some people like me have the problem of having several wordpress installations at the same time; people like me and some others i know. i have one wordpress running for this blog, one for my math blog, one for a hidden, password protected project which might or might not ever see the light of the world, and anther one for another music related project showing up soon.
whenever a new wordpress version comes out, a question bugs me: how to update all of these installations without doing it manually for every one? of course, there’s the automatic update, but i don’t really trust it. and i don’t have an ftp server installed, so i’m not sure if it would work at all. so i need another solution.
a first idea was to use symbolic links. have one wordpress installation in a directory outside the web tree, and link these files into all wordpress directories in the web tree, so for updating i only need to change one directory, and i only have to touch the others when the configuration file has to be changed.
unfortunately, this doesn’t work, thanks to php and wordpress. wordpress determines the path to the config file by the path names of the files, and since the files are symbolic links, the paths of the files pointed to are used. but in that directory, no config file is available, and wordpress fails. too bad.
now i got another idea. namely, have a wordpress directory outside the web tree, and put it into subversion. then, in all other wordpress directories, drop in the files using subversion, except the configuration file, uploads, latex caches, etc. so to update an installation, i have to go into its directory and type svn up. that’s it. there’s one thing left to do: namely hide the .svn directories from the web server. i didn’t found the perfect method yet, but adding this to the apache configuration makes them forbidden:

<DirectoryMatch “^/.*/\.svn/”>
  Order deny,allow
  Deny from all
</DirectoryMatch>

then every access to something in an .svn directory results in an access denied error:

Forbidden
You don’t have permission to access /.svn/ on this server.