understanding shared libraries using gcc

Question

I am trying to understand the following behavior of shared libraries in C

Machine One

$ cat one.c 
#include

         


        

Answer 1

The number is the memory address where the library is loaded when the executable is run. It is determined at link time and is usually randomized in order to make library function addresses unpredictable and thus more difficult to use in exploits. The standard C library is linked by default by GCC. libcwait is probably another default library, possibly used by older GCC versions.