passing command line arguments

[gozo97]

Hello.
My first posting on this forum.
I am trying to open the get_iplayer program (which runs in a terminal) and displaying the output in a TListBox from within Lazarus.  I have been successful in opening the basic program, but if I try to pass a string argument using Parameters nothing changes, it just opens the program as before.  I used the following

procedure TForm1.DownloadSelItem(PID: String);
   var  AProcess    : TProcess;
       
begin
    AProcess:= TProcess.Create(nil);
    AProcess.Executable := ('get_iplayer');
    AProcess.Parameters.Add(' --get 8');
    AProcess.Options:= AProcess.Options + [poUsePipes];
    Aprocess.Execute;
     ListBox3.Items.LoadFromStream(AProcess.Output);
    Aprocess.Free;
 
end;

If I include the argument ' --get 8'  in the executable  (i.e.  ' get_iplayer --get 8')  I receive the error Executable not found which is understandable.  Is this a problem with calling  terminal programs, or is it specific to get_iplayer ?
Any help would be very welcome. 

[engkin]

The way TProcess handles Parameters might not be what you expect:

Code: Pascal  [Select][+][-]

1.     For I:=0 to Parameters.Count-1 do
2.       Cmd:=Cmd+' '+MaybeQuoteIfNotQuoted(Parameters[i]);

This turns your command from:

get_iplayer --get 8

to:

get_iplayer "--get 8"

Try:

Code: Pascal  [Select][+][-]

1. procedure TForm1.DownloadSelItem(PID: String);
2.    var  AProcess    : TProcess;
3.        
4. begin
5.     AProcess:= TProcess.Create(nil);
6.     AProcess.Executable := ('get_iplayer');
7.     AProcess.Parameters.Add('--get');
8.     AProcess.Parameters.Add('8');
9.     AProcess.Options:= AProcess.Options + [poUsePipes];
10.     Aprocess.Execute;
11.      ListBox3.Items.LoadFromStream(AProcess.Output);
12.     Aprocess.Free;
13.  
14. end;

[gozo97]

Hello engkin.
Thank you for your suggestion.  It did not quite work as you had posted, but when I slightly altered it from

     aProcess.Parameters.Add('--get');
     aProcess.Parameters.Add('8');
to
     aProcess.Parameters.Add(' --get');
     aProcess.Parameters.Add(' 8');
in other words, I added spaces before the two arguments, the program accepted it!
Splitting the Parameters and adding them separately was the key to the problem.

get_iplayer is very strict on it's syntax and needed the spaces to work.  Also, if you include quotes, it interprets it as something quite different, for example, a URL), so I am rather confused about your first block of code and how you would implement it, but then I am a bit of a beginner!

Thank you very much for putting me on the right path.