Shell Script

A shell script is a computer program designed to be run by the Unix/Linux shell which could be one of the following:

• The Bourne Shell
• The C Shell
• The Korn Shell
• The GNU Bourne-Again Shell

A shell is a command-line interpreter and typical operations performed by shell scripts include file manipulation, program execution, and printing text.

Sample Shell Scripts
#!/bin/sh

echo "What is your name?"
read PERSON

echo "Hello, $PERSON"

How to Run Shell Script

sh <Script Name>

Defining variable
Name="Suma"
age=34

Accessing Values
To access the value stored in a variable, prefix its name with the dollar sign ($)
Name="Suma"
age=34

echo $Name
echo $age

Variable Type 

• Local Variable
• Environment Variable
• Shell Variable

 if Statement 
#!/bin/sh
echo "Enter first number"
read a
echo "Enter second number"
read b
if [ $a == $b ]
then
   echo "a is equal to b"
fi

if [ $a != $b ]
then
   echo "a is not equal to b"
fi