file list in a directory

file list in a directory

[EtienneB]

How can get it in Ada ?
Thanks
Etienne Baudin

Re: file list in a directory

[Pascal Obry]

"EtienneB" <etienne.baudin@wanadoo.fr> writes:

> How can get it in Ada ?

Ada can't do that. Some program just don't have access to a file system
(e.g. embedded programs).

You can do this with POSIX (Florist for UNIX and POSIX-Win32 from my
homepage). If you use GNAT look for GNAT.Directory_Operations. Other compilers
certainly provide this features, read the doc :)

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: file list in a directory

[Robert A Duff]

Pascal Obry <p.obry@wanadoo.fr> writes:

> Ada can't do that. Some program just don't have access to a file system
> (e.g. embedded programs).

Not a very good excuse, I think.  Ada has Text_IO, after all.

The ARG is working on a portable (standard) Directory_Operations
package, but it won't happen quickly.

- Bob

Re: file list in a directory

[Pascal Obry]

Robert A Duff <bobduff@world.std.com> writes:

> Pascal Obry <p.obry@wanadoo.fr> writes:
> 
> > Ada can't do that. Some program just don't have access to a file system
> > (e.g. embedded programs).
> 
> Not a very good excuse, I think.  Ada has Text_IO, after all.

This is not excuse just my understanding of why so much libraries are missing
in Ada. Ada95 is better in this respect than Ada83 but yet many interfaces to
the file system, windowing system, screen control are still missing.

Indeed this should be fixed, now we have a specific Annex for Information
Systems but just can't get the list of files in a directory :)

Anyway, nice to hear that this is worked on.

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: file list in a directory

[Nick Roberts]

Is there a working doucment on this on the Internet anywhere?

One idea that occurred to me as to how an implementation could supply this
sort of facility, without actually requiring a special package, would be to
provide a special syntax for the file name when opening or creating a text
file, where the relevant names or other data/parameters were output/input as
lines of text. For example:

with Ada.Text_IO; use Ada.Text_IO;
procedure List_Ada is
   Name: String(1..200);
   Last: Natural;
   Search: File_Type;
begin
   Open(Search,In_File,"dir:*.ads;*.adb//source/ada/");
   Get_Line(Search,Name,Last);
   Put_Line(Name(1..Last));
   Close(Search);
end;

Operations such as copying, linking, archiving/backup, and inquiry and
update of attributes could be provided in a similar way. This technique
makes use of the file I/O idiom to provide a ready iterator. In particular
it says when a single search begins and ends (at opening and closing), so
that the list can be 'frozen' (or the directory locked) during the search.
It could also help with debugging, and help facilitate ersatz functionality.

Obviously, a definition of a standard name syntax would be advantageous.
This would be a technique that could have the advantage of being largely
language-independent.

A copying example might be:

with Ada.Text_IO; use Ada.Text_IO;
procedure Copy_Safely is
   Name: String(1..200);
   Last: Natural;
   Search, Copier: File_Type;
begin
   Open(Search,In_File,"dir:*.ads;*.adb//source/ada/");
   Create(Copier,Out_File,"copy:|//source/ada");
   Get_Line(Search,Name,Last);
   Put_Line(Copier, Name(1..Last) & "|backup/" & Name(1..Last) );
   Close(Search);
   Close(Copier);
end;

When the Copier file is closed, the copy operations are performed,
preferably with all-or-nothing semantics (if something goes wrong, an
exception is raised).

NB: These examples don't have the checking they should.

--
Nick Roberts
http://www.AdaOS.org



"Robert A Duff" <bobduff@world.std.com> wrote in message
news:wccelvxqxrj.fsf@world.std.com...
> Pascal Obry <p.obry@wanadoo.fr> writes:
>
> > Ada can't do that. Some program just don't have access to a file system
> > (e.g. embedded programs).
>
> Not a very good excuse, I think.  Ada has Text_IO, after all.
>
> The ARG is working on a portable (standard) Directory_Operations
> package, but it won't happen quickly.
>
> - Bob

Re: file list in a directory

[Randy Brukardt]

Nick Roberts wrote in message
<9907tp$3ula5$1@ID-25716.news.dfncis.de>...
>Is there a working doucment on this on the Internet anywhere?


