Re: [Jython-dev] new system and environ support in javaos

[Kevin B. <kb...@ca...>]

Humbel Otmar wrote:

>I am willing to give the new javaos.py a try on eServer iSeries
>(formerly AS/400) during the next 2 weeks, but I am feeling kinda newbie
>concerning the os module.
>
Great!

The particular items that Finn was wondering about for AS/400 are the 
'current directory' and 'parent directory' strings (in Unix/dos they are 
'.' and '..', respectively).  Do you know those strings? More below.

>
>Therefore two questions:
>
>1. 
>Can I take the released 2.1a2 version and just replace javaos.py, or do
>I have to build the current cvs snapshot ?
>
The most recent non-cvs snaphot release is 2.1a3, and that should work 
fine (it is what I've been using). Not sure about .1a2 and older.

>
>2.
>What kind of tests are you interested in mostly ?
>Are there any automated tests (I remember reading something about
>__test() but haven't any clue how to use it).
>
There is a (rather poorly factored) __test() method, and basically, if 
it didn't throw an exception, it mostly worked.  :-)  However, it 
executes several 'system' commands and it really only looks at the first 
line of output, and doesn't check that very well... You can check 
visually as it prints the command it is executing, and you can see if 
the output makes sense for that command... (yuck)

I would expect it to fail pretty miserably on AS400 right now (and 
Macintosh, if anyone out there is interested in getting it working for 
Mac), because it only knows to execute commands with 'cmd /c COMMAND' or 
'command.com /c COMMAND' or 'sh -c COMMAND', so on Mac we don't get any 
system/environment functionality, and on AS400 it will likely try to 
work like Unix, and fail.

javaos.py needs the following information for a new platform (and if you 
can give some earlier items w/o the later items, it can give partial 
functionality):

1- how to recognize the new platform, that is, what System.getProperty( 
"os.name" ) returns and any variations on it, and an internal name for 
the platform (as400?). This is used to determine which values are used 
for the following items.
2- os.curdir, os.pardir need current directory and parent directory 
strings ('.', and '..', respectively).
3- os.system needs the command to "execute a command in a shell" ('sh -c').
4- os.environ needs os.system and the command to print out the 
environment as "name=value" pairs. Also, needs to know if the 
environment variable names are case sensitive (unix) or insensitive (dos).

... which reminds me that we can provide 'os.system' even if we can't 
get environment variables, which isn't supported by the current 
_ShellEnv/_NullEnv factoring...

I need to fix the default behavior - I don't think the CPython behavior 
(import error if no os-specific module available) is right for Jython. I 
think I'll convert back to the original "empty environment" as the 
fallback - though the additional testing/feedback provided by having it 
enabled is nice!  :-)

kb