[ChocolateTeapot]

I'd like to create an install that updates an application.

I think I can work out how to install the necessary files using PackageManager but I'd also like to update an existing .plist file.

Would I update the property list file using AppleScript and run the script during the installation? If so can somebody please point me in the right direction as I've never used AppleScript.

Thanks very much.

[Mithras]

This has several tips on accessing plists (the login items plist in particular) programatically:
Adding Items to Login Items From the CLI | Mac Geekery

[larkost]

AppleScript is really not a good tool for this. Rather you should look into:

1) Perl with the Obj-C bridge (takes a bit of getting used to if you don't know Cocoa)
2) The command line program 'defaults' ('man defaults' for more informatino)
3) 'plistbuddy' a command line program that Apple uses to do this sort of work in all of their installers. You can find a whole bunch of copies scattered in amonst /Library/Receipts/ (burried in the installers)