Mac下窥探私有API

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　　苹果已走向平民化，所以着手mac下的开发，发现一篇文章，与大家分享：http://cocoainchromium.blogspot.com/2011/05/disassembling-private-apis-on-mac-os-x.html
　　
　　
Disassembling Private APIs on Mac OS X

There are several ways to reverse engineer private APIs on Mac OS X. For example, if you needed to know how a certain AppKit function was implemented, you could try some of the following.

To find APIs in a library:

nm -g /System/Library/Frameworks/AppKit.framework/AppKit

To generate headers of Objective-C classes in a library:

class-dump-H -o /AppKit_Headers /System/Library/Frameworks/AppKit.framework/AppKit

To view the disassembly of a function:

gdb /Applications/Calculator.app/Contents/MacOS/Calculator
break -[NSApplication run]
run
disas

To generate disassembly for an entire library:

otool -tV /System/Library/Frameworks/AppKit.framework/AppKit

I've recently also started usingotx. This works very similarly to otool but in addition it will annotate the assembly. The best part is that it will resolve Objective-C calls making it much easier to tell what a function is doing. Here's a sample output of otool (top) vs otx (bottom):

Until I discovered otx I had to trace Objective-C using the si/ni commands in gdb to figure out what a function was doing.