c - Xcode Mach-O 链接器 ID 错误

Question

我是 Xcode 新手，我正在尝试使用 Xcode 学习 C 语言。当我尝试运行它时，出现错误 apple macho-o linker and link command failed with exit code 1。我不明白有关堆栈溢出的有关删除 Pod 或库路径的其他答案。请帮助并告诉我修复此错误的每一步。 {编辑} 抱歉，信息非常少。这是代码和错误

The Code which was Simple

Click here for The error which is disturbing

    Ld /Users/pratikkadam/Library/Developer/Xcode/DerivedData/Education-dhazvkwqsporefgyqgfaxhlzhscj/Build/Products/Debug/Education normal x86_64
    cd /Users/pratikkadam/Documents/GitHub/Education
    export MACOSX_DEPLOYMENT_TARGET=10.13
    /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang -arch x86_64 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.13.sdk -L/Users/pratikkadam/Library/Developer/Xcode/DerivedData/Education-dhazvkwqsporefgyqgfaxhlzhscj/Build/Products/Debug -F/Users/pratikkadam/Library/Developer/Xcode/DerivedData/Education-dhazvkwqsporefgyqgfaxhlzhscj/Build/Products/Debug -filelist /Users/pratikkadam/Library/Developer/Xcode/DerivedData/Education-dhazvkwqsporefgyqgfaxhlzhscj/Build/Intermediates.noindex/Education.build/Debug/Education.build/Objects-normal/x86_64/Education.LinkFileList -Xlinker -rpath -Xlinker @executable_path/../Frameworks -Xlinker -rpath -Xlinker @loader_path/../Frameworks -mmacosx-version-min=10.13 -Xlinker -object_path_lto -Xlinker /Users/pratikkadam/Library/Developer/Xcode/DerivedData/Education-dhazvkwqsporefgyqgfaxhlzhscj/Build/Intermediates.noindex/Education.build/Debug/Education.build/Objects-normal/x86_64/Education_lto.o -Xlinker -export_dynamic -Xlinker -no_deduplicate -fobjc-link-runtime -L/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift_static/macosx -Xlinker -force_load_swift_libs -lc++ -framework Foundation -Xlinker -add_ast_path -Xlinker /Users/pratikkadam/Library/Developer/Xcode/DerivedData/Education-dhazvkwqsporefgyqgfaxhlzhscj/Build/Intermediates.noindex/Education.build/Debug/Education.build/Objects-normal/x86_64/Education.swiftmodule -Xlinker -dependency_info -Xlinker /Users/pratikkadam/Library/Developer/Xcode/DerivedData/Education-dhazvkwqsporefgyqgfaxhlzhscj/Build/Intermediates.noindex/Education.build/Debug/Education.build/Objects-normal/x86_64/Education_dependency_info.dat -o /Users/pratikkadam/Library/Developer/Xcode/DerivedData/Education-dhazvkwqsporefgyqgfaxhlzhscj/Build/Products/Debug/Education

duplicate symbol _main in:
    /Users/pratikkadam/Library/Developer/Xcode/DerivedData/Education-dhazvkwqsporefgyqgfaxhlzhscj/Build/Intermediates.noindex/Education.build/Debug/Education.build/Objects-normal/x86_64/Example.o
    /Users/pratikkadam/Library/Developer/Xcode/DerivedData/Education-dhazvkwqsporefgyqgfaxhlzhscj/Build/Intermediates.noindex/Education.build/Debug/Education.build/Objects-normal/x86_64/main.o
ld: 1 duplicate symbol for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Answer 1

C语言命令行项目的XCode标准模板包含main.c，其中包含示例实现:

#include <stdio.h>
int main(int argc, const char * argv[]) {
    // insert code here...
    printf("Hello, World!\n");
    return 0;
}

您还没有向我们展示您的项目文件结构，但我假设您没有从项目中删除 main.c 。您的屏幕截图表明您创建的 Example.c 还包含 main() 函数定义。在C语言中，所有函数都位于同一平面全局级别(没有命名空间和类)，因此链接器(制作可执行文件的最后阶段)提示重复的_main 符号。要解决此问题，您应该:

1. 将 main 函数中的测试代码从 Example.c 移至 main.c 中。并删除 Example.c 任何内容。
2. 将 Example.c 中的函数重命名为 main() 之外的其他内容，并在 int main(int argc , const char * argv[]) 在 main.c 中。