This is AI-248. (www.ada-auth.org/ais.html) I still have to revise it
with the suggestions from the last meeting. You're welcome to send
comments directly to me.

            Randy Brukardt.

Re: file list in a directory

[Georg Bauhaus]

Nick Roberts (nickroberts@adaos.worldonline.co.uk) wrote:


:    Open(Search,In_File,"dir:*.ads;*.adb//source/ada/");

That would mean a directory is nothing more than a list
of file names...

Re: file list in a directory

[Jean-Pierre Rosen]

Have a look at package OS_Services, which is available from Adalog's components page at http://www.adalog.fr/compo2.htm

--
---------------------------------------------------------
           J-P. Rosen (rosen@adalog.fr)
Visit Adalog's web site at http://www.adalog.fr

Re: file list in a directory

[srini]

How about gnat.directory_operations from gnat. I have had good success
with it. This in combination with gnat.command_line perform most
directory related services one might require. I hope any enhancements to
the Ada package hierarchy would mirror these packages.



Jean-Pierre Rosen wrote:
> 
> Have a look at package OS_Services, which is available from Adalog's components page at http://www.adalog.fr/compo2.htm
> 
> --
> ---------------------------------------------------------
>            J-P. Rosen (rosen@adalog.fr)
> Visit Adalog's web site at http://www.adalog.fr

Re: file list in a directory

[Jean-Pierre Rosen]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain, Size: 1115 bytes --]


"srini" <r.srinivasan@worldnet.att.net> a �crit dans le message news: 3AD153E2.D03565FC@worldnet.att.net...
> How about gnat.directory_operations from gnat. I have had good success
> with it. This in combination with gnat.command_line perform most
> directory related services one might require. I hope any enhancements to
> the Ada package hierarchy would mirror these packages.
>
It's fine, but supported only by Gnat. Actually, one of the implementations of OS_Services is built on top of these packages.
Also, OS_Services is intended to be flexible and extensible, i.e. allow you to benefit from OS pecularities, while still providing a
hard kernel of operations that work on every OS. The way it is designed, if you try to use a feature that is not available on your
OS, the program will simply not compile. (Put it the other way round: if it compiles, it works). And it avoids the "least common
denominator" problem when you want a portable interface.

--
---------------------------------------------------------
           J-P. Rosen (rosen@adalog.fr)
Visit Adalog's web site at http://www.adalog.fr

Re: file list in a directory

[tmoran]

>How can get it in Ada ?
  That's an OS question.
If you are using MS Windows, you can look at Claw.Directories
in the intro version downloadable from www.rrsoftware.com

Re: file list in a directory

[EtienneB]

So, I tryed quickly to do it interfacing with but the linker did't agree

./test_rep.o(.text+0x3e):test_rep.adb: undefined reference to `_opendir'
./test_rep.o(.text+0x4f):test_rep.adb: undefined reference to `readDir'
./test_rep.o(.text+0x60):test_rep.adb: undefined reference to `closeDir'
gnatmake: *** link failed.

look at the imports
   function openDir (szPath : chars_ptr) return dir_access;
   pragma import (C, openDir, "_opendir");
   function closeDir (Dir : dir_access) return integer;
   pragma import (C, closeDir, "closeDir");
   function readDir (Dir : dir_access) return dirent_access;
   pragma import (C, readDir, "readDir");

Thanks
Etienne Baudin

Re: file list in a directory

[David C. Hoos, Sr.]

You have to tell the linker in which library unit to find the missing
functions.  This is done (for example) by adding
-largs -L <library-directory> -l<abbreviated-library-file-name>
where the abbreviated <library-file-name> is formed by removing
"lib" from the beginning of the full file name, and removing
".a" from the end of the full file name.

