Class-dump any Mach-o file without extracting it from dyld_shared_cache
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limneos Merge pull request #11 from coolstar/master
Fix error when dumping from an image that has a space in its path.
Latest commit 56ebf39 Aug 9, 2016


Major update

As of February 5 2016, I have added cycript integration.

You can now dlopen /usr/lib/libclassdumpdyld.dylib in cycript after injecting any application,

and dlsym the dumpClass and dumpBundle functions.

extern "C" NSString * dumpClass(Class *aClass);

extern "C" NSString * dumpBundle(NSBundle *aBundle);

extern "C" NSString * dumpBundleForClass(Class *aClass);

This is extremely useful in cases when classdump-dyld cannot inject and dump applications.

(This makes weak_classdump project obsolete)

A typical usage in cycript would be:

#cycript -p SpringBoard

@import net.limneos.classdumpdyld;

@"Wrote file /tmp/SpringBoard.h"

classdumpdyld.dumpBundle([NSBundle mainBundle]);
@"Wrote all headers to /tmp/SpringBoard"

// Dump any bundle other than the main bundle 
classdumpdyld.dumpBundle([NSBundle bundleWithIdentifier:@""]);
@"Wrote all headers to /tmp/UIKit"

// Dump any image loaded in the process using any class name it contains
@"Wrote all headers to /tmp/CallBar7"

General Info

Added 64bit executables dumping and single class dumping

A class dumping command line tool that generates header files from app binaries, libraries, frameworks, bundles or the whole dyld_shared_cache.

Eliminates the need to extract files from the dyld_shared_cache in order to class-dump them or get symbols.

Mass-dumps whole dyld_shared_cache or directories containing any mach-o file recursively.

You can instantly classdump any compatible Mach-o file, either if it is physically stored on disk or it resides in the dyld_shared_cache.

Features and options:

  • Classdump files that appear malformed to the usual tools on device.
  • Classdump files or frameworks on runtime without extracting them from dyld_shared_cache.
  • Classdump files that reside on disk as usual
  • Recursively search for compatible files and dump them (e.g. whole directory of "/System/Library", "/Applications" or "/" )
  • Recursively dump all the images stored in dyld_shared_cache
  • Generate symbols list for files that are stored in dyld_shared_cache without extracting them.
  • Generation of all structs, symbols and necessary #imports to correctly fill up each header file. (I pray for that)

You can find a recursive sample output on this project under iphoneheaders. It also works on a Mac for dyld_shared_cache and some libraries

Usage: classdump-dyld [<options>] <filename|framework>

	   classdump-dyld [<options>] -r <sourcePath>


		-g   Generate symbol names 
		-h   Add a \"Headers\" directory to place headers in
		-b   Build original directory structure in output dir
		-u   Do not include framework when importing headers ("Header.h" instead of <frameworkName/Header.h>)

		-o   <outputdir> Save generated headers to defined path

	Single Class:
		-j   <className> Dump only the specified class name. (Does not work with -c or -r )
                    This might also dump additional imported or required headers.
	Mass dumping: (requires -o)
		-c   Dump all images found in dyld_shared_cache 
		-r   <sourcepath> Recursively dump any compatible Mach-O file found in the given path (requires -o) 
		-s   In a recursive dump, skip header files already found in the same output directory 
		-D   Enable debug printing for troubleshooting errors
		-e   dpopen 32Bit executables instead of injecting them (iOS 5+, use if defaults fail.This will skip any 64bit executable) 
		-a   In a recursive dump, include 'Applications' directories (skipped by default)
		Example 1: classdump-dyld -o outdir /System/Library/Frameworks/UIKit.framework
		Example 2: classdump-dyld -o outdir /usr/libexec/backboardd
    	Example 3 (recursive): classdump-dyld -o outdir -c  (Dumps all files residing in dyld_shared_cache)
		Example 4 (recursive): classdump-dyld -o outdir -r /Applications
		Example 5 (recursive): classdump-dyld -o outdir -r / -c  (Mass-dumps almost everything on device)

Usage limitations

classdump-dyld works with Mach-o files only. Some files have protection against being dynamically loaded from a different process. In those cases, you can use weak_classdump or other tools.

by Elias Limneos


email: iphone (at) limneos (dot) net

twitter: @limneos


classdump-dyld is Copyright (c) 2013-2016 Elias Limneos, licensed under GPLv3.


classdump-dyld works in a command line shell on any iOS 5+ device and Mac OS X. Tested from iOS 5.x to iOS 8.x and Mac OSX 10.8+.