Shell_Scripting.txt

Shell scripting -- Is a process of automate day to day activites or regular activies in your linux  compute 

Info of any command
=======================
man ls
man touch
man cat

We can also create the file directly using
nano ( It creates and open the file )
Ex: nano second-shell-script.sh

Then why to touch 
Be'coz touch is used in the automation

Note : For every bash file, We have to write shabang
#!/bin/bash   ** Madatoroy

bash , dash , sh , rsh  === These are different executables of the  shell script

#!/bin/sh --- Internally uses #!/bin/bash with the concept of linking But But .....

--> Recent years ubuntu started using #!/bin/dash instead of #!/bin/dash

**** Use #!/bin/bash  ******

To Run a shell scripting 
=====================
sh first-shell-script.sh
bash first-shell-script.sh
./first-shell-script.sh

After writing the scripting
we have to give permissions to run the script ( Linux is secure )

chmod === Grant permissions
ch == change 
mod == permission

Ex: chmod first-shell-script.sh

Grant permission for every one
=============================
Ex:  chmod 777 frist.sh

4 == read
2 == write
1 == execute

7 == means all read, write, and execute

Ex: chmod 444 first.sh
-- Read permission for root
-- Read permssion for User
-- Read persmission for group


histroy 
=========
history == This command is used to get all the used commands