Double bracket giving error

Shell Programming and Scripting
1

here is a small script I wrote:

#! /bin/bash
 
if [[ $# == 0 ]]
then
echo "argument is null"
fi

It is giving error:

test.sh: [[: not found

any idea, why is it so?

2

It's most likely your shell is outdated.

3

My bash version is:

$ bash --version
GNU bash, version 3.00.16(1)-release (sparc-sun-solaris2.10)
Copyright (C) 2004 Free Software Foundation, Inc.