StreamWriter Adds FFFE at the start of the file with Unicode Encoding!!

  • Thread starter Thread starter Majed
  • Start date Start date
M

Majed

hi jay
the other app is Ntbackup which saves its backup files list in unicode
without FFFE at the start of the file. any idea how can I remove it from the
file.
TIA
 
jay,
i'm sorry about that,I was late up because of this problem. yuor reply was
great and did solve it.
tahnks and sorry again.:)
majed
 
Hi , all
I'm trying to write unicode to a file for another app (not developed with
vs2003) to read it. I used StreamWriter with unicode encoding.but I was
surprised that the streamwriter adds FFFE to the start of the file,which
stopes the other app from reading it!!
any idea how to stope it frome doing that,do I have to use another class
#####writer that supports unicode?

help me Please!
Thanks
majed
I did some code with diferent encoding and here is the result:
UTF7 48656C6C6F2B4143454149512D0D0A
Hello+ACEAIQ-..
DEFAULT 48656C6C6F21210D0A
Hello!!..
ASCII 48656C6C6F21210D0A
Hello!!..
BIGENDIANUNICODE FEFF00480065006C006C006F00210021000D000A
....H.e.l.l.o.!.!....
UNICODE FFFE480065006C006C006F00210021000D000A00
...H.e.l.l.o.!.!.....
UTF8 EFBBBF48656C6C6F21210D0A
....Hello!!..

and here is the code

Imports System

Imports System.Text

Imports System.IO

Class filestream

Public Shared Sub main()

Dim ASCIIStream As New StreamWriter("ASCIIStream.txt", False,
System.Text.Encoding.ASCII)

Dim BigEndianUnicodeStream As New StreamWriter("BigEndianUnicodeStream.txt",
False, System.Text.Encoding.BigEndianUnicode)

Dim UnicodeStream As New StreamWriter("UnicodeStream.txt", False,
System.Text.Encoding.Unicode)

Dim DefaultStream As New StreamWriter("DefaultStream.txt", False,
System.Text.Encoding.Default)

Dim UTF7Stream As New StreamWriter("UTF7Stream.txt", False,
System.Text.Encoding.UTF7)

Dim UTF8Stream As New StreamWriter("UTF8Stream.txt", False,
System.Text.Encoding.UTF8)

ASCIIStream.WriteLine("Hello!!")

ASCIIStream.Close()

ASCIIStream = Nothing

BigEndianUnicodeStream.WriteLine("Hello!!")

BigEndianUnicodeStream.Close()

BigEndianUnicodeStream = Nothing

UnicodeStream.WriteLine("Hello!!")

UnicodeStream.Close()

UnicodeStream = Nothing

DefaultStream.WriteLine("Hello!!")

DefaultStream.Close()

DefaultStream = Nothing

UTF7Stream.WriteLine("Hello!!")

UTF7Stream.Close()

UTF7Stream = Nothing

UTF8Stream.WriteLine("Hello!!")

UTF8Stream.Close()

UTF8Stream = Nothing

Console.WriteLine ("Done!)



End Sub

End Class
 
Majed,
Sounds like a bug in your other app!

FFFE is the byte order mark of Unicode, it signifies to Unicode that the
bytes are little endian. While FEFF signifies to Unicode that the bytes are
big endian!

Notice that in your samples, FEFF is Big Endian
BIGENDIANUNICODE FEFF00480065006C006C006F00210021000D000A
...H.e.l.l.o.!.!....
Click to expand...

, while FFFE is little endian:
UNICODE FFFE480065006C006C006F00210021000D000A00
..H.e.l.l.o.!.!.....
Click to expand...

You can prevent the byte order mark from being written by creating a new
UnicodeEncoding object that you pass as the Encoding parameter of the
STreamWriter constructor.

Something like(untested):

' little endian, no byte order marks
Dim encoding As New UnicodeEncoding(False, False)

Dim stream as FileStream
Dim writer As New StreamWriter(stream, encoding)

Of course you will need to be certain that you other app does not have an
issue with little endian verses big endian Unicode characters.

Hope this helps
Jay
 
Majed,
any idea how can I remove it from the
file.
Click to expand...
I take it you did not read my response! As I indicated in my response how
you remove it from the file!

Hope this helps
Jay
 
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