, then ${#filename} would have the value 6.
The other operator (${#array[*]}) has to do with array vari... If you're interested in more hints about bash (or other stuff I've written about), please take a look at ... If you're interested in more hints about bash (or other stuff I've written about), please take a look at ... Linux.
If your concerned about portability to other shells and systems -- you may want to stick with