Distinguish between "file doesn't exist" and "access denied" - vbscript

Question

In a VBScript, I want to know if a file exists:
Set fso = CreateObject("Scripting.FileSystemObject")
If Not (fso.FileExists(file)) Then
msg = " doesn't exist."
End If
My files are on internal network.
Is there a way to distinguish:
file really doesn't exist
access denied
I try with fso.OpenTextFile but the result for these two cases is always: Err.Number = 5.

Answer 1

To distinguish between non-existing and non-accessible files you need .FileExists and .OpenTextFile:
Option Explicit
Dim goFS : Set goFS = CreateObject("Scripting.FileSystemObject")
Function ReadFile(p, ByRef m)
If goFS.FileExists(p) Then
Dim aErr
On Error Resume Next
Set ReadFile = goFS.OpenTextFile(p)
aErr = Array(Err.Number, Err.Description)
On Error GoTo 0
If aErr(0) Then
m = p & " - " & aErr(1)
Set ReadFile = Nothing
Else
m = ""
End If
Else
Set ReadFile = Nothing
m = p & " - no such file"
End If
End Function
Dim p, m
For Each p In Split("e:\roots.own e:\nosuchfile e:\dirsbf.tmp")
Dim tsIn : Set tsIn = ReadFile(p, m)
If tsIn Is Nothing Then
WScript.Echo "fail", m
Else
' read from tsIn
tsIn.Close
WScript.Echo "ok"
End If
Next
Output:
cscript 35338634.vbs
fail e:\roots.own - Permission denied
fail e:\nosuchfile - no such file
ok
Thanks to Ansgar's observation, the function can be improved:
Function ReadFile(p, ByRef m)
Dim aErr
On Error Resume Next
Set ReadFile = goFS.OpenTextFile(p)
aErr = Array(Err.Number, Err.Description)
On Error GoTo 0
If aErr(0) Then
m = p & " - " & aErr(1)
Set ReadFile = Nothing
Else
m = ""
End If
End Function