How to sum floats variables in bash?

Question

I am trying to run a script in which a variable is updated every time by a float number "given as user input" in a while loop. I know that bash doesn't support floats, I tried using | bc but it doesn't seem to work to me...

step_l0=0.25
step_l=0
while [ $step_l -le 2 ] do
  step_r=$radius_input
  while [ $step_r -le $radius_define ] do

    stuff done in the while loops

    step_r=$(( $step_r + $step_r0 ))
  done
  step_l=$(( $step_l + $step_l0 ))
done

Use a language that *does* support floating-point arithmetic. — chepner, Dec 02 '19 at 14:18
That seams to work but then in my while loops it says "integer expression expected" I am trying to have everything on bash — Gianmarco Broilo, Dec 02 '19 at 14:22
```bash``` does _NOT_ support floating point operations. You can try ```ksh``` or ```zsh``` instead. — accdias, Dec 02 '19 at 14:30

Paul Hodges · Accepted Answer · 2019-12-02T14:38:48.210

2

Per chepner's suggestion -

$: a=0.25
$: b=1.753
$: awk "BEGIN{ print $a + $b }"
2.003
$: python -c "print $a + $b"
2.003
$: perl -e "print $a + $b"$'\n'
2.003

Where possible (and it's virtually always possible), if you need to invoke a more precise or powerful language to accomplish a task in your script, consider converting the entire script. You'll be glad you did.

edited Dec 02 '19 at 14:38

answered Dec 02 '19 at 14:27

Paul Hodges

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How to sum floats variables in bash?

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