Re: Filenames in Ada

[Martin Krischik <krischik@users.sourceforge.net>]

Dmitry A. Kazakov wrote:

> On Wed, 23 Nov 2005 18:36:47 +0100, Martin Krischik wrote:
> 
>> However, filenames in music collections contain all sort of funny
>> characters (especially the my wife's music - allmost entirely in
>> Cyrillic) - no big deal for modern file systems. But a big deal for Ada
>> as it seams. Not only are all filenames in Ada.Directories of type String
>> - actually all filenames anywhere are just String.
 
>> How does one deal with modern (utf-8) filenames in Ada?
> 
> An interesting question! Indeed the file name parameter is of String type.
> 
> Well, some quick check. The following works fine under Fedora / GNAT:
> 
> with Ada.Text_IO;                 use Ada.Text_IO;
> with Strings_Edit.UTF8.Handling;  use Strings_Edit.UTF8.Handling;
> 
> procedure UTF8_Test is
>    Name : Wide_String :=
>           (  Wide_Character'Val (1092)
>           &  Wide_Character'Val (1072)
>           &  Wide_Character'Val (1081)
>           &  Wide_Character'Val (1083)
>           );
>    File : File_Type;
> begin
>    Create (File, Out_File, To_UTF8 (Name));
>    Close (File);
> end UTF8_Test;

Nice and good to know. Only I never did open any files since I was still
reading the directories with Ada.Directories to know what to write into the
files.

Find the code at:
http://cvs.sourceforge.net/viewcvs.py/wikibook-ada/demos/Source/make_m3u.adb?only_with_tag=HEAD&view=markup

at let it loose at a directory with Cyrillic filenames.

> If you have Cyrillic code page installed you will see the file name
> correctly spelt in Russian. No wonder, Fedora Linux is natively UTF-8!

So is SuSE since 9.0.

> Though it cannot work under Windows, because GNAT run-time translates
> Create into some CreateFileA Windows API. Moreover Windows is UTF-16. So
> there is no chance for Ada.Text_IO.Create. I presume one could directly
> use CreateFileW from Windows API with a Wide_String file name, but that's
> another story.

I fear that is the only option available. But how to turn the Windows
filehandle into a Ada one...

>> Is there a chance for an add-on package (to late for Ada 2005) or are we
>> snookered until Ada 2015.
 
> I don't see any great problem here. I would add UTF-8 variants for all
> calls where a file name is mentioned. We could even switch from Latin-1 to
> UTF-8. This seems to be independent on Text_IO vs. Wide_Text_IO issue.

I am not sure. There are quite a few OS dependent functions involved here.

Martin
-- 
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Ada programming at: http://ada.krischik.com