ACC2: Sample Function to Retrieve File's Date and Time Stamp (124392)

SUMMARY

Advanced: Requires expert coding, interoperability, and multiuser skills.

This article demonstrates a sample user-defined Access Basic function called GetFileDateTime() that you can use to retrieve a file's date and time stamp.

This article assumes that you are familiar with Access Basic and with creating Microsoft Access applications using the programming tools provided with Microsoft Access. For more information about Access Basic, please refer to the "Building Applications" manual.

MORE INFORMATION

The following example demonstrates how to create and use the GetFileDateTime() function.

NOTE: In the following sample code, an underscore (_) at the end of a line is used as a line-continuation character. Remove the underscore from the end of the line when re-creating this code in Access Basic.

Create a new module and enter the following lines in the Declarations section:

      Option Explicit

      Type OFSTRUCT
         cBytes As String * 1
         fFixedDisk As String * 1
         nErrCode As Integer
         szReserved As String * 4
         szPath As String * 128
      End Type

      Global Const OF_EXIST = &amp;H4000

      Declare Function WinOpenFile Lib "KERNEL.EXE" Alias _
      "OpenFile" (ByVal szFileName As String, _
      OpenBuff As OFSTRUCT, ByVal Flag As Integer) As Integer

Enter the following code in the module:

      Function GetFileDateTime (ByVal FileName As String) As Variant
         Dim ofs As OFSTRUCT
         Dim iDate As Long
         Dim iTime As Long

         Const DAY_MASK = &H1F
         Const MONTH_MASK = &H1E0
         Const YEAR_MASK = &HFE00

         Const SECOND_MASK = &H1F
         Const MINUTE_MASK = &H7E0
         Const HOUR_MASK = &HF800

         If WinOpenFile(FileName, ofs, OF_EXIST) <> -1 Then
            iDate = Asc(Mid$(ofs.szReserved, 2, 1)) * 256& _
            + Asc(Mid$(ofs.szReserved, 1, 1))
            iTime = Asc(Mid$(ofs.szReserved, 4, 1)) * 256& _
            + Asc(Mid$(ofs.szReserved, 3, 1))
            GetFileDateTime = DateSerial(((iDate And YEAR_MASK) \ _
            &H200) + 1980, (iDate And MONTH_MASK) \ &H20, (iDate And _
            DAY_MASK)) + TimeSerial((iTime And HOUR_MASK) \ &H800, _
            (iTime And MINUTE_MASK) \ &H20, (iTime And SECOND_MASK) * 2)
         Else
            GetFileDateTime = Null
         End If
      End Function

From the View menu, choose Immediate Window.
Type the following line in the Immediate window, and then press ENTER:

?GetFileDateTime("c:\autoexec.bat")

The date and time stamp of the AUTOEXEC.BAT file is returned in the Immediate window.