dlopen

I'm using dlopen to load a shared library at run time dlopen("SharedLibarary1.so", RTLD_NOW | RTLD_GLOBAL); In that shared object I refer to a const char* defined in another shared library "SharedLibarary2.so". The Executable, and both the libraries are built using -rdynamic. But I still get the run time error when using dlopen: "/usr/lib/SharedLibarary1.so: undefined symbol" and points to the mangled const char* has the undefined symbol. Whith GDB "info share" I can see that the second library is not loaded at the point of the error. How ever that problem goes away if I do a dlopen on the

I need to call a function from another program. If the other program were a library, I could simply use dlopen and dlsym to get a handle to the function. Unfortunately, the other program is a Unix Executable, and building it as a library is not an option. Trying dlopen() on the executable gives this error message: dlopen([...]/testprogram, 1): no suitable image found. Did find: [...]/testprogram: can't map This isn't surprising, as dlopen is meant for use with libraries, not executables. Is there any way to get dlopen and dlsym to work with executables? If not, is there an alternative way of

My question, as the title mentioned, is obvious, and I describe the scenario in details. There is a class named singleton implemented by singleton pattern as following, in file singleton.h: /* * singleton.h * * Created on: 2011-12-24 * Author: bourneli */ #ifndef SINGLETON_H_ #define SINGLETON_H_ class singleton { private: singleton() {num = -1;} static singleton* pInstance; public: static singleton& instance() { if (NULL == pInstance) { pInstance = new singleton(); } return *pInstance; } public: int num; }; singleton* singleton::pInstance = NULL; #endif /* SINGLETON_H_ */ then, there is a

Intro Let me apologise upfront for the long question. It is as short as I could make it, which is, unfortunately, not very short. Setup I have defined two interfaces, A and B: class A // An interface { public: virtual ~A() {} virtual void whatever_A()=0; }; class B // Another interface { public: virtual ~B() {} virtual void whatever_B()=0; }; Then, I have a shared library "testc" constructing objects of class C, implementing both A and B, and then passing out pointers to their A-interface: class C: public A, public B { public: C(); ~C(); virtual void whatever_A(); virtual void whatever_B(); };

Is there a way for a shared library to be "notified" when it is loaded? In other words, let's say I use dlopen on a shared library, is there a function that is automatically called (if present) on the shared library (e.g. main?) Libraries should export initialization and cleanup routines using the gcc __attribute__((constructor)) and __attribute__((destructor)) function attributes. See the gcc info pages for information on these. Constructor routines are executed before dlopen returns (or before main() is started if the library is loaded at load time). Destructor routines are executed before