Installer Package Requirments

Recently I’ve been looking over the kinds of criteria/ requirements that I’m able to set for installer packages. One thing I’ve been trying to figure out is how to require certain versions of software for an installer to install a file. The idea I’ve found is to require info from a bundle. There’s an option for this in the package requirement setup, but there’s still the key of what bundle to look in. For normal apps it’s quite clear, use their “Info.plist” file inside at the root of the app. But the trick that I’ve found is how to require certain OS versions. If you know where to look this not a hard thing, but that’s what took me a little bit of hunting. In the end my answer is to look in the bundle at “/System/Library/CoreServices/SystemVersion.plist”, this file contains the OS version flat-out and easy to note. In that file there are two keys that tell the OS version, those are “ProductUserVisibleVersion” and “ProductVersion”. The value is currently “10.4.9” for both keys. I just wonder if this is in fact the way that developers use to tell what OS the mac is running, or if there’s some other way to find out? I know there must be some other test that you could run, but this simple method is a way that works for simple testing. This kind of OS testing will start to be important for InputManager installers now that we know that Apple won’t allow those kinds of plugins come 10.5.x.