Floating-point division in bash

Question

I\'m trying to convert whatever numbers the user inputs into 2 decimal places. For instance

What is the total cost in cents? 2345
output: 23.45

Answer 1

Bash itself could not process floats.

It can, however, printf them:

$ printf 'value: %06.2f\n' 23.45
value: 023.45

So, you need an external program to do the math:

$ echo "scale=4;2345/100*20/100" | bc
4.6900

Or, equivalent:

$ bc <<<"scale=4;2345*20/10^4"
4.6900

Then, you can format the float with printf:

$ printf 'result: %06.2f\n' $(bc <<<"scale=4;2345*20/10^4")
result: 004.69

Or you can use a program that can process floats; like awk.