Re: [Jython-dev] Do we intend the -jar option to work?

[Stefan R. <ste...@gm...>]

No real opinion from me here, deprecation sounds better to me than complete
removal. However now that you are looking into this I wanted to ask about
this thing that bothered me a bit since I started with Jython:
I always found it cumbersome that it isn't possible to run

java -cp JyNI.jar -jar jython.jar

Well, it runs but the -cp option is like ignored in this case. Same if I try

java -cp jython.jar:JyNI.jar -jar jython.jar

One has to use one of these variants:

java -cp jython.jar:JyNI.jar org.python.util.jython

jython -J-cp JyNI.jar

That means for me, the most natural/intuitive way to launch Jython with
additional jars on the classpath does not work. Especially when I was
getting started with Jython I tried to use it as an ordinary jar in terms
of launching. I found it confusing that -cp didn't work. Do you se a way to
fix this? Or is this a JVM limitation?

Am Fr., 14. Sep. 2018 um 09:21 Uhr schrieb Jeff Allen <ja...@fa...>:

> The question is a lot like that of SystemRestart, although I haven't
> done as much code archaeology. At present, we appear to support an
> option -jar to the jython command. Just type jython -h or see:
>
> https://hg.python.org/jython/file/tip/src/org/python/util/jython.java#l91
>
> But we don't. When you try to use it, all that happens, and has happened
> for a while, is this:
>
> PS startup2> jython -jar test.jar
> C:\Jython\2.7.0\bin\jython.exe: No module named __main__
>
> The reason it doesn't work as promised is that before we try to run the
> JAR, we try this:
>
> https://hg.python.org/jython/file/tip/src/org/python/util/jython.java#l316
>
> and since the attempt to get an importer for a JAR is successful, that
> method returns true, and so we never check the -jar option. The handler
> runMainFromImporter() can't run it, because it expects a __main__ module
> (the -jar flag expects a __run__.py instead), and that leads locally to
> a System.exit().
>
> Functionally, runMainFromImporter(), which was added in 2.7 to implement
> CPython behaviour, is very similar to the much older runJar() although
> not exactly the same. I think if we were doing this now, we'd only
> provide that later mechanism. CPython can run exactly the same JAR (with
> a __main__.py) that I'm using to test runMainFromImporter().
>
> When I correct the logic so that -jar calls runJar() as it used to, it
> doesn't work that well anyway: the script runs, but my import produces
> warning messages about the (assumed) package name of my script, and what
> ought to be the source code context in the message looks like binary
> from the JAR. However, runJar() is public so maybe there are
> applications that call it.
>
> I'll make a commit with the -jar option restored for comparison, but I
> think the command option could be removed immediately and a deprecation
> warning slapped on runJar().
>
> Any contrary thoughts?
>
> Jeff
>
> --
> Jeff Allen
>
>
>
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