How do you enforce the minimum OS requirements in a Cocoa app?

My app needs to run on 10.4 or later. If I launch it on 10.3 it just fails to launch or crashes.

How do you tactfully enforce minimum system requirements? Can you customize the message it sh开发者_开发百科ows?

Add a key to your applications Info.plist, specifying LSMinimumSystemVersion as 10.4.X for whatever X you need as a minor version. For more, see Apple's documentation.

I have not used either of these techniques/advice, just passing along the information I have gathered.

You might try something like the SystemVersionCheck “shim” executable to provide a working OS version check for versions that do not honor LSMinimumSystemVersion (e.g. 10.3).

The pre-compiled executable is PPC-only. You might need to rebuild it to support PPC and Intel machines so that it works with 10.3, but also so that 10.6 users are not prompted to needlessly install Rosetta. I found a blog entry that has a hint on how to setup the PPC build to target 10.3 and the Intel build to target 10.4u (it was written about 10.5 and Xcode 3.0 though—do the latest versions of Xcode even include the 10.3 SDK?).

If you experience a crash after adding the LSMinimumSystemVersion key to your app's plist manually, then this is due to the Finder not recognizing the changed state of the app properly. Either restart the Finder (e.g. log out) or duplicate the app in the Finder. The copy will then behave correctly.