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