Programming Tips

GET FREE DISK SPACE

VB.Net

• Dim di As New DriveInfo("C")
  Dim tf As Long = di.TotalFreeSpace

VB6

• Private Declare Function GetDiskFreeSpace Lib "kernel32" Alias "GetDiskFreeSpaceA" (ByVal lpRootPathName As String, lpSectorsPerCluster As Long, lpBytesPerSector As Long, lpNumberOfFreeClusters As Long, lpTtoalNumberOfClusters As Long) As Long
  Private Sub Form_Load()
      Dim Sectors As Long
      Dim Bytes As Long
      Dim FreeC As Long
      Dim TotalC As Long
      Dim Freeb As Variant
      GetDiskFreeSpace "C:\", Sectors, Bytes, FreeC, TotalC
      Freeb = CDec(FreeC) * CDec(Sectors) * CDec(Bytes)
  End Sub
  
  

QuickBasic

• '$INCLUDE: 'qb.bi'
  DIM regs AS RegType
  
  regs.ax = &H3600
  regs.dx = &H0
  CALL interrupt(&H21, regs, regs)
  CLS
  PRINT "Sectors per cluster    : "; regs.ax
  PRINT "Number of free clusters: "; regs.bx
  PRINT "Bytes per sector       : "; regs.cx
  PRINT "Total clusters on drive: "; regs.dx
  PRINT "Free space             : "; CLNG(regs.ax) * CLNG(regs.bx) * CLNG(regs.cx)
  PRINT "Total space            : "; CLNG(regs.ax) * CLNG(regs.cx) * CLNG(regs.dx)
  END
  

Interrupt

• INT 21 - DOS 2+ - GET FREE DISK SPACE
  	AH = 36h
  	DL = drive number (00h = default, 01h = A:, etc)
  Return: AX = FFFFh if invalid drive
  	else
  	    AX = sectors per cluster
  	    BX = number of free clusters
  	    CX = bytes per sector
  	    DX = total clusters on drive
  Notes:	free space on drive in bytes is AX * BX * CX
  	total space on drive in bytes is AX * CX * DX
  	"lost clusters" are considered to be in use
  	according to Dave Williams' MS-DOS reference, the value in DX is
  	  incorrect for non-default drives after ASSIGN is run
  	this function does not return proper results on CD-ROMs;
  	  use AX=4402h"CD-ROM" instead
  	(FAT32 drive) the reported total and free space are limited to 2G-32K
  	  should they exceed that value