I built a small .exe application. Currently I take the compiled .exe file and all necessary .dll's and put them in one folder. So it looks like this: (working)
appfolder/
lib1.dll
lib2.dll
...
app.exe
I'd like to organize it and bring it in following form: (not working)
appfolder/
libs/
lib1.dll
lib2.dll
...
app.exe
However, I do not find a way to make this work. I'm using VS2010 where I tried to add ".\libs" to the Additional Include Directories (Project Properties > Configuration > C/C++).
I also read about LoadLibrary which seems to be not a solution to this problem...
Is that possible at all?
Maybe the SetDllDirectory function will work for you see here.
Besides this you can use LoadLibraryEx and GetProcAddress to do "lazy" loading.
Similar function also exist for Linux.
Related
I have a project where the library sources were set up the following way:
MyProject
|_MyProject.pro
|_MainStuff
|_MainStuff.pro
|_ManyFiles
|_Tests
|_Tests.pro
|_LotsOfTests
|_MyLibs
| FunLibs.pro
|_FunLib1.h
|_FunLib1.cpp
|_FunLib2.h
|_FunLib2.cpp
This is not ideal, because as the number of FunLibs increases, all of it would be included into a single shared object. With this setup, everything builds and runs just fine. Just to be clear: MyProject.pro is a subdirs template, the MainStuff.pro is an app template, and the FunLibs is a lib template.
The problem stats, when I rearrange the files the following way:
MyProject
|_MainStuff
|_ ManyFiles
|_Tests
|_LotsOfTests
|_MyLibs
|_MyLibs.pro
|_FunLib1
|_FunLib1.pro
|_FunLib1.h
|_FunLib1.cpp
|_FunLib2
|_FunLib2.pro
|_FunLib2.h
|_FunLib2.cpp
Here the MyLibs.pro becomes a subdir tempalte, while the FunLibx.pro files will be lib templates. All configurations have been updated accordingly and the application builds. The problem is that when I now try to launch the application, the following message pops up:
libFunLib1.so.1: cannot open shared object file: No such file or
directory
I don't really understand why doesn't it work now, when it worked with the previous directory structure. This post for example (as many others) recommends to set the LD_LIBRARY_PATH by exporting the dir, but to be honest, I didn't have to do this with the previous setup.
I also have everything set up pretty much as described in the official docs under the "Creating a shared library" part.
Does anybody have an idea what might be the problem? Is there a way to solve this by not exporting the path?
Thanks in advance.
OK, I think I found out what can fix the aforementioned problem. Qt Creator also uses LD_LIBRARY_PATH environment variable for executing compiled programs, but it is somewhat hidden. As it turns out, it is able to use separate sets of env variables for compiling and running applications, and if the env vars for running are not properly defined, the user will get the error message mentioned in the original post, even if the program compiled properly.
To make sure all lib paths are included for running as well, one needs to check out the included paths here:
Projects (mode) --> Run Settings (under Build & Run) --> Run
Environment (expand the Details) --> LD_LIBRARY_PATH (somewhere in the
list)
If that var doesn't include the proper paths, it can be edited after which it is going to get highlighted. After setting this, everything seems to work.
Update Sorry, guys, I was incorrectly determined the problem. All is working, error was in "other program logic". Please delete or close the question.
Qt5 is designed to load libeay32.dll and ssleay32.dll on program start before any instruction in main() (because it is static).
(Details: it is located in qtbase\src\network\ssl\qsslsocket_openssl_symbols.cpp:
static QPair<QSystemLibrary*, QSystemLibrary*> loadOpenSslWin32()
)
Issue:
my program starts with not its exe dir as working directory
libeay32.dll and ssleay32.dll resides in its exe dir
user cannot install OpenSSL in system dir
user cannot change PATH variable
I cannot recompile Qt, i.e. ship program with static Qt compiled with openssl-linked
Qt loads searches dlls in this order (from qtbase\src\corelib\plugin\qsystemlibrary.cpp):
Application path.
System libraries path.
Trying all paths inside the PATH environment variable.
No. 1 is Application path, but in fact it does not search there.
My program:
int main()
{
// at this point Qt5 already checked and tried to load the DLLs
// so this:
ChangeCurrentWorkingDirectoryToExeDir(); // some function to change cwd to current exe dir
// does not work :-(
// ... other program logic ..
}
How to force Qt5 to reload OpenSSL DLLs after changing working directory?
May be someone already faced this problem...
Update Sorry, guys, I was incorrectly determined the problem. All is working, error was in "other program logic". Please delete or close the question.
QSystemLibrary::load is called with onlySystemDirectory = false for SSL, so QFileInfo(qAppFileName()).path() is the first place where the DLLs are searched. Search order:
application dir
system path (e.g. C:\Windows\System32)
all paths in PATH
I don't find documentation for that, but in our software, Qt finds SSL libeay32.dll and ssleay32.dll when they are in the same directory as the application .exe, given that
the .dll files are not in PATH
the .dll files are not in the working directory
no qt.conf exists
If you have a qt.conf, the default library value might apply, which is .\lib.
Library search orders are discussed on MSDN at Dynamic-Link Library Search Order.
There's a few ways to handle loading libraries, but it sounds like most of them won't apply.
Its not clear to me why you can call ChangeCurrentWorkingDirectoryToExeDir, but you can't call SetDllDirectory. I'm probably missing something obvious.
It seems like your last option is to create an Qt.exe.local file. This is called Dynamic-Link Library Redirection, and will cause the linker to load the DLL specified in the local file.
Trying to run the following:
#include<iostream>
#include<boost/filesystem/operations.hpp>
namespace bfs=boost::filesystem;
int main()
{
bfs::path p("second.cpp");
if(bfs::exists(p))
std::cout<<p.leaf()<<std::endl;
}
I got some errors in cygwin so I decided to try out netbeans, and used the following as a guide. I added all links and the following for filesystem Project -> properties -> Linker ->Libraries -> Add option -> Other -> -lfile_system as noted here. I have run a separate test using #include<boost/any.hpp> so I am not currently doubting that my boost is not installed correclty.
It seems weird to me that it is "file_system", so I also tried "filesystem" but to no avail.
When i hold Ctrl and click on #include<boost/filesystem/operations.hpp> my netbeans brings up my operations.hpp file so it seems okay (linked properly internally that it can "see" what I want it to see).
The solution to installing boost came in the following form:
1 - If you have any path variables that are being used for Visual Studio you should temporarily change the variable during installation. This is a good guide. Once that is done, this is one step completed.
2 - Download and install MinGW. This is a very easy process and you can find the installer files here.
Once you have done these things (if you are in the same situation as me), you will now be able to properly install boost.
Horay!
Using Boost with cygwin step by step
Create a new Project
It is better to take the names given here in this tutorial exactly. Later ask: It does not work, can then be easier to find.
I do not think I need to mention all T:\ must of course be replaced with your drive.
Project Name : Boost-cyg-Test
Now your Project should look like
Open main.cpp
Overwrite the generated code with the following. We want to that, first of all everything works without error.
Therefore, please do not use your own special code.
It is difficult to find a fault. Then told after several ask, to get:
I have used my own code
#include <iostream>
#include <boost/filesystem.hpp>
using namespace std;
using namespace boost::filesystem;
int main()
{
path p("second.cpp");
if (exists(p)) { std::cout<<p.leaf()<<std::endl; }
}
In this section we assume that "boost" is already compiled.
goto Tools -> Options
Your C++ Code Assistance options should look something like this.
If this is not so, we should let Netbeans create that for us.
Add New Tool Collection
After we have completed this dialog with OK, we should find the settings shown above. ( C++ Code Assistance options).
Copy all libs into the right place
Let's create a new folder 'boost'.
With a search tool, search in your compiled Boost folder for *.a
My Boost is compiled with the shared option so we find :
For our short App. we need only 2 files.
libboost_filesystem-gcc45-mt-d-1_53.dll.a
libboost_system-gcc45-mt-d-1_53.dll.a
But if we're at it to copy two files, we can copy all files.
So mark all found .a files and copy them into the directory just created
T:\cygwin\lib\boost .
Now we do the same with our .dll files.
Mark all .dll files and copy it in your ?:\cygwin\bin directory.
If you only have compiled static librarys, you can skip this point.
Now it's time to modify our project settings.
As you can see i put my source Boost folder into cygwin
and
As we have already noted above, we need two .a files.
with Add Library navigate to T:\cygwin\lib\boost and select
libboost_filesystem-gcc45-mt-d-1_53.dll.a
libboost_system-gcc45-mt-d-1_53.dll.a
Now you'll notice that this name was shortened by netbeans to:
boost_filesystem-gcc45-mt-d-1_53.dll
boost_system-gcc45-mt-d-1_53.dll
This is somewhat confusing. It looks as if a .dll is standing here. But it is really a .a file.