"EtienneB" <etienne.baudin@wanadoo.fr> wrote in message
news:mailman.984777550.11120.comp.lang.ada@ada.eu.org...
> So, I tryed quickly to do it interfacing with but the linker did't agree
>
> ./test_rep.o(.text+0x3e):test_rep.adb: undefined reference to `_opendir'
> ./test_rep.o(.text+0x4f):test_rep.adb: undefined reference to `readDir'
> ./test_rep.o(.text+0x60):test_rep.adb: undefined reference to `closeDir'
> gnatmake: *** link failed.
>
> look at the imports
>    function openDir (szPath : chars_ptr) return dir_access;
>    pragma import (C, openDir, "_opendir");
>    function closeDir (Dir : dir_access) return integer;
>    pragma import (C, closeDir, "closeDir");
>    function readDir (Dir : dir_access) return dirent_access;
>    pragma import (C, readDir, "readDir");
>
> Thanks
> Etienne Baudin
>
>

Re: file list in a directory

[DuckE]

"EtienneB" <etienne.baudin@wanadoo.fr> wrote in message
news:mailman.984777550.11120.comp.lang.ada@ada.eu.org...
> So, I tryed quickly to do it interfacing with but the linker did't agree
>
> ./test_rep.o(.text+0x3e):test_rep.adb: undefined reference to `_opendir'
> ./test_rep.o(.text+0x4f):test_rep.adb: undefined reference to `readDir'
> ./test_rep.o(.text+0x60):test_rep.adb: undefined reference to `closeDir'
> gnatmake: *** link failed.
>

Since you're using GNAT, you might want to have a look at the GNAT specific
package:
  GNAT.Directory_Operations

On my W2K installation it is located in the file named: g-dirope.ads.

SteveD

> look at the imports
>    function openDir (szPath : chars_ptr) return dir_access;
>    pragma import (C, openDir, "_opendir");
>    function closeDir (Dir : dir_access) return integer;
>    pragma import (C, closeDir, "closeDir");
>    function readDir (Dir : dir_access) return dirent_access;
>    pragma import (C, readDir, "readDir");
>
> Thanks
> Etienne Baudin
>
>

Re: file list in a directory

[Staffan Dittmer]

In article <9iAs6.580631$U46.17301137@news1.sttls1.wa.home.com>,
	"DuckE" <nospam_steved94@home.com> writes:
> 
> Since you're using GNAT, you might want to have a look at the GNAT specific
> package:
>   GNAT.Directory_Operations
> 
> On my W2K installation it is located in the file named: g-dirope.ads.
> 
> SteveD

There are some GNAT specific source code examples at www.adapower.com.
One of which deals with GNAT.Directory_Operations.
See http://www.adapower.com/lang/index.html

/Staffan

Re: file list in a directory

[Pascal Obry]

"EtienneB" <etienne.baudin@wanadoo.fr> writes:

> So, I tryed quickly to do it interfacing with but the linker did't agree
> 
> ./test_rep.o(.text+0x3e):test_rep.adb: undefined reference to `_opendir'
> ./test_rep.o(.text+0x4f):test_rep.adb: undefined reference to `readDir'
> ./test_rep.o(.text+0x60):test_rep.adb: undefined reference to `closeDir'
> gnatmake: *** link failed.

See my answer in fr.comp.lang.ada.

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: file list in a directory

[EtienneB]

So, I tryed quickly to do it interfacing with but the linker did't agree

./test_rep.o(.text+0x3e):test_rep.adb: undefined reference to `_opendir'
./test_rep.o(.text+0x4f):test_rep.adb: undefined reference to `readDir'
./test_rep.o(.text+0x60):test_rep.adb: undefined reference to `closeDir'
gnatmake: *** link failed.

look at the imports
   function openDir (szPath : chars_ptr) return dir_access;
   pragma import (C, openDir, "_opendir");
   function closeDir (Dir : dir_access) return integer;
   pragma import (C, closeDir, "closeDir");
   function readDir (Dir : dir_access) return dirent_access;
   pragma import (C, readDir, "readDir");

Thanks
Etienne Baudin

Re: file list in a directory

[Martin Dowie]

If you're using Unix, something like this has worked for me in the past
(no guarantees here, I'm on a Windohs machine just now and this is
from memory :-)

procedure Command_Line is

  function C_System (Value : String) return Integer;
  pragma Import (C, C_System, "System");

  Result : integer;
begin
  Result := C_System (Value => "ls > ./temp.txt");
end Command_Line;

EtienneB <etienne.baudin@wanadoo.fr> wrote in message
news:AOss6.124$76.376857@nnrp1.proxad.net...
> How can get it in Ada ?
> Thanks
> Etienne Baudin
>
>