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I have built and installed a library called OhNet. After make install the corresponding header files of the framework have been installed under usr/local/include/ohNet. Now I want to use the Library in my C++ project (i am using eclipse) but when i try to include some header files, eclipse is not able to find the files. As far as i know eclipse should search for header files in these directories (/usr/include , /usr/local/include ,...) by default.... What do i have to do to use the library? I am pretty new to C++ and haven't used third party sources before.

Thank you.

--EDIT-- I simply want to write an easy "helloworld" programm to verify that i have included the framework correctly. In order to do that i want to instatiate the class OpenHome::Net::DvDeviceStdStandard. see: ohNet C++ reference

I can now include the header file using: #include <ohNet/OpenHome/Net/Core/DvDevice.h> That works fine. But how can i create an object of type OpenHome::Net::DvDeviceStdStandard ? now? Eclipse says that this type cannot be resolved. :( 

#include <iostream>
#include <ohNet/OpenHome/Net/Core/DvDevice.h>

using namespace std;

int main() {

    OpenHome::Net::DvDeviceStdStandard device; //type cannot be resolved
    cout << "!!!Hello World!!!" << endl;
    return 0;
}
simonc
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Moonlit
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2 Answers2

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  1. Use the -I compiler option to point to the 3rd party libraries directory (-I/usr/local/include/ohNet)
  2. Use #include "[whatever you need from oHNet].h" in your header files and compilation units as needed (Note: you might need to put relative prefix pathes for subdirecories in the 3rd party include paths tree here!)
  3. Use the -L linker option to specify a path to the 3rd party libs you need (-L/usr/local/lib probably)
  4. Use the -l linker option to specify any concrete 3rd libs you need (-l[oHNet] probably)

Look in the directories what actually was installed there to figure what to place for [whatever you need from oHNet].h and [oHNet], s.th. like liboHNet.a for the latter.

You didn't tag [tag:Eclipse CDT] explicitly here, but go to the Project->Properties->C++ Builder->Settings Dialog and look for C/C++ Includes and Linker Options.

πάντα ῥεῖ
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  • thx, i'll try that. but to clarify: It's NOT true that the c++ compiler will recognize per default any header files in /usr/include, /usr/local/include, /usr/lib, etc... ? I always have to link the libraries with the -I compiler option? – Moonlit Jul 26 '13 at 17:40
  • @user1291235 As Benjamin Lindley already mentioned it may depend on how you're specifying the `#include` statement. So show what you're doing in more detail please. – πάντα ῥεῖ Jul 26 '13 at 17:45
  • @user1291235 And yes, it is true, but the compiler linker doesn't look up recursively there. – πάντα ῥεῖ Jul 26 '13 at 17:53
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You will have to put the header files that you want to use, in your project folder and then use #include in your .cpp file just like how you would do for any other header files.

user2543325
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  • why copy? it's only needed to tell the compiler where to look for the files (by using `-I` with `g++` as an example) – stefan Jul 26 '13 at 17:30
  • Actually i installed the library using `make install` and all the files where copied to `/usr/local/lib` and `/usr/local/include`, so i guess i do not have to put those files into the project?! – Moonlit Jul 26 '13 at 17:31