BASHSHSHHSHS

 #!/bin/bash


    echo "Liczba nr 1:"
    read a
    echo "Liczba nr 2:"
    read b
    echo "Wybierz znak +, -, X, /, ^, _"
    read opr

    echo Wynik:

    if [ $opr = "+" ]
    then
        op=`expr $a + $b`
        echo "$op"
    elif [ $opr = "-" ]
    then
        op=`expr $a - $b`
        echo "$op"
    elif [ $opr = "/" ]
    then
        op=`expr $a / $b`
        echo "$op"
    elif [ $opr = "X" ]
    then
        op=`expr $a \* $b`
        echo "$op"
    elif [ $opr = "^" ]
    then
        op=`$(($a ** $b))`
        echo "$op"
    elif [ $opr = "_" ]
    then
        op=`echo "sqrt($a)" | bc`
        echo "$op"

fi