Question

我现在已经尝试过在Windows机器上运行在Netbeans（编译器是cygwin）中运行的libcurl示例c ++代码，但每次都会失败。我也通过网络搜索（也通过stackoverflow），但找不到解决方案...... :(

以下是我想要运行的示例代码...

#include <cstdlib>
#include <curl/curl.h>

using namespace std;

/*
 * 
 */
int main(int argc, char** argv) {
    CURL *curl;
    CURLcode res;

    curl = curl_easy_init();
    if(curl) {
    curl_easy_setopt(curl, CURLOPT_URL, "http://google.com");
    res = curl_easy_perform(curl);

    curl_easy_cleanup(curl);
    }

    return 0;
}

这是编译结果：

"/usr/bin/make" -f nbproject/Makefile-Debug.mk QMAKE= SUBPROJECTS= .build-conf
make[1]: Entering directory `/cygdrive/c/Users/Alexander/Documents/NetBeansProjects/CppApplication_3'
"/usr/bin/make"  -f nbproject/Makefile-Debug.mk dist/Debug/Cygwin_4.x_1-Windows/cppapplication_3.exe
make[2]: Entering directory `/cygdrive/c/Users/Alexander/Documents/NetBeansProjects/CppApplication_3'
mkdir -p build/Debug/Cygwin_4.x_1-Windows
rm -f build/Debug/Cygwin_4.x_1-Windows/main.o.d
g++.exe -lcurl   -c -g -MMD -MP -MF build/Debug/Cygwin_4.x_1-Windows/main.o.d -o build/Debug/Cygwin_4.x_1-Windows/main.o main.cpp
mkdir -p dist/Debug/Cygwin_4.x_1-Windows
g++.exe -lcurl    -o dist/Debug/Cygwin_4.x_1-Windows/cppapplication_3 build/Debug/Cygwin_4.x_1-Windows/main.o  
build/Debug/Cygwin_4.x_1-Windows/main.o: In function `main':
/cygdrive/c/Users/Alexander/Documents/NetBeansProjects/CppApplication_3/main.cpp:20: undefined reference to `_curl_easy_init'
/cygdrive/c/Users/Alexander/Documents/NetBeansProjects/CppApplication_3/main.cpp:22: undefined reference to `_curl_easy_setopt'
/cygdrive/c/Users/Alexander/Documents/NetBeansProjects/CppApplication_3/main.cpp:23: undefined reference to `_curl_easy_perform'
/cygdrive/c/Users/Alexander/Documents/NetBeansProjects/CppApplication_3nbproject/Makefile-Debug.mk:61: recipe for target `dist/Debug/Cygwin_4.x_1-Windows/cppapplication_3.exe' failed
make[2]: Leaving directory `/cygdrive/c/Users/Alexander/Documents/NetBeansProjects/CppApplication_3'
nbproject/Makefile-Debug.mk:58: recipe for target `.build-conf' failed
make[1]: Leaving directory `/cygdrive/c/Users/Alexander/Documents/NetBeansProjects/CppApplication_3'
/main.cpp:25: undefined reference to `_curl_easy_cleanup'
nbproject/Makefile-impl.mk:39: recipe for target `.build-impl' failed
collect2: ld returned 1 exit status
make[2]: *** [dist/Debug/Cygwin_4.x_1-Windows/cppapplication_3.exe] Error 1
make[1]: *** [.build-conf] Error 2
make: *** [.build-impl] Error 2

BUILD FAILED (exit value 2, total time: 2s)

libcurl也作为包安装在cygwin中... libcurl.a位于'E：\ cygwin \ lib'，而cygcurl-4.dll位于'E：\ cygwin \ bin'。

如果有人可以帮助我，那就太棒了！

提前致谢！问候，亚历

Answer 1

将-l选项放在link命令的末尾，如下所示：

g++ -o main main.o -lcurl

因此，在您的情况下，输出应如下所示：

g++.exe -o dist/Debug/Cygwin_4.x_1-Windows/cppapplication_3 build/Debug/Cygwin_4.x_1-Windows/main.o -lcurl

从gcc manual

逐字逐句

在命令中你写这个[-l]选项会有所不同;该链接器按顺序搜索和处理库和目标文件它们是指定的。因此，foo.o -lz bar.o' searches library z'之后文件foo.o但在bar.o之前如果bar.o引用'z'中的函数，这些功能可能无法加载。

Netbeans中的libcurl：'未定义引用...'

1 个答案: