Print shared library dependencies from C++

Question

I need to allocate an exact set of shared library dependencies of a binary program. I'm working on linux and the project is written in my C++. Thus, I need a recursive ldd-like functionality in C++. How can I do it?

Answer 1

To quote Han Solo, "I got a bad feeling about this". Setting up a chroot for a child process from within a C++ program sounds like some architectural misconception / screwup further up the line. Sorry, no ready-made C++ solution that springs to mind. You could , of course, run ltrace / strace / recursive-ldd and parse their output...

...but generally speaking, the idea is to set up the chroot environment statically (ie before any processes are started), not dynamically. With a dynamic approach, an attacker could fool the main process into believing it should give the child process things it shouldn't have in the chroot. That defeats the whole purpose.

Tools for statically setting up chroot environments for a given executable are plenty, tools for doing so dynamically I couldn't find any. This is a hint in itself.

Answer 2

In the meantime I've found the following: linux/gcc: ldd functionality from inside a C/C++ program where the accepted answer suggests to use:
setenv("LD_TRACE_LOADED_OBJECTS", "1", 1); FILE *ldd = popen("/lib/libz.so");
I tried it out and worked both from bash and from C++ (ofc in this case I think of an equivalent version). However if I ran either versions for a SUID binary (what I actually have) then I got exit code 5 (i guess permission problems).

Then I traced what ldd exactly does and the following seems fine (at least in command line):
LD_TRACE_LOADED_OBJECTS=1 /lib64/ld-linux-x86-64.so.2 binary_name
The (dummy) question is: what is the equivalent implementation of this in C++?