[WIN32] Retrieve disk information from available drives.

GetDiskFreeSpace.cpp

// Retrieve disk information from available drives.
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <locale.h>
#include <tuple>

std::tuple<uint64_t, uint64_t, uint64_t> getDiskFreeSpace(const wchar_t* path) {
    wchar_t volumePath[256];
    if(FALSE == GetVolumePathNameW(path, volumePath, static_cast<DWORD>(std::size(volumePath)))) {
        return { 0, 0, 0 };
    }
    ULARGE_INTEGER freeBytesAvailableToCaller, totalNumberOfBytes, totalNumberOfFreeBytes;
    if(0 == GetDiskFreeSpaceExW(volumePath, &freeBytesAvailableToCaller, &totalNumberOfBytes, &totalNumberOfFreeBytes)) {
        return { 0, 0, 0 };
    }
    return { freeBytesAvailableToCaller.QuadPart, totalNumberOfBytes.QuadPart, totalNumberOfFreeBytes.QuadPart };
}

void test() {
    const DWORD drives = GetLogicalDrives();
    for(int i = -1; i < 26; ++i) {
        wchar_t path[3];
        if(i == -1) {
            path[0] = '.';
            path[1] = 0;
            path[2] = 0;
        } else {
            if(((drives >> i) & 1) == 0) {
                continue;
            }
            path[0] = i + L'A';
            path[1] = ':';
            path[2] = 0;
        }
        const auto [freeBytesAvailableToCaller, totalNumberOfBytes, totalNumberOfFreeBytes] = getDiskFreeSpace(path);
        const auto totalSize = totalNumberOfBytes / 1024.0 / 1024.0 / 1024.0;
        const auto freeSize = freeBytesAvailableToCaller / 1024.0 / 1024.0 / 1024.0;
        wprintf(L"path=%2s, totalSize=%8.2fGiB, free=%8.2fGiB\n", path, totalSize, freeSize);
    }
}

int main() {
    setlocale(LC_ALL, "");
    test();
}