen

Screen Movement

Command	Purpose
G	move to the last line in the file
xG	move to line x
z+	move current line to top of screen
Z	move current line to the middle of screen
z-	move current line to the bottom of screen
^F	move forward one screen
^B	move backward one line
^D	move forward one half screen
^U	move backward one half screen
^R	redraw screen ( does not work with VT100 type terminals )
^L	redraw screen ( does not work with Televideo terminals )

Inserting

Command	Purpose
r	replace character under cursor with next character typed
R	keep replacing character until [esc] is hit
i	insert before cursor
a	append after cursor
A	append at end of line
O	open line above cursor and enter append mode

Deleting

Command	Purpose
x	delete character under cursor
dd	delete line under cursor
dw	delete word under cursor
db	delete word before cursor

Copying Code

Command	Purpose
yy	(yank)'copies' line which may then be put by the p(put) command. Precede with a count for multiple lines.

Put Command

Brings back previous deletion or yank of lines, words, or characters

Command	Purpose
P	bring back before cursor
p	bring back after cursor

Find Commands

Command	Purpose
?	finds a word going backwards
/	finds a word going forwards
f	finds a character on the line under the cursor going forward
F	finds a character on the line under the cursor going backwards
t	find a character on the current line going forward and stop one character before it
T	find a character on the current line going backward and stop one character before it
;	repeat last f, F, t, T

Indentation Commands

Command	Purpose
gg=G	It will Indent the whole file automatically. Go to the command mode (Pressing "ESC") and then type the command. Explanation:     g   - go to     gg - go to beginning of the file     G  - go to end of the file Note: =G   Will indent all code from the current line to the end of the file. ==   Will indent the current line.
:set autoindent (or :set ai)	This command will turn on auto-indent in VI Editor
Ctrl-d	It will un-indent (AKA outdent) your code
:set tabwidth=4 (or :set tw=4)	It will control how many spaces a tab should indent code
>>	This command will indent the current line. To indent specific number of lines starting with the current line, then prefix ">>" by a number (say 4>> then it will indent 4 lines, from current line).
<<	This command will un-indent current line

Miscellaneous Commands

Command	Purpose
.	repeat last command
u	undoes last command issued
U	undoes all commands on one line
xp	deletes first character and inserts after second (swap)
J	join current line with the next line
^G	display current line number
%	if at one parenthesis, will jump to its mate
mx	mark current line with character x
‘x	find line marked with character x

NOTE: Marks are internal and not written to the file.

Line Editor Mode

Any commands form the line editor ex can be issued upon entering line mode.

To enter: type  ':'

To exit: press [return] or [esc]

ex Commands

For a complete list consult the UNIX Programmer's Manual

READING FILES

copies (reads) filename after cursor in file currently editing

:r filename

WRITE FILE

Command	Purpose
:w	saves the current file without quitting

MOVING

Command	Purpose
:#	move to line #
:$	move to last line of file

SHELL ESCAPE

executes 'cmd' as a shell command.

:!'cmd'

Video Tutorial for Editing Files using VIM in Linux

Some Useful Pages:
vi Editor Commands