C++如何处理网络文件系统路径 远程文件访问的特殊考虑

#include <fstream>
#include <iostream>
#include <string>

void access_unc_path(const std::string& unc_path) {
    std::fstream file(unc_path, std::ios::in | std::ios::out);
    if (file.is_open()) {
        std::cout << "Successfully opened " << unc_path << std::endl;
        // Perform read/write operations
        std::string line;
        while (std::getline(file, line)) {
            std::cout << line << std::endl;
        }
        file.close();
    } else {
        std::cerr << "Failed to open " << unc_path << std::endl;
        // On Windows, GetLastError() might provide more details
    }
}
// 调用示例：access_unc_path("\\YourServer\YourShare\test.txt");

#include <fstream>
#include <iostream>
#include <string>
#include <filesystem> // C++17

void access_mounted_path(const std::filesystem::path& mount_path) {
    if (std::filesystem::exists(mount_path)) {
        std::cout << "Mount point " << mount_path << " exists." << std::endl;
        std::fstream file(mount_path / "test.txt", std::ios::in);
        if (file.is_open()) {
            std::cout << "Successfully opened file on mounted share." << std::endl;
            // ... read/write operations
            file.close();
        } else {
            std::cerr << "Failed to open file on mounted share." << std::endl;
            // Check errno for details
        }
    } else {
        std::cerr << "Mount point " << mount_path << " does not exist or is not accessible." << std::endl;
    }
}
// 调用示例：access_mounted_path("/mnt/remote_share");

#include <fstream>
#include <iostream>
#include <string>
#include <system_error> // For std::system_category
#ifdef _WIN32
#include <windows.h>
#else
#include <cerrno>
#endif

// 自定义异常类，包含OS错误码
class NetworkFileError : public std::runtime_error {
public:
    NetworkFileError(const std::string& msg, int os_error_code = 0)
        : std::runtime_error(msg), os_error_code_(os_error_code) {}
    int get_os_error_code() const { return os_error_code_; }
private:
    int os_error_code_;
};

void safe_access_remote_file(const std::string& path) {
    try {
        std::fstream file(path, std::ios::in);
        if (!file.is_open()) {
            int err_code = 0;
#ifdef _WIN32
            err_code = GetLastError();
            // You might want to use FormatMessage here for a human-readable message
#else
            err_code = errno;
#endif
            throw NetworkFileError("Failed to open remote file: " + path, err_code);
        }
        std::string line;
        while (std::getline(file, line)) {
            std::cout << line << std::endl;
        }
        file.close();
    } catch (const std::filesystem::filesystem_error& e) {
        // C++17 std::filesystem specific errors
        std::cerr << "Filesystem error: " << e.what() << " [" << e.code() << "]" << std::endl;
    } catch (const NetworkFileError& e) {
        std::cerr << "Network file error: " << e.what() << " (OS Error: " << e.get_os_error_code() << ")" << std::endl;
        // 根据错误码判断是否可重试
        if (e.get_os_error_code() == 64 || e.get_os_error_code() == 53) { // NETNAME_DELETED or NET_PATH_NOT_FOUND (Windows specific)
            std::cerr << "  -> Network path seems unavailable. Consider retrying later." << std::endl;
        }
    } catch (const std::exception& e) {
        std::cerr << "An unexpected error occurred: " << e.what() << std::endl;
    }
}

#include <filesystem>
#include <iostream>

void demonstrate_path_ops() {
    std::filesystem::path base_path;
#ifdef _WIN32
    base_path = "\\MyServer\MyShare"; // UNC path
#else
    base_path = "/mnt/remote_data";     // Mount point
#endif

    std::filesystem::path full_path = base_path / "documents" / "report.txt";
    std::cout << "Constructed path: " << full_path << std::endl;
    // full_path will be "\MyServerMySharedocuments
eport.txt" on Windows
    // and "/mnt/remote_data/documents/report.txt" on Linux
}