These are some of my notes from my time spent learning Bash script. Read and be blessed.

1. Print statement: echo “Hello, World“
2. Functions in bash:

• Bash functions don’t take input parameters like functions in languages like JS, this might throw you off a bit. Instead, it saves the inputs used when calling the function and puts them in variables starting with a dollar sign and the position of the argument for instance, “$1“ -> this means it’s the first parameter supplied to the function.

// function signature (with and without an input parameter)
greeting () {
  echo "Yoo $1"
}

Assuming we call the above function like so

greeting “Chi“

The string “Yoo Chi“ will be printed on the screen.

3. To check if an input argument exists when calling a bash script

   if [ $# -eq 0 ] <---- $# returns the number of input arguments passed to the script
     then
     else
   fi
   

$# returns the number of input arguments passed to the script.

-eq 0 evaluates if the input arguments are equal to 0.

4. Exit status: If a command exits with 0, it is a success. If it exists, with anything other than a 0, it is a failure.