Shell Scripting On Kali Linux

SHELL SCRIPTING

PART 1

INTRODUCTION

• A shell is the interface between us and the kernel.And in this tutorial we are going to learn shell scripting .


• First we start with the basic commands.And this tutorial is the basic tutorial , soon we will cover the advanced shell scripting .


• And the operating system we use is " Kali-Linux".


• Now go through with it and practise as much as you can .

SIMPLE COMMANDS

• whoami


• pwd

 

SYSTEM DATE AND CALENDER

• To see the calender in linux we use the cal command .


• As you enter the cal command , it will show you the current month calender.


• See the below image for more details -

2013 CALENDER

• Now if you are interested to view the 2013 calender , then enter the commands as shown below.


• Command : cal 2013


• See the below image for more details -

CREATING FILES AND DIRECTORIES

TOUCH COMMAND

• Using touch command you can create the empty files in linux .


• Also you can create more than 1 files together .


• These are the empty files but you can also put text inside it using different text editors  like vim , nano etc .


• Example : See the below image i have created 3 empty files together using touch command .

CREATING DIRECTORIES

• To create directory , we have to use the mkdir command .


• Syntax : mkdir < directory name >


• Example : See the below example for more details -

 

CHANGING DIRECTORY

• To change directory you can simply use the 'cd' command .


• See the below image for more details -

 

CREATING TEXT FILE USING CAT COMMAND

• To create file use the command cat > filename


• Then enter the text .


• To terminate press ctrl+d.


• See the below image for more details -

TO VIEW FILES 

• To view files you have to use ' < ' (less than ) sign as shown in the below example .


• Example : cat < hackingDNA


• Here hackingDNA is the filename .


• See the below image for more details -

 

MERGE FILES

• Merge files means  joining two files together and put it into one single file .


• Example : In the below example you can see two files :

1. hackingDNA


2. test

• Then we put these two files into 1 single file i.e merge.


• And at the last we view the merge file using 'cat < merge' command .


• See the below image for more details -

 

RENAMING AND DELETE FILES AND DIRECTORIES 

RENAME

• To rename file mv command is used .


• Syntax : mv filename newfilename


• Example : mv test test1


• See the below image for more details -

CREATING AND DELETING DIRECTORIES

COPY FILE INTO MUKUND DIRECTORY

LINK BETWEEN FILES : hardlink example


SOFTLINK EXAMPLE

• In this example ,   i use " ln -s  " to create a soft link .And also i link mukund  to the mukund_soft .


• When we use the ls command , you will observe the color of the soft link file , it's different from others.


• So now when i remove the mukund file  and then try to access the mukund_soft file , you will observe you cannot see  that file because you have deleted the hardlink (i.e mukund ).

FILE PERMISSION
CREATING A SAMPLE FILE

USING OF " ls "

VIEW FILES AND DIRECTORY WITHOUT PERMISSION

LONG MODE ( ls -l )

DISPLAY ALL THE HIDDEN FILES (ls -a)

DISPLAY ALL WITH INODE (ls -i )

CHANGE FILE PERMISSION WITH CHMOD

• Giving numeric permission is the easiest method .


• Numeric permission : 4 is for Read , 2 is for write and 1 is for execute .


• So for example : If you want to give  rwx permission to group , users and other , you have to enter the numeric value 777 as shown in the below image .


• See the below example for more details -

OTHER EXAMPLES

UNAME
To see the version of kernel , name of machine , OS etc .

• SOON PART -2 will be upload ed, till then practise these commands and bring some perfection in your command line .


• That help you a lot in many situation .