win32utils devel - Nov 2004 - File.nopen alpha

Hi all,

I''ve committed an alpha version of File.nopen (native open) to
win32-file.  This is a wrapper for CreateFile().  A quick synopsis:

 * File.nopen(file,access_mode,share_mode,creation_mode,flags)
 * 
 * A ''native'' open method.  This uses CreateFile() behind the
scenes
instead of
 * the _open() function.  This allows much greater flexibility when it
comes
 * to Windows files.  It also allows you to open directories, which
File.open
 * cannot do on Windows.
 * 
 * The access mode defaults to READ_DATA | WRITE_DATA
 * The share mode defaults to SHARE_READ | SHARE_WRITE
 * The creation mode defaults to OPEN_EXISTING
 * The flags default to NORMAL
 * 
 * To open a directory, pass File::BACKUP_SEMANTICS as the
''flags''
argument.

So, with this I can do:

dir = "C:\\TEST" # directory
fh = File.nopen(dir,nil,nil,nil,File::BACKUP_SEMANTICS)
p fh # Yup, it''s a File object
p fh.class # File
fh.close

I can also open a plain file and read the contents.  So far, so good.
But, when I try to write to the file, I get an IOError claiming the file
isn''t opened for writing.  Shouldn''t the WRITE_DATA flag have
given me
permission to write?  I tried combinations of some other flags with no
luck.

Also, I noticed that if I try to use some of the new instance methods
like this:

fh = File.nopen("C:\\temp.txt",File::WRITE_ATTRIBUTES)
fh.hidden = true
fh.close

I get "test.rb:16:in `hidden='': cannot convert nil into String
(TypeError)"

Any ideas on these?

Please take a look and also let me know what you think in general of an
nopen() method.

Regards,

Dan

Just a quick followup:
 
> I can also open a plain file and read the contents.  So far, 
> so good. But, when I try to write to the file, I get an 
> IOError claiming the file isn''t opened for writing.  
> Shouldn''t the WRITE_DATA flag have given me permission to 
> write?  I tried combinations of some other flags with no luck.
For a second I thought it was this line causing the problems:

fd = _open_osfhandle((long)h,O_RDONLY);

But, changing that to O_RDWR had no effect.

Dan

Hi,
> 
> Hi all,
> 
> I''ve committed an alpha version of File.nopen (native open) to
> win32-file.  This is a wrapper for CreateFile().  A quick synopsis:
> 
>  * File.nopen(file,access_mode,share_mode,creation_mode,flags)
>  * 
>  * A ''native'' open method.  This uses CreateFile() behind
the scenes
> instead of
>  * the _open() function.  This allows much greater flexibility when it
> comes
>  * to Windows files.  It also allows you to open directories, which
> File.open
>  * cannot do on Windows.
>  * 
>  * The access mode defaults to READ_DATA | WRITE_DATA
>  * The share mode defaults to SHARE_READ | SHARE_WRITE
>  * The creation mode defaults to OPEN_EXISTING
>  * The flags default to NORMAL
>  * 
>  * To open a directory, pass File::BACKUP_SEMANTICS as the
''flags''
> argument.
> 
> So, with this I can do:
> 
> dir = "C:\\TEST" # directory
> fh = File.nopen(dir,nil,nil,nil,File::BACKUP_SEMANTICS)
> p fh # Yup, it''s a File object
> p fh.class # File
> fh.close
> 
> I can also open a plain file and read the contents.  So far, so good.
> But, when I try to write to the file, I get an IOError claiming the file
> isn''t opened for writing.  Shouldn''t the WRITE_DATA flag
have given me
> permission to write?  I tried combinations of some other flags with no
> luck.
> 
> Also, I noticed that if I try to use some of the new instance methods
> like this:
> 
> fh = File.nopen("C:\\temp.txt",File::WRITE_ATTRIBUTES)
> fh.hidden = true
> fh.close
> 
> I get "test.rb:16:in `hidden='': cannot convert nil into
String
> (TypeError)"
> 
> Any ideas on these?
> 
> Please take a look and also let me know what you think in general of an
> nopen() method.
> 
WARNING: You are gone too far into the ruby core :-)

I think the Ruby developer should implement the win32 open function compatible
with unix.
We might take over nopen function to win32 expert ruby developer like NAKAMURA
Usaku  <usa@ruby-lang.org> or Nobuyoshi Nakada 
<nobu@ruby-lang.org>.

Regards,

Park Heesob



--MIME Multi-part separator--

> > 
> WARNING: You are gone too far into the ruby core :-)
> 
> I think the Ruby developer should implement the win32 open 
> function compatible with unix. We might take over nopen 
> function to win32 expert ruby developer like NAKAMURA Usaku  
> <usa@ruby-lang.org> or Nobuyoshi Nakada  <nobu@ruby-lang.org>.
> 
> Regards,
> 
> Park Heesob
How would you make a native win32 open function Unix compatible?  I
don''t follow.  Of course, I certainly wouldn''t mind if Nobu
were to join
Win32Utils. :)

In other news, I''ve eliminated the path issue by aliasing File#path,
and
then redefining it.  If the original File#path fails, it resorts to
GetFullPathName().  Seems to work just fine.

As for the write issue, it looks like it''s being caused by the
rb_io_check_writable() function in io.c.  I''ll dig deeper into this.

- Dan