Member Avatar for kal_crazy

How to save the created txt file to a specified path? For example to C:\ Drive. When the code creates a file it saves to the workspace folder of the project. Do I have to set the directory to C:\? I tried using SetCurrentDirectoryA function but does not change to the specified directory.

This is one of the ways I tried:

void createFile(){

    ofstream file("C:\\sample.txt");

    file.close();
}
  • 3 Contributors
  • 5 Replies
  • 2K Views
  • 1 Day Discussion Span
  • Latest Post Latest Post by kal_crazy

Dani AI

Generated

is right about permissions: on modern Windows the default ACL on C:\ lets standard users read and create subfolders, but not create files directly in the root. That is why saw it work only when running elevated. You can confirm this by checking the default entries for C:\ (Users: Create files/write data = Subfolders only). (stigviewer.com)

Also note: SetCurrentDirectory only changes the process working directory and affects relative paths. An absolute path like C:\sample.txt ignores the current directory, which explains why switching directories did not help. (learn.microsoft.com)

Instead of writing to C:\, write to a user-writable Known Folder (Documents, LocalAppData, etc.) and build the path safely. Example with C++17:

#include <windows.h>
#include <ShlObj.h>           // SHGetKnownFolderPath
#include <filesystem>
#include <fstream>

namespace fs = std::filesystem;

void createFileInDocs() {
    PWSTR p = nullptr;
    if (SUCCEEDED(SHGetKnownFolderPath(FOLDERID_Documents, 0, nullptr, &p))) {
        fs::path out = fs::path(p) / "sample.txt";
        CoTaskMemFree(p);
        std::ofstream file(out);
        if (!file) throw std::runtime_error("open failed");
        file << "hello\n";
    }
}

Known Folders are the Microsoft-recommended way to find per-user storage, and SHGetKnownFolderPath returns the correct path for the current user. With C++17, std::filesystem::path handles native Windows paths and feeds them directly to std::ofstream. (learn.microsoft.com)

Practical tips:

  • If you truly must write under C:\ for testing, create a subfolder you own (e.g., C:\Temp\MyApp) or run elevated, but avoid this in production for UAC and security reasons. (learn.microsoft.com)
  • For literals, raw strings help avoid backslash escaping: R"(C:\Temp\sample.txt)".
  • In Visual Studio, relative paths resolve against the project’s Debugging > Working Directory, so be explicit when debugging.

Recommended Answers

All 5 Replies

Member Avatar for Suzie999

Probably need to add some info, os platform, bitness etc...

To me, that looks like should create file in C root, but if windows and vista+ you must invoke admin to create file there.

If I'm wrong, try ftream.

Edited by Suzie999
Member Avatar for kal_crazy

fstream does not work either :(

I have seen some examples and that is how they stored the file to C drive.

Any other options?

Member Avatar for Suzie999

Probably need to add some info, os platform, bitness etc...

Member Avatar for mike_2000_17

Using ofstream file("C:\\sample.txt"); should work, unless you do not have to permissions to create a file in the C:\\ directory.

In general, in C++, if you want more control over the file-system (folders, files, etc.), you need to resort to a library for that (at least, until it becomes standard, probably in C++14, I think). You can use the Boost.FileSystem library, or any other file-system manipulation library (e.g., in Qt).

Otherwise, you will have to use API functions directly, such as Win32 API functions (Windows).

But again, your program will only have the file permissions of the user account it runs under. If you need to read / write files in admin-only folders, you will have to run the program with administrator rights.

Member Avatar for kal_crazy

Probably need to add some info, os platform, bitness etc...

Windows 8

Using ofstream file("C:\sample.txt"); should work, unless you do not have to permissions to create a file in the C:\ directory.

Yup ofstream should work. At my uni lab this way worked but at my home laptop it just cant seem to write in C:\ drive. I went to check the C:\ drive properties and saw as a User I can not write to C:\ drive, however, as the administrator I had permissions to write(of course). So I ran the MSVC IDE as admin and voila it worked.

Thank you Suzie and Mike :)

Edited by kal_crazy
Be a part of the DaniWeb community

We're a friendly, industry-focused community of developers, IT pros, digital marketers, and technology enthusiasts meeting, networking, learning, and sharing knowledge.