Re: Emulating STRPCCMD

[Scott Klement <rpg400-l@xxxxxxxxxxxxxxxx>]

Hi Rory,

Is this 5250 emulator something you have the code for?   If so, what you 
could do is have the emulator launch a signed Java applet.  That way, 
the 5250 emulator running in a browser can still handle STRPCCMD.  (This 
is what Profound's 5250-in-a-browser product does, by the way -- though 
I haven't looked at the details of how the Java applet works.)

Or, you don't have the code for the emulator, then I suppose you could 
provide your own STRPCCMD that runs above IBM's in the library list -- 
but there's a significant challenge in doing this securely.  With 
sockets, you'd need a program installed on the PC that can accept a 
connect from the IBM i, securely, without providing a userid/password, 
etc. So you'd need some way to do this without opening up the PC to any 
sort of command from anywhere, and that can be a significant challenge. 
 But, something like digital keys or certificates might be a good solution.

When it comes to actually running the command, what I did in the open 
source TN5250 was attempt to run the command via the Win32 
CreateProcess() API.  If that returns -1, indicating an error, we try 
again, this time prefixing the command with "cmd.exe /c ".  (Assuming 
that it's a DOS command)

It's not totally perfect... Client Access appears to do something 
slightly differently, I haven't put my finger on what it is.  But, it 
seems to be close enough.

-SK



On 12/10/2012 5:19 PM, Rory Hewitt wrote:
> All,
>
> Does anyone know of a way that I can emulate the behavior of STRPCCMD?
>
> I know that STRPCCMD sends a 'hidden' screen to the emulator that contains
> some control characters, followed by the actual command to be run, and the
> emulator then executes that command.
>
> I have access to the 5250 data-stream but my 'emulator' (actually a
> data-stream parser which displays the screen in the browser) is not able to
> run STRPCCMD. I would like to be able to 'recognize' the hidden screen
> (easy) and then invoke some processing to execute the same functionality as
> is executed by STRPCCMD. Is this possible, perhaps using a socket to run a
> command on the PC?
>
> I've posted this in the RPG400-l list as the software will most likely be
> written using RPG...
>
> Thanks,
>
> Rory