Here’s another update of my checklibs script for analyzing dynamic library dependencies of Mach-O binaries. See earlier articles for an introduction.

It’s in fact not an update but a complete rewrite that was needed to handle the complex load path relationships that can be expressed with some of dyld’s newer features such as @rpath. The script should be able to properly display every possible linking combination. If it doesn’t, let me know so I can try to make it smarter.

The main use case is still to catch the unintentional linking against nonstandard frameworks and libraries. Here’s how to use it:

checklibs.py /path/to/Foo.app/Contents/MacOS/Foo

There are some command line options, use the --help option to get a list of them.

Referenced non-embedded frameworks in nonstandard locations are highlighted in blue. Frameworks that are not found on the file system are marked with a red (missing).

If a framework is embedded and referenced with one of the @ placeholders @executable_path, @loader_path or @rpath, the script shows both the original and the resolved path so you can see how a particular binary was found.

In the case of @rpath, the script also shows which binary supplied the rpath value that was used.

The new version, called checklibs.py, is on github. Feel free to enhance it and send pull requests.