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我正在尝试在 curlcpp 和 cmake 的帮助下用 C++ 做一个项目，但我无法编译该项目。

我是 CMakeLists 的新手，很难理解如何添加使项目正常运行所需的东西。我基本上通常会复制我在其他帖子中可以找到的内容，而没有真正了解它们是如何工作的；教程和文档通常要么太基础要么太复杂。更糟糕的是，我的印象是每个库都添加了不同的库，所以当有一个新的库要添加时，我必须添加它的唯一方法是搜索以前的帖子询问如何做。在这种情况下，我找不到任何对我有帮助的东西。

所以这就是我所做的：

使用自制软件安装 curlpp 和 curl 后

brew install curl
brew install curlpp

我写我的项目：

Cmakelists.txt：

cmake_minimum_required(VERSION 3.0)

project(stock_analysis)

set(CMAKE_CXX_FLAGS "-g -Wall -std=c++11")


######## BOOST STUFF ########
#DELETE NEXT LINE
set(Boost_NO_BOOST_CMAKE ON)

# set(Boost_USE_STATIC_LIBS        ON) # only find static libs
# set(Boost_USE_MULTITHREADED      ON)
# set(Boost_USE_STATIC_RUNTIME    OFF)
find_package(Boost COMPONENTS
                   filesystem
)

######## CURL STUFF ########
include(FindCURL)
find_package(CURL REQUIRED)
if(CURL_FOUND)
 message(STATUS "Found CURL version: ${CURL_VERSION_STRING}")
 message(STATUS "Using CURL include dir(s): ${CURL_INCLUDE_DIRS}")
 message(STATUS "Using CURL lib(s): ${CURL_LIBRARIES}")
else()
 message(FATAL_ERROR "Could not find CURL")
endif()




SET(HEADERS
   include
)

SET(SOURCE_FILES
  src/main.cpp
  src/analyse.cpp
  src/helpers.cpp
  src/simulation.cpp
  src/data.cpp
)

include_directories(${HEADERS}
                   ${Boost_INCLUDE_DIRS}
                   ${CURL_INCLUDE_DIRS}
)

add_executable(app ${SOURCE_FILES})

target_link_libraries(app
       ${Boost_LIBRARIES}
       ${CURL_LIBRARIES}
)

data.cpp 中的函数（我基本上是复制 curlcpp 网页中的示例）：

#include "data.h"

#include <iostream>

#include <curlpp/cURLpp.hpp>
#include <curlpp/Easy.hpp>
#include <curlpp/Options.hpp>

using namespace curlpp::options;


void fetchData(){

  try
    {
    // That's all that is needed to do cleanup of used resources (RAII style).
        curlpp::Cleanup myCleanup;

        // Our request to be sent.
        curlpp::Easy myRequest;

        // Set the URL.
        myRequest.setOpt<Url>("http://example.com");

        // Send request and get a result.
        // By default the result goes to standard output.
        myRequest.perform();
  }

  catch( curlpp::RuntimeError &e )
    {
        std::cout << e.what() << std::endl;
    }

    catch( curlpp::LogicError &e )
    {
        std::cout << e.what() << std::endl;
    }
}

我得到的错误：

Undefined symbols for architecture x86_64:
  "curlpp::OptionBase::OptionBase(CURLoption)", referenced from:
      curlpp::Option<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >::Option(CURLoption, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&) in data.cpp.o
  "curlpp::OptionBase::~OptionBase()", referenced from:
      curlpp::Option<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >::Option(CURLoption, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&) in data.cpp.o
      curlpp::Option<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >::~Option() in data.cpp.o
  "curlpp::UnsetOption::UnsetOption(char const*)", referenced from:
      curlpp::Option<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >::updateMeToOption(curlpp::OptionBase const&) in data.cpp.o
      curlpp::OptionTrait<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, (CURLoption)10002>::updateHandleToMe(curlpp::internal::CurlHandle*) const in data.cpp.o
      curlpp::Option<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >::getValue() const in data.cpp.o
  "curlpp::RuntimeError::~RuntimeError()", referenced from:
      curlpp::UnsetOption::~UnsetOption() in data.cpp.o
  "curlpp::libcurlRuntimeAssert(char const*, CURLcode)", referenced from:
      void curlpp::internal::CurlHandle::option<void*>(CURLoption, void*) in data.cpp.o
  "curlpp::Easy::perform()", referenced from:
      StockAnalysis::fetchData(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, bool const&) in data.cpp.o
  "curlpp::Easy::Easy()", referenced from:
      StockAnalysis::fetchData(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, bool const&) in data.cpp.o
  "curlpp::Easy::~Easy()", referenced from:
      StockAnalysis::fetchData(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, bool const&) in data.cpp.o
  "curlpp::Cleanup::Cleanup()", referenced from:
      StockAnalysis::fetchData(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, bool const&) in data.cpp.o
  "curlpp::Cleanup::~Cleanup()", referenced from:
      StockAnalysis::fetchData(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, bool const&) in data.cpp.o
  "curlpp::OptionBase::operator<(curlpp::OptionBase const&) const", referenced from:
      vtable for curlpp::OptionTrait<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, (CURLoption)10002> in data.cpp.o
      vtable for curlpp::Option<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > > in data.cpp.o
  "typeinfo for curlpp::LogicError", referenced from:
      GCC_except_table0 in data.cpp.o
  "typeinfo for curlpp::OptionBase", referenced from:
      curlpp::Option<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >::updateMeToOption(curlpp::OptionBase const&) in data.cpp.o
      typeinfo for curlpp::Option<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > > in data.cpp.o
  "typeinfo for curlpp::RuntimeError", referenced from:
      GCC_except_table0 in data.cpp.o
      typeinfo for curlpp::UnsetOption in data.cpp.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[2]: *** [app] Error 1
make[1]: *** [CMakeFiles/app.dir/all] Error 2
make: *** [all] Error 2

我之前关注过下一个帖子： Linking curl in a project using CMake

将curlcpp添加到cmakelists 中的 target_link_libraries ()只会出现另一个错误：


ld: library not found for -lcurlpp
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[2]: *** [app] Error 1
make[1]: *** [CMakeFiles/app.dir/all] Error 2
make: *** [all] Error 2

顺便说一句，我不明白为什么 curlcpp 出现在没有传统 cmakelists 符号${Some_variable}的地方

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0 回答 0