Set a breakpoint in main.cpp. Now we start debug.
I have marked the important part, the two libs, with an arrow.
All libs are found and after make has finished, stops at the breakpoint.
The output:
Build Boost for Cygwin
For all who want to create boost with shared library itself.
Download boost_1_53_0.zip
Create a folder in your ?:\cygwin directory.
boost_1_53_0
Extract the zip file into that directory.
It should look like:
open a cmd window, cd to boost_1_53_0 directory.
To have a clean build we need a PATH that have only the cygwin home and bin.
In the cmd type.
SET PATH=T:\cygwin;T:\cygwin\bin
and test the path.
PATH
Type
bootstrap.bat
Type
.\b2 --build-dir=T:\boost-cyg toolset=gcc variant=debug link=shared runtime-link=shared
After some time the build is finished.
Now you have the same environment that we have used in the tutorial.
If you get a Error : gcc not found
copy (not rename) in ?:\cygwin\bin folder, for example : (names may differ).
i686-pc-cygwin-gcc-4.5.3.exe to gcc.exe
and
i686-pc-cygwin-g++-4.exe to g++.exe
Hope it helps you.
Could you paste the error you get when compiling ?
I am not used to compile programs in a Windows environment, but I think as Jesse Good suggested in a comment that you have a linker error.
You may solve it by using -lboost_filesystem instead of lfile_system.
To find out how your libs are called, you get the name of your lib (on my unix environment I have libboost_filesystem.so), strip the "lib" prefix and the ".so" or ".a" suffix (must be different in a Windows environment).
if your boost installation is correct and you are sure about it then for Unable to resolve identifier try Code Assistance->Reparse Project from context menu of the project. It tries to recover broken code model by reparsing project from scratch. if that didn't workout try closing IDE and removing code model cache.
p.s. do you have compilation errors?
How to get from C/C++ extension source code to a pyd file for windows (or other item that I could import to Python)?
edit: The specific library that I wanted to use (BRISK) was included in OpenCV 2.4.3 so my need for this skill went away for the time being. In case you came here looking for BRISK, here is a simple BRISK in Python demo that I posted.
I have the Brisk source code (download) that I would like to build and use in my python application. I got as far as generating a brisk.pyd file... but it was 0 bytes. If there is a better / alternative way to aiming for a brisk.pyd file, then of course I am open to that as well.
edit: Please ignore all the attempts in my original question below and see my answer which was made possible by obmarg's detailed walkthrough
Where am I going wrong?
Distutils without library path: First I tried to build the source as is with distutils and the following setup.py (I have just started learning distutils so this is a shot in the dark). The structure of the BRISK source code is at the bottom of this question for reference.
from distutils.core import setup, Extension
module1 = Extension('brisk',
include_dirs = ['include', 'C:/opencv2.4/build/include', 'C:/brisk/thirdparty/agast/include'],
#libraries = ['agast_static', 'brisk_static'],
#library_dirs = ['win32/lib'],
sources = ['src/brisk.cpp'])
setup (name = 'BriskPackage',
ext_modules = [module1])
That instantly gave me the following lines and a 0 byte brisk.pyd somewhere in the build folder. So close?
running build
running build_ext
Distutils with library path: Scratch that attempt. So I added the two library lines that are commented out in the above setup.py. That seemed to go ok until I got this linking error:
creating build\lib.win32-2.7
C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\BIN\link.exe /DLL /nologo /INCREMENTAL:NO /LIBPATH:win32/lib /LIB
PATH:C:\Python27_32bit\libs /LIBPATH:C:\Python27_32bit\PCbuild agast_static.lib brisk_static.lib /EXPORT:initbrisk build
\temp.win32-2.7\Release\src/brisk.obj /OUT:build\lib.win32-2.7\brisk.pyd /IMPLIB:build\temp.win32-2.7\Release\src\brisk.
lib /MANIFESTFILE:build\temp.win32-2.7\Release\src\brisk.pyd.manifest
LINK : error LNK2001: unresolved external symbol initbrisk
build\temp.win32-2.7\Release\src\brisk.lib : fatal error LNK1120: 1 unresolved externals
error: command '"C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\BIN\link.exe"' failed with exit status 1120
Uncontrolled flailing: I thought maybe the libraries needed to be built, so I did a crash course (lots of crashing) with cmake + mingw - mingw + vc++ express 2010 as follows:
cmake gui: source: c:/brisk, build: c:/brisk/build
cmake gui: configure for Visual Studio 10
cmake gui: use default options and generate (CMAKE_BACKWARDS_COMPATIBILITY, CMAKE_INSTALL_PREFIX, EXECUTABLE_OUTPUT_PATH, LIBRARY_OUTPUT_PATH)
VC++ Express 10: Change to Release and build the solution generated by cmake and get about 20 pages of what look like non-critical warnings followed by all succeeded. Note - no dlls are generated by this. It does generate the following libraries of similar size to the ones included with the download:
win32/lib/Release/
agast_static.lib
brisk_static.lib
Further flailing.
