C++17的filesystem如何使用 跨平台文件系统操作的完整指南

#include <iostream>
#include <filesystem>

namespace fs = std::filesystem; // 方便起见，使用命名空间别名

#include <iostream>
#include <filesystem>

namespace fs = std::filesystem;

int main() {
    fs::path my_dir = "my_directory";
    fs::path my_file = my_dir / "my_file.txt"; // 使用 / 操作符拼接路径

    // 创建目录
    if (!fs::exists(my_dir)) {
        if (fs::create_directory(my_dir)) {
            std::cout << "Directory created successfully." << std::endl;
        } else {
            std::cerr << "Failed to create directory." << std::endl;
        }
    }

    // 创建文件 (简单示例，实际应用中需要写入内容)
    std::ofstream outfile(my_file);
    if (outfile.is_open()) {
        outfile << "Hello, filesystem!" << std::endl;
        outfile.close();
        std::cout << "File created successfully." << std::endl;
    } else {
        std::cerr << "Failed to create file." << std::endl;
    }


    // 检查文件是否存在
    if (fs::exists(my_file)) {
        std::cout << "File exists." << std::endl;
    }

    // 删除文件
    if (fs::remove(my_file)) {
        std::cout << "File deleted successfully." << std::endl;
    } else {
        std::cerr << "Failed to delete file." << std::endl;
    }

    // 删除目录 (如果目录为空)
    if (fs::remove(my_dir)) {
        std::cout << "Directory deleted successfully." << std::endl;
    } else {
        std::cerr << "Failed to delete directory. Ensure it's empty." << std::endl;
    }

    return 0;
}

#include <iostream>
#include <filesystem>

namespace fs = std::filesystem;

int main() {
    fs::path dir_path = "."; // 当前目录

    // 遍历当前目录
    std::cout << "Files in current directory:" << std::endl;
    for (const auto& entry : fs::directory_iterator(dir_path)) {
        std::cout << entry.path() << std::endl;
    }

    // 递归遍历目录
    std::cout << "\nAll files and directories recursively:" << std::endl;
    for (const auto& entry : fs::recursive_directory_iterator(dir_path)) {
        std::cout << entry.path() << std::endl;
    }

    return 0;
}

#include <iostream>
#include <filesystem>
#include <chrono>
#include <ctime>

namespace fs = std::filesystem;

int main() {
    fs::path file_path = "example.txt";

    // 创建一个示例文件
    std::ofstream outfile(file_path);
    outfile << "This is an example file." << std::endl;
    outfile.close();

    try {
        // 获取文件大小
        std::uintmax_t file_size = fs::file_size(file_path);
        std::cout << "File size: " << file_size << " bytes" << std::endl;

        // 获取最后修改时间
        auto last_write_time = fs::last_write_time(file_path);
        std::time_t cftime = std::chrono::system_clock::to_time_t(last_write_time);
        std::cout << "Last write time: " << std::ctime(&cftime);

        // 检查是否是符号链接
        if (fs::is_symlink(file_path)) {
            std::cout << "It's a symbolic link." << std::endl;
        } else {
            std::cout << "It's not a symbolic link." << std::endl;
        }

    } catch (const fs::filesystem_error& e) {
        std::cerr << "Filesystem error: " << e.what() << std::endl;
    }

    fs::remove(file_path); // 清理示例文件

    return 0;
}

#include <iostream>
#include <filesystem>

namespace fs = std::filesystem;

int main() {
    fs::path target_file = "original.txt";
    fs::path link_file = "link_to_original.txt";

    // 创建一个示例文件
    std::ofstream outfile(target_file);
    outfile << "This is the original file." << std::endl;
    outfile.close();

    // 创建符号链接
    fs::create_symlink(target_file, link_file);

    // 读取符号链接指向的目标
    fs::path resolved_path = fs::read_symlink(link_file);
    std::cout << "Symbolic link points to: " << resolved_path << std::endl;

    // 检查是否是符号链接
    if (fs::is_symlink(link_file)) {
        std::cout << "It's a symbolic link." << std::endl;
    }

    // 删除符号链接
    fs::remove(link_file);
    fs::remove(target_file); // 清理示例文件

    return 0;
}

#include <iostream>
#include <filesystem>

namespace fs = std::filesystem;

int main() {
    fs::path dir_path = "/root/my_secret_directory"; //  假设你没有访问 /root 的权限

    try {
        // 尝试创建目录
        fs::create_directory(dir_path);
        std::cout << "Directory created successfully." << std::endl;
    } catch (const fs::filesystem_error& e) {
        std::cerr << "Filesystem error: " << e.what() << std::endl;
        // 可以在这里添加更详细的错误处理逻辑，例如记录日志、通知用户等
    }

    return 0;
}

#include <iostream>
#include <filesystem>

namespace fs = std::filesystem;

int main() {
    fs::path my_path = "my_directory" / "my_file.txt"; // 使用 / 操作符，自动适应不同平台的路径分隔符
    std::cout << "Path: " << my_path << std::endl;

    #ifdef _WIN32
        // Windows specific code
        std::cout << "Running on Windows." << std::endl;
    #else
        // Linux or macOS specific code
        std::cout << "Running on Linux or macOS." << std::endl;
    #endif

    return 0;
}