ASP Upload
Hi,
I use a ASP Upload script the same as http://www.freeaspupload.net/ . Works great, but....
Does any one know the code to stop a file being uploaded if same file name is already on the server? and then redirects them to an error page?
Regards
Abhishek Reddy posted this at 18:47 — 30th May 2005.
He has: 3,348 posts
Joined: Jul 2001
Use FileSystemObject.FileExists to check if the file exists. If it does exist, have it trigger your redirection (Response.Redirect or however it is your server or scripts does it). Else, proceed with the upload.
FileExists: http://www.w3schools.com/asp/showfile.asp?filename=demo_fileexists
More on FSO: http://www.w3schools.com/asp/asp_ref_filesystem.asp
dhotchin posted this at 19:29 — 30th May 2005.
He has: 183 posts
Joined: Nov 2003
I'm still having no luck. The script used above, acts if i already know the file, which i dont. I may be wrong.
I have two pages. the upload page with a text field and browse to computer form. Which has a file attached (code is below). Then when the file is uploaded browser open a new page which input the file name in to a text box and other details the user imputs then adds the data to a access database.
But i need something when the file is trying to be uploaded it then comes up with an error.
Upload script
<%
Class FreeASPUpload
Public UploadedFiles
Public FormElements
Private VarArrayBinRequest
Private StreamRequest
Private uploadedYet
Private Sub Class_Initialize()
Set UploadedFiles = Server.CreateObject("Scripting.Dictionary")
Set FormElements = Server.CreateObject("Scripting.Dictionary")
Set StreamRequest = Server.CreateObject("ADODB.Stream")
StreamRequest.Type = 1 'adTypeBinary
StreamRequest.Open
uploadedYet = false
End Sub
Private Sub Class_Terminate()
If IsObject(UploadedFiles) Then
UploadedFiles.RemoveAll()
Set UploadedFiles = Nothing
End If
If IsObject(FormElements) Then
FormElements.RemoveAll()
Set FormElements = Nothing
End If
StreamRequest.Close
Set StreamRequest = Nothing
End Sub
Public Property Get Form(sIndex)
Form = ""
If FormElements.Exists(LCase(sIndex)) Then Form = FormElements.Item(LCase(sIndex))
End Property
Public Property Get Files()
Files = UploadedFiles.Items
End Property
'Calls Upload to extract the data from the binary request and then saves the uploaded files
Public Sub Save(path)
Dim streamFile, fileItem
if Right(path, 1) <> "\" then path = path & "\"
if not uploadedYet then Upload
For Each fileItem In UploadedFiles.Items
Set streamFile = Server.CreateObject("ADODB.Stream")
streamFile.Type = 1
streamFile.Open
StreamRequest.Position=fileItem.Start
StreamRequest.CopyTo streamFile, fileItem.Length
streamFile.SaveToFile path & fileItem.FileName, 2
streamFile.close
Set streamFile = Nothing
fileItem.Path = path & fileItem.FileName
Next
End Sub
Public Function SaveBinRequest(path) ' For debugging purposes
StreamRequest.SaveToFile path & "\debugStream.bin", 2
End Function
Public Sub DumpData() 'only works if files are plain text
Dim i, aKeys, f
response.write "Form Items:<br>"
aKeys = FormElements.Keys
For i = 0 To FormElements.Count -1 ' Iterate the array
response.write aKeys(i) & " = " & FormElements.Item(aKeys(i)) & "<BR>"
Next
response.write "Uploaded Files:<br>"
For Each f In UploadedFiles.Items
response.write "Name: " & f.FileName & "<br>"
response.write "Type: " & f.ContentType & "<br>"
response.write "Start: " & f.Start & "<br>"
response.write "Size: " & f.Length & "<br>"
Next
End Sub
Private Sub Upload()
Dim nCurPos, nDataBoundPos, nLastSepPos
Dim nPosFile, nPosBound
