Shell Scripting

How to create shell scripts

• using simple touch

touch test.sh

• VIM Editor/nano
• VIM Tutorial here

Arguments

• $@: Whole arguments passed to script
• $#: Count of arguments

Excercise

1. Write a script which prints number of arguments passed

#!/bin/bash
echo "Number of arguments passed are $#"

2. Write a script which gives an error message if no arguments are passed
3. Write a shell script to add all the arguments passed

add.sh 1 2 3 4 5 => 15

Summary

1. Positional Arguments: Symbols: $@, $#, $1
2. Conditional Statement: if, if else, if else if , nested if
3. Exit Codes: 0 => success , 1 => failure
4. running mini bash script => ls;pwd;
5. running multiple scripts => a.sh && b.sh , a.sh || b.sh
6. looping structure: for , for index in $@ == for index