I read price from user input. When i multiply the input with int like this
T=
"$((PRICE*QTY))"|bc; gives line 272: 12.00: syntax error: invalid arithmetic operator (error token is ".00") or .50
depending on user input. How do i multiply these two variables and get a total with 2 decimal points?
this works:
PRICE=1.1 QTY=21 RES=$(echo "scale=4; $PRICE*$QTY" | bc) echo $RES 
var=$(echo "scale=2;$PRICE*$QTY" |bc) You can also use awk
awk -vp=$PRICE -vq=$QTY 'BEGIN{printf "%.2f" ,p * q}' 
$(()) . bash doesn't do floating arithmetic. If you want to set 2 decimal places, use scale=2
T="$(echo "$PRICE*$QTY" | bc)" 
bc.You can use mul=0.8 exp=200 texp=awk -vp=$mul -vq=$exp 'BEGIN{printf "%.2f" ,p * q}'
Hope this is going to work.
First, trying to do floating-point arithmetic with bc(1) without using the -l flag is bound to give you some funny answers:
sarnold@haig:~$ bc -q 3.5 * 3.5 12.2 sarnold@haig:~$ bc -q -l 3.5 * 3.5 12.25 Second, the $((...)) is an attempt to do arithmetic in your shell; neither my bash nor dash can handle floating point numbers.
If you want to do the arithmetic in your shell, note printf(1) as well as (probably) your shell's built-in printf function. If you want to do the arithmetic in bc, note the special variable scale.
echo $QTYS\* $PRICE | bc; Its also rounding price to 2 decimal places without scale. For some reason just price*QTY was giving me command not found error.