Some quick research shows that a clean method would be to redefine the TMP
constant (by default define('TMP', APP.'tmp'.DS)
) in /app/webroot/index.php
to point the whole temp directory someplace else. This is not a good solution if the folder is supposed to be shared though, since different apps may step on each others feet with their temp files.
The only apparent way to point only the log directory someplace else seems to be to edit /cake/config/paths.php
.
If your goal is only to make it easy to skim through log files of different apps quickly, you could simply put a bunch of symlinks to those logs into one directory.
Or, the other way around, you can make each /app/tmp/logs
folder a symlink to some shared folder. Not sure I'd recommend that though; having different apps write to the same log may get confusing, since you may not always be sure which app a message came from.