Relative paths in otool output?

Question

I'm having some issues with a library file compiled from C++, so I've used the otool command line utility (on OSX) to look at the files it links against.

This is the output:

! otool -L pyopenvdb.so 
pyopenvdb.so:
    pyopenvdb.so (compatibility version 0.0.0, current version 0.0.0)
    /usr/local/opt/tbb/lib/libtbb.dylib (compatibility version 0.0.0, current version 0.0.0)
    /usr/local/lib/libHalf.11.dylib (compatibility version 12.0.0, current version 12.0.0)
    /usr/lib/libz.1.dylib (compatibility version 1.0.0, current version 1.2.5)
    /usr/local/lib/libIlmImf-Imf_2_1.21.dylib (compatibility version 22.0.0, current version 22.0.0)
    /usr/local/lib/libjemalloc.1.dylib (compatibility version 0.0.0, current version 0.0.0)
    /System/Library/Frameworks/Python.framework/Versions/2.7/Python (compatibility version 2.7.0, current version 2.7.5)
    libboost_python.dylib (compatibility version 0.0.0, current version 0.0.0)
    libopenvdb.so.2.3.0 (compatibility version 0.0.0, current version 0.0.0)
    /usr/lib/libc++.1.dylib (compatibility version 1.0.0, current version 120.0.0)
    /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1197.1.1)

Most of the files linked against are referenced by an absolute path, e.g. /usr/local/opt/tbb/lib/libtbb.dylib.

However, some are referenced by what seems to be a relative path, just as filenames, e.g. libboost_python.dylib.

What does this mean?

Does it mean that at runtime a different version of libboost_python.dylib could be linked against, depending on what is found first on the path? Or is it some other method by which these 'relative' paths are searched?

score 3 · Answer 1 · answered Jul 12 '15 at 11:32

This is no problem. That means that you library with out a absolute path are relative with respect to the thing you have otool'ed (pyopenvdb.so). However, if you would like to standardise it, you can change the path with install_name_tool. In the case you mentioned, use the -change argument.

Usage: install_name_tool [-change old new] ... [-rpath old new] ... [-add_rpath new] ... [-delete_rpath old] ... [-id name] input

For example, install_name_tool pyopencdv.so -change libboost_python.dylib /usr/local/lib/libboost_python.dylib

Note that you also see that pyopenvdb.so references itself too, in the first line of output. Of course that is a relative path, but even that can be changed to an absolute path if you'd like using install_name_tool, for that, use the '-id' argument.

Relative paths in otool output?

1 Answers1