asterisk users - Dec 2006 - Binary AGI Scripts

Hi Everyone,

I'm wondering if anyone here write AGI's in compiled binaries.  I'm 
writing a small Cepstral AGI in Freepascal/Lazarus.  I know there are 
some other AGI's out there, but I wanted to add some more functionality 
than what is available such as having the AGI determine if the "data" 
argument is plain text or a path to a text file and act accordingly.

The problem that I'm having is that Asterisk is not sending back any 
responses to commands.  I'm using stdin/stdout through the ReadLn and 
WriteLn commands in freepascal.

Reading in the initial env variables is no problem, but once I issue a 
command like so:

// >>> Create wav file from swift here <<<

WriteLn('EXEC PLAYBACK /tmp/NewlyCreatedFile');

ReadLn(StringVar); // <=========  Never returns

// >>> Clean up code to delete file, etc <<<


(The command STREAM FILES always comes back and complains the file is 
not found when it really is there so I have settled for using the 
Playback application.)

Am I mistaken in thinking that Asterisk is supposed to send back a 
response over stdin?

Of course, if I do not attempt to read the response, I run into bigger 
problem as the sound file will not be found because the next portion of 
code deletes the file created for playback, but before asterisk has a 
chance to play it!

I worked on this thing all day yesterday and tried everything that I can 
think of, but this morning I figured I will ask for some help.
-- 

Warm Regards,

Lee

use "agi debug" command from the Asterisk CLI to see what is going on.

Also, the last time I checked, "\n" is needed at the end of any
command sent to Asterisk.

Regards.

On 12/29/06, Lee Jenkins <lee@datatrakpos.com>
wrote:
>
> Hi Everyone,
>
> I'm wondering if anyone here write AGI's in compiled binaries. 
I'm
> writing a small Cepstral AGI in Freepascal/Lazarus.  I know there are
> some other AGI's out there, but I wanted to add some more functionality
> than what is available such as having the AGI determine if the
"data"
> argument is plain text or a path to a text file and act accordingly.
>
> The problem that I'm having is that Asterisk is not sending back any
> responses to commands.  I'm using stdin/stdout through the ReadLn and
> WriteLn commands in freepascal.
>
> Reading in the initial env variables is no problem, but once I issue a
> command like so:
>
> // >>> Create wav file from swift here <<<
>
> WriteLn('EXEC PLAYBACK /tmp/NewlyCreatedFile');
>
> ReadLn(StringVar); // <=========  Never returns
>
> // >>> Clean up code to delete file, etc <<<
>
>
> (The command STREAM FILES always comes back and complains the file is
> not found when it really is there so I have settled for using the
> Playback application.)
>
> Am I mistaken in thinking that Asterisk is supposed to send back a
> response over stdin?
>
> Of course, if I do not attempt to read the response, I run into bigger
> problem as the sound file will not be found because the next portion of
> code deletes the file created for playback, but before asterisk has a
> chance to play it!
>
> I worked on this thing all day yesterday and tried everything that I can
> think of, but this morning I figured I will ask for some help.
> --
>
> Warm Regards,
>
> Lee
>
> _______________________________________________
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-- 
"Su nombre es GNU/Linux, no solamente Linux, mas info en
http://www.gnu.org"

Lee Jenkins wrote:
> 
Hi all, after trying a number of different ways to get this to work, I 
have found a way.

For some reason, it does not appear to me that using standard Writeln() 
to send commands to Asterisk are ignored for some reason, even when 
appending #10 or #13#10 or #13 to the end.

At any rate, see following the example here:

http://www.freepascal.org/docs-html/rtl/system/flush.html

I create explicit file association with stdout:

var
F: Text;
sRead, sRet: string;
begin
repeat;
    begin
    Readln(sRead);
    // other assign values as needed
    end;
until (sRead = '');

Assign(F,'');
Rewrite(F);
Write('NOOP Here is some sample output to CLI' + #10);
Flush(F);
ReadLn(sRet);

Close(f);
end;

This works.  One thing that I ran across was that if I also tried to use 
ReadLn using the explicit F file variable, I got an AV.

So it seems (at least for me and my particular setup) that ReadLn reads 
ok with Asterisk, but an explicit control over stdout must be used with 
explicit flush()'s to ensure that Asterisk gets the ouputted command.

Keep in mind that I am not debugging my app in real time.  I'm compiling 
it on a VMWare linux image on my windows box and then copying it over to 
my asterisk linux box.  Just been using a lot of file logging to see 
what's going on under the hood when the app runs and this is what 
appears to be the problem, especially taking into account that the 
following simple program does not work:

var
sRead, sRet: string;
begin
repeat;
    begin
    Readln(sRead);
    // other assign values as needed
    end;
until (sRead = '');

Writeln('NOOP Here is some sample output to CLI' + #10); // nope
// Writeln('NOOP Here is some sample output to CLI'); // Nope
// Writeln('NOOP Here is some sample output to CLI' + #13#10); //Nope
// Writeln('NOOP Here is some sample output to CLI' + #13); //nope

ReadLn(sRet);  // <======= Hangs here

Close(f);
end;

Thanks for the responses.

-- 

Warm Regards,

Lee