(Linux) syntax error: operand expected (error token is "**")

Question

To calculate $1*$1*$1

#!/bin/bash

volume=$1*$1*$1
echo "The volume of the cube is"$volume

How can I fix this?

Please don't post images of text. Use the _select_ then the _copy_ functionality provided by your OS and then _paste_ the text in the question. Use the `{}` button in the toolbar of the question editor to format it nicely. — axiac, Mar 05 '21 at 16:22

Barmar · Accepted Answer · 2021-03-05T16:17:52.067

1

Use $(( )) to evaluate arithmetic expressions in bash.

volume=$(($1 * $1 * $1))

You can also use the let command:

let volume=$1*$1*$1

or you can use (( )) to execute an arithmetic statement

((volume = $1 * $1 * $1))

What you wrote was being treated as a filename wildcard.

You also need to provide an argument to the script, this will be used as $1.

$ bash testarith.sh 5
The volume of the cube is 125

edited Mar 05 '21 at 16:17

answered Mar 05 '21 at 16:03

Barmar

1

It still keeps saying syntax error: operand expected (error token is "**") - I typed your all solutions... I cannot figure out why – NewCoderAna Mar 05 '21 at 16:13
1

Your script requires an argument, the number to be multiplied. – Barmar Mar 05 '21 at 16:15
ohh thank you so much I finally realized what was wrong! thank you so much for your help! – NewCoderAna Mar 05 '21 at 16:22
Bash also provides a power arithmetic operator `**`: `volume=$(($1**3))` – Léa Gris Mar 05 '21 at 17:11

1 Answers1