Win32 filetype problem

Win32 filetype problem

[Martin Dowie]

System: WIntel NT, GNAT 3.13p

I don't seem to be able to determine if a filename (specified in
an Ada string) is a directory or not using the Win32 bindings in
GNAT.

I've been through the help file but there is nothing that answer
what is happening.

Here's a code snip of what I have:

declare
   function To_LPCSTR is
      new Ada.Unchecked_Conversion (Source => System.Address,
                                    Target => Win32.LPCSTR);
   C_Filename : Chars_Ptr := New_String (Trimmed_Filename);
   Result : Win32.DWORD;
begin
   Result := Win32.Winbase.GetFileAttributesA (lpFileName => To_LPCSTR (S =>
C_Filename'Address));
   Ada.Text_IO.Put_Line ("oops? " & Boolean'Image (Result =
6#FFFF_FFFF#));  -- always displays "oops? TRUE"
   return Result /= 16#FFFF_FFFF# and then
          (Result and Win32.WinNT.FILE_ATTRIBUTE_DIRECTORY) =
Win32.WinNT.FILE_ATTRIBUTE_DIRECTORY;
end;

--
Kernighan and Ritchie : "C was designed on the assumption
                         that the programmer is someone
                         sensible who knows what he's
                         doing"
Ada Reference Manual : "Ada was designed with the
                        concern of programming as a
                        human activity"

Re: Win32 filetype problem

[Martin Dowie]

Martin Dowie <martin.dowie@nospam.baesystems.com> wrote in message
news:3ba1d1b9$1@pull.gecm.com...
> System: WIntel NT, GNAT 3.13p
[snip]
> declare
>    function To_LPCSTR is
>       new Ada.Unchecked_Conversion (Source => System.Address,
                                                ^^^^^^^^^^^^^^

I'm an idiot, this should be Chars_Ptr...

>                                     Target => Win32.LPCSTR);
>    C_Filename : Chars_Ptr := New_String (Trimmed_Filename);
>    Result : Win32.DWORD;
> begin
>   Result := Win32.Winbase.GetFileAttributesA (lpFileName => To_LPCSTR (S
=>
>      C_Filename'Address));
                 ^^^^^^^^
...and then remove this!

RE: Win32 filetype problem

[Beard, Frank]

The return statement should probably be:

   return Result /= 16#FFFF_FFFF# and then
          (Result and Win32.WinNT.FILE_ATTRIBUTE_DIRECTORY) /= 0;

Get Pascal Obry's POSIX binding, which is a wrapper around the
Win32 APIs, off of AdaPower and look at POSIX_Files.Is_File and
POSIX_Files.Is_Directory.

Even if you don't use the POSIX binding directly, it's a good
source for seeing how to use the Window's API.

Frank

-----Original Message-----
From: Martin Dowie [mailto:martin.dowie@nospam.baesystems.com]
Sent: Friday, September 14, 2001 6:18 AM
To: comp.lang.ada@ada.eu.org
Subject: Re: Win32 filetype problem


Martin Dowie <martin.dowie@nospam.baesystems.com> wrote in message
news:3ba1d1b9$1@pull.gecm.com...
> System: WIntel NT, GNAT 3.13p
[snip]
> declare
>    function To_LPCSTR is
>       new Ada.Unchecked_Conversion (Source => System.Address,
                                                ^^^^^^^^^^^^^^

I'm an idiot, this should be Chars_Ptr...

>                                     Target => Win32.LPCSTR);
>    C_Filename : Chars_Ptr := New_String (Trimmed_Filename);
>    Result : Win32.DWORD;
> begin
>   Result := Win32.Winbase.GetFileAttributesA (lpFileName => To_LPCSTR (S
=>
>      C_Filename'Address));
                 ^^^^^^^^
...and then remove this!





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Re: Win32 filetype problem

[martin.m.dowie]

"Beard, Frank" <beardf@spawar.navy.mil> wrote in message
news:mailman.1000484414.2704.comp.lang.ada@ada.eu.org...
> The return statement should probably be:
>
>    return Result /= 16#FFFF_FFFF# and then
>           (Result and Win32.WinNT.FILE_ATTRIBUTE_DIRECTORY) /= 0;
>
> Get Pascal Obry's POSIX binding, which is a wrapper around the
> Win32 APIs, off of AdaPower and look at POSIX_Files.Is_File and
> POSIX_Files.Is_Directory.
>
> Even if you don't use the POSIX binding directly, it's a good
> source for seeing how to use the Window's API.

comes to the same thing doesn't it?

anyway, thanks for the tip - I assume this is the one in adapower?..

Re: Win32 filetype problem

[Pascal Obry]

"martin.m.dowie" <martin.m.dowie@ntlworld.com> writes:

> anyway, thanks for the tip - I assume this is the one in adapower?..


There is a link on Adapower to my POSIX binding. The direct Web space is:

        http://perso.wanadoo.fr/pascal.obry/w32posix.html

Not that it does not cover 100% of the POSIX binding but a good part to
abstract out most of the OS stuff.

Pascal.

-- 

--|------------------------------------------------------
--| Pascal Obry                           Team-Ada Member
--| 45, rue Gabriel Peri - 78114 Magny Les Hameaux FRANCE
--|------------------------------------------------------
--|         http://perso.wanadoo.fr/pascal.obry
--|
--| "The best way to travel is by means of imagination"

Re: Win32 filetype problem

[David Botton]

> Even if you don't use the POSIX binding directly, it's a good
> source for seeing how to use the Window's API.

I would also suggest looking at the body of GWindows packages
(http://www.adapower.com/gwindows) for an alternative style to using the
Win32 bindings. It is easier to roll your own and take advantage of Ada's
superior ability to interface with C over a raw translated binding. Although
GWindows does not include support for most file related functions since GNAT
has very good packages for handling that already:

I _HIGHLY_ recommend looking at

GNAT.OS_Lib (take a look at
/GNAT/lib/gcc-lib/pentium-mingw32msv/2.8.1/adainclude/g-os_lib.ads)

and

GNAT.Directory_Operations
(/GNAT/lib/gcc-lib/pentium-mingw32msv/2.8.1/adainclude/g-dirope.ads)

I highly recommend spending time looking through the directory above at all
the g-* files for a lot of "goodies". Also, look at
http://www.adapower.com/lang there is a section of examples on using some of
the GNAT packages there.

David Botton

Re: Win32 filetype problem

[Pascal Obry]

"David Botton" <David@Botton.com> writes:

> I highly recommend spending time looking through the directory above at all
> the g-* files for a lot of "goodies". Also, look at

And all of them are described in the GNAT Reference Manual.

Pascal.

-- 

--|------------------------------------------------------
--| Pascal Obry                           Team-Ada Member
--| 45, rue Gabriel Peri - 78114 Magny Les Hameaux FRANCE
--|------------------------------------------------------
--|         http://perso.wanadoo.fr/pascal.obry
--|
--| "The best way to travel is by means of imagination"