Relevant BRISK source file structure for reference:
build/ (empty)
include/brisk/
brisk.h
hammingsse.hpp
src
brisk.cpp
demo.cpp
thirdparty/agast/
include/agast/
agast5_8.h ....
cvWrapper.h
src/
agast5_8.cc ...
CMakeLists.txt
win32/
bin/
brisk.mexw32
opencv_calib3d220.dll ...
lib/
agast_static.lib
brisk_static.lib
CMakeLists.txt
FindOpenCV.cmake
Makefile
Are you sure that this brisk library even exports python bindings? I can't see any reference to it in the source code - it doesn't even seem to import python header files. This would certainly explain why you've not had much success so far - you can't just compile plain C++ code and expect python to interface with it.
I think your second distutils example is closest to correct - it's obviously compiling things and getting to the linker stage, but then you encounter this error. That error just means it can't find a function named initbrisk which I'm guessing would be the top level init function for the module. Again this suggests that you're trying to compile a python module from code that isn't meant for it.
If you want to wrap the C++ code in a python wrapper yourself you could have a look at the official documentation on writing c/c++ extensions. Alternatively you could have a look into boost::python, SIP or shiboken which try to somewhat (or completely) automate the process of making python extensions from C++ code.
EDIT: Since you seem to have made a decent amount of effort to solve the problem yourself and have posted a good question, I've decided to give a more detailed response on how to go about doing this.
Quick Tutorial On Wrapping C++ Libraries Using boost::python
Personally I've only ever used boost::python for stuff like this, so I'll try and give you a good summary of how to go about doing that. I'm going to assume that you're using Visual C++ 2010. I'm also going to assume that you've got a 32bit version of python installed, as I believe the boost pro libraries only provide 32bit binaries.
Installing boost
First you'll need to grab a copy of the boost library. The easiest way to do this is to download an installer from the boost pro website. These should install all the header files and binary files that are required for using the boost c++ library on windows. Take note of where you install these files to, as you'll need them later on - it might be best to install to a path without a space in it. For easyness I'm going to assume you put these files in C:\boost but you can substitute that for the path you actually used.
Alternatively, you can follow these instructions to build boost from source. I'm not 100% sure, but it might be the case that you need to do this in order to get a version of boost::python that is compatible with the version of python you have installed.
Setting up a visual studio project
Next, you'll want to setup a visual studio project for brisk.pyd. If you open visual studio, go to New -> Project then find the option for Win32 Project. Set up your location etc. and click ok. In the wizard that appears select a DLL project type, and then tick the empty project checkbox.
Now that you've created your project, you'll need to set up the include & library paths to allow you to use python, boost::python and the brisk.lib file.
In Visual Studios solution explorer, right click on your project, and select properties from the menu that appears. This should open up the property pages for your project. Go to the Linker -> General section and look for the Additional Library Directories section. You'll need to fill this in with the paths to the .lib files for boost, python and your brisk_static.lib. Generally these can be found in lib (or libs) subdirectories of
wherever you've installed the libraries. Paths are seperated with semicolons. I've attached a screenshot of my settings below:
Next, you'll need to get visual studio to link to the .lib files. These sections can be found in the Additional Dependencies field of the Linker -> Input section of the properties. Again it's a semicolon delimited list. You should need to add in libraries for python (in my case this is python27.lib but this will vary by version) and brisk_static.lib. These do not require the full path as you added that in the previous stage. Again, here's a screenshot:
You may also need to add the boost_python library file but I think boost uses some header file magic to save you the trouble. If I'm incorrect then have a look in you boost library path for a file named similar to boost_python-vc100-mt.lib and add that in.
Finally, you'll need to setup the include paths to allow your project to include the relevant C++ header files. To get the relevant settings to appear in project properties, you'll need to add a .cpp file to your project. Right click the source files folder in your solution explorer, and then go to add new item. Select a C++ File (.cpp) and name it main.cpp (or whatever else you want).
