Linux – Page 3

vi Editor Cheat sheet

May 11, 2020May 12, 2020 by GET, posted in Linux

Page Contents

Opening File
Saving & Quitting
Switching to Shell & Run Commands
Modes – Command, Insert/Append & Exit
Deleting Text
Moving Cursor in file
Moving on Screen
Moving on Screen using Ctrl key

Go to desired line by line number
Changing Text
Copying, Pasting and Moving lines
Show/Hide Line Numbers
Searching – Ignore/Set case
Search and Replace

Opening File

Command	Purpose
vi	Open new file to be named later
vi file_name	Open an existing file or create a new file
vi -r file_name	Recover crashed file
view filename	Open file in read-only mode

Savings & Quitting

Command	Purpose
:q	Quit
:q!	Quit without saving the changes
:w	Save
:wq or :wq!	Save and Quit
:w filen_name	Save to file “file_name”
:e!	Discard unsaved changes, and reopen the file.
:sh	Switch to shell temporarily, and return back using Ctrl+d

Switching to Shell & Run Commands

Command	Purpose
:sh	Switch to shell temporarily, and return back using Ctrl+d
:!cmd1	Execute the command cmd1

Modes – Command, Insert/Append & Exit

Command	Purpose
i	Insert characters left of cursor
I	Insert characters beginning of line
a	Insert characters right of cursor
A	Insert characters end of line
o	Insert line below cursor
O	Insert line above cursor
Esc	Insert Mode to Command Mode Exit Mode to Command Mode

Deleting Text

Command	Purpose
x	Delete character at the cursor
X	Delete character to the left of the cursor
dw	Delete word or part of word, to right of cursor
dd	Delete current line
D	Delete part of line to right of cursor
dG	Delete to end of file
d1G	Delete – beginning of file to cursor
:1,5d	Delete lines 1 to 5

Navigation – Moving Cursor in file

Command	Purpose
h	Move one character left
j	Move one line down
k	Move one line up
l	Move one character to right
w	Move one word right
W	Move one word (past punctuation) right
b	Move one word left
B	Move one word (past punctuation) left
e	Move to the end of the current word

Navigation – Moving on Screen

Command	Purpose
H	Move to top of screen (1st line)
M	Move to middle of screen
L	Move to bottom of screen (last line on screen)

Navigation – Moving on Screen using Ctrl key

Command	Purpose
Ctrl+f	Page forward one screen forward
Ctrl+d	Scroll forward one half screen
Ctrl+b	Page backward one screen
Ctrl+u	Scroll backward one-half screen

Navigation – Go to desired line by line number

Command	Purpose
G	Go to the last line
1G	Go to the 1st line
24G	Go to the 24th line

Changing Text

Command	Purpose
cc	Change line
cw	Change characters in a word or entire word right of cursor
C	Change from cursor to end of line
s	Substitute string for character(s) from cursor forward
r	Replace character with other character at cursor
R	Replace characters from the cursor position
r Return	Break line at cursor
J	Join to current line line below
xp	Transpose character cursor and character to right
~	Change case of letter to uppercase or lowercase at cursor
u	Undo previous command
U	Undo all changes to current line

Copying, Pasting and Moving lines

Command	Purpose
yy	Yank or copy current line
5yy	Copy 5 lines
Y	Yank or copy line
p	Put yanked or deleted line below current line
P	Put yanked or deleted line above current line
:1,5 co 9	Copy lines 1-5 and put after line 9
:2,5 m 9	Move lines 4-5 and put after line 9

Show/Hide Line Numbers

Command	Purpose
:set nu	Show line numbers for all lines
:set nonu	Hide numbers for all line

Searching – Ignore/Set case

Command	Purpose
:set ic	Ignore case while searching
:set noic	Case sensitive searching

Search and Replace

Command	Purpose
/string	Search for string anywhere in file
?string	string Search backward for string
n	Find next occurrence of string in search direction
N	Find previous occurrence of string in search direction
:s/old/new/	Replace the first occurrence of the word “old” with “new” on the current line
:s/old/new/g	Replace all occurrences of the word “old” with “new” on the current line.
:.,+50s/old/new/	Replace all occurrence of the word “old” with “new” starting at the current line for the next 50 lines.
:1,50s/old/new/	Replace all occurrence of the word “old” with “new” on lines 1 thru 50.
:%s/old/new/	Replace all occurrences of the word “old” with “new” in the entire file.:e!

How to empty a large file quickly?

May 11, 2020May 12, 2020 by GET, posted in Linux

Deleting the contents of a large file is a similar task. All we need to do is utilize the /dev/null and direct it’s contents to the large file.

The following command delete all the contents of the file largefile.img

cat /dev/null > largefile.img

How to install Oracle VirtualBox on Ubuntu 16.04?

May 11, 2020May 12, 2020 by GET, posted in Linux, VirtualBox

Follow these simple steps to install Oracle VirtualBox on Ubuntu 16.04 & 18.04:

Step 1: Update Packages

$ sudo apt-get update
$ sudo apt-get upgrade

Step 2: Configure apt Repo

$ wget -q https://www.virtualbox.org/download/oracle_vbox_2016.asc -O- | sudo apt-key add -
$ wget -q https://www.virtualbox.org/download/oracle_vbox.asc -O- | sudo apt-key add -

$ sudo add-apt-repository "deb http://download.virtualbox.org/virtualbox/debian `lsb_release -cs` contrib"

Step 3: Installation

$ sudo apt-get update
$ sudo apt-get install virtualbox-5.2

Step 4: Launch Virtual Box

$ virtualbox &

Great Job! You now have Oracle VirtualBox installed and ready to explore.

How to change the hostname on Ubuntu 16.04?

May 10, 2020July 29, 2020 by GET, posted in Linux

Follow these simple steps to change the hostname on a ubuntu machine:

Step 1: Update /etc/hostname file

This file contains the current hostname of the machine. Update the name to your

desired name.

$ sudo vi /etc/hostname

Step 2: Update /etc/hosts file

Replace the current hostname in the file with the desired name.

$ sudo vi /etc/hosts

Step 3: Set the hostname using the hostnamectl command

$ sudo hostnamectl set-hostname new_hostname