sed edit file in place

Question

I am trying to find out if it is possible to edit a file in a single sed command without manually streaming the edited content into a new file and

Answer 1

The -i option streams the edited content into a new file and then renames it behind the scenes, anyway.

Example:

sed -i 's/STRING_TO_REPLACE/STRING_TO_REPLACE_IT/g' filename

and

sed -i '' 's/STRING_TO_REPLACE/STRING_TO_REPLACE_IT/g' filename

on macOS.