jython - how to call command.com?

[pirx at mail.com]

more general issue here - and I don't pretend to understand details
Windows has JScript/VBScript as scripting languages.
Their main power is derived from a couple of com objects - WSH.Shell
Filesystem
would it be very difficult to create some encapsulation of these
objects with Java beans, then Jython can by used as both Java and
Windows Scripting language?

Alex Martelli <aleax at aleax.it> wrote in message news:<R%v48.26530$hi.648842 at news1.tin.it>...
> charles wrote:
> 
> > I'm using Jython on Windows. How can I execute from it a DOS command
> > line, wait till it finishes and return?
> 
> I'm not sure if there are shortcuts, but you can do it via java's underlying
> libraries, for example:
> 
> >>> import java
> >>> p = java.lang.Runtime.getRuntime().exec('ls')
> >>> fin = 
>  java.io.BufferedReader(java.io.InputStreamReader(p.getInputStream())) 
> >>> while 1:
> ...   line = fin.readLine()
> ...   if not line: break
> ...   print line
> ...
> 
> I think this should work in DOS, too, using e.g. 'command.com' instead of
> 'ls', but I don't currently have a Jython installation on DOS to try it out.
> 
> If the external program you want to run does not emit its results on 
> standard output (command.com might well not), you don't have to
> work via java.io's classes -- you might well just call p.waitFor() to
> wait for process p to finish, for example.
> 
> Note that, when you need to get as coupled to the underlying platform
> as this, it's unlikely (though not impossible) that Jython can serve you
> better than Classic Python.  Jython's main strength is after all the
> ability to run on any JVM, independently of the underlying platform.
> However, it can happen that the reason for choosing Jython is not
> platform-independence but, for example, access to certain specific
> Java-only libraries, in which case this kind of platform coupling may
> of course be OK.
> 
> 
> Alex