Create a directory if it doesn't exist

Question

In my app I want to copy a file to the other hard disk so this is my code:

 #include <windows.h>  using namespace std;  int main(int argc, char* argv[] ) {     string Input = "C:\\Emploi NAm.docx";     string CopiedFile = "Emploi NAm.docx";     string OutputFolder = "D:\\test";     CopyFile(Input.c_str(), string(OutputFolder+CopiedFile).c_str(), TRUE);      return 0; } 

so after executing this, it shows me in the D:HDD a file testEmploi NAm.docx but I want him to create the test folder if it doesn't exist.

I want to do that without using the Boost library.

Answer 1

Use the WINAPI CreateDirectory() function to create a folder.

You can use this function without checking if the directory already exists as it will fail but GetLastError() will return ERROR_ALREADY_EXISTS:

if (CreateDirectory(OutputFolder.c_str(), NULL) ||     ERROR_ALREADY_EXISTS == GetLastError()) {     // CopyFile(...) } else {      // Failed to create directory. } 

The code for constructing the target file is incorrect:

string(OutputFolder+CopiedFile).c_str() 

this would produce "D:\testEmploi Nam.docx": there is a missing path separator between the directory and the filename. Example fix:

string(OutputFolder+"\\"+CopiedFile).c_str() 

Answer 2

#include <experimental/filesystem> // or #include <filesystem> for C++17 and up      namespace fs = std::experimental::filesystem;   if (!fs::is_directory("src") || !fs::exists("src")) { // Check if src folder exists     fs::create_directory("src"); // create src folder }