title	_getdrives | Microsoft Docs
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_getdrives

Returns a bitmask that represents the currently available disk drives.

Important

This API cannot be used in applications that execute in the Windows Runtime. For more information, see CRT functions not supported with /ZW.

Syntax

unsigned long _getdrives( void );  

Return Value

If the function succeeds, the return value is a bitmask that represents the currently available disk drives. Bit position 0 (the least-significant bit) is drive A, bit position 1 is drive B, bit position 2 is drive C, and so on. If the function fails, the return value is zero. To get extended error information, call GetLastError.

Requirements

Routine	Required header
_getdrives	<direct.h>

For more compatibility information, see Compatibility.

Example

// crt_getdrives.c  
// This program retrives and lists out  
// all the logical drives that are   
// currently mounted on the machine.  
  
#include <windows.h>  
#include <direct.h>  
#include <stdio.h>  
#include <tchar.h>  
  
TCHAR g_szDrvMsg[] = _T("A:\n");  
  
int main(int argc, char* argv[]) {  
   ULONG uDriveMask = _getdrives();  
  
   if (uDriveMask == 0)  
   {  
      printf( "_getdrives() failed with failure code: %d\n",  
              GetLastError());  
   }  
   else  
   {  
      printf("The following logical drives are being used:\n");  
  
      while (uDriveMask) {  
         if (uDriveMask & 1)  
            printf(g_szDrvMsg);  
  
         ++g_szDrvMsg[0];  
         uDriveMask >>= 1;  
      }  
   }  
}  

The following logical drives are being used:  
A:  
C:  
D:  
E:  

See Also

Directory Control