Question

Say I have a libmy.a static library, and I want to know what libraries it links dynamically. Actually I need that for the following: I am gonna create a new dynamic lib say libmy2.so which will link say an .o file (object file) and the libmy.a. So I wonder what libs will load libmy2.so eventually.

Answer 1

Static libraries do not link other libraries, either static or dynamic.

OK, assuming two C++ files, a.cpp and b.cpp.

g++ -c a.cpp -o a.o         // compile a.cpp to a.o
rm -f lib1.a                // no existing lib1.a (this is not essential)
ar rvs lib1.a a.o           // create library lib1.a and add a.o to it
g++ -c b.cpp -o b.o         // compile b.cpp to b.o
ar rvs lib1.a b.o           // ad b.o to existing lib1.a

You can obviously do any amount of copying between stages to produce the library with the name you want. You can also do

ar --help

to get the ar options which might simplify the process slightly. Frankly, it’s a command I almost never use except to build static libraries from a list of objects.