devzkndeMacBook-Pro:Desktop devzkn$ class-dump -H /Applications/Calculator.app -o ~/Desktop/calculate\ heads
解释：
/Applications/Calculator.app是计算器app的路径
~/Desktop/calculate\ heads 是存放dump出来头文件的文件夹路径
利用 class-dump 可以导出 AppKit，UIKit
class-dump AppKit:
class-dump /System/Library/Frameworks/AppKit.framework
class-dump UIKit:
class-dump /Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/System/Library/Frameworks/UIKit.framework
