invalid arithmetic operator in if condition in bash script

Question

I tried:

if [[ ${numbers[4]} -ge $best_res ]]; then
                             ...
fi

I got the following error for the if condition line:

7 ./q1.sh: line 58: [[: 0.346: syntax error: invalid arithmetic operator (error token is ".346")

there are similar questions, but my error is in "if" condition. How can I fix it with "bc" or "dc"?

Bash doesn't support floating point arithmetics. – choroba Nov 01 '19 at 15:41 — choroba, Nov 01 '19 at 15:41

score 2 · Accepted Answer · answered Nov 01 '19 at 15:41

2

The problem is that bash doesn't support floating point arithmetic, which is what one of your variables appears to have.

Here's simple example:

$ [[ 0.346 -ge 0 ]] && echo "true"
bash: [[: 0.346: syntax error: invalid arithmetic operator (error token is ".346")

You'll have to use external tools like bc or dc, etc.

answered Nov 01 '19 at 15:41

P.P

Okay, but how I can have bc in if condition – Ahmad Nov 01 '19 at 15:49
1

With `bc`, you could do: `$ a=0.346; b=0; echo "$a > $b" | bc` which prints 0 or 1 (in this case 1). – P.P Nov 01 '19 at 15:52

1 Answers1