Moving on

Simon Perreault nomis80 at
Fri Jun 15 21:27:10 PDT 2001

On Thursday 14 June 2001 20:33, Gerard Beekmans wrote:
> One of the barriers shell scripting introduces is when we need it to
> communicate with a front-end. Ideally we won't have to run the backend
> or even know it's there. We start out front-end, say QT based, and click
> on a "Start install" button. How would we have bash talk back to the QT
> app? As bash has no XML support I'm aware of, it'll have to resort to
> echo'ing a status to a file, stdout, stderr, or QT's stdin and QT will
> have to interprete that 'echo' and do something with it. This becomes a
> little bit harder when it has to be done over a network. I suppose bash
> could start a c program that makes a network connection to the QT app,
> dumps some status message, waits for reponse. To me I guess this would
> need to be a continuous open socket so the fe and be can send message at
> any given time.

Ah, then XML gives us the advantage over shell scripts that you can gather 
status information. Very neat. But how is it any different from RPM? What 
kind of status do you want?

> So I guess technically we could stop using XML and start using shell
> scripts, but when we get to networking support I'm afraid bash won't
> meet our goals.

That would be very easy. A little CGI, and you have a nice networkable GUI 
frontend. And no, I'm not thinking about Apache. There are very tiny perl web 
servers that are CGI capable.

> If we were to use XML-RPC (or RPC-XML; whichever way) we
> could tell QT "interrupt backend, send this new profile". Over RPC-XML
> we send an XML profile, be gets it, does not need to do anything with,
> can run it immediately (then again you could tell the RPC thing to just
> send a bunch of command sequences to the shell on the other side and
> tell it "run this, until  EOF.....commands.....EOF".

We could all code that around the RPM thing, and it would be very easy to do. 
Why all the XML stuff?

(I'm beginning to bore even myself with these questions... ;)

Simon Perreault -- Public key:
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