Question

In the example of my computer the desired output should be: “C: E: F: H: N:” . I know it’s possible, but what is the simpliest way to do that? Pottering in QueryDosDevice output

#ifndef UNICODE
#define UNICODE
#endif


#include <Windows.h>
#include <fstream>
#include <iostream>

const int REPORT_LENGTH = 5000;

int main(void)
{
    TCHAR targetPath[REPORT_LENGTH];

    std::ofstream oFile;

    oFile.open("dos device query.txt");

    QueryDosDevice(NULL,targetPath,REPORT_LENGTH);

    for(int i=0; i<REPORT_LENGTH;i++)
    if (targetPath[i]=='\0')(targetPath[i]='\n');



    for(int i=0; i<REPORT_LENGTH; i++)
    oFile<<static_cast<char>(targetPath[i]);

    oFile.close();

    return 0;
}

would be a huge waste of time and resources. Also function GetLogicalDriveStrings has betrayed me a lot.

#include <Windows.h>

int main()
{
    TCHAR buffer[50];

    GetLogicalDriveStrings(50,buffer);

    MessageBox(0,buffer,"Drives in the system",MB_OK); 


    return 0;
}

It shows only the “C:\” volumine.

Answer 1

Example with GetLogicalDrives, albeit not with concatenating to a string (which is left as an exercise to the OP and the readers ;)):

#include <stdio.h>
#include <tchar.h>
#include <Windows.h>

int __cdecl _tmain(int argc, _TCHAR *argv[])
{
    // Get the bit mask of drive letters
    DWORD drives = ::GetLogicalDrives();
    // Go through all possible letters from a to z
    for(int i = 0; i < 26; i++)
    {
        // Check if the respective bit is set
        if(drives & (1 << i))
        {
            // ... and if so, print it
            _tprintf(TEXT("Drive %c: exists\n"), _T('A') + i);
        }
    }
    return 0;
}