How to know in which library function is located?

Question

I have an executable and it calls a function. There are a lot of static and dynamic libraries that are linked with this exe. I need to know which one provides this function.

Answer 1

You can get a list of shared libraries used by the executable foo like this:

ldd -v foo

This post:

How do I list the symbols in a .so file

explains how to list symbols (exported functions) in a shared library.

If your library is linked statically, it'll show up in the list of symbols inside the executable itself:

nm -C foo

The same command will also list the names of all exported symbols (function names) in a static library:

nm -C libasan.a

You may want to construct a shell script to enumerate your libraries, looking for the specific function that you want inside each one. For example, to figure out which .a file provides sprintf():

for x in *.a; do echo --- ${x} ---; nm -C $x | grep sprintf ; done