Search Results: "will"

21 July 2012

Petter Reinholdtsen: Free Culture in Norwegian - 5 chapters done, 74 percent left to do

I reported earlier that I am working on a norwegian version of the book Free Culture by Lawrence Lessig. Progress is good, and yesterday I got a major contribution from Anders Hagen Jarmund completing chapter six. The source files as well as a PDF and EPUB version of this book are available from github. I am happy to report that the draft for the first two chapters (preface, introduction) is complete, and three other chapters are also completely translated. This completes 26 percent of the number of strings (equivalent to paragraphs) in the book, and there is thus 74 percent left to translate. A graph of the progress is present at the bottom of the github project page. There is still room for more contributors. Get in touch or send github pull requests with fixes if you got time and are willing to help make this book make it to print. :) The book translation framework could also be a good basis for other translations, if you want the book to be available in your language.

Andrew Pollock: [life] Sarah sans gallbladder

I can't remember exactly when, it was either pre-Zoe heart-related diagnostic imaging or during her pregnancy with Zoe, that it became apparent that Sarah had gall stones. Apparently it's not uncommon for women to develop them after pregnancy, and it turns out that Sarah is slightly more genetically predisposed to getting them to boot. So it wasn't terribly surprising when she started having some pain recently. She had another ultrasound to confirm it, and went off to see a surgeon. Apparently they care more about the symptoms than the number of stones in the gallbladder, and they don't bother removing the stones and keeping the gallbladder, so she was booked in for a cholecystectomy last Thursday. It was a pretty straightforward procedure, she was out of the operating room in just under an hour, and awake a bit over an hour after that. I've had a few friends need to have a cholecystectomy, and the photos on Wikipedia have always fascinated me, particularly this one. It seems so freaky to have a gallbladder full of that much gravel. It can't be comfortable. We're going to be able to pick up Sarah's stones on Monday, so it'll be interesting to see what they look like. Sarah's recovering now. It's one of the few surgeries she's had under general anaesthesia where she hasn't been sick afterwards, so that was a good start. The procedure was done laparoscopically, using four incisions, and to give themselves room to work, they inflate the body with carbon dioxide gas, which then has to work its way out of her body over the following days. So she's dealing with some bloating, bruising and swelling at the moment, but not doing too badly. Apparently if you're vertical for too long, the gas can work its way up to your diaphragm, which causes some shoulder pain, so the trick has been to walk around a bit, then lie down for a bit, and then rinse and repeat. She's not allowed to lift Zoe for 3-4 weeks, which presents a few challenges for us, but nothing insurmountable (hopefully). We converted Zoe's crib to a toddler bed a week before the surgery, and Zoe thought that was just the best thing ever, and has taken to it really well. I'm around at home for breakfast and dinner, so I can take care of the lifting into and out of the high chair for those meals, and Zoe can eat lunch at her little table. Zoe's also pretty good about getting into and out of the car by herself (not that Sarah can drive until she's off the painkillers) and she's normally in daycare two days a week. She's in daycare again on Monday, so Sarah won't have to deal with Zoe on her own until Tuesday, and we have backup daycare arrangements we can fall back on if need be. Zoe's been very good about Sarah not being able to pick her up, and been very gentle. It helped with the explanation that Sarah could show her all of her "owwies". The surgeon was saying that only 1 in 400 people need to alter their diet after removing their gallbladder, so we're hopeful that Sarah will do just fine without it. She'll certainly be more comfortable in the long run.

Julien Danjou: ERC notifications

Today, I've merged my erc notifications module inside Emacs trunk. This way, it will be available for everybody in Emacs 24.2. erc-notifications example This module allows you to be notified via notifications-notify (the Emacs implementation of the Freedesktop desktop notifications) on private message received on IRC, or when your nickname is mentioned on a channel. To enable it in Emacs > 24.1, you just have to add the following line to your configuration file: 
(add-to-list 'erc-modules 'notifications)
If you want to download it and use it stand-alone for a previous Emacs version, you can fetch the latest file revision and load it before adding the previously given line.

Siegfried Gevatter: A gentle introduction to Zeitgeist s Python API

In this post I ll make a quick introduction by example on how to use Zeitgeist s Python API for good and profit. If you re interested in using Zeitgeist from C instead, see the libzeitgeist examples; to use it with C++/Qt, Trever s a web browser in 4 steps may be of interest. First things first In case you re not familiar with Zeitgeist, it may prove helpful to first read Mikkel s introduction to Zeitgeist post. If that s too much to read, just should know that Zeitgeist is an event log. Like the history in your browser, it keeps track of what websites you open at which point in time. It also keeps track of when you close them, and of what browser you used, since it s a system-wide service. Furthermore, it does the same for files, conversations, e-mails, and anything else you want to insert into it. So Zeitgeist is a database of events, and an event can be pretty much anything. But what does it look like? It s main attributes are the following: Additionally, each event has one or more subjects, which have the following attributes: Retrieving recent data Okay, so let s say you want to know the last song you ve listened to (if you have a Zeitgeist-enabled music player). It s a simple as: 
from zeitgeist.client import ZeitgeistClient
from zeitgeist.datamodel import *
 
zeitgeist = ZeitgeistClient()
 
def on_events_received(events):
    if events:
        song = events[0]
        print "Last song: %s" % song.subjects[0].uri
    else:
        print "You haven't listened to any songs."
 
template = Event.new_for_values(subject_interpretation=Interpretation.AUDIO)
zeitgeist.find_events_for_template(template, on_events_received, num_events=1)
 
