Where can I find filemerge after Xcode is upgraded to 4.3?
Kurt Revis
In Xcode, choose this menu item: Xcode -> Open Developer Tool -> FileMerge. The app itself is here:
/Applications/Xcode.app/Contents/Applications/FileMerge.app
On the command line, use opendiff. You must have the command line tools installed -- go to Xcode, Preferences, Downloads tab, and install Command Line Tools if you haven't already.
Run this in your terminal:
sudo /usr/bin/xcode-select -switch /Applications/Xcode.app/Contents/Developer
来源：https://stackoverflow.com/questions/9562761/is-filemerge-still-available-after-xcode-4-3-installation