Next, go back to your project properties and go to C/C++ -> General. Under the additional libraries directory you need to add the include paths for brisk, python and boost. Again, semicolons for seperators, and again here's a screenshot:
I suspect that you might need to update these settings to include the opencv2 & agast libraries as well but I'll leave that as a task for you to figure out - it should be much the same process.
Wrapping existing c++ classes with boost::python.
Now comes the slightly trickier bit - actually writing C++ to wrap your brisk library in boost python. You can find a tutorial for this here but i'll try and go over it a bit as well.
This will be taking place in the main.cpp file you created earlier. First, add the relevant include statements you'll need at the top of the file:
#include <brisk/brisk.h>
#include <Python.h>
#include <boost/python.hpp>
Next, you'll need to declare your python module. I'm assuming you'd want this to be called brisk, so you do something like this:
BOOST_PYTHON_MODULE(brisk)
{
}
This should tell boost::python to create a python module named brisk.
Next it's just a case of going through all the classes & structs that you want to wrap and declaring boost python classes with them. The declerations of the classes should all be contained in brisk.h. You should only wrap the public members of a class, not any protected or private members. As a quick example, I've done a couple of the structs here:
BOOST_PYTHON_MODULE(brisk)
{
using namespace boost::python;
class_< cv::BriskPatternPoint >( "BriskPatternPoint" )
.def_readwrite("x", &cv::BriskPatternPoint::x)
.def_readwrite("y", &cv::BriskPatternPoint::y)
.def_readwrite("sigma", &cv::BriskPatternPoint::sigma);
class< cv::BriskScaleSpace >( "BriskScaleSpace", init< uint8_t >() )
.def( "constructPyramid", &cv::BriskScaleSpace::constructPyramid );
}
Here I have wrapped the cv::BriskPatternPoint structure and the cv::BriskScaleSpace class. Some quick explanations:
class_< cv::BriskPatternPoint >( "BriskPatternPoint" ) tells boost::python to declare a class, using the cv::BriskPatternPoint C++ class, and expose it as BriskPatternPoint in python.
.def_readwrite("y", &cv::BriskPatternPoint::y) adds a readable & writeable property to the BriskPatternPoint class. The property is named y, and will map to the BriskPatternPoint::y c++ field.
class< cv::BriskScaleSpace >( "BriskScaleSpace", init< uint8_t >() ) declares another class, this time BriskScaleSpace but also provides a constructor that accepts a uint8_t (an unsigned byte - which should just map to an integer in python, but I'd be careful to not pass in one greater than 255 bytes - I don't know what would happen in that situation)
The following .def line just declares a function - boost::python should (I think) be able to determine the argument types of functions automatically, so you don't need to provide them.
It's probably worth noting that I haven't actually compiled any of these examples - they might well not work at all.
Anyway, to get this fully working in python it should just be a case of doing similar for every structure, class, property & function that you want accessible from python - which is potentially quite a time consuming task!
If you want to see another example of this in action, I did this here to wrap up this class
Building & using the extension
Visual studio should take care of building the extension - then using it is just a case of taking the .DLL and renaming it to .pyd (you can get VS to do this for you, but I'll leave that up to you).
Then you just need to copy your python file to somewhere on your python path (site-packages for example), import it and use it!
import brisk
patternPoint = brisk.BriskPatternPoint()
....
Anyway, I have spent a good hour or so writing this out - so I'm going to stop here. Apologies if I've left anything out or if anything isn't clear, but I'm doing this mostly from memory. Hopefully it's been of some help to you. If you need anything clarified please just leave a comment, or ask another question.
In case someone needs it, this what I have so far. Basically a BriskFeatureDetector that can be created in Python and then have detect called. Most of this is just confirming/copying what obmarg showed me, but I have added the details that get all the way to the pyd library.
The detect method is still incomplete for me though since it does not convert data types. Anyone who knows a good way to improve this, please do! I did find, for example, this library which seems to convert a numpy ndarray to a cv::Mat, but I don't have the time to figure out how to integrate it now. There are also other data types that need to be converted.
Install OpenCV 2.2
for the setup below, I installed to C:\opencv2.2
Something about the API or implementation has changed by version 2.4 that gave me problems (maybe the new Algorithm object?) so I stuck with 2.2 which BRISK was developed with.
