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Visual Basic Code > Create a name for a temporary file

Create a name for a temporary file

The following function creates a name for a temporary file which can be used to store temporary data.

Private Declare Function GetTempFileName Lib "kernel32" Alias "GetTempFileNameA" (ByVal lpszPath As String, ByVal lpPrefixString As String, ByVal wUnique As Long, ByVal lpTempFileName As String) As Long
Private Declare Function GetTempPath Lib "kernel32" Alias "GetTempPathA" (ByVal nBufferLength As Long, ByVal lpBuffer As String) As Long

'Purpose     :  The FileGetTempName function returns a name of a temporary file.
'Inputs      :  [sFilePrefix]               The prefix of the file name.
'Outputs     :  Returns the name of the next free temporary file name (and path).
'Notes       :  The filename is the concatenation of specified path and prefix strings,
'               a hexadecimal string formed from a specified integer, and the .TMP extension
'Revisions   :

Function FileGetTempName(Optional sFilePrefix As String = "TMP") As String
    Dim sTemp As String * 260, lngLen As Long
    Static ssTempPath As String
    
    If LenB(ssTempPath) = 0 Then
        'Get the temporary path
        lngLen = GetTempPath(260, sTemp)
        'strip the rest of the buffer
        ssTempPath = Left$(sTemp, lngLen)
        If Right$(ssTempPath, 1) <> "\" Then
            ssTempPath = ssTempPath & "\"
        End If
    End If
    
    'Get a temporary filename
    lngLen = GetTempFileName(ssTempPath, sFilePrefix, 0, sTemp)
    'Remove all the unnecessary chr$(0)'s
    FileGetTempName = Left$(sTemp, InStr(1, sTemp, Chr$(0)) - 1)
End Function