You have a compiled C binary which you can execute and run, but
you suspect it may be hanging. You do not have the source. What
can you do to gather information and/or clues about what the
program is doing?
Any help will be really appreciated!!
This really smells like homework to me. If it is an interview question and you do not know the answer, you would be more than foolish to attend the interview. Even if you make it past the interview you would be let go for falsifying your credentials later on.
Either way - I don't know.
Answer depends on the OS - possibly one of these: truss, tusc, strace, maybe ptrace.