Dim sFieldName, osPathSep, auxStr
'RFC1867 Tokens
Dim vDataSep
Dim tNewLine, tDoubleQuotes, tTerm, tFilename, tName, tContentDisp, tContentType
tNewLine = Byte2String(Chr(13))
tDoubleQuotes = Byte2String(Chr(34))
tTerm = Byte2String("--")
tFilename = Byte2String("filename=""")
tName = Byte2String("name=""")
tContentDisp = Byte2String("Content-Disposition")
tContentType = Byte2String("Content-Type:")
uploadedYet = true
on error resume next
VarArrayBinRequest = Request.BinaryRead(Request.TotalBytes)
if Err.Number <> 0 then
response.write "<br><br><B>System reported this error:</B><p>"
response.write Err.Description & "<p>"
response.write "The most likely cause for this error is the incorrect setup of AspMaxRequestEntityAllowed in IIS MetaBase. <p>"
Exit Sub
end if
on error goto 0 'reset error handling
nCurPos = FindToken(tNewLine,1) 'Note: nCurPos is 1-based (and so is InstrB, MidB, etc)
If nCurPos <= 1 Then Exit Sub
'vDataSep is a separator like -----------------------------21763138716045
vDataSep = MidB(VarArrayBinRequest, 1, nCurPos-1)
'Start of current separator
nDataBoundPos = 1
'Beginning of last line
nLastSepPos = FindToken(vDataSep & tTerm, 1)
Do Until nDataBoundPos = nLastSepPos
nCurPos = SkipToken(tContentDisp, nDataBoundPos)
nCurPos = SkipToken(tName, nCurPos)
sFieldName = ExtractField(tDoubleQuotes, nCurPos)
nPosFile = FindToken(tFilename, nCurPos)
nPosBound = FindToken(vDataSep, nCurPos)
If nPosFile <> 0 And nPosFile < nPosBound Then
Dim oUploadFile
Set oUploadFile = New UploadedFile
nCurPos = SkipToken(tFilename, nCurPos)
auxStr = ExtractField(tDoubleQuotes, nCurPos)
' We are interested only in the name of the file, not the whole path
' Path separator is \ in windows, / in UNIX
' While IE seems to put the whole pathname in the stream, Mozilla seem to
' only put the actual file name, so UNIX paths may be rare. But not impossible.
osPathSep = "\"
if InStr(auxStr, osPathSep) = 0 then osPathSep = "/"
oUploadFile.FileName = Right(auxStr, Len(auxStr)-InStrRev(auxStr, osPathSep))
if (Len(oUploadFile.FileName) > 0) then 'File field not left empty
nCurPos = SkipToken(tContentType, nCurPos)
auxStr = ExtractField(tNewLine, nCurPos)
' NN on UNIX puts things like this in the streaa:
' ?? python py type=?? python application/x-python
oUploadFile.ContentType = Right(auxStr, Len(auxStr)-InStrRev(auxStr, " "))
nCurPos = FindToken(tNewLine, nCurPos) + 4 'skip empty line
oUploadFile.Start = nCurPos-1
oUploadFile.Length = FindToken(vDataSep, nCurPos) - 2 - nCurPos
If oUploadFile.Length > 0 Then UploadedFiles.Add LCase(sFieldName), oUploadFile
End If
Else
Dim nEndOfData
nCurPos = FindToken(tNewLine, nCurPos) + 4 'skip empty line
nEndOfData = FindToken(vDataSep, nCurPos) - 2
If Not FormElements.Exists(LCase(sFieldName)) Then FormElements.Add LCase(sFieldName), String2Byte(MidB(VarArrayBinRequest, nCurPos, nEndOfData-nCurPos))
End If
'Advance to next separator
nDataBoundPos = FindToken(vDataSep, nCurPos)
Loop
StreamRequest.Write(VarArrayBinRequest)
End Sub
Private Function SkipToken(sToken, nStart)
SkipToken = InstrB(nStart, VarArrayBinRequest, sToken)
If SkipToken = 0 then
Response.write "Error in parsing uploaded binary request."
Response.End
end if
SkipToken = SkipToken + LenB(sToken)
End Function
Private Function FindToken(sToken, nStart)
FindToken = InstrB(nStart, VarArrayBinRequest, sToken)
End Function
Private Function ExtractField(sToken, nStart)
Dim nEnd
nEnd = InstrB(nStart, VarArrayBinRequest, sToken)
If nEnd = 0 then
Response.write "Error in parsing uploaded binary request."
