I'm confused by the paragraph in http://codex.wordpress.org/Updating_WordPress starting
"For Automatic Update to work, all of your WordPress files have to either be owned by, or group writable by, the user WordPress runs as. WordPress does not necessarily run as the Apache server user (named "apache", "web", "nobody", or some such), nor is the server user necessarily the owner of the files.
It never does say how one determines who is the "user WordPress runs as." It looks like it's implying that the user is the owner of the WP files.
What's confusing is that I am the owner of all the files. Or is the user 'admin', whom I'm logged into WP as? And in any case (reference later in the paragraph), I've got all the files currently set at 777, which should let the automatic update run in any case--but I still get prompted for the FTP information.
So what's the story? I've got a bunch of different WP installations, so it would be really good to be able to use the automatic update rather than have to use the manual update for each of those installations.