std::fstream / std::filesystem 创建具有重复编号的文件

Question

我想创建一个文件末尾有一个数字的文件： filename ( number goes here ).txt。该数字将告诉我文件创建目录中是否存在重复文件：filename.txt .

示例：helloworld (1).txt

Windows 在尝试创建文件副本时也具有此功能。我可以在 C++ 17 中做到这一点吗？

Answer 1

由于没有人给我任何答案，我决定花一些时间在这个函数上做我想做的事，并回答我自己的问题，它在 C++ 17 中适用于任何认为这有用的人：

#include <filesystem>
#include <regex>
#include <fstream>
#include <string>

namespace fs = std::filesystem;

// Just file "std::ostream::open()" except it handles duplicates too
    void create_file_dup(std::string path)
    {
        // Check if file doesnt have duplicates
        if (!fs::exists(path)) {
            std::ofstream(path);
            return;
        }

        // Get filename without path
        std::string filename = (fs::path(path).filename()).string();

        // Since its already a duplicate add "(1)" inbetween the basename and extension
        filename = (fs::path(filename).stem()).string() + " (1)" + (fs::path(filename).extension()).string();

        // Get file's parent directory
        std::string parent = (fs::path(path).parent_path()).string();


        // Loops to check for more duplicates
        for (int dup_count = 2;!fs::exists(parent + filename);dup_count++) {

            std::string dup_c = "(" + std::to_string(dup_count);      // old number
            dup_c + ")";

            std::string dup_cn = "(" + std::to_string(dup_count + 1);   // new number 
            dup_cn + ")";

            filename = std::regex_replace(filename, std::regex(dup_c), dup_cn); // increments : '(1)' -> '(2)'
        }

        // We have found the how many duplicates there are , so create the file with the duplicate number
        std::ofstream(parent + filename);
        return;
    }

std::fstream / std::filesystem 创建具有重复编号的文件

std::fstream / std::filesystem create file with duplicate number

c++

filesystems

fstream

c++17