Basic UNIX Commands

As we know Hadoop  works on UNIX OS before proceeding to learn Hadoop we have to know basic commands of UNIX. PSB...

Command	Example	Description
1.     ls	ls ls -alF	Lists files in current directory List in long format
2.     cd	cd tempdir cd .. cd ~dhyatt/web-docs	Change directory to tempdir Move back one directory Move into dhyatt's web-docs directory
3.     mkdir	mkdir graphics	Make a directory called graphics
4.     rmdir	rmdir emptydir	Remove directory (must be empty)
5.     cp	cp file1 web-docs cp file1 file1.bak	Copy file into directory Make backup of file1
6.     rm	rm file1.bak rm *.tmp	Remove or delete file Remove all file
7.     mv	mv old.html new.html	Move or rename files
8.     more	more index.html	Look at file, one page at a time
9.     touch	Touch filename	touch command is used to make files
10.   man	man ls	Online manual (help) about command
11. cat	Cat filename	Sends file contents to standard output

Basic VI editor Commands  

Letter	Action
i	Starts inserting in front of the current cursor position
<Esc>	Gets out of Insert Mode
<ctrl>f	Moves the cursor forward a full page of text at a time
<ctrl>b	Moves the cursor backward a full page of text at a time
x	Deletes the character under the cursor
dd	Deletes the line where the cursor is located (type d twice!)
n dd	Delete n consecutive lines ( n is an integer)
u	Undoes the last edit operation
yy	Copies or yanks a line ( 5yy yanks 5 lines)
p	Puts the yanked text on the line below the cursor (lower case p)
P	Puts the yanked text above the current line (capital P)
Note: If vi is already in the input mode, text from that or another window may be highlited using the left mouse button, and copied into place by pressing the middle mouse button.
: r <file>	reads a file from disk into the vi editor
: w <file>	writes current file to disk
: wq	writes the file and quits vi
: q!	quits without writing (useful if you've messed up!)