You can check the dependencies of *.so file by executing ldd command like this

   1  % ldd foo.so
   2          linux-gate.so.1 =>  (0xb7efe000)
   3          libc.so.6 => /lib/tls/i686/cmov/libc.so.6 (0xb7d7e000)
   4          /lib/ld-linux.so.2 (0xb7eff000)

It's useful to attack problems regarding dlopen