I started playing with a Mac just a couple of days ago, and it seems, without warning I've caused some major damage.
The system is running OS X version 10.5.8, and without paying much attention, I replaced the system supplied libxml2 (/usr/lib/libxml2.2.* ) with a new version that I compiled --- I should have paid more attention to just creating a local copy of everything, and not touching the system directories, but tooo late for that now!)
What I did not reckon with was that doing so breaks the entire system, because I didn't know how fundamental libxml2 is to everything on a mac.
Before clobbering the system libxml2 with my own, I made backup copies --- but those copies are useless because with the new libxml2 that I put in there, no important command like "sudo" etc. works anymore --- (Finder, System Prefs, etc., everything has stopped working).
How can I repair the system to restore to it the clobbered files?