# Start a mainloop - note: the Qt mainloop also works
from gi.repository import GLib
GLib.MainLoop().run()
This may need some explaining. We start by importing the Zeitgeist client and some associated data structures (such as Event and Interpretation), and create an instance of the client. The ZeitgeistClient class is a wrapper around Zeitgeist s D-Bus API which not only makes it much nicer to use, but also makes it easy to install monitors (as we will see later) and provides convenient functionality such as automatic reconnection if the connection to the engine is lost. To query for the most recent song, we just need to create a template with the restrictions we want to impose and submit it to Zeitgeist using the find_events_for_template call. If you haven t read Mikkel s post yet, please do so, as it introduces the structure of events and subjects (in short: an event has a timestamp, some other properties, and one or more subjects representing the resources -files, websites, people - involved in the event). The Python API is inherently asynchronous (if for some reason you need a synchronous API, you may still use the lower level ZeitgeistDBusInterface class), so we need to define a callback function to handle the results we receive from the Zeitgeist engine. Finally, we need to create a main loop so the asynchronous functions can run.
Now this was a pretty simple example. Let s make it more interesting. One song isn t much, so let s get the 5 most recent songs. Also, now we want both songs and videos. The first part is pretty easy, we just need to change the num_events parameter. For the second extension, we have to change the event template. In fact, now we need two different event templates and the find_events_for_templates function, which takes an arbitrary number of event templates and ORs them. The result is as follows: 
from zeitgeist.client import ZeitgeistClient
from zeitgeist.datamodel import *
 
zeitgeist = ZeitgeistClient()
 
def on_events_received(events):
    for event in events:
        print "- %s" % event.subjects[0].uri
 
tmpl1 = Event.new_for_values(subject_interpretation=Interpretation.AUDIO)
tmpl2 = Event.new_for_values(subject_interpretation=Interpretation.VIDEO)
zeitgeist.find_events_for_templates([tmpl1, tmpl2],
                                    on_events_received, num_events=5)
 
# Start a mainloop
from gi.repository import GLib
GLib.MainLoop().run()
This will work, but unless you re lucky you re likely to get some duplicate line. Why is this? Well, other than that you may have used the same file twice, don t forget that what you are requesting are actually events. If you ve started playing a given song, you probably also stopped playing it, so that s actually two of them (an AccessEvent and a LeaveEvent). Since this isn t what we want, we ll change the query a bit: 
zeitgeist.find_events_for_templates(
    [tmpl1, tmpl2],
    on_events_received,
    num_events=5,
    result_type=ResultType.MostRecentSubjects,
    storage_state=StorageState.Available)
By requesting the most recent subjects, vs. the most recent events, we can filter out events with duplicate URI. See the ResultType documentation for other modes you can use. Note particularly the MostPopularSubjects result type. I also used the chance to introduce the storage_state parameter. This one will filter out events for files Zeitgeist knows aren t available (this mostly means online resources won t be shown if you don t have a network connnection; there s also support for handling external storage media, but because of problems with GIO this is currently disabled). Last but not least, the find_events_for_* methods also accept a timerange parameter. It defaults to TimeRange.until_now(), but you may change it to TimeRange.always() (if for some reason you re working with events in the future) or to any other time range of your choice. Here it s important to note that Zeitgeist s timestamps use millisecond precision.
For more advanced queries, you can use more complex combinations of events and subject templates. The rule to keep in mind here is that events are OR d and subjects are ANDed. Additionally, some field (actor, origin, mimetype, uri and current_uri) may be prefixed with an exclamation mark ( ! ) for NOT, or you may append an asterisc ( * ) to them for prefix search. You can even combine the two operators together. Here s an example of a template you could build: 
subj1 = Subject.new_for_values(interpretation=Interpretation.SOURCE_CODE,
                               uri="file:///home/rainct/Development/*")
subj2 = Subject.new_for_values(uri="!file:///home/rainct/Development/zeitgeist/*")
tmpl1 = Event.new_for_values(interpretation=Interpretation.MODIFY_EVENT,
                             subjects=[subj1, subj2])
templates = [tmpl1]
In my case, this template would fetch a list of the source code files I modified most recently but excluding those related to the Zeitgeist project. Working with big sets of data In case you re trying to do something crazy, you may end up with a Zeitgeist query complaining that it exceeded the memory limit. You re not supposed to do that. Instead, we provide some methods for working with large collections of events. 
from zeitgeist.client import ZeitgeistClient
from zeitgeist.datamodel import *
 
zeitgeist = ZeitgeistClient()
 
def on_events_received(events):
    for event in events:
        print '- %s' % event.subjects[0].uri
 
def on_ids_received(event_ids):
    print 'A total of %d source code files were found.' % len(event_ids)
    print 'Fetching the first 100...'
    zeitgeist.get_events(event_ids[:100], on_events_received)
 
tmpl = Event.new_for_values(subject_interpretation=Interpretation.SOURCE_CODE)
zeitgeist.find_event_ids_for_templates(
    [tmpl],
    on_ids_received,
    num_events=10000, # you can use 0 for "all events", but do you really need to?
    timerange=TimeRange.from_seconds_ago(3600*24*30*3),
    result_type=ResultType.MostPopularSubjects)
 
# Start a mainloop
from gi.repository import GLib
GLib.MainLoop().run()
And there you have the source code files you worked with during the last 3 months, ordered from most to least popular (popularity is measured counting the number of events; for more precision, maybe you could limit the results to events with interpretation AccessEvent). Why do we provide this mechanism instead of querying with a simple offset? Well, this avoids problems when the log changes (events are inserted or deleted). Have you ever been exploring the latest posts in some website, and as you change to the next page some of the results from the previous page show up again (because new posts have been added in the meantime)? With Zeitgeist this won t happen. Receiving information in real time At this point you re an expert at requesting all sorts of data from Zeitgeist, but now you want to show a list of the last kitten images you ve viewed, updated in real time. Don t worry, Zeitgeist can provide for this: 
from zeitgeist.client import ZeitgeistClient
from zeitgeist.datamodel import *
 
zeitgeist = ZeitgeistClient()
 
def on_insert(time_range, events):
    # do awesome stuff with the events here
    print events
 
def on_delete(time_range, event_ids):
    # a previously inserted event was deleted
    print event_ids
 
templates = [Event.new_for_values(subject_uri='file:///home/user/kittens/*',
                                  subject_interpretation=Interpretation.IMAGE)]
zeitgeist.install_monitor(TimeRange.always(), templates, on_insert, on_delete)
 
