how to rename image file name while uploading on web folder - vbscript

Question

i m using asp classic. i want to rename image file while i upload image on web folder created by me. please help me out of this issue.
If there is a file in targeted folder with same name (like lokesh.jpg) what i am uploading, than new file should b automatically renamed(like lokesh(1).jpg) instead of overwriting
my code is as below:
upload.asp
<%
Class FileUploader
Public Files
Private mcolFormElem
Private Sub Class_Initialize()
Set Files = Server.CreateObject("Scripting.Dictionary")
Set mcolFormElem = Server.CreateObject("Scripting.Dictionary")
End Sub
Private Sub Class_Terminate()
If IsObject(Files) Then
Files.RemoveAll()
Set Files = Nothing
End If
If IsObject(mcolFormElem) Then
mcolFormElem.RemoveAll()
Set mcolFormElem = Nothing
End If
End Sub
Public Property Get Form(sIndex)
Form = ""
If mcolFormElem.Exists(LCase(sIndex)) Then Form = mcolFormElem.Item(LCase(sIndex))
End Property
Public Default Sub Upload()
Dim biData, sInputName
Dim nPosBegin, nPosEnd, nPos, vDataBounds, nDataBoundPos
Dim nPosFile, nPosBound
biData = Request.BinaryRead(Request.TotalBytes)
nPosBegin = 1
nPosEnd = InstrB(nPosBegin, biData, CByteString(Chr(13)))
If (nPosEnd-nPosBegin) <= 0 Then Exit Sub
vDataBounds = MidB(biData, nPosBegin, nPosEnd-nPosBegin)
nDataBoundPos = InstrB(1, biData, vDataBounds)
Do Until nDataBoundPos = InstrB(biData, vDataBounds & CByteString("--"))
nPos = InstrB(nDataBoundPos, biData, CByteString("Content-Disposition"))
nPos = InstrB(nPos, biData, CByteString("name="))
nPosBegin = nPos + 6
nPosEnd = InstrB(nPosBegin, biData, CByteString(Chr(34)))
sInputName = CWideString(MidB(biData, nPosBegin, nPosEnd-nPosBegin))
nPosFile = InstrB(nDataBoundPos, biData, CByteString("filename="))
nPosBound = InstrB(nPosEnd, biData, vDataBounds)
If nPosFile <> 0 And nPosFile < nPosBound Then
Dim oUploadFile, sFileName
Set oUploadFile = New UploadedFile
nPosBegin = nPosFile + 10
nPosEnd = InstrB(nPosBegin, biData, CByteString(Chr(34)))
sFileName = CWideString(MidB(biData, nPosBegin, nPosEnd-nPosBegin))
oUploadFile.FileName = Right(sFileName, Len(sFileName)-InStrRev(sFileName, "\"))
Dim oFileExtension
If sFileName <> "" then
oFileExtension = (Right(sFileName, Len(sFileName)-InStrRev(sFileName, ".")))
If oFileExtension <> "jpg" AND oFileExtension <> "jpeg" AND oFileExtension <> "gif" AND oFileExtension <> "pdf" then
response.write("<h1>Post New File</h1><p><font color=#ff0000>An error has occurred while processing your request.<br><br>We are sorry, Extensions other than JPG, JPEG, Gif, PDF are not allowed to upload<p><b>Click <a href='javascript:history.go(-1);'>here</a> to go back and address the error.</b></font>")
response.end
Exit Sub
End if
end If
nPos = InstrB(nPosEnd, biData, CByteString("Content-Type:"))
nPosBegin = nPos + 14
nPosEnd = InstrB(nPosBegin, biData, CByteString(Chr(13)))
oUploadFile.ContentType = CWideString(MidB(biData, nPosBegin, nPosEnd-nPosBegin))
nPosBegin = nPosEnd+4
nPosEnd = InstrB(nPosBegin, biData, vDataBounds) - 2
oUploadFile.FileData = MidB(biData, nPosBegin, nPosEnd-nPosBegin)
If sfileName <> "" then
If oUploadFile.FileSize > 10000000 Then
response.write("<h1>Post New Image</h1><p><font color=#ff0000>An error has occurred while processing your request.<br><br>We are sorry, Upload file containing 10000000(10mb) bytes only.<p><b>Click <a href='javascript:window:history.go(-1);'>here</a> to go back and address the error.</b></font>")
response.end
Exit Sub
End if
End if
If oUploadFile.FileSize > 0 Then Files.Add LCase(sInputName), oUploadFile
Else
