Changing the name of a project-asset in C#

I’m trying to build a renamimg/prefix/suffix-tool for organizing the project.
I’m using Selection.gameObjects for the selecting part.
While it works with everything in the herarchy in projectview, it only changes the internal names of prefabs.
Is there a way of selecting and manipulating the name of everything in the projectview?
(Selection.objects does not work too.)

Selection refers to objects in the scene/hierarchy. You might want to read up on the AssetDatabase class to work with your project files:

https://docs.unity3d.com/ScriptReference/AssetDatabase.html

You can rename assets with:

static function RenameAsset (pathName : String, newName : String) : String 

Good luck!