Install Boost with Boost Python
for the setup below, I installed to C:\boost\boost_1_47
Create a Visual Studio 10 Project:
new project --> win32
for the setup below, I named it brisk
next --> DLL application type; empty project --> finished
at the top, change from Debug Win32 to Release Win32
Create main.cpp in Source Files
Do this before the project settings so the C++ options become available in the project settings
#include <boost/python.hpp>
#include <opencv2/opencv.hpp>
#include <brisk/brisk.h>
BOOST_PYTHON_MODULE(brisk)
{
using namespace boost::python;
//this long mess is the only way I could get the overloaded signatures to be accepted
void (cv::BriskFeatureDetector::*detect_1)(const cv::Mat&,
std::vector<cv::KeyPoint, std::allocator<cv::KeyPoint>>&,
const cv::Mat&) const
= &cv::BriskFeatureDetector::detect;
void (cv::BriskFeatureDetector::*detect_vector)(const std::vector<cv::Mat, std::allocator<cv::Mat>>&,
std::vector< std::vector< cv::KeyPoint, std::allocator<cv::KeyPoint>>, std::allocator< std::vector<cv::KeyPoint, std::allocator<cv::KeyPoint>>>>&,
const std::vector<cv::Mat, std::allocator<cv::Mat>>&) const
= &cv::BriskFeatureDetector::detect;
class_< cv::BriskFeatureDetector >( "BriskFeatureDetector", init<int, int>())
.def( "detect", detect_1)
;
}
Project Settings (right-click on the project --> properties):
Includes / Headers
Configuration Properties --> C/C++ --> General
add to Additional Include Directories (adjust to your own python / brisk / etc. base paths):
C:\opencv2.2\include;
C:\boost\boost_1_47;
C:\brisk\include;C:\brisk\thirdparty\agast\include;
C:\python27\include;
Libraries (linker)
Configuration Properties --> Linker --> General
add to Additional Library Directories (adjust to your own python / brisk / etc. base paths):
C:\opencv2.2\lib;
C:\boost\boost_1_47\lib;
C:\brisk\win32\lib;
C:\python27\Libs;
Configuration Properties --> Linker --> Input
add to Additional Dependencies (adjust to your own python / brisk / etc. base paths):
opencv_imgproc220.lib;opencv_core220.lib;opencv_features2d220.lib;
agast_static.lib; brisk_static.lib;
python27.lib;
.pyd output instead of .dll
Configuration Properties --> General
change Target Extension to .pyd
Build and rename if necessary
Right-click on the solution and build/rebuild
you may need to rename the output from "Brisk.pyd" to "brisk.pyd" or else python will give you errors about not being able to load the DLL
Make brisk.pyd available to python by putting it in site packages or by putting a .pth file that links to its path
Update Path environment variable
In windows settings, make sure the following are included in your path (again, adjust to your paths):
`C:\boost\boost_1_47\lib;C:\brisk\win32\bin`
I'm making a program in visual c++. The program relies on some dll files, which I don't want to place in system32. Now the dll files is in the same folder as my .exe, but i would like to move them to a sub folder. The problem is, if I move the files, my application fails to start and comes with this error message:
MyProgram.exe - Unable to Locate Component
This application has failed to start because myDll.dll was not found. Re-installing the application may fix the problem.
I have had the same problem before, where if found a solution, which included adding something to the registry, but i forgot how it worked, and now I can't find the guide again.
Can someone please help me?
There is more than one way to solve this problem. As other mentioned you can modify search path for your application in registry. Sometimes, you don't have rights to write to the registry, or you cannot do it for other reasons, then you can set dll path explicitly, the WinAPI function for that is SetDllDirectory, see MSDN.
Sounds like you're after the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths key. See here for complete information. In short, a string called Path points to a DLL search path. For example if your application was called "MyApp" a .reg file like this would do the trick:
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\AppPaths\MyApp.exe]
#="C:\\Program Files\\MyCompany\\MyApp\\MyApp.exe"
"Path"="C:\\Program Files\\MyCompany\\MyApp\\DLLs"
I believe this is the article you are looking for:
http://www.codeguru.com/Cpp/W-P/dll/article.php/c99
Each application can now store it own path the registry under the following key:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths
The use the application path, set a key for your application, using ONE.EXE from the example above:
HKEY_LOCAL_MACHINE...\CurrentVersion\App Paths\ONE.exe
Set the (Default) value to the full path of your executable, for example:
C:\Program Files\ONE\ONE.exe
Add a sub-key named Path