[Newbies] troubleshooting question

[Thomas Keller]

David,
That is very interesting. Thanks. I am just getting the start of the
sensation you describe. Perhaps astronauts have the same problem getting
used to weightlessness.

Thanks again.
Tom Keller


On 7/22/06, David T. Lewis <lewis at mail.msen.com> wrote:
>
> On Thu, Jul 20, 2006 at 11:03:11AM -0700, Thomas Keller wrote:
> > Perhaps this is the problem?
> > When I ran this in a worksheet:
> > a _ OSProcess thisOSProcess stdOut.
> > Transcript show: a
> >
> > show: returned "nil"
> > So nextPutAll: has no where to print to?
>
> Yes, that's exactly right. Your system cannot find its standard output
> (because it does not have the necessary platform-specific OSProcess
> plugin installed), so its standard output is nil. And nil is really
> an object, like everything else in Squeak. When you send the message
> #nextPutAll: to the nil object, the nil object responds by throwing
> a MessageNotUnderstood error (MessageNotUnderstood is also an object,
> you can find in in a browser if you like). The default response to
> a MessageNotUnderstood error is to open a debugger, which lets you
> poke around and figure out what went wrong.
>
> > So my next question is how do I find the systems STDOUT pid?
>
> There are several ways to answer this, so let me start by taking
> the question literally. With the VM and plugins you are currently
> using, you cannot see either the pid of the process that Squeak
> is running in, or the identity of the STDOUT steam.  But not to
> worry, you probably don't really need either of these.
>
> It may seem odd at first, but try to think of Squeak as a self
> contained object environment, rather than as a program that does
> I/O to STDOUT and to files. The Transcript usually plays the role
> of STDOUT in the sense that you can evaluate things and show the
> result on the Transcript. Even more commonly, you can evaluate
> an expression (which may invoke some computation of arbitrary
> complexity), and "inspect it" to see the results directly.
>
> But back to being literal. If you really want to see the pid
> of the current Squeak process, and to have access to the
> STDOUT, STDIN, and STDERR streams, then you need to run your
> Squeak image with a virtual machine that has the OSProcess plugin
> extension. You can get this from http://www.squeakvm.org/unix/.
> If you install the MacOSX VM from this page, it will provide
> the OSProcess plugin, and if you run your Squeak image with
> this VM, it should do exactly what you want.
>
> I'm glad that you are interested in OSProcess, because I wrote
> it. But what I really hope is that you will quickly discover
> that OSProcess is completely unnecessary for almost everything
> you will want to do in Squeak. In my own experience, the more I
> became comfortable with Squeak, the less I worried about traditional
> file I/O and the like. It's nice to be able to do that stuff
> (hence the OSProcess extensions), but it's rarely needed once
> you get comfortable with the Squeak environment.
>
> Dave
>
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-- 
Tom
"Ecrasez l'Infame!" -- Voltaire
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