Win32 Windows Volume Program and Code Example 9
Getting the Logical Drive String Program Example
Create a new Win32 console application project and give a suitable project name.
Add the source file and give a suitable name.
Add the following source code.
#include <windows.h>
#include <stdio.h>
#define BUFSIZE 512
int wmain(int argc, WCHAR *argv[])
{
// Translate path with device name to drive letters.
WCHAR szTemp[BUFSIZE];
// Hmmm...why the first index need to be NULL?
szTemp[0] = '\0';
// Allocate extra space for NULL lol! An initial value
// WCHAR szDrive[3] = L :;
WCHAR szDrive[5] = L :\\;
// Initially not found
BOOL bFound = FALSE;
// Point pointer p to the temporary buffer
WCHAR *p = szTemp;
// Fills szTemp buffer with strings that specify valid drives in the system.
if (GetLogicalDriveStrings(BUFSIZE-1, szTemp))
{
wprintf(LGetLogicalDriveStrings() should be fine!\n);
wprintf(LAvailable drives in this machine are:\n);
do
{
// Copy the drive letter to the template string
// Both pointers point to the same data, *p will be used to skip the NULL
*szDrive = *p;
// Print the found drives
wprintf(L%s\n, szDrive);
// This is WEIRD!!! Can you see the while was used twice!!!
while (*p++);// skip the next NULL character, starts reading new drive string
} while (!bFound && *p); // end of string
}
else
wprintf(LGetLogicalDriveStrings() failed, error %u\n, GetLastError());
return 0;
}
Build and run the project. The following screenshot is an output sample.
