Tuesday, August 30, 2016

Linux Bash Shell Script Expression Evaluation Examples

August 30, 2016 bash , code , expression evaluation , linux , shell script , tutorial

This just an example of expression evaluation in different ways. Also equality and even odd checking in a different way.

It asks for an input to check if the number is even or odd.

Save the code in a file named "ExpressionEvaluation.sh".

	#!/bin/bash


	# Do not use space before and after equal sign.

	a=1
	b=3

	sum=`expr $a + $b`
	sum=$(( $sum + 5 ))

	echo $sum


	# If condition, must be closed with fi

	a=2
	b=2

	if [ $a -eq $b ];then
	echo "match"
	else
	echo "not match"
	fi


	# Check if even

	read input

	two=2

	val=$(( $input / $two ))
	val=$(( $val * $two ))

	#echo $val

	if [ $val -eq $input ];then
	echo "Even"
	else
	echo "Odd"
	fi

Just type the code below in terminal. Make sure to cd into that directory if you have not opened the terminal in that directory.

bash ExpressionEvaluation.sh