shell float number in expr

Question

I'm trying to get a float number from this :

totalmark=$(expr $sum / $subjects )

Is this correct?

Answer 1

bash doesn't support floats, use awk or bc/dc

eg awk

totalmark=$(awk 'BEGIN{print $sum / $subjects}')

or bc

totalmark=$(echo "scale=2;$sum/$subjects"|bc)

if you have the luxury to use different shells other than bash, try zsh or ksh

$ zsh -c 'echo $((4/1.3))'
3.0769230769230766

$ ksh -c 'echo $((4/1.3))'
3.07692307692307692

Answer 2

I don't think bash has floating-point capabilities. You can try:

echo "$sum/$subjects" | bc -l