# Start a mainloop
from gi.repository import GLib
GLib.MainLoop().run()
It s important to note that on_delete won t be called when an image is deleted (that d be a newly inserted event with interpretation=DELETE_EVENT); rather, it s called when a previously inserted event is deleted (for example, using the forget recent history option in Activity Log Manager). In case you re curious: for best performance, this doesn t actually use D-Bus signals. Instead, this little call will setup a D-Bus object behind the scenes and register it with the Zeitgeist engine, so it can notify said object when (and only when) an event of its interest is registered. To stop receiving notifications for a template, you ll need the save the object returned by the install_monitor call: 
m = zeitgeist.install_monitor(TimeRange.always(), templates, on_insert, on_delete)
zeitgeist.remove_monitor(m)
Pro Tip: You can use the Zeitgeist Explorer GUI to quickly try out different queries (note: it s still work in progress, so much funcionality is missing, but it does work somewhat). Contextual awesomeness: finding related events By now you re familiar with retrieving events and keeping them up to date. Now it s time for a little secret: 
import time
from zeitgeist.client import ZeitgeistClient
from zeitgeist.datamodel import *
 
zeitgeist = ZeitgeistClient()
 
def on_related_received(uris):
    print 'Related URIs:'
    for uri in uris:
        print ' - %s' % uri
 
query_templates = [Event.new_for_values(
    subject_interpretation=Interpretation.SOURCE_CODE,
    subject_uri='file:///home/rainct/Development/zeitgeist/*',
    subject_mimetype="text/x-vala")]
 
result_templates = [Event.new_for_values(
    subject_interpretation=Interpretation.WEBSITE,
    subject_manifestation=Manifestation.WEB_DATA_OBJECT)]
 
now = time.time()*1000
zeitgeist.find_related_uris_for_events(
    query_templates,
    on_related_received,
    time_range=TimeRange(now - 1000*3600*24*30*6, now),
    result_event_templates=result_templates,
    num_events=10)
 
# Start a mainloop
from gi.repository import GLib
GLib.MainLoop().run()
This little query example will return up to 10 websites I used at the same time as the Vala files inside my Zeitgeist directory, considering only data from the last 6 months. Nice, huh? This is an experimental feature, and it doesn t work well when operating on big inputs, so it s usually better to use the find_related_uris_for_uris variant (which replaces the first query_templates parameter with a list of URIs). Advanced searching: the FTS extension Some people think prefix searches aren t good enough for them, and this is why the Zeitgeist engine ships by default with a FTS (Full Text Search) extension. Using the methods provided by this extension you can perform more advanced queries against subjects current_uri and text properties (unlike the name may suggest, the FTS extension doesn t index the content of the files, but just the information in the event). This is exposed as zeitgeist_index_search in libzeitgeist (the C library), but unfortunately isn t currently available in the Python API. If you still need it, you ll have to fallback to pretty much using the D-Bus interface (you still get reconnection support, though). Here s an example: 
from zeitgeist.client import ZeitgeistClient
from zeitgeist.datamodel import *
 
zeitgeist = ZeitgeistClient()
index = zeitgeist._iface.get_extension('Index', 'index/activity')
 
query            = 'hello' # search query
time_range       = TimeRange.always()
event_templates  = []
offset           = 0
num_events       = 10
result_type      = 100 # magic number for "relevancy" (ResultType.* also work)
 
def on_reply(events, num_estimated_matches):
    print 'Got %d out of ~%d results.' % (len(events), num_estimated_matches)
    events = map(Event, events)
    for event in events:
        print ' - %s' % event.subjects[0].uri
 
def on_error(exception):
    print 'Error from FTS:', exception
 
index.Search(query, time_range, event_templates,
             offset, num_events, result_type,
             reply_handler=on_reply, error_handler=on_error)
 
# Start a mainloop
from gi.repository import GLib
GLib.MainLoop().run()
The most interesting thing here is the query parameter. Quoting from the C documentation: 
The default boolean operator is AND. Thus the query foo bar will
be interpreted as foo AND bar. To exclude a term from the result
set prepend it with a minus sign - eg foo -bar. Phrase queries
can be done by double quoting the string "foo is a bar". You can
truncate terms by appending a *.
There are a few keys you can prefix to a term or phrase to search
within a specific set of metadata. They are used like key:value.
The keys name and title search strictly within the text field of
the event subjects. The key app searches within the application
name or description that is found in the actor attribute of the
events. Lastly you can use the site key to search within the
domain name of the subject URIs.
You can also control the results with the boolean operators AND
and OR and you may use brackets, ( and ), to control the operator
precedence.
Modifying the log So far we ve only queried Zeitgeist for information, let s get a bit more active. You can delete events from Zeitgeist with the following query: 
from zeitgeist.client import ZeitgeistClient
 
zeitgeist = ZeitgeistClient()
 
def on_deleted(timerange):
    print 'Deleted events going from %s to %s' % (timerange[0], timerange[1])
 
event_ids = [50] # put the IDs of the events you want to delete here
 
zeitgeist.delete_events(event_ids, on_deleted)
 
