CPP: Windows: GetDiskFreeSpaceExW

Retrieves information about the amount of space that is available on a disk volume, which is the total amount of space, the total amount of free space, and the total amount of free space available to the user that is associated with the calling thread.

	#include <iostream>
	#include <iomanip>
	#include <Windows.h>
	int main()
	{
	ULARGE_INTEGER FreeBytesAvailableToCaller, TotalNumberOfBytes, TotalNumberOfFreeBytes;
	auto ret = GetDiskFreeSpaceExW(L"C:\\", &FreeBytesAvailableToCaller, &TotalNumberOfBytes, &TotalNumberOfFreeBytes);
	if (ret) {
	auto MB = 1.0 / (1024 * 1024 * 1024);
	std::wcout << std::setprecision(4);
	std::wcout << "FreeBytesAvailableToCaller: " << FreeBytesAvailableToCaller.QuadPart*MB << std::endl;
	std::wcout << "TotalNumberOfBytes(MB): " << TotalNumberOfBytes.QuadPart * MB << std::endl;
	std::wcout << "TotalNumberOfFreeBytes: " << TotalNumberOfFreeBytes.QuadPart*MB << std::endl;
	return 0;
	}
	else {
	return -1;
	}
	}

view raw GetDiskFreeSpaceExW.cpp hosted with ❤ by GitHub

Notes:
- Tested using Visual Studio 2022 (17.2.6) C++ Windows Console template
Reference(s):
https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-getdiskfreespaceexw

CPP: Windows: FindFirstVolumeW

Retrieves the name of a volume on a computer. FindFirstVolume is used to begin scanning the volumes of a computer. See line 85 for sample usage

	#include <windows.h>
	#include <stdio.h>
	void DisplayVolumePaths(
	__in PWCHAR VolumeName
	)
	{
	DWORD CharCount = MAX_PATH + 1;
	PWCHAR Names = NULL;
	PWCHAR NameIdx = NULL;
	BOOL Success = FALSE;
	for (;;)
	{
	//
	// Allocate a buffer to hold the paths.
	Names = (PWCHAR) new BYTE[CharCount * sizeof(WCHAR)];
	if (!Names)
	{
	//
	// If memory can't be allocated, return.
	return;
	}
	//
	// Obtain all of the paths
	// for this volume.
	Success = GetVolumePathNamesForVolumeNameW(
	VolumeName, Names, CharCount, &CharCount
	);
	if (Success)
	{
	break;
	}
	if (GetLastError() != ERROR_MORE_DATA)
	{
	break;
	}
	//
	// Try again with the
	// new suggested size.
	delete[] Names;
	Names = NULL;
	}
	if (Success)
	{
	//
	// Display the various paths.
	for (NameIdx = Names;
	NameIdx[0] != L'\0';
	NameIdx += wcslen(NameIdx) + 1)
	{
	wprintf(L" %s", NameIdx);
	}
	wprintf(L"\n");
	}
	if (Names != NULL)
	{
	delete[] Names;
	Names = NULL;
	}
	return;
	}
	void __cdecl wmain(void)
	{
	DWORD CharCount = 0;
	WCHAR DeviceName[MAX_PATH] = L"";
	DWORD Error = ERROR_SUCCESS;
	HANDLE FindHandle = INVALID_HANDLE_VALUE;
	BOOL Found = FALSE;
	size_t Index = 0;
	BOOL Success = FALSE;
	WCHAR VolumeName[MAX_PATH] = L"";
	//
	// Enumerate all volumes in the system.
	FindHandle = FindFirstVolumeW(VolumeName, ARRAYSIZE(VolumeName));
	if (FindHandle == INVALID_HANDLE_VALUE)
	{
	Error = GetLastError();
	wprintf(L"FindFirstVolumeW failed with error code %d\n", Error);
	return;
	}
	for (;;)
	{
	//
	// Skip the \\?\ prefix and remove the trailing backslash.
	Index = wcslen(VolumeName) - 1;
	if (VolumeName[0] != L'\\' ||
	VolumeName[1] != L'\\' ||
	VolumeName[2] != L'?' ||
	VolumeName[3] != L'\\' ||
	VolumeName[Index] != L'\\')
	{
	Error = ERROR_BAD_PATHNAME;
	wprintf(L"FindFirstVolumeW/FindNextVolumeW returned a bad path: %s\n", VolumeName);
	break;
	}
	//
	// QueryDosDeviceW does not allow a trailing backslash,
	// so temporarily remove it.
	VolumeName[Index] = L'\0';
	CharCount = QueryDosDeviceW(&VolumeName[4], DeviceName, ARRAYSIZE(DeviceName));
	VolumeName[Index] = L'\\';
	if (CharCount == 0)
	{
	Error = GetLastError();
	wprintf(L"QueryDosDeviceW failed with error code %d\n", Error);
	break;
	}
	wprintf(L"\nFound a device:\n %s", DeviceName);
	wprintf(L"\nVolume name: %s", VolumeName);
	wprintf(L"\nPaths:");
	DisplayVolumePaths(VolumeName);
	//
	// Move on to the next volume.
	Success = FindNextVolumeW(FindHandle, VolumeName, ARRAYSIZE(VolumeName));
	if (!Success)
	{
	Error = GetLastError();
	if (Error != ERROR_NO_MORE_FILES)
	{
	wprintf(L"FindNextVolumeW failed with error code %d\n", Error);
	break;
	}
	//
	// Finished iterating
	// through all the volumes.
	Error = ERROR_SUCCESS;
	break;
	}
	}
	FindVolumeClose(FindHandle);
	FindHandle = INVALID_HANDLE_VALUE;
	return;
	}

view raw FindFirstVolumeW.cpp hosted with ❤ by GitHub

Notes:
- Tested using Visual Studio 2022 (17.2.6) C++ Windows Console template
Reference(s):
https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-findfirstvolumew