Basic UNIX commands

How to create a new file ?

syntax : cat>filename
file data
file data
fild data

CTTL+D

How to rename existing file name ?

Syntax : mv oldfilename >> newfilename

How to change existing file content ?

Syntax: vi filename 

do all changes, if you want to save the file type the below command

:wq!

How to see the content of file ?

Syntax : cat <file name >

How to identify duplicate records in file ?(any file like DAT,CSV,TXT)

Syntex: cat <file name> | uniq -d

How to fetch unique records in file ?(any file like DAT,CSV,TXT)

Syntex: cat <file name> | uniq