Using otool (recursively) to find shared libraries needed by an app

Question

I have a Cocoa app that uses otool to find required shared libraries that an app needs to function properly. For example, say I run otool -L on an app that uses QTKit.framework. I get a list of the shared libraries used by the program (including the basic frameworks like Cocoa.framework and AppKit.framework):

/System/Library/Frameworks/QTKit.framework/Versions/A/QTKit (compatibility version 1.0.0, current version 1.0.0)
/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation (compatibility version 150.0.0, current version 476.0.0)
    /System/Library/Frameworks/AppKit.framework/Versions/C/AppKit (compatibility version 45.0.0, current version 949.0.0)

..... and so on for a bunch of other frameworks

Which shows that the app uses QTKit.framework. However if I use "otool -L" again on the binary for QTKit.framework (/System/Library/Frameworks/QTKit.framework/Versions/A/QTKit) I get this:

/System/Library/Frameworks/QTKit.framework/Versions/A/QTKit (compatibility version 1.0.0, current version 1.0.0)
/System/Library/Frameworks/AudioToolbox.framework/Versions/A/AudioToolbox (compatibility version 1.0.0, current version 1.0.0)
/System/Library/PrivateFrameworks/CoreMedia.framework/Versions/A/CoreMedia (compatibility version 1.0.0, current version 1.0.0)
/System/Library/PrivateFrameworks/MediaToolbox.framework/Versions/A/MediaToolbox (compatibility version 1.0.0, current version 1.0.0)
/System/Library/PrivateFrameworks/VideoToolbox.framework/Versions/A/VideoToolbox (compatibility version 1.0.0, current version 1.0.0)
/System/Library/PrivateFrameworks/CoreMediaIOServices.framework/Versions/A/CoreMediaIOServices (compatibility version 1.0.0, current version 1.0.0)
/System/Library/Frameworks/Foundation.framework/Versions/C/Foundation (compatibility version 300.0.0, current version 751.0.0)
/System/Library/Frameworks/AppKit.framework/Versions/C/AppKit (compatibility version 45.0.0, current version 1038.0.0)
/System/Library/Frameworks/IOKit.framework/Versions/A/IOKit (compatibility version 1.0.0, current version 275.0.0)
/System/Library/Frameworks/QuickTime.framework/Versions/A/QuickTime (compatibility version 1.0.0, current version 1584.0.0)
/System/Library/Frameworks/CoreAudio.framework/Versions/A/CoreAudio (compatibility version 1.0.0, current version 1.0.0)
/System/Library/Frameworks/OpenGL.framework/Versions/A/OpenGL (compatibility version 1.0.0, current version 1.0.0)
/System/Library/Frameworks/QuartzCore.framework/Versions/A/QuartzCore (compatibility version 1.2.0, current version 1.6.0)
/System/Library/Frameworks/IOSurface.framework/Versions/A/IOSurface (compatibility version 1.0.0, current version 1.0.0)
/System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox (compatibility version 1.0.0, current version 435.0.0)
/usr/lib/libstdc++.6.dylib (compatibility version 7.0.0, current version 7.9.0)
/usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 123.0.0)
/usr/lib/libobjc.A.dylib (compatibility version 1.0.0, current version 227.0.0)
/System/Library/Frameworks/CoreServices.framework/Versions/A/CoreServices (compatibility version 1.0.0, current version 44.0.0)
/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation (compatibility version 150.0.0, current version 550.0.0)
/System/Library/Frameworks/ApplicationServices.framework/Versions/A/ApplicationServices (compatibility version 1.0.0, current version 38.0.0)
/System/Library/Frameworks/CoreVideo.framework/Versions/A/CoreVideo (compatibility version 1.2.0, current version 1.6.0)

That shows a load more frameworks that the original otool output on the app binary showed. Is there a way to have otool run recursively, meaning it grabs the frameworks that the app needs, then goes in and searches each of those frameworks for dependencies?

Answer 1

No, you'll have to run otool repeatedly, or incorporate its parsing code (here). Don't forget about handling @executable_path.

Here it is in Python (without @executable_path, canonicalization, or filenames-with-spaces supported), since this was easier than trying to debug pseudocode:

import subprocess

def otool(s):
    o = subprocess.Popen(['/usr/bin/otool', '-L', s], stdout=subprocess.PIPE)
    for l in o.stdout:
        if l[0] == '\t':
            yield l.split(' ', 1)[0][1:]

need = set(['/Applications/iTunes.app/Contents/MacOS/iTunes'])
done = set()

while need:
    needed = set(need)
    need = set()
    for f in needed:
        need.update(otool(f))
    done.update(needed)
    need.difference_update(done)

for f in sorted(done):
    print f