[fpc-pascal] Interactive process with TProcess

[leledumbo]

OK, since no one answers this in Lazarus forum, I'll ask here as it's more
FPC (FCL, actually) related than LCL. I want to create an interactive
process, so I need to read the output as soon as it's available and write it
to the screen (or somewhere else). Here's the partial code (a little
different from the original post to avoid visual component):

var
  CmdProcess: TProcess;
  MemStr: TMemoryStream;
  StrList: TStringList;
  n: Integer;
  ErrMsg: PChar;
begin
  try
    CmdProcess:=TProcess.Create(nil);
    MemStr:=TMemoryStream.Create;
    StrList:=TStringList.Create;
    MemStr.SetSize(READ_BYTES);
    with CmdProcess do begin
      CommandLine:=InputStr;
      Options:=[poUsePipes,poStderrToOutPut];
      ShowWindow:=swoHide;
      Execute;
      while Running do begin
        n:=Output.Read(MemStr.Memory^,READ_BYTES);
        if n>0 then begin
          StrList.LoadFromStream(MemStr);
          WriteLn(StrList.Text); 
          MemStr.Clear;
        end else
          Sleep(100);
      end;
    end;
  except
    on e: EProcess do begin
      {$IFDEF Windows}
      FormatMessage(
        FORMAT_MESSAGE_ALLOCATE_BUFFER or FORMAT_MESSAGE_FROM_SYSTEM,
        nil,GetLastError,MAKELANGID(LANG_NEUTRAL,SUBLANG_DEFAULT),
        @ErrMsg,0,nil
      );
      {$ELSE}
      ErrMsg:=@e.Message[1];
      {$ENDIF}
      WriteLn(ErrMsg);
      Exit;
    end;
  on e: Exception do begin
      MessageDlg('Error',e.Message,mtError,[mbOK],0);
      Exit;
    end;
  end;
  repeat
    n:=CmdProcess.Output.Read(MemStr.Memory^,READ_BYTES);
    if n>0 then begin
      StrList.LoadFromStream(MemStr);
      WriteLn(StrList.Text);
    end;
  until n<=0;
  StrList.Free;
  MemStr.Free;
  CmdProcess.Free; 
end;

-- 
View this message in context: http://www.nabble.com/Interactive-process-with-TProcess-tp21029222p21029222.html
Sent from the Free Pascal - General mailing list archive at Nabble.com.