Re: opening files with unicode characters in the file name on windows

[Mathias Dahl <brakjoller@hotmail.com>]

"Eli Zaretskii" <eliz@gnu.org> writes:

> Your original message said ``file names with Unicode characters''.
> Can you tell what characters are those, and why do you think they
> are encoded in some Unicode-related encoding, like UTF-16?  Can you
> look at the file's name as recorded in the directory with some
> low-level tool that actually shows the byte values that encode the
> file's name?

I have done some investigation and I am pretty sure UTF-16 is the
encoding used. The following VBScript program (sorry for pasting
non-emacs related stuff here) loops through all files in a folder and
if the file names contain character values > 255 displays a list with
unicode code point values:

' -- TestUnicoceFileNames.vbs ---

Option Explicit

' --------- Main program starts

Dim sFileName
Dim oFSO
Dim oFile

Set oFSO = CreateObject("Scripting.FileSystemObject")

For Each oFile In oFSO.GetFolder("c:\document\my docs").Files
  checkUnicodeFileName(oFile.Name)
Next

Set oFSO = Nothing

' --------- Main program ends

Private Sub checkUnicodeFileName(fileName)

  Dim i
  Dim c
  Dim n

  For i = 1 to Len(fileName)

    c = Mid(fileName, i, 1)
    n = AscW(c)

    If n > 255 Then
      MsgBox "File name contains unicode characters: " & _
             Chr(10) & Chr(10) & _
             "File name: " & fileName & _
             Chr(10) & Chr(10) & _
             "Characters and their unicode code points:" & _
             Chr(10) & Chr(10) & _
             getStringInfo(fileName)
      Exit Sub
    End If

  Next

End Sub

Private Function getStringInfo(s)
  Dim i
  Dim n
  Dim c
  Dim h
  Dim result

  result = "Char" & Chr(9) & "U+NNNN" & Chr(10) & Chr(10)

  For i = 1 to Len(s)
    c = Mid(s, i, 1)
    n = AscW(c)
    h = Hex(n)
    result = result & c & Chr(9) & Right("0000" & h, 4) & Chr(10)
  Next

  getStringInfo = result

End Function

' -- TestUnicoceFileNames.vbs end here---

The output looks like this (you do not see the actual characters which
I do if I use a "unicode font" for message boxes):

File name contains unicode characters: 

File name: pravda_правда.txt

Characters and their unicode code points:

Char	U+NNNN

p	0070
r	0072
a	0061
v	0076
d	0064
a	0061
_	005F
п	043F
р	0440
а	0430
в	0432
д	0434
а	0430
.	002E
t	0074
x	0078
t	0074

/Mathias