List files in sorted order using 'du'

Listing of all the files (and subdirectories) within a directory along with their sizes in sorted and readable format.

$ sudo du /backup/ -h | sort -h

vi Commands

vi is a Visual Editor (hence the name -- vi for VIsual). vi is a widely-used and popular UNIX-based text editor. Like most UNIX system interfaces and other text editors, it lets you control the system by using the keyboard rather than a combination of mouse selections and keystrokes.

Edit a File

Edit a file from command prompt	vi
Edit a file from command prompt for reading only	vi -R
Edit a file from within vi	:e
Edit a new file from within vi, discard changes to current file	:e!
Reload current file, discarding changes	:e!
Go forwards a page	Ctrl+F (or PgDn)
Go backwards a page	Ctrl+B (or PgUp)
Move around single lines or characters	Arrow keys
Save changes	:w
Save changes and override protected (read-only) files	:w!
Save changes and exit vi	ZZ
Quit	:q
Quit and discard changes	:q!
Get general help	:help
Get help on a command (eg. :set)	:help set

Go to lines, find matching text 

Go to line 1234 (do not see typing)	1234G
Go to line 1234 (see typing)	:1234
Go to start of file	1G
Go to end of file	G
Find (forwards) a line containing "swordfish"	/swordfish
Find (forwards) a line using a regular expression	/you see .* here
Repeat last search	n
Repeat last search in opposite direction	N
Find (backwards) a line containing "swordfish"	?swordfish
Find (backwards) a line using a regular expression	?you see .* here
Search case insensitive (Ignore Case)	:set ic
Search with case sensitivity	:set noic
Wrap searches back to start of file	:set wrapscan
Do not wrap searches	:set nowrapscan

Insert Text

Insert after cursor	i
Insert before cursor	a
Insert at beginning of line	I
Insert at end of line (append)	A
Open (start) new line below cursor	o
Open (start) new line above cursor	O

Advance Deletion

Delete next 5 lines	5dd
Delete to end of line	d$
Delete to start of line	d0
Delete to word "swordfish"	d/swordfish
Delete to the letter "x"	dfx
Delete lines 10 to 20	:10,20d
Delete current line and another 5 lines	:.,+5d
Delete all lines	:%d
Delete current word	dw
Find line containing pattern, delete it	:/pattern/d
Find line containing "dog", delete until line containing "cat"	:/dog/,/cat/d
Delete from current line to line containing "foo"	:.,/foo/d

VI Editor Tips

The VI editor is a screen-based editor used by Linux/Unix users. The VI editor has powerful features to aid programmers.  VI has two modes insertion mode and command mode.  The editor begins in command mode. Insertion mode begins upon entering an insertion or pressing 'i' in keyboard. [ESC] returns the editor to command mode.

Following tips may be helpful for programmers / content writers.
Execute the command from VI Editor command mode. (press Esc, If Insert mode)


Insert space/character between 2 adjacent characters

Example 1
'LinuxFor' becomes 'Linux For' (Sentence Case)

:%s/\([a-z]\)\([A-Z]\)/\1 \2/g

Example 2
'Kerala government' becomes 'Kerala Governemnt'

:%s/\([a-z]\) \([A-Z]\)/\1 \U\2/g


Removes all lines starts with a word/patterrn.

Removes all lines begin with 'Ele'

:g/^Ele.*$/d

Removes all lines end with 'are'

:g/$*.are/d

Removes blank lines

:g/^$/d

Make First Letter Capital

:%s/^./\U&/



Compress and split large files under linux

One of the common problems we used to face is transferring large files from Linux through mediums that doesn't support large files, especially when it comes to more than 4 GB files, usually that is a virtual machine hard disk, or backup file.

To compress and split files under linux, this command can be used:


$ tar -cvj big-file.dvi | split -b 650M -d - "small-file.tar.bz."

This command will compress and split the "big-file.dvi" to many files with size 650MB for each, giving it the name "small-file.tar.bz.0, small-files.tar.bz.1, etc...."

To join the files together again, this command can be used:

$ cat small-file.tar.bz.* > big-file.tar.bz

and to extract the output file :

$ tar -xvj large-file.tar.bz