Poco library linking errors in ubuntu platform

Question

I have downloaded the latest Poco library poco-1.7.3.tar. Configured with few properties and did make install. Tried the following sample helloworld program.

#include <iostream>
#include <Poco/Util/Application.h>

class HelloPocoApplication : public Poco::Util::Application
{
protected:
    virtual int main(const std::vector<std::string> &args)
    {
            std::cout << "Hello, POCO C++ Libraries!" << std::endl;

            return EXIT_OK;
    }
};
POCO_APP_MAIN(HelloPocoApplication);

Compiled it using

g++ -I poco-1.7.3/Util/include -I poco-1.7.3/XML/include -I poco-1.7.3/JSON/include -I poco-1.7.3/Foundation/include -L poco-1.7.3/lib/Linux/x86_64 -lPocoUtil -lPocoFoundation -lPocoXML -lPocoJSON helloworld.cpp -o prog

But it is throwing following errors

 /tmp/ccFvl4ll.o: In function `main':
 helloworld.cpp:(.text+0x4f): undefined reference to     `Poco::Util::Application::init(int, char**)'
      helloworld.cpp:(.text+0xd9): undefined reference to    `Poco::Logger::log(Poco::Exception const&)'
    /tmp/ccFvl4ll.o: In function `Poco::RefCountedObject::release() const':
    helloworld.cpp:(.text._ZNK4Poco16RefCountedObject7releaseEv[_ZNK4Poco16RefCountedObject7releaseEv]+0x6e): undefined reference to `Poco::Bugcheck::unexpected(char const*, int)'
    /tmp/ccFvl4ll.o: In function `Poco::Util::Application::logger() const':
    helloworld.cpp:(.text._ZNK4Poco4Util11Application6loggerEv[_ZNK4Poco4Util11Application6loggerEv]+0x2c): undefined reference to `Poco::Bugcheck::nullPointer(char const*, char const*, int)'
    /tmp/ccFvl4ll.o: In function `HelloPocoApplication::HelloPocoApplication()':
    helloworld.cpp:(.text._ZN20HelloPocoApplicationC2Ev[_ZN20HelloPocoApplicationC5Ev]+0x14): undefined reference to `Poco::Util::Application::Application()'
    /tmp/ccFvl4ll.o:(.gcc_except_table+0x2c): undefined reference to `typeinfo for Poco::Exception'
    /tmp/ccFvl4ll.o: In function `Poco::AutoPtr<HelloPocoApplication>::operator->()':
    helloworld.cpp:(.text._ZN4Poco7AutoPtrI20HelloPocoApplicationEptEv[_ZN4Poco7AutoPtrI20HelloPocoApplicationEptEv]+0x3a): undefined reference to `Poco::NullPointerException::NullPointerException(int)'
    helloworld.cpp:(.text._ZN4Poco7AutoPtrI20HelloPocoApplicationEptEv[_ZN4Poco7AutoPtrI20HelloPocoApplicationEptEv]+0x3f): undefined reference to `Poco::NullPointerException::~NullPointerException()'
    helloworld.cpp:(.text._ZN4Poco7AutoPtrI20HelloPocoApplicationEptEv[_ZN4Poco7AutoPtrI20HelloPocoApplicationEptEv]+0x44): undefined reference to `typeinfo for Poco::NullPointerException'
    /tmp/ccFvl4ll.o:(.rodata._ZTV20HelloPocoApplication[_ZTV20HelloPocoApplication]+0x20): undefined reference to `Poco::Util::Application::name() const'
    /tmp/ccFvl4ll.o:(.rodata._ZTV20HelloPocoApplication[_ZTV20HelloPocoApplication]+0x28): undefined reference to `Poco::Util::Application::initialize(Poco::Util::Application&)'
    /tmp/ccFvl4ll.o:(.rodata._ZTV20HelloPocoApplication[_ZTV20HelloPocoApplication]+0x30): undefined reference to `Poco::Util::Application::uninitialize()'
    /tmp/ccFvl4ll.o:(.rodata._ZTV20HelloPocoApplication[_ZTV20HelloPocoApplication]+0x38): undefined reference to `Poco::Util::Application::reinitialize(Poco::Util::Application&)'
    /tmp/ccFvl4ll.o:(.rodata._ZTV20HelloPocoApplication[_ZTV20HelloPocoApplication]+0x40): undefined reference to `Poco::Util::Application::defineOptions(Poco::Util::OptionSet&)'
    /tmp/ccFvl4ll.o:(.rodata._ZTV20HelloPocoApplication[_ZTV20HelloPocoApplication]+0x48): undefined reference to `Poco::Util::Application::run()'
    /tmp/ccFvl4ll.o:(.rodata._ZTV20HelloPocoApplication[_ZTV20HelloPocoApplication]+0x50): undefined reference to `Poco::Util::Application::handleOption(std::string const&, std::string const&)'
    /tmp/ccFvl4ll.o: In function `HelloPocoApplication::~HelloPocoApplication()':
    helloworld.cpp:(.text._ZN20HelloPocoApplicationD2Ev[_ZN20HelloPocoApplicationD5Ev]+0x1f): undefined reference to `Poco::Util::Application::~Application()'
    /tmp/ccFvl4ll.o:(.rodata._ZTI20HelloPocoApplication[_ZTI20HelloPocoApplication]+0x10): undefined reference to `typeinfo for Poco::Util::Application'
    collect2: error: ld returned 1 exit status

Can you please help me?

Answer 1

I managed to run exactly that code but using CMake rather than Makefile and it worked. you have just to change the paths according to your machine.

Here's my CMakeLists.txt :

cmake_minimum_required(VERSION 2.8.3)
project(tutocpp14)

set(Poco_DIR "/usr/local/lib/cmake/Poco/") 
set(Poco_INCLUDE_DIRS "/usr/include/Poco/")

find_package(Poco REQUIRED COMPONENTS Foundation Net XML Util) # add other components here

# check c++11 / c++0x
include(CheckCXXCompilerFlag)
CHECK_CXX_COMPILER_FLAG("-std=c++11 " COMPILER_SUPPORTS_CXX11)
CHECK_CXX_COMPILER_FLAG("-std=c++0x" COMPILER_SUPPORTS_CXX0X)
if(COMPILER_SUPPORTS_CXX11)
    set(CMAKE_CXX_FLAGS "-std=c++11")
elseif(COMPILER_SUPPORTS_CXX0X)
    set(CMAKE_CXX_FLAGS "-std=c++0x")
else()
    message(FATAL_ERROR "The compiler ${CMAKE_CXX_COMPILER} has no C++11 support. Please use a different C++ compiler.")
endif()

include_directories( ${Poco_INCLUDE_DIRS}) 

add_executable(publisher src/publisher.cpp)
target_link_libraries(publisher ${Poco_LIBRARIES}) 

Cheers,