Elfrewriter is a small set of tools built on top of pyelftools to retrieve and change informations about elf binaries. It is mostly concerned with ELF features relevant to make relocatable binaries (DT_RUNPATH feature).

Example:

from elfrewriter import ELFRewriter

rewriter = ELFRewriter("a.out")
print rewriter.dependencies
print rewriter.rpaths

# One can change rpaths, but changes will only be written after commit
# has been called (see also known limitations).
rewriter = ELFRewriter("a.out")
rewriter.rpaths = ["yo", "mama"]
rewriter.commit()

# Use a context manager to ensure changes are committed
with ELFRewriter("a.out") as rewriter:
    rewriter.rpaths = ["yo", "mama"]

Main features:

• ability to query/change rpath
• ability to query/change the dependencies

Known limitations:

• modification is done through patchelf binary in a subprocess: http://nixos.org/patchelf.html. In theory, one could implement the feature using pyelftools, but that would be quite a bit of work in the case where the rpath entry needs to grow. Patches welcome though !
• consequence of the above: while querying works on any platform supported by pyelftools, modifying a binary only works on a machine with patchelf (most likely only Linux).

Development happens on github