# Start a mainloop
from gi.repository import GLib
GLib.MainLoop().run()
The confirmation callback will receive a timerange going from the first to the last event. If no events were deleted (because they didn t exist), you ll get (-1, -1).
And now for the interesting part. If your application involves resources (files, websites, contacts, etc.) of any sort, you ll probably want to let Zeitgeist know that you re using them. It s time that you write a data-source! We start by registering the data-source. Here we go: 
import time
from gi.repository import GLib
from zeitgeist.client import ZeitgeistClient
from zeitgeist.datamodel import *
 
zeitgeist = ZeitgeistClient()
 
def on_status_changed_callback(enabled):
    """ This method will be called whenever someone enables or disables
        the data-source. """
    if enabled:
        print 'Data-source enabled and ready to send events!'
    else:
        print 'Data-source disabled; don\'t send event, they\'ll be ignored.'
 
def register():
    # Always use the same unique_id. Name and description can change
    # freely.
    unique_id = 'com.example.your.data.source'
    name = 'user visible name (may be translated)'
    description = 'user visible description (may be translated)'
 
    # Describe what sort of events will be inserted (optional)
    subject_template = Subject()
    subject_template.interpretation = Interpretation.PLAIN_TEXT_DOCUMENT
    subject_template.manifestation = Manifestation.FILE_DATA_OBJECT
    templates = []
    for interp in (Interpretation.ACCESS_EVENT, Interpretation.LEAVE_EVENT):
        event_template = Event()
        event_template.interpretation = interp
        event_template.manifestation = Manifestation.USER_ACTIVITY
        event_template.append_subject(subject_template)
        templates.append(event_template)
 
    zeitgeist.register_data_source(unique_id, name, description, templates,
                                   on_status_changed_callback)
Once that s done (and if it is enabled), we are free to send our events: 
def log(title, uri, opened):
    subject = Subject.new_for_values(
        uri=uri,
        interpretation=Interpretation.PLAIN_TEXT_DOCUMENT,
        manifestation=Manifestation.FILE_DATA_OBJECT,
        origin=GLib.path_get_dirname(uri),
        mimetype='text/plain',
        text=title)
    event = Event.new_for_values(
        timestamp=time.time()*1000,
        manifestation=Manifestation.USER_ACTIVITY,
        actor='application://your_application_name.desktop',
        subjects=[subject])
    if opened:
        event.interpretation = Interpretation.ACCESS_EVENT
    else:
        event.interpretation = Interpretation.LEAVE_EVENT
 
    def on_id_received(event_ids):
        print 'Logged %s (%d) with event id %d.' % (title, opened, event_ids[0])
 
    zeitgeist.insert_events([event], on_id_received)
 
if __name__ == '__main__':
    register()
 
    log('test.txt', 'file:///tmp/test.txt', opened=True)
    log('another_file.txt', 'file:///tmp/another_file.txt', opened=True)
    log('another_file.txt', 'file:///tmp/another_file.txt', opened=False)
    log('test.txt', 'file:///tmp/test.txt', opened=False)
 
    # Start a mainloop
    GLib.MainLoop().run()
If you don t know what interpretation and manifestation your subject should have, you can use the following utility methods: 
from zeitgeist.mimetypes import *
 
print get_interpretation_for_mimetype('text/plain')
print get_manifestation_for_uri('file:///tmp/test.txt')
Event better, with Zeitgeist 0.9 you can just leave the subject (but not event!) interpretation and manifestation fields empty, and they ll be guessed the same way as if you used those utility methods. Pro Tip: You can examine all registered data-sources and toggle whether they are enabled or not using the zeitgeist-data-sources-gtk.py tool. Conclusion Wow, I m impressed if you ve got this far. By now you should have quite a good idea on how to use the Zeitgeist API, and I m looking forward to seeing what you do with it in your next awesome project. If you have any problem with Zeitgeist, feel free to visit us on IRC (#zeitgeist on irc.freenode.net), or join our mailing list. We ll also be at GUADEC next week, so if you re there make sure to say hi! In case you missed them, here are some useful links:
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Siegfried-Angel Gevatter Pujals, 2012. Permalink License Post tags: ,
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20 July 2012

Joey Hess: are there any gotchas with enabling the -threaded GHC runtime?

