Unix Shell - Digital Algorithm

#!/bin/ksh

 

X=10
Y=2

 

Z=`expr $X + $Y`    # or
echo $Z

(( Z = $X / 4 + 2 ))   # or
echo $Z

Z=$((X+Y))
echo $Z

Z=$(awk '/^PermSize=/ {print substr($0, 10, 30)}' $ODBCINI)
echo $Z
Z=$(echo 100 | grep '[1-9][0-9]*$')
echo $Z

if [ X -ne Y ]
then
        echo "X!=Y"
fi

 

[ X -eq Y ]
[ X -ne Y ]
[ X -gt Y ]    >
[ X -ge Y ]    >=
[ X -lt Y ]    <
[ X -le Y ]    <=