Dear colleges and friends

As all know the following bash syntax verify if pram isnt zero

 [[ ! -z $param ]] 

For example

param=”” [[ ! -z $param ]] && echo “ I am not zero ” No output and its fine 

But when param have even empty one space then the case is different

param=” ”  <-- one space [[ ! -z $param ]] && echo “I am not zero ” I am not zero 

So my question is how to define in the brackets to ignore empty spaces (empty spaces will defined as zero )

so only in case $param have one character or more then it will be non zero case

The following bash syntax verifies if param isn't empty:

 [[ ! -z $param ]] 

For example:

param="" [[ ! -z $param ]] && echo "I am not zero" 

No output and its fine.

But when param is empty except for one (or more) space characters, then the case is different:

param=" " # one space [[ ! -z $param ]] && echo "I am not zero" 

"I am not zero" is output.

How can I change the test to consider variables that contain only space characters as empty?