brackets in bash shell

lipun4u · 06-19-2010, 08:04 AM

Plz check the code...

Code:

#!/bin/sh

var1=100
var2=50
var3=45

var4=$[$var1 * ($var2 - $var3)]
echo "The final result is $var4"

Why it gives the following error ??

Quote:

/test101.sh: 7: Syntax error: "(" unexpected

jlinkels · 06-19-2010, 08:16 AM

Because this is not the correct syntax

http://www.faqs.org/docs/abs/HTML/arithexp.html

jlinkels

colucix · 06-19-2010, 08:19 AM

Maybe because you're running the code with /bin/sh and in compatibility mode with the old Bourne Shell the syntax is not correct. Anyway, the $[...] construct for integer expansion is deprecated and it should be avoided in favor of the arithmetic operator ((...)).

On the other hand, if you're really writing a script for the Bourne shell, better to use expr.

lipun4u · 06-19-2010, 08:24 AM

after changing to /bin/bash, everything ran correctly...