ASPCode.net

<%
Const File_OpenForReading = 1 
Const File_OpenForWriting = 2
Const  File_OpenForAppending = 8

Function File_OpenExisting( strPath, nAccess )
	' strPath = the path to file
	' nAccess should be one of the constants above
	On Error Resume Next
	
	Dim objFileObj
	Dim objFile
	
	Set objFileObj = Server.CreateObject("Scripting.FileSystemObject")
	Set objFile = objFileObj.OpenTextFile( strPath, nAccess, False, False )
	If Err = 0 Then
		Set File_OpenExisting = objFile
	Else
		Set File_OpenExisting = Nothing
	End If
End Function
%>

The function returns a File object if successful otherwise Nothing.

Use it like this:

<%
Dim oFile
Set oFile = File_OpenExisting( "c:\test.log", File_OpenForReading )
If oFile Is Nothing Then
	Response.Write "Not existing"
Else
	Response.Write "Existing"
	'Here we can start reading from it
End If
%>

If you don't know the exact path to the file ( like c:\www\hello.txt ) - you might just know the file is located under the /files/ subdirectory at your webhost then you need to convert the path using Server.MapPath. Check out our String functions section for examples.