How to check if a file is empty in Bash?

Question

I have a file called diff.txt. I Want to check whether it is empty.

I wrote a bash script something like below, but I couldn\'t get it work.

Answer 1

To check if file is empty or has only white spaces, you can use grep:

if [[ -z $(grep '[^[:space:]]' $filename) ]] ; then
  echo "Empty file" 
  ...
fi