Probably already answered, but can't find a howto.

I've got a shared (Windows/multiuser Linux) laptop, and I've got installed World of Warcraft and some steam games in Windows.

With steam games, there is (almost) no problems. I've installed steam in Linux, and soft linked the 'steamapps' directory (per-game compatibility is another issue).

With WoW, the problem is different. I would like to have almost (but not) all files. Under World of Warcraft, every file and directory must be linked except the Interface directory and WTF/config.wtf file (so every user can play with their own settings and addons).

How can I have a mix of linked and not linked files without linking every file? If I link manually every file/dir, when updating from Linux other users and Windows Wow is not updated; when updating from Windows, new files remains "unlinked".

If you are speaking of the ln command, as I think that you are, then ... yes, the links must be to individual files and/or directories. You might be able to use a bash-script command-line (see for, find, xargs) to automate the process somewhat.

I don't know this game, but I am mildly surprised that it does not have configuration-settings that point to the different directories, e.g. to accommodate "multiple users."

Not exactly sure what you're asking, but to filter which files are linked you can use 'find' with some arguments. To link all files under the current directory that don't end in '.ctf' would be like this...

find ./ -type f -not -iname "*.ctf" -exec ln '{}' \;

you can contour the filter as much as you can contour the find command (a good bit including regexes). To make the links in their own directories would be a bit more work.

Thanks for the answers!

I've been sniffing everywhere, and it seems that another choice would be using aufs or unionfs to join two directories, but I'm still looking for a How To on that subject...