That's a seemingly simple question I started asking various people two weeks ago. I didn't get many useful answers, but now I have experience doing it myself, and so here's a blog post brain dump. I have been trying to convert git-annex to use GHC's threaded runtime, for a variety of reasons. Naively adding the -threaded option resulted in a git-annex command that seemed to randomly freeze, but only sometimes (and, infuriatingly, never when I straced it), and a test suite that froze at a random point almost every time I ran it. Not a good result, and lacking any knowledge about gotchas with using the threaded runtime, I was at a loss for a long time (most of DebConf) about how to fix it. I now know of at least three classes of problems that enabling the threaded runtime can turn up in programs that have been developed using the non-threaded runtime. accessing a MVar after forkprocess can hang MissingH has some code similar to this, which works ok with the non-threaded runtime: 
forkProcess $ do
    debugM "about to run some command"
    executeFile ...
In the above example, debugM accesses a MVar. Doing that after forkProcess can result in a MVar deadlock, as it tries to access a MVar value, that is, apparently, not accessible to the forked process. (Bug report with test case) So, using System.Cmd.Utils from MissingH is asking for trouble. I switched all my code to the newer and, apparently, threaded runtime safe System.Process. forkProcess is a massively bad idea Even when not accessing a MVar after forkProcess, it's very unsafe to use. It's easy to miss the warning attached to forkProcess, when the code seems to work. But with the threaded runtime, I've found that most any call to forkProcess will sometimes succeed, and sometimes freeze the whole program. This might only happen around 1 time in 1000. Then you'll find this warning and do a lot of head-scratching about what it really means:
forkProcess comes with a giant warning: since any other running threads are not copied into the child process, it's easy to go wrong: e.g. by accessing some shared resource that was held by another thread in the parent.
The hangs I saw could be due to laziness issues deferring code to run after the forkProcess that you'd expect to have run before it ... or who knows what else. It's not clear to me that it's possible to use forkProcess safely in Haskell code. I think it's notable that System.Process runs the whole fork/exec in C code instead. unsafe FFI calls block According to most of the documentation you'll find in eg, the Haskell wiki, Real World Haskell, etc, the only difference between the safe and unsafe imports in the FFI is that unsafe is faster, and shouldn't be used for C code that calls back into Haskell code. But the documentation is out of date. Actually, if you're using the FFI, and the foreign function can block, you need to use safe. When using unsafe, a blocking foreign function can block all threads of the program. In my case, I was using kqueue to wait for changes to files, and this indeed blocked my whole program when linked with -threaded. Marking it safe fixed this. The details are well described in this paper: http://community.haskell.org/~simonmar/papers/conc-ffi.pdf Somewhat surprisingly, this blocking only happens when using the threaded runtime. If you're using the non-threaded runtime with unsafe blocking FFI functions, your other pseudo-threads won't be blocked. This is because the non-threaded runtime has an SIGALARM timer that interrupts (most) blocking system calls. This leads to other troubles of its own (like needing to restart interrupted FFI functions, or blocking the other pseudo-threads from running if the C code ignores SIGALARM), but that's offtopic for this post. summary Converting a large Haskell code base from the default, non-threaded runtime to the threaded runtime can be quite tricky. None of the problems are the sort of thing that Haskell helps to manage either. I will be developing new programs using the threaded runtime from the beginning from now on. By the way, don't take this post to say that threading in Haskell sucks. I've really been enjoying writing threaded Haskell code. The control Haskell gives over isolation of state to threads, and the excellent and wide-ranging suite of thread communications data types (MVar, Chan, QSemN, TMVar, SampleVar, etc) have made developing a complex threaded program something I feel comfortable doing for the first time, in any language.

John Goerzen: A Linux-Based RFID Thing Finder

Sometimes I have things nicely organized. Power adapters for radios in one drawer, for cameras in the next. And sometimes not so much. Sometimes I m not sure if things are in the basement or the attic. It seems like technology should be able to help solve this problem, but as far as I can tell, no such solution exists yet. So I m planning to build one. Here s my general idea. Feedback, of course, is welcome. Each item to be tracked can have an RFID tag of some sort attached to it. These tags can be read by an RFID reader at a distance of somewhere between 1ft and 1m in typical conditions. The reader could then act as a proximity alert to an object being searched for a you re close beep, for instance. That helps, but is only part of the battle. It doesn t help if you don t even know which room to look in. So the second part of the plan is that the RFID reader is constantly talking to an object database. Besides the obvious association between RFID tag IDs and object descriptions, the database will also capture background reads of RFID tags. Logged with accurate timestamps, we can then conjecture that RFID reads that occurred within a few seconds of each other are probably physically nearby. If boxes have RFID tags on them, then I can probably get a reasonable idea, down to a box or two, of which box that elusive book is in. If I further put tags on certain immovable physical locations in the house, such as every few feet along shelving, then these will also be captured in the background and hopefully associated with objects nearby, giving a good physical idea of where things are. What s more, the simple act of looking for things using the RFID reader would help keep the proximity tables up-to-date, since it could of course log the RFID tags it sees on the way. The only discipline required to keep this info current is to periodically hover nearby storage areas when moving things around. I like this concept a lot. That doesn t mean it s necessarily simple. Implementation requirements Software side I m envisioning the software being split into two components. One would run on an embedded system with the RFID reader. Its job is simple transmitting of scanned RFIDs to the server, receiving instructions from the server, and generating a tone if it s in search mode and the item being searched is nearby. On the server lies a database. The database would contain descriptions for the objects that are tagged (so that the tag ID can be looked up). It would also contain the timestamped scan logs. I envision a simple CGI-based frontend to it that is mobile-friendly, so a laptop, phone, tablet, etc. could be the user interface for the thing saving the cost of a display and input device by reusing what most people already have. This is the part I feel most qualified to work on already. Hardware The first question is what kind of RFID tags to use. Optimizing for cost per tag, the 800/900MHz UHF tags (EPC gen 2) seem ideal. I have found them in costs approaching $0.10 per tag when bought in rolls of 500 or 1000 Avery RFID labels. That s reasonable. The RFID reader is the more complicated part. UHF RFID readers are a lot more costly than their HF or LF counterparts. So far, the cheapest solution I have found started with a post about an Arduino UHF reader. It used a SolidDigi UHF reader board with UART interface for $177. That same board is also available with a USB interface at the same cost. There is also the need for an antenna. There is a small 5dBi one rated 0-50cm for $8, or a $100 8dBi version rated 1-6m designed for wall mounting. They sell these in kit form that include power adapter, USB cables, etc. as well. The kit with the small antenna runs $192, including reader board. Next is the compute platform. A DreamPlug might work for this at $160, though both the cost and the power consumption (5VDC 3A) are high. A Raspberry Pi seems perfect, though for whatever reason seem to be backordered by months everywhere and don t include wifi. The Pi is $35, and the USB wifi is another $30, plus a cheap SD card, so we re around $80 of computing. The running total of the project, then, is at least $272. Add on provisions for batteries, some sort of case, etc. and we re probably past the $300 mark. That s a lot cheaper than the $1000 for handheld RFID readers. The final item is tags. Bulk tags can be found in the $100 to $200 range, making the total cost of the project $400 to $500. Higher than I d like, but providing some valuable experience building something. Risks There are a few major risks to the project. First among them is read distance. If it s not long enough, the usefulness of the project will be low. Fortunately, $100 gets a more high-gain antenna and I d only be out the $8 if the cheaper one doesn t pan out. But that s something of a cold comfort, as it s another, well, $100. Having a bunch of RFID hardware can be used for all sorts of other interesting things, though, so it could perhaps be reused or repurposed. Another risk is that RFID collisions wouldn t be handled as intelligently as I d like, meaning that the read range required to be useful would activate so many tags that collision algorithms break down. I don t know enough about RFID collision algorithms to know if this is a serious councern.

