To get the main bundle in Cocoa application, call the mainBundle class method of the NSBundle class.
NSBundle *mainBundle; // Get the main bundle for the app; mainBundle = [NSBundle mainBundle];
Use the CFBundleGetMainBundle function to retrieve the main bundle for your C-based application.
CFBundleRef mainBundle; // Get the main bundle for the app mainBundle = CFBundleGetMainBundle();