basic linux/unix terminal commands

linux/unix are the open source operating systems that allow user to access everything free of cost.
most of the work in these type of operating systems is done by terminal,a command shell

down below are some commands that are used in terminal

1.(A)  ls = to view contents in a directory
ls -a = to view hidden contents

1(B) ifconfig = to view mac address , ipv4 and ipv6 address

1. cd = to change path between directories

cd / destination       

to go back in directory you can type cd ..
to go next directory type cd ./directoryname
to go some other directory type cd /path from root

2. exit = to close the terminal

3.su = allow to login as super user which has the access to each content of os

 type su then root password

4.chmod = is used to give permission to access by user

chmod 777 /desktop/cp.txt  will give read,write and executable permissions to all

for more help about chmod go this link
http://www.computerhope.com/unix/uchmod.htm

5.mkdir = is used to create a diretory

mkdir /desktop/directory name

6. touch = to create a file

touch /filepath/filename

7.cat = to view content of file

cat /filepath/filename

it can't edit the file

8.vi = to edit the file

vi /filepath/filename

to insert,add or delete  press i
to save and exit press esc and :wq
to exit without saving press esc :x