Thank you for your answer,, but I found funny things.
First I tried,
(defrule find-os
?ask-stmt <- (ask-os ?hostname)
(has-os ?hostname ?osname)
=>
(retract ?ask-stmt)
(store OSNAME ?osname)
(assert (has-os myhost unix))
Rete rete = ...
rete.executeCommand("(assert (ask-os myhost))");
rete.run();
System.out.println("OS is "+rete.fetch("OSNAME").stringValue());
The result is NullPointerException.
The return value of rete.fetch("OSNAME") is null
Next I modifed find-os rule,
inserting (printout t ?hostname......)
(defrule find-os
?ask-stmt <- (ask-os ?hostname)
(has-os ?hostname ?osname)
=>
(retract ?ask-stmt)
(printout t ?hostname" has "?osname crlf)
(store OSNAME ?osname)
The result is "OS is osname", not what I expected "OS is unix"
The problem is that the variable ?osname is not dereferenced.
Could you let me know where I did make mistakes?
I'm using "jess50a2".
Thanks in advance.
On Wed, 13 Jan 1999, Ernest Friedman-Hill wrote:
> There are many ways. One easy one is to use the 'store' and 'fetch'
> functions.
>
> (defrule find-os
> ?ask-stmt <- (ask-os ?hostname)
> (has-os ?hostname ?osname)
> =>
> (retract ?ask-stmt)
> (store OSNAME ?osname)
> (assert (host-os myhost unix))
>
>
> Rete rete = ...
> rete.executeCommand("(assert (ask-os myhost))");
> rete.run();
> String osname = rete.fetch("OSNAME").stringValue();
>
> See the README for details.
>
> I think Kyung Koo Jun wrote:
> >
> >
> > Hi, all,
> >
> > In my case, test.clp is
> >
> > (defrule find-os
> > ?ask-stmt <- (ask-os ?hostname)
> > (has-os ?hostname ?osname)
> > =>
> > (retract ?ask-stmt)
> > (printout t ?osname crlf))
> > (assert (host-os myhost unix))
> >
> > in Java application
> >
> > Rete rete = ...
> > rete.executeCommand("(assert (ask-os myhost))");
> > rete.run();
> >
> > then Jess will print the result "unix" into
> > standard output.
> > However I'd like to make the Java application get
> > the result.
> >
> > Which way is the smartest one?
> > Thanks in advance for the answers to the studpid question.
> >
> >
> >
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>
> ---------------------------------------------------------
> Ernest Friedman-Hill
> Distributed Systems Research Phone: (925) 294-2154
> Sandia National Labs FAX: (925) 294-2234
> Org. 8920, MS 9214 [EMAIL PROTECTED]
> PO Box 969 http://herzberg.ca.sandia.gov
> Livermore, CA 94550
>
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