18 July 2012

C.J. Adams-Collier: NIST::NVD::Store::SQLite3 1.00.00

It s been released. Use this with NIST::NVD 1.00.00 and you will be able to perform immediate look-ups of CVE and CWE data given a CPE URN. For instance: 
cjac@foxtrot:/usr/src/git/f5/NIST-NVD-Store-SQLite3$ perl Makefile.PL ; make ; make test ; cjac@foxtrot:/usr/src/git/f5/NIST-NVD-Store-SQLite3$ perl -MNIST::NVD::Query -MData::Dumper -e '
$q = NIST::NVD::Query->new(store    => q SQLite3 ,database => q t/data/nvdcve-2.0.db );
$cve_list = $q->cve_for_cpe( cpe => q cpe:/a:microsoft:ie:7.0.5730.11  );
print Data::Dumper::Dumper   cve_list => $cve_list, first_cvss => $q->cve( cve_id => $cve_list->[0] )-> q vuln:cvss   
'
$VAR1 =  
          'cve_list' => [
                          'CVE-2002-2435',
                          'CVE-2010-5071'
                        ],
          'first_cvss' =>  
                            'cvss:base_metrics' =>  
                                                   'cvss:confidentiality-impact' => 'PARTIAL',
                                                   'cvss:score' => '4.3',
                                                   'cvss:authentication' => 'NONE',
                                                   'cvss:access-vector' => 'NETWORK',
                                                   'cvss:source' => 'http://nvd.nist.gov',
                                                   'cvss:generated-on-datetime' => '2011-12-08T06:47:00.000-05:00',
                                                   'cvss:availability-impact' => 'NONE',
                                                   'cvss:integrity-impact' => 'NONE',
                                                   'cvss:access-complexity' => 'MEDIUM'
                                                  
                           
         ;
https://metacpan.org/release/CJCOLLIER/NIST-NVD-Store-SQLite3-1.00.00

17 July 2012

Sylvain Le Gall: Coding by example, migrating ocsoap to OASIS and ocamlbuild

In my effort to automate most of the stuff needed to release, I am working on a SOAP to OCaml converter. Richard W.M. Jones has kindly allowed me to take-over its project "ocsoap". The project is now located here and I am working on making it compatible with FusionForge SOAP. My first step was to make it compatible with OASIS and ocamlbuild. The project is Makefile based and needs some extra care to make it ocamlbuild based. The oasis-fication itself was a piece of cake. Just describe the dependencies of the project and make some extra choice like compiling the camlp5 extension to a .cma rather than a .cmo. You can see the _oasis and myocamlbuild.ml results, compared to the initial Makefile. The _oasis is simple: 
OASISFormat:  0.3
Name:         ocsoap
Version:      0.7.1
Synopsis:     SOAP converter to OCaml code
Authors:      Richard W.M. Jones, Sylvain Le Gall
License:      LGPL-2.1 with OCaml linking exception
Plugins:      DevFiles (0.3), META (0.3), 
              StdFiles (0.3)
BuildTools:   ocamlbuild,
              cduce
BuildDepends: dynlink,
              pxp-lex-utf8,
              pxp-engine,
              netclient,
              cduce,
              extlib,
              calendar,
              pcre
Library ocsoap
  Path:       src
  Modules:    OCSoap
Library pa_ocsoapclientstubs
  Path:          src
  Modules:       Pa_ocsoapclientstubs
  BuildTools:    camlp5o
  BuildDepends:  camlp5
  FindlibParent: ocsoap
  FindlibName:   syntax
  CompiledObject: byte
  
