IDE - Visual studio code

• shell types supported in your system

root@zllart3:~# cat /etc/shells
/bin/ash
/bin/bash
/bin/rbash

• tell the script it is a bash

 #! /bin/bash
 echo "Hello World" #this is a comment after the "#"

• Variables

 two types system and user variables
 system variables are predefined and are in capital letters

• example system variables

echo "Hello World" #this is a comment after the "#"
echo $BASH
echo $BASH_VERSION
echo $PWD
echo $HOME
echo Our shell name is $BASH
echo Our shell version name is $BASH_VERSION
echo Our home directory is $HOME
echo Our current working directory is $PWD

• User defined variables, user defined variables may not start with numbers.

name=Mark
VALUE=10
echo The name is $name
echo value $VALUE