I searched several questions in this forum about:
How to search a specific function ...
For example, I have a folder with several notebooks. And several of these notebooks, I used, for instance, Sin function.
That is, I intend to find, among these notebooks, examples using Sin function.
I already tried to use the command Filenames for to get anything, but I did not have succeed.
Edit: The link below show that I want:
Good ways to organize and document collections of mathematica notebooks?