Executable wsdl_validate
  Path:       src
  MainIs:     wsdl_validate.ml
  
Executable wsdltointf
  Path:       src
  MainIs:     wsdltointf.ml
Executable adwords_test1
  Path: examples/adwords
  BuildDepends: ocsoap
  MainIs: test1.ml
  Build$: flag(tests)
  Install: false
  BuildTools: camlp5o
  BuildDepends: ocsoap.syntax
Executable adwords_test2 
  Path: examples/adwords
  BuildDepends: ocsoap
  MainIs: test2.ml
  Build$: flag(tests)
  Install: false
  BuildTools: camlp5o
  BuildDepends: ocsoap.syntax
Executable adwords_examples 
  Path: examples/adwords
  BuildDepends: ocsoap
  MainIs: example.ml
  Build$: flag(tests)
  Install: false
  BuildTools: camlp5o
  BuildDepends: ocsoap.syntax
Document "api-ocsoap"
  Title: API reference of OCSoap
  Type: ocamlbuild (0.3)
  BuildTools+: ocamldoc
  XOCamlbuildLibraries: ocsoap
  XOCamlbuildPath:      src/
Most of it was generated using oasis quickstart, that helps you to write _oasis. This part was not tricky and mostly a translation of what the previous Makefile was explaining, in its language. Now comes the tricky part, translating Makefile rules into ocamlbuild rules. This part is more tricky because the general principle behind Makefile and ocamlbuild are not exactly the same. Let's start with a simple rule: compiling a CDuce .cd file into a .cdo. Here is the Makefile rule: 
%.cdo: %.cd
        $(CDUCE) --compile $<
In the oasis-fication, we have added an extra complexity, because we move the source to src, which needs extra flags. Here is the ocamlbuild rule: 
rule "cduce: %.cd -> %.cdo"
  ~prod:"%.cdo"
  ~dep:"%.cd"
  begin
    fun env build ->
      Cmd(S[cduce;
            T(tags_of_pathname (env "%.cd")++"cduce"++"compile");
            A"--compile";
            A"-I"; P(Filename.dirname (env "%.cd"));
            P (env "%.cd")])
  end
;;
It is a little bit more complex, lets explain it. The function rule create a rule with a name and a function that execute it. The labels ~prod and ~dep are the right and left parts of %.cdo: %.cd of the Makefile. When we call env "%cd", it replaces the % by the matching part of ~prod and ~dep. Next we return a Rule.action. The rule in this case is a command Cmd. This rules use a sequence S, which are the command line itself. The sequence is made of smaller pieces that can be a placeholder for tag content (T + what will trigger it), atom (A, typically command line option), and filename (P). For a file src/foo.ml, the command generated will 
cduce $(TAG) --compile -I src src/foo.ml
where $(TAG) will be replaced by the content of flag ["file:src/foo.ml"; "cduce"; "compile"] content. But also by the content of flag ["cduce"; "compile"] content, the flag just need to be subset. For example if you want to add --verbose to the command line, just add flag ["cduce"; "compile"] (S[A"--verbose"]);; somewhere in myocamlbuild.ml. Next rules, we need to compile %.cdo to %.cmo. It is trickier because in this case, we want to have %.cmi eventually built before. It is not require to build it before, if there is no %.mli file. Here is the code to do that: 
let cduce_mkstubs includes =
  Quote (S([cduce;
            S(List.map
                (fun fn -> S[A"-I"; P fn])
                includes);
            A"--mlstub"]));;
(* cduce < 0.3.9:  cdo2ml -static *) 
let cduce_compile_args env =
  [
    A"-c"; A"-package"; A"cduce";
    A"-pp"; cduce_mkstubs [Filename.dirname (env "%.cmi")];
    A"-I"; P(Filename.dirname (env "%.cmi"));
    A"-impl"; P(env "%.cdo")
  ]
;;
let cduce_prepare_compile env build =
  List.iter
    (function
         Outcome.Bad _ ->
           (* Fail but it just means that the .cmi will be generated 
            * during compilation.
            *)
           ()
         Outcome.Good _ ->
           ())
    (build [[env "%.cmi"]])
;;
rule "cduce: %.cdo -> %.cmo"
  ~prod:"%.cmo"
  ~dep:"%.cdo"
  begin
    fun env build ->
      cduce_prepare_compile env build;
      Cmd(S(
        [ocamlfind; ocamlc;
         T(tags_of_pathname (env "%.cdo")
           ++"cduce"++"ocamlc"++"compile"++"byte")]
        @ (cduce_compile_args env)))
  end
;;
The difference with the former rules, is that we call cduce_prepare_compile which in turns call (build [[env "%.cmi"]]). The call to build will ask ocamlbuild to compile src/foo.cmi, but we don't care about the result, i.e. in case of Outcome.Bad exn we don't fail. This way we don't stop the build process that will continue and produce a .cmo and .cmi just out of the .cdo. The .cdo itself is compiled as a .ml file with ocamlfind ocamlc except that we apply cduce --mlstub as a preprocessor A"-pp"; Quote(S[cduce; ..; A"--mlstub"]). The last rule that I will comment is the one that transform a .intf into a .ml. This rule is particular because it is totally different than the pieces of code of the original Makefile. Here are the couple of rules that was needed to translate .intf: 
examples/adwords/%Service.cmx: examples/adwords/%Service.intf                                                       
   ocamlfind ocamlopt $(OCAMLOPTFLAGS) -c \                                                                          
     -pp "camlp5o ./pa_ocsoapclientstubs.cmo -impl" -c -impl $<
.depend: $(wildcard *.mli) $(wildcard *.ml) \
  $(wildcard examples/adwords/*.mli) $(wildcard examples/adwords/*.ml)
  $(OCAMLDEP) $^ > .depend
  for f in examples/adwords/*.intf; do \
    $(OCAMLDEP) \
    -pp "camlp5o ./pa_ocsoapclientstubs.cmo pr_o.cmo -impl" $$f \
    >> .depend; \
  done
Here is the ocamlbuild rule: 
rule "ocsoap: %.intf -> %.ml"
  ~prod:"%.ml"
  ~deps:(if !ocsoap_dev then
           ["%.intf"; !pa_ocsoapclientstubs]
         else
           ["%.intf"])
  begin
    fun env build ->
      Cmd(S[Px !camlp5o; P !pa_ocsoapclientstubs; P "pr_o.cmo"; A"-impl";
            P(env "%.intf"); A"-o"; P(env "%.ml")])
  end
;;
Here we decided to translate directly the .intf into a .ml file. The good thing about ocamlbuild is that it has a powerfull dynamicy dependencies scheme. So here you will generate the .ml file, which in turns will generate a .ml.depends and then will be compiled the standard way. In the makefile, you need to compute the .depends file using a different process that will do everything before the compilation even starts (in fact, before the inclusion of the .depends). We also use the trick to use an OCaml printer (pr_o.cmo) with camlp5o, that will directly output the standard .ml file. Don't hesitate to post comment if you have question about OASIS and ocamlbuild Enjoy.

