Xcode and iPhone SDK version number in the path - how to live with it right?

Question

iPhone

I inherited a project that is built with a script containing paths like /Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS4.2.sdk
If the script is moved to a machine with a different version of the iPhone SDK, everything breaks.
I would like to understand how to correctly write such paths using an environment variable, but I can’t find any environment variables, it’s set | grep iPhoneOSsilent like a fish on ice.
It is possible to cut the Gordian Knot by writing a script that looks for installed versions and determines the correct path, but these are crutches. How to do it right?

Answer 1

Why not use something like
ls -1d /Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS*.sdk
to define the path?
I just don't know how it is in OS X

Answer 2

As far as I understand, in a normal way this is set by the key gcc -miphoneos-version-mineither IPHONEOS_DEPLOYMENT_TARGETSee. man gcc:)

Answer 3

xcode-select --print-path, then add the rest of the path, profit.
Hardcoding is bad, of course.