command line arguments in bash script

To input arguments into a bash script, like any normal command line program, there are special variables set aside for this

The arguments are stored in variables with a number in the order of the argument starting at 1

• First Argument: $1
• Second Argument: $2
• Third Argument: $3

• Example
  • command: ./script.sh alpha beta gamma
  • Variables: $1=='alpha'; $2=='beta'; $3=='gamma'

The variable $0 is the script's name.  
The total number of arguments is stored in $#. 
The variables $@ and $* return all the arguments.

Script Example
#!/bin/bash

echo "the $1 eats a $2 every time there is a $3" echo "bye:-)"

• Command: ./script.sh dog bone moose
• Output:
  
  the dog eats a bone every time there is a moose  bye:-)