C++文件系统

Question

我正在尝试添加这些功能。

std::string GetDirectory(std::string path_name) {
    boost::filesystem::path path(path_name.c_str());

    path_name = path.string();

    path_name.erase(
        path_name.substr(
            path_name.find_last_of(DIRECTORY_SEPARATOR),
            path_name.length()
        )
    );
    return path_name;
}

std::string GetName(std::string path_name) {
    boost::filesystem::path path(path_name.c_str());

    path_name = path.string();

    path_name.erase(
        path_name.substr(
            0, 
            path_name.find_last_of(DIRECTORY_SEPARATOR)
        )
    );

    path_name.erase(
        path_name.substr(
            path_name.find_last_of("."), 
            path_name.length()
        )
    );
    return path_name;
}

std::string GetExtension(std::string path_name) {
    boost::filesystem::path path(path_name.c_str());

    path_name = path.string();

    path_name.erase(
        path_name.substr(
            0, 
            path_name.find_last_of('.')
        )
    );
    return path_name;
}

我正在尝试添加：

C:\Windows\Users\Example\Desktop\test.txt

获取目录

C:\Windows\Users\Example\Desktop

GetName

test

获取扩展

txt

我在 path_name 和擦除（句号）之间遇到错误。帮助将不胜感激，谢谢。

请请求错误消息：

1>C:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0\V140\Microsoft.CppBuild.targets(368,5): warning MSB8004: Output Directory does not end with a trailing slash. This build instance will add the slash as it is required to allow proper evaluation of the Output Directory. 1> main.cpp 1>main.cpp(287): error C2664: 'std::_String_iterator>> std::basic_string,std::allocator>::erase(std::_String_const_iterator>>,std::_String_const_iterator>>)': cannot convert argument 1 from 'std::basic_string,std::allocator>' to 'unsigned int' 1> main.cpp(287): note: No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called 1> main.cpp(301): error C2664: 'std::_String_iterator>> std::basic_string,std::allocator>::erase(std::_String_const_iterator>>,std::_String_const_iterator>>)': cannot convert argument 1 from 'std::basic_string,std::allocator>' to 'unsigned int' 1> main.cpp(301): note: No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called 1> main.cpp(307): error C2664: 'std::_String_iterator>> std::basic_string,std::allocator>::erase(std::_String_const_iterator>>,std::_String_const_iterator>>)': cannot convert argument 1 from 'std::basic_string,std::allocator>' to 'unsigned int' 1> main.cpp(307): note: No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called 1> main.cpp(321): error C2664: 'std::_String_iterator>> std::basic_string,std::allocator>::erase(std::_String_const_iterator>>,std::_String_const_iterator>>)': cannot convert argument 1 from 'std::basic_string,std::allocator>' to 'unsigned int' 1> main.cpp(321): note: No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called

Answer 1

删除无用和有害的path_name.substr(和)。
您可以省略 std::string::erase 的第二个参数以擦除直到字符串结束。

Answer 2

你应该使用

template <class Path> typename Path::string_type extension(const Path& p);

获取扩展名的函数。

你应该使用

template <class Path> typename Path::string_type basename(const Path& p);

获取文件基本名称的函数。

我假设您使用的是 Windows OS.

#include <iostream>
#include <boost/filesystem.hpp>

int main()
{
    namespace fs = boost::filesystem;

    std::string p = "C:\Windows\Users\Example\Desktop\test.txt";

    std::string ext = fs::extension(p);
    std::string bas = fs::basename(p);

    std::cout << ext << " " << bas << std::endl;

    return 0;
}

C++文件系统

C++ File System

c++

filesystems

boost

c++11