let 연산자 BASH num1=42 num2=9 let re=num1+num2 #Add echo "add:$re" let re=num1-num2 #Sub echo "sub:$re" let re=num1*num2 #Mul echo "mul:$re" let re=num1/num2 #Div echo "div:$re" let re=num1%num2 #Mod echo "mod:$re" SHELL $ ./script.sh add:51 sub:33 mul:378 div:4 mod:6 $(( )) 연산자 BASH num1=42 num2=9 echo add:$((num1+num2)) echo sub:$((num1-num2)) echo mul:$((num1*num2)) echo div:$((num1/num2)) echo..