# Operators

Contoh

``````val=`expr 2 + 2`
echo "Total value : \$val"
``````

``````#!/bin/sh

a=10
b=20

val=`expr \$a + \$b`
echo "a + b : \$val"

val=`expr \$a - \$b`
echo "a - b : \$val"

val=`expr \$a \* \$b`
echo "a * b : \$val"

val=`expr \$b / \$a`
echo "b / a : \$val"

val=`expr \$b % \$a`
echo "b % a : \$val"

if [ \$a == \$b ]
then
echo "a is equal to b"
fi

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

``````#!/bin/sh

a=10
b=20

if [ \$a -eq \$b ]
then
echo "\$a -eq \$b : a is equal to b"
else
echo "\$a -eq \$b: a is not equal to b"
fi

if [ \$a -ne \$b ]
then
echo "\$a -ne \$b: a is not equal to b"
else
echo "\$a -ne \$b : a is equal to b"
fi

if [ \$a -gt \$b ]
then
echo "\$a -gt \$b: a is greater than b"
else
echo "\$a -gt \$b: a is not greater than b"
fi

if [ \$a -lt \$b ]
then
echo "\$a -lt \$b: a is less than b"
else
echo "\$a -lt \$b: a is not less than b"
fi

if [ \$a -ge \$b ]
then
echo "\$a -ge \$b: a is greater or  equal to b"
else
echo "\$a -ge \$b: a is not greater or equal to b"
fi

if [ \$a -le \$b ]
then
echo "\$a -le \$b: a is less or  equal to b"
else
echo "\$a -le \$b: a is not less or equal to b"
fi
``````

``````#!/bin/sh

a=10
b=20

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

if [ \$a -lt 100 -a \$b -gt 15 ]
then
echo "\$a -lt 100 -a \$b -gt 15 : returns true"
else
echo "\$a -lt 100 -a \$b -gt 15 : returns false"
fi

if [ \$a -lt 100 -o \$b -gt 100 ]
then
echo "\$a -lt 100 -o \$b -gt 100 : returns true"
else
echo "\$a -lt 100 -o \$b -gt 100 : returns false"
fi

if [ \$a -lt 5 -o \$b -gt 100 ]
then
echo "\$a -lt 100 -o \$b -gt 100 : returns true"
else
echo "\$a -lt 100 -o \$b -gt 100 : returns false"
fi
``````

``````#!/bin/sh

a="abc"
b="efg"

if [ \$a = \$b ]
then
echo "\$a = \$b : a is equal to b"
else
echo "\$a = \$b: a is not equal to b"
fi

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

if [ -z \$a ]
then
echo "-z \$a : string length is zero"
else
echo "-z \$a : string length is not zero"
fi

if [ -n \$a ]
then
echo "-n \$a : string length is not zero"
else
echo "-n \$a : string length is zero"
fi

if [ \$a ]
then
echo "\$a : string is not empty"
else
echo "\$a : string is empty"
fi
``````

``````#!/bin/sh

file="/var/www/tutorialspoint/unix/test.sh"

if [ -r \$file ]
then
echo "File has read access"
else
echo "File does not have read access"
fi

if [ -w \$file ]
then
echo "File has write permission"
else
echo "File does not have write permission"
fi

if [ -x \$file ]
then
echo "File has execute permission"
else
echo "File does not have execute permission"
fi

if [ -f \$file ]
then
echo "File is an ordinary file"
else
echo "This is sepcial file"
fi

if [ -d \$file ]
then
echo "File is a directory"
else
echo "This is not a directory"
fi

if [ -s \$file ]
then
echo "File size is not zero"
else
echo "File size is zero"
fi

if [ -e \$file ]
then
echo "File exists"
else
echo "File does not exist"
fi
``````