MoveFile function convert syntax / how to use MoveFile with variables to rename folders

Question

This part of my programm tries to rename all folders and subfolders. All other functionality is in another code, here I'm just renaming a single folder by providing a path.

Since rename doesnt seem to work for me I tried using MoveFile.

I understand that it requires an LPCTSTR value.. but the paths I am currently providing (casted from std::filesystem::directory_entry -> std::filesystem::path) -> LPCTSTR) aren't accepted.

I'm getting that I'm not casting it the right way and I probably have to provide it with an "L" in front of the variable, but I can't find nor figure out the syntax.

bool renameFolder(std::string confirmStr3, auto dirEntry, std::string& replacedStr, std::string& insertStr, int& foldername_replacements)
{
    std::string path_string = dirEntry.path().string();

    path_string = std::filesystem::path(path_string).filename().string();

    replace_all(path_string, replacedStr, insertStr);

    path_string = getFolderPath(std::filesystem::path(dirEntry).string()) + "\\" + path_string;
 

    if (std::filesystem::path(dirEntry) != std::filesystem::path(path_string))
        foldername_replacements++;


    //std::filesystem::rename(std::filesystem::path(dirEntry), std::filesystem::path(path_string));
    MoveFile(LPCTSTR(std::filesystem::path(dirEntry)), LPCTSTR(std::filesystem::path(path_string)));

}

[Why should I not upload images of code/data/errors when asking a question?](https://meta.stackoverflow.com/questions/285551/why-should-i-not-upload-images-of-code-data-errors-when-asking-a-question) — Remy Lebeau, Aug 02 '22 at 07:20
Have you read the [help] yet? Particularly [How do I ask a good question?](https://stackoverflow.com/help/how-to-ask). — Remy Lebeau, Aug 02 '22 at 18:13
Ok I realized it was you again :D Yes, I did read it. I mark everything I feel.. I only forgot to include the code the right way.. Oh and yeah Ill ignore to not post the error messages.. thats just plain dumb imo.. It's a short question and errormessages are very important for people that don't own a biological interpreter in their body. — Gisbert12843, Aug 03 '22 at 08:29

Remy Lebeau · Accepted Answer · 2022-08-03T15:49:27.020

2

You can't type cast a std::filesystem::path object directly to a character pointer. That is exactly what the error message is telling you. And you can't use the L prefix with variables, only with compile-time literals.

You need to call the path::c_str() method instead, eg:

MoveFileW(std::filesystem::path(dirEntry).c_str(), std::filesystem::path(path_string).c_str());

Or, call the path::(w)string() method, and then call c_str() on the returned std::(w)string object, eg:

MoveFileW(std::filesystem::path(dirEntry).wstring().c_str(), std::filesystem::path(path_string).wstring().c_str());

That being said, std::rename() is likely to be implemented on Windows using MoveFile/Ex() internally, so this is a possible XY Problem. std::rename() is the preferred solution, so you should focus your efforts on figuring out why it is not working for you.

UPDATE:

On a side note, the code you have shown makes repetitive use of temporary std::filesystem::path objects that are unnecessary. Try simplifying the code, like this:

bool renameFolder(std::string confirmStr3, auto dirEntry, std::string& replacedStr, std::string& insertStr, int& foldername_replacements)
{
    auto dirEntryPath = dirEntry.path();
    auto file_name = dirEntryPath.filename().string();

    replace_all(file_name, replacedStr, insertStr);

    auto newDirEntryPath = dirEntryPath / file_name;    
    if (dirEntryPath != newDirEntryPath)
    {
        ++foldername_replacements;

        //std::filesystem::rename(dirEntryPath, newDirEntryPath);
        MoveFileW(dirEntryPath.c_str(), newDirEntryPath.c_str());
    }
}

edited Aug 03 '22 at 15:49

answered Aug 02 '22 at 07:17

Remy Lebeau

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yeah i think i get you! thank you very much! :) – Gisbert12843 Aug 02 '22 at 07:24
Hey, maybe you'll read this. Wanted to thank you again for making me aware of the possible XY Problem, better the overall concept of it! :D It fixed a design flaw and brought me further in my studies <3 @remy-lebeau – Gisbert12843 Aug 02 '22 at 10:32
I will look into that! Thanks for the insight! :) Got the project ready and done by now. It just renames all files, folders and content in less than a second, but Optimisation especially in C++ is always very important, so thanks for that! If someone wants to copy it (though its prob bad code :D), you can find it here https://github.com/Gisbert12843/FindAndReplace. – Gisbert12843 Aug 03 '22 at 08:36
Don't yet understand why, but that code as it is and even in versions I altered a bit just doesn't work.. Doesn't matter if MoveFile or MoveFileW is used too mhhh It just won't rename the folder, but says it does :D I'll update this if I figure it out. – Gisbert12843 Aug 03 '22 at 10:13
Define "doesn't work" exactly. You need to be more specific. Is `rename()` returning an error code, or throwing an exception? Is `MoveFileEx()` returning false, and if so then what does `GetLastError()` return? – Remy Lebeau Aug 03 '22 at 15:53
Didn't fully debug it tbh.. it's not returning any errors at compile or runtime.. it just won't rename the folder ^^ I would guess it has something to do with formatting the path.. we had like 36°C the last 3 days so I didn't have the nerves to work that much :S will do that later to learn from it though! – Gisbert12843 Aug 04 '22 at 10:40
@Gisbert12843 it can't fail to rename and not report an error. The only way I could think of for it to report success but still not rename is if the folder/file is in use and the OS is waiting for that to be released before then renaming it. Unless your debugging is faulty and you are simply diagnosing it wrong. – Remy Lebeau Aug 04 '22 at 18:11
What i meant is, that it doesn't throw an exception of any kind.. I didn't debug it fully yet ^^ It just doesn't rename the folders but just seems to skip it.. you don't have to do more on that :D you really helped me more than enough! thx a bunch!! – Gisbert12843 Aug 04 '22 at 20:19

MoveFile function convert syntax / how to use MoveFile with variables to rename folders

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