[Twisted-Python] Use of 'twistd' utility with command-line arguments
I came across some problem using 'twistd' utility - that I would not have expected from it. The problem is - using 'twistd' to start application that requires command-line arguments. In other words, I would expect that 'twistd' passes command-line arguments to Python application - just as Python does. But... I get following error: Usage: twistd [options] Options: --savestats save the Stats object rather than the text output of the profiler. -o, --no_save do not save state on shutdown -e, --encrypted The specified tap/aos/xml file is encrypted. ......................... ......................... /usr/bin/twistd: option -a not recognized when application is started either as 'twistd -y <fileName.py>' or 'twistd --file <fileName.py>' followed by a list of command-line arguments My question is: how is it possible to use 'twistd' to start applications that do require command-line arguments? Does anyone have suggestions? In other words, I want to be able to start application using 'twistd' - just as it would have been started using standard Python:
python <fileName.py> [argList] twistd -y <fileName.py> [argList]
Second question to Twisted development team: how such an important case has slipped attention? I suggest this to be added to bug fix requests, with high priority. Kind regards, Valeriy Pogrebitskiy vpogrebi@verizon.net
On Thu, Oct 1, 2009 at 2:17 PM, Valeriy Pogrebitskiy <vpogrebi@verizon.net>wrote:
I came across some problem using 'twistd' utility - that I would not have expected from it. The problem is - using 'twistd' to start application that requires command-line arguments. In other words, I would expect that 'twistd' passes command-line arguments to Python application - just as Python does.
While this is a reasonable expectation, twistd does quite a lot and it wouldn't be quite right to pass on all the arguments in a flat list the way Python does.
My question is: how is it possible to use 'twistd' to start applications that do require command-line arguments? Does anyone have suggestions?
twistd doesn't do this for scripts passed with the '-y' option. Those are supposed to be fully-formed configuration files; the options are present in the file itself. However, it's fairly straightforward to get what you want. Instead of writing a python configuration file, write a plug-in for twistd. The technique for doing so is documented here: <http://twistedmatrix.com/projects/core/documentation/howto/tap.html> Hope this helps.
Thank you! I still disagree with the following statement:
While this is a reasonable expectation, twistd does quite a lot and it wouldn't be quite right to pass on all the arguments in a flat list the way Python does.
Something can be done about that. One possible approach could be to use two argument lists (one - 'twistd' arguments, second - application's arguments) and enforce following rule(s): - all arguments that follow after 'twistd' but before Python file name (*.py) are considered as 'twistd' arguments (loaded into <twistdArgs> list; - all arguments that follow Python file name (*.py) are considered as Python application's arguments (loaded into <appArgs> list and get passed to that application) Thus, it should be possible to execute following commands: twistd <twistd_args> *.py <app_args> Using this approach, it should be simple enough (at least - logically) to allow passing arguments to an application. Of course, this would also limit "duplicate" arguments (same argument appearing in both lists) - due to 'getopt' limitations... But if these rules and limitations are well documented - developers should be able to work around this problem. I suggest that Twisted dev. team looks into implementing this... Kind regards, Valeriy Pogrebitskiy vpogrebi@verizon.net On Oct 1, 2009, at 4:55 PM, Glyph Lefkowitz wrote:
On Thu, Oct 1, 2009 at 2:17 PM, Valeriy Pogrebitskiy <vpogrebi@verizon.net
wrote: I came across some problem using 'twistd' utility - that I would not have expected from it. The problem is - using 'twistd' to start application that requires command-line arguments. In other words, I would expect that 'twistd' passes command-line arguments to Python application - just as Python does.
While this is a reasonable expectation, twistd does quite a lot and it wouldn't be quite right to pass on all the arguments in a flat list the way Python does.
My question is: how is it possible to use 'twistd' to start applications that do require command-line arguments? Does anyone have suggestions?
twistd doesn't do this for scripts passed with the '-y' option. Those are supposed to be fully-formed configuration files; the options are present in the file itself.
However, it's fairly straightforward to get what you want. Instead of writing a python configuration file, write a plug-in for twistd. The technique for doing so is documented here:
<http://twistedmatrix.com/projects/core/documentation/howto/tap.html>
Hope this helps. _______________________________________________ Twisted-Python mailing list Twisted-Python@twistedmatrix.com http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python
On Oct 2, 2009, at 12:14 PM, Valeriy Pogrebitskiy wrote:
I suggest that Twisted dev. team looks into implementing this...
Since we're telling other people how to spend their time...I suggest that you supply a patch. Thanks, S
On 04:14 pm, vpogrebi@verizon.net wrote:
Thank you!
I still disagree with the following statement:
While this is a reasonable expectation, twistd does quite a lot and it wouldn't be quite right to pass on all the arguments in a flat list the way Python does.
Something can be done about that. One possible approach could be to use two argument lists (one - 'twistd' arguments, second - application's arguments) and enforce following rule(s):
Given this:
However, it's fairly straightforward to get what you want. Instead of writing a python configuration file, write a plug-in for twistd. The technique for doing so is documented here:
what is your motivation for seeking out this feature? Also, Glyph didn't mention #1490, an open ticket describing yet another way twistd might be invoked which allows command line arguments to be passed to the application. Jean-Paul
On Fri, Oct 2, 2009 at 12:14 PM, Valeriy Pogrebitskiy <vpogrebi@verizon.net>wrote:
Something can be done about that. One possible approach could be to use two argument lists (one - 'twistd' arguments, second - application's arguments) and enforce following rule(s):
As Jean-Paul mentioned, there is a ticket which almost exactly describes your idea: #1490. In particular, you can read my last comment explaining what that ticket is supposed to be about: http://twistedmatrix.com/trac/ticket/1490#comment:39 If you'd like to implement what's specified there, we would be happy to receive your patch :). Making 'twistd foo.py' equivalent to 'twistd run foo' is a trivial afterthought once #1490 is implemented.
I came across some problem using 'twistd' utility - that I would not have expected from it. The problem is - using 'twistd' to start application that requires command-line arguments. In other words, I would expect that 'twistd' passes command-line arguments to Python application - just as Python does.
But... I get following error:
... You can do this with twistd plugins: http://twistedmatrix.com/projects/core/documentation/howto/tap.html
participants (5)
-
exarkun＠twistedmatrix.com -
Glyph Lefkowitz -
Itamar Turner-Trauring -
Steve Steiner (listsin) -
Valeriy Pogrebitskiy