Response.End
end if
ExtractField = String2Byte(MidB(VarArrayBinRequest, nStart, nEnd-nStart))
End Function
'String to byte string conversion
Private Function Byte2String(sString)
Dim i
For i = 1 to Len(sString)
Byte2String = Byte2String & ChrB(AscB(Mid(sString,i,1)))
Next
End Function
'Byte string to string conversion
Private Function String2Byte(bsString)
Dim i
String2Byte =""
For i = 1 to LenB(bsString)
String2Byte = String2Byte & Chr(AscB(MidB(bsString,i,1)))
Next
End Function
End Class
Class UploadedFile
Public ContentType
Public Start
Public Length
Public Path
Private nameOfFile
' Need to remove characters that are valid in UNIX, but not in Windows
Public Property Let FileName(fN)
nameOfFile = fN
nameOfFile = SubstNoReg(nameOfFile, "\", "_")
nameOfFile = SubstNoReg(nameOfFile, "/", "_")
nameOfFile = SubstNoReg(nameOfFile, ":", "_")
nameOfFile = SubstNoReg(nameOfFile, "*", "_")
nameOfFile = SubstNoReg(nameOfFile, "?", "_")
nameOfFile = SubstNoReg(nameOfFile, """", "_")
nameOfFile = SubstNoReg(nameOfFile, "<", "_")
nameOfFile = SubstNoReg(nameOfFile, ">", "_")
nameOfFile = SubstNoReg(nameOfFile, "|", "_")
End Property
Public Property Get FileName()
FileName = nameOfFile
End Property
'Public Property Get FileN()ame
End Class
' Does not depend on RegEx, which is not available on older VBScript
' Is not recursive, which means it will not run out of stack space
Function SubstNoReg(initialStr, oldStr, newStr)
Dim currentPos, oldStrPos, skip
If IsNull(initialStr) Or Len(initialStr) = 0 Then
SubstNoReg = ""
ElseIf IsNull(oldStr) Or Len(oldStr) = 0 Then
SubstNoReg = initialStr
Else
If IsNull(newStr) Then newStr = ""
currentPos = 1
oldStrPos = 0
SubstNoReg = ""
skip = Len(oldStr)
Do While currentPos <= Len(initialStr)
oldStrPos = InStr(currentPos, initialStr, oldStr)
If oldStrPos = 0 Then
SubstNoReg = SubstNoReg & Mid(initialStr, currentPos, Len(initialStr) - currentPos + 1)
currentPos = Len(initialStr) + 1
Else
SubstNoReg = SubstNoReg & Mid(initialStr, currentPos, oldStrPos - currentPos) & newStr
currentPos = oldStrPos + skip
End If
Loop
End If
End Function
%>
Abhishek Reddy posted this at 08:18 — 31st May 2005.
He has: 3,348 posts
Joined: Jul 2001
Probably in here:
For Each fileItem In UploadedFiles.Items'you'll want to test if fs.FileExists(Server.MapPath(fileItem.FileName))=true. If it does exist, redirect to an error page. If it doesn't exist, proceed with the copy & save.
Or, rather than redirecting immediately, store a list a of conflicts somewhere, and use that in a report in the second page.
Any good?
dhotchin posted this at 22:03 — 31st May 2005.
He has: 183 posts
Joined: Nov 2003
bja888 (not verified) posted this at 18:06 — 31st May 2005.
They have: 5,633 posts
Joined: Jan 1970
I hate VB
Abhishek Reddy posted this at 12:34 — 1st June 2005.
He has: 3,348 posts
Joined: Jul 2001
Well, I'm sticking to a semi-conceptual description of what to do as I'm not confident guaranteeing my rusty VB/ASP will work.
What I'm suggesting is at the point where you know the name of the file trying to be uploaded and before it is copied to the final location, you simply check to see if a file of the same name already exists. This point is, if I'm right, within the loop that iterates over the files being sent that are to be copied.
This is done by using an if conditional and the FileExists method of a FileSystemObject. Server.MapPath is used to provide the proper physical path of the file to FileExists (adjust as necessary). Note that you might need to create a new FileSystemObject to do this, which, for illustrative purposes, I've called fs.
So if a pre-existing file is not found, then you can proceed with the copying as is presently the case. However if a conficting file does exist, you can handle the error in any number of ways. You could right then redirect the user to an error page (but this would halt uploads of subsequent files in fileItems). Or you could store the names of the conflicting items in another location/variable/file/database (whatever you please), and use that to report errors in the final page. Selecting the best strategy for this depends really on how the rest of your program operates, how errors are generally handled if there's already an error handling mechanism, and so on.
Hope that makes sense. If it's no help, tell me, and I'll see if I can write up some code.
dhotchin posted this at 13:05 — 1st June 2005.
He has: 183 posts
Joined: Nov 2003
erm.... well i best start of by saying thank you for that. But its way over may head.
The system i trying to get working to a Intractive Intranet. staff can upload documents and so others can search for them. But.... what i dont want them to do is upload the same file and replace them.
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