nPos = InstrB(nPos, biData, CByteString(Chr(13)))
nPosBegin = nPos + 4
nPosEnd = InstrB(nPosBegin, biData, vDataBounds) - 2
If Not mcolFormElem.Exists(LCase(sInputName)) Then mcolFormElem.Add LCase(sInputName), CWideString(MidB(biData, nPosBegin, nPosEnd-nPosBegin))
End If
nDataBoundPos = InstrB(nDataBoundPos + LenB(vDataBounds), biData, vDataBounds)
Loop
End Sub
'String to byte string conversion
Private Function CByteString(sString)
Dim nIndex
For nIndex = 1 to Len(sString)
CByteString = CByteString & ChrB(AscB(Mid(sString,nIndex,1)))
Next
End Function
'Byte string to string conversion
Private Function CWideString(bsString)
Dim nIndex
CWideString =""
For nIndex = 1 to LenB(bsString)
CWideString = CWideString & Chr(AscB(MidB(bsString,nIndex,1)))
Next
End Function
End Class
Class UploadedFile
Public ContentType
Public FileName
Public FileData
Public Property Get FileSize()
FileSize = LenB(FileData)
End Property
Public Sub SaveToDisk(sPath)
Dim oFS, oFile
Dim nIndex
If sPath = "" Or FileName = "" Then Exit Sub
If Mid(sPath, Len(sPath)) <> "\" Then sPath = sPath & "\"
Set oFS = Server.CreateObject("Scripting.FileSystemObject")
If Not oFS.FolderExists(sPath) Then Exit Sub
Set oFile = oFS.CreateTextFile(sPath & FileName, True)
For nIndex = 1 to LenB(FileData)
oFile.Write Chr(AscB(MidB(FileData,nIndex,1)))
Next
oFile.Close
End Sub
Public Sub SaveToDatabase(ByRef oField)
If LenB(FileData) = 0 Then Exit Sub
If IsObject(oField) Then
oField.AppendChunk FileData
End If
End Sub
End Class
%>
submit.asp
<!-- #include file="upload.asp" -->
<%
response.buffer = true
Dim Uploader, File, i, j
Set Uploader = New FileUploader
Uploader.Upload()
Dim brandnm, filename
brandnm = Uploader.form("brandname")
Dim objRSa, objCmda, stra
Set objCmda = server.CreateObject("adodb.connection")
Set Objrsa = Server.CreateObject("ADODB.Recordset")
objCmda.open MM_connDUdirectory_STRING
stra = "SELECT * FROM brand"
Objrsa.Open stra,objCmda,1,2
if Uploader.Files.count <> 0 then
File = Uploader.Files.Items()
File(0).SavetoDisk Server.MapPath("upload/brands") 'Folder path where image will save
filename = File(0).Filename
else
filename = ""
End if
Objrsa.addnew
Objrsa.fields("brand_name") = brandnm
Objrsa.fields("brand_createddt") = now()
if filename <>"" then Objrsa.fields("brand_picpath") = filename
For Each File In Uploader.Files.Items
Objrsa("brand_ctype") = File.ContentType
next
Objrsa.Update
Objrsa.Close
Set Objrsa = Nothing
set objCmda = Nothing
%>
Please help me out of this issue.

Answer 1

If you want to rename it to follow a known pattern as in your example ("filename(number).ext"), you must to use a pseudo-code like this:
let counter = 1
let original = file(0).Filename
let current = file(0).Filename
while(current file exists)
current = original-without-extension + (counter) + original-extension
counter = counter + 1
end
However, I think that would be better to store the user provided filename into your database and choose a random-like filename to store the actual file into the filesystem.
let current = userLogin + (currentTime as yyyyMMddHHmmss) + ".uploaded"
By using a bogus file extension you make your application way more secure, as your file will not be interpretable/executable -- imagine a malicious user uploading an .ASP file and executing it.
If this break the image MIME type, you should consider creating another .ASP page read the database to discover the appropriate MIME type based on the user provided file extension, write that content-type and the binary file content.
TL;DR: don't use the user provided file name, create a new one. This will avoid server hacking.