Accessing - files in use -

[blueznl]

tada... all streams and all data

what took me so much trouble is the value returned by backupread_() that doesn't return a zero when it is supposed to...

all that's left is figure out the relation between id and stream name, i don't see a 'deafult' stream named $data so i suppose stream id plays a role in there...

if you want to make multiple streams, try notepad from the prompt using: notepad test.txt:hidden_stream and have fun

Code: Select all

filename.s = "c:\test.txt" 
file_h = CreateFile_(@filename, #GENERIC_READ, 0, 0, #OPEN_EXISTING, #FILE_FLAG_BACKUP_SEMANTICS, 0) 
;
*buffer = AllocateMemory(4096) 
*stream.WIN32_STREAM_ID = *buffer
;
context.l = 0
bytes_read.l = 0
;
Repeat
  ;
  z = BackupRead_(file_h, *buffer, 20, @bytes_read, 0, 1, @context)
  ;
  ; dunno why, but sometimes backupread() returns a 1 when it should be zero, next if / endif fixes it
  ;
  If bytes_read = 0
    z = 0
  EndIf
  ;
  If z > 0
    ;
    n+1
    Debug ""
    Debug "stream "+Str(n)
    Debug "stream id "+Str( *stream\dwStreamID )
    Debug "stream attributes %"+Bin( *stream\dwStreamAttributes )
    ;
    size.l = *stream\dwStreamSizeLow + *stream\dwStreamSizeHigh *256*256*256*256
    namesize.l = *stream\dwStreamNameSize
    ;
    Debug "stream size "+Str(size)
    Debug "name size "+Str(namesize)
    ;
    If namesize > 0
      BackupRead_(file_h, *buffer, namesize, @bytes_read, 0, 1, @context)
      Debug "name... "+Str(bytes_read)
    EndIf
    If size > 0
      BackupRead_(file_h, *buffer, size, @bytes_read, 0, 1, @context)
      Debug "data..."+Str(bytes_read)
    EndIf
  EndIf
Until z = 0
;
BackupRead_(file_h, *buffer,0,@bytes_read,1,0,@context)
CloseHandle_(file_h)

[fweil]

I will look forward ... was testing your last post which gets well data, but trying to add BackupWrite_() with no success ATM.

I will rework it later today.

Thanx anyway to share efforts like this.

[blueznl]

ok, got it mostly done, one thing i'm not totally clear on is the unicode stream name, there are some question marks and i haven't got a clue if i made the mistake or if they should be there (behind the stream name if multiple streams exist in a file)...

to test this:

0. only when using ntfs (!)
1. use notepad from the command prompt, notepad.exe c:\test.txt
2. edit some text save exit
3. create a new stream using notepad.exe c:\test.txt:hidden.txt
4. edit some text save exit
5. run the following code:

Code: Select all

filename.s = "c:\test.txt" 
file_h = CreateFile_(@filename, #GENERIC_READ, 0, 0, #OPEN_EXISTING, #FILE_FLAG_BACKUP_SEMANTICS, 0) 
;
*buffer = AllocateMemory(4096) 
*stream.WIN32_STREAM_ID = *buffer
;
context.l = 0
bytes_read.l = 0
;
Repeat
  ;
  z = BackupRead_(file_h, *buffer, 20, @bytes_read, 0, 1, @context)
  ;
  ; dunno why, but sometimes backupread() returns a 1 when it should be zero
  ;
  If bytes_read = 0
    z = 0
  EndIf
  ;
  If z > 0
    ;
    n+1
    Debug ""
    Debug "stream "+Str(n)
    id = *stream\dwStreamID
    Debug "stream id "+Str( id )
    Select id
      Case #BACKUP_DATA
        Debug "data"
      Case #BACKUP_EA_DATA
        Debug "extended attribute"
      Case #BACKUP_SECURITY_DATA
        Debug "security data"
      Case #BACKUP_ALTERNATE_DATA
        Debug "alternate data"
      Case #BACKUP_LINK
        Debug "hard link information"
      Default
        Debug "unknown id type"
    EndSelect
    ;
    Debug "stream attributes %"+Bin( *stream\dwStreamAttributes )
    ;
    size.l = *stream\dwStreamSizeLow + *stream\dwStreamSizeHigh *256*256*256*256
    namesize.l = *stream\dwStreamNameSize
    ;
    Debug "stream size "+Str(size)
    Debug "name size "+Str(namesize)
    ;
    If namesize > 0
      BackupRead_(file_h, *buffer, namesize, @bytes_read, 0, 1, @context)
      l = WideCharToMultiByte_(#CP_OEMCP,0,*buffer,-1,0,0,0,0) 
      name.s = Space(l) 
      l = WideCharToMultiByte_(#CP_OEMCP,0,*buffer,-1,@name,l,0,0) 
      Debug "name... "+Str(bytes_read)+" "+name
    EndIf
    If size > 0
      BackupRead_(file_h, *buffer, size, @bytes_read, 0, 1, @context)
      Debug "data..."+Str(bytes_read)
    EndIf
  EndIf
Until z = 0
;
BackupRead_(file_h, *buffer,0,@bytes_read,1,0,@context)
CloseHandle_(file_h)

this will allow you to...

1. open and read any file, including those locked
2. look at all streams within a file

i haven't tested this yet on a file with changing contents, it is supposed to work, but i haven't got a clue if it really does

[fweil]

Blueznl, you are a star today

[fweil]

.... same quote marks on my side but it is going to be more talkative.

I will focus again tonight or tomorrow.

[blueznl]

although you can read from open files there are some issues, if the filesize is increasing, reading files this way is somewhat dangerous and can return incorrect results, to my surprise i must add...

you might have to resort to 'shadow copy' but i dunno how that works

[Max.]

this will allow you to...

1. open and read any file, including those locked
2. look at all streams within a file

i haven't tested this yet on a file with changing contents, it is supposed to work, but i haven't got a clue if it really does

Bluez, you puzzle me.

How does your code solve the basic problem that CreateFile doesn't return a handle and therefor also doesn't perform any operation on the file?

[blueznl]

files that are locked (or that are opened without the share flag set) cannot be opened in any regular way, not even for reading, unless you use this approach, that's all

[blueznl]

fweil, see tips and tricks section, think i've solved it

[fweil]

I switch there now !

[blueznl]

It went here...

http://www.purebasic.fr/english/viewtop ... highlight=

[blueznl]

... and doesn't work a 100%... Fweil, if you're still around (perhaps not, last mail in the forum was 2006 I think), did you ever get it fixed?

It looks like I need to give my process certain privileges... Anyone who knows how to do that