dynamic-linking

Minimum amount of information necessary to do (dynamic) linking?

This is a question I've come across repeatedly, usually concerning plug ins, but recently I came across it trying to hammer out some build system issues. My concern is primarily for *nix based systems, but I suppose it applies to windows as well. The question is, what is the minimum amount of information necessary to do dynamic linking?...

QT4 GDB debugger doesn't link to shared libraries on Ubuntu

Hello: I'm new to UNIX and QT4 but ubuntu is coming along. My first QT4 project links a simple test app to a shared dll of ported code. I am able to build the application using QT Creator and to run it from the terminal. However the embedded GDB debugger reports: unable to load shared ... no such file or directory. The .pro file c...

How does symbol binding work for shared libraries in linux

When compiling a cpp program with g++ -O0 I noticed that my binary does not contain the symbol for the empty string (basic_string): _S_empty_rep_storage When I do compile this same program with -O2 I notice that the aforementioned symbol is indeed contained within the binary as follows (using nm on the bin): 00000000006029a0 V _ZNSs4_R...

Force GCC to notify about undefined references in shared libraries

I have a shared library that is linked with another (third-party) shared library. My shared library is then loaded using dlopen in my application. All this works fine (assuming files are in the proper path etc). Now, the problem is that I don't even need to specify to link against the third-party shared library when I link my library. G...

Can I catch an exception relating to a .DLL file not been found

I have a 3rd party component that includes a .LIB and .DLL file. In order to use the component I link the .LIB into my C++ program, and distribute the .DLL with application. The functionality provided is very specific, and only relevent to a small sub-set of my users, but distributing the .DLL incurs a license fee. One work around her...

Ignore LD_LIBRARY_PATH and stick with library given through -rpath at link time

I'm sitting in an environment which I have no real control over (it's not just me, so basically, I can't change the environment or it won't work for anyone else), the only thing I can affect is how the binary is built. My problem is, the environment specifies an LD_LIBRARY_PATH containing a libstdc++ which is not compatible with the com...

Which dynamic libraries on OS X can be taken for granted?

If I want to make an OS X program as self-contained as possible to ease installation, what dynamic libraries can I expect everyone or most people to have? If I know that, I won't have to compile static libraries for everything. ...

How can I set where a Qt app finds a Qt module?

I would like to include libQtGui.so.4 libQtNetwork.so.4 and libQtCore.so.4 in the same directory as where my app resides. How would I make Qt understand this? y purpose is to have a standalone app that uses shared libraries ...

shared library path inconsistent from one host to another

I built my qt app so that all the Qt modules it uses are contained in the same directory as the executable. It works on the machine I used to build the app and I made sure to test this by removing those shared libraries everywhere except in the current directory of the app. Doing a ldd shows that its looking for those libraries in the c...

How to call a function from a shared library?

What is the easiest and safest way to call a function from a shared library / dll? I am mostly interested in doing this on linux, but it would be better if there were a platform-independent way. Could someone provide example code to show how to make the following work, where the user has compiled his own version of foo into a shared lib...

Finding missing symbols in libstdc++ on Debian/squeeze

I'm trying to use a pre-compiled library provided as a .so file. This file is dynamically linked against a few librairies : $ ldd /usr/local/test/lib/libtest.so linux-gate.so.1 => (0xb770d000) libstdc++-libc6.1-1.so.2 => not found libm.so.6 => /lib/i686/cmov/libm.so.6 (0xb75e1000) libc.so.6 => /lib/i686/cmov/libc.so.6 (0xb7499000) /l...

How to determine if an OS X dylib was linked with -flat_namespace

I have a third party OS X dylib that I'm using in my app and don't have easy access to its creator. I'd like to determine if it was linked with -flat_namespace. Is that possible? If so, how? ...

What's the difference between starting a process from the dock vs. the command line on OS X

I'm debugging an issue on OS X that only occurs when the application is started from the dock. It does not happen when the app is started from the command line. What is the difference between the two scenarios? The code I'm working with is a c++ based bundled plug-in being loaded in a third party app. I've attached to the process wit...

Building a python module and linking it against a MacOSX framework

I'm trying to build a Python extension on MacOSX 10.6 and to link it against several frameworks (i386 only). I made a setup.py file, using distutils and the Extension object. I order to link against my frameworks, my LDFLAGS env var should look like : LDFLAGS = -lc -arch i386 -framework fwk1 -framework fwk2 As I did not find any 'fra...

Python ctypes and synamic linking

OK, I've beaten my head against this problem for a while now, it's time to ask for help. I'm writing some libraries in C, for to be called from Python via ctypes. I've done this sucessfully with one library, but this library only very vanilla dependancy, namely (fstream, math, malloc, stdio, stdlib). Now the other library I'm working ...

GCC Dynamic library building problem

I am new to linux, while compiling with dynamic library I am getting the segmentationfault error. I have two files ctest1.c void ctest1(int *i) { *i =10; } ctest2.c void ctest2(int *i) { *i =20; } I have compiled both files to a shared library named libtest.so using following command gcc -shared -W1,-soname,libtest.so....

Avoiding stack overflows in wrapper DLLs

I have a program to which I'm adding fullscreen post-processing effects. I do not have the source for the program (it's proprietary, although a developer did send me a copy of the debug symbols, .map format). I have the code for the effects written and working, no problems. My issue now is linking the two. I've tried two methods so f...

Dynamic Web Linking

Can anyone give me an idea about dynamic web linking. Where the file has to be saved to desktop in HTML/XML format (C# website). ...

Dynamic-linked DLL needs to share a global variable with its caller.

I have a static library libStatic that defines a global variable like this Header file libStatic/globals.h: extern int globvar; Code file libStatic/globals.cpp: int globvar = 42; The DLL libDynamic and the executable runner are using this global variable. Furtheron, libDynamic is linked at run-time into runner (via LoadLibrary(), ...

Strange altered behaviour when linking from .so file with ctypes in python

I am writing a program to handle data from a high speed camera for my Ph.D. project. This camera comes with a SDK in the form a .so file on Linux, for communicating with the camera and getting images out. As said it is a high speed camera delivering lots of data, (several GB a minute). To handle this amount of data the SDK has a very han...