Ritesh Raj Sarraf: Reporting bugs with Apport - II

This is a follow up to the previous post regarding Reporting bugs with ApportApport, version 2.2.3-2, has been pushed to experimental. There were some nice feedback that led to some more changes that I will talk here.Opt out: As a developer, if you see the volume of reports to be annoying, you have the option to opt out of apport reports. To do this, you should specify the XBS-Apport: No field in your package's control file. When your application crashes, apport first checks for that field in your package's description and acts based on what you chose.Following image is that the user sees for packages where the developer has opted out.opt outRepetition: Repetition of the same crash could lead to multiple reports on the same buggy behavior. For this, apport, if senses that you have already filed a bug, it provides you with the option to further ignore all crashes for that particular type.Following image should explain it better.ignore report My initial thought regarding defaults was to make apport a default opt out tool for the entire archive and only file reports for packages where the developer has manually enabled to opt-in for apport reports. But that'd have been very slow in terms of adoption, hence, for now, instead, the version in experimental does it the other way around. It will file bug reports for all packages. If you need to opt out, you will have to add the above expalined control field. That's it for this post. Please provide feedback once you spend some time with apport.PS: Please take conscious steps when filing bug reports with apport. I think it is a great tool. It just needs great users. :-)
Categories:
Debian-Blog
Tools
Keywords:
apport
debian
RHUT

16 July 2012

Petter Reinholdtsen: Call for help from docbook expert to tag Free Culture by Lawrence Lessig

I am currently working on a project to translate the book Free Culture by Lawrence Lessig to Norwegian. And the source we base our translation on is the docbook version, to allow us to use po4a and .po files to handle the translation, and for this to work well the docbook source document need to be properly tagged. The source files of this project is available from github. The problem is that the docbook source have flaws, and we have no-one involved in the project that is a docbook expert. Is there a docbook expert somewhere that is interested in helping us create a well tagged docbook version of the book, and adjust our build process for the PDF, EPUB and HTML version of the book? This will provide a well tagged English version (our source document), and make it a lot easier for us to create a good Norwegian version. If you can and want to help, please get in touch with me or fork the github project and send pull requests with fixes. :)

Tanguy Ortolo: MySQL save/restore: an example of what not to do

Database icon I had to play a bit with MySQL, saving and restoring databases with mysqldump and mysql. These two tools have one severe discrepancy, which I would like to comment here because I think it is an excellent example of what not to do when designing tools to be used together.Save mysqldump(1) is a database backup tool, that takes a MySQL database and prints the necessary SQL statements to restore it to a new server. It has one interesting option:
--default-character-set=charset_name Use charset_name as the default character set. See Section 10.5, Character Set Configuration . If no character set is specified, mysqldump uses utf8.
As you can see, it is quite modern in its default choice: if you do not specify which encoding you want to encode your database content into, it uses UTF-8. This way, it can save any database content, whatever characters it may contain. A more sensible choice may have been to use the LC_CTYPE environment variable. Restore mysql(1) is the command-line MySQL client, which can is used to restore such dumps. It has a similar option:
--default-character-set=charset_name Use charset_name as the default character set for the client and connection. A common issue that can occur when the operating system uses utf8 or another multi-byte character set is that output from the mysql client is formatted incorrectly, due to the fact that the MySQL client uses the latin1 character set by default. You can usually fix such issues by using this option to force the client to use the system character set instead.
As you can see, this utility is still has an antique design: if you do not specify a character set, it assumes you are giving it data encoded in latin-1. Discrepancy You can see the obvious discrepancy here: mysqldump encodes your database backups in UTF-8 by default, and mysql restores them as if they were encoded in latin-1. This way, when you have to restore your databases, if you thought you could do it without wondering, congratulations: voil , you have just fucked your databases up! And as an additional present, chances are high that this mistake is discreet enoughto be detected only after a while, when modifications have been done to the restored database and the original backups have been deleted. So, if you are dealing with MySQL databases, remember that you must take care of the encoding of your backups, because MySQL utilities will not by itself, or rather it will do just what should not be done. And if you are designing similar tools, please think, and if you want an example of what not to do, here is one!

R&#233;mi Vanicat: Sofware as service

Someone recently give me a link to a web picasa photo album. I wanted to download all the photo in good resolution, but the only official way to download it is by using the picasa proprietary software. Not only I'm not thrilled to install yet another unfree software, but Google refuse me to download it because "Picasa is not currently available for your operating system". Another solution exist, but need some research: Some time, its great to be able to beat limitation of unfree software thanks to free software.

15 July 2012

Jordi Mallach: Season of change

It feels like I'm sitting in a roller-coaster wagon. There's probably too much change going on for me to assimilate naturally. In particular: I just wrapped up (well, mostly) one of the toughest Uni semestres. I had to deal with lots of very time consuming assignments, and then the usual round of final exams. Even if this semester I got the best marks in my journey (or shall we say Via Crucis) through University, I still managed to fail one exam, for the Advanced Networks subject, which is quite annoying, given I got high marks (even the highest in one case) in other subjects I really don't master at all. In any case, this is the end of the pain. The only thing that's left is just one exam and a project based on GNU/Linux technologies which will basically mean formatting for prettyness the sysadmin docs we've been collecting at the office during the last few years. This effort will be nothing to what I've been doing during the past 18 months, so I'm really relieved to have it past me already. Getting rid of studies comes just two weeks before a big change in my professional career. Friday was my last day at the Institut Tecnol gic d'Inform tica, after five and a half fantastic years working with awesome people in a very friendly atmosphere. I've learned a great deal, and taking this decision wasn't easy at all. I leave lots of good friends behind, people I really love, and tomorrow will be difficult to not have them around me. I wish my ITI ex-workmates the best of luck in these difficult times for everyone in Spain and specially in the Valencian Country with the massive cuts going on. I feel the timing for this jump couldn't be better. Tomorrow, when I get ready to go for work, I won't be leaving home at all, instead I will just sit where I am right now, at home, and log into some corporate IRC server. Tomorrow I'll be joining Collabora, and I'm a mix of excited, curious and happy about this incredible opportunity. Thanks to Sjoerd for nags, I might not be writing this if it wasn't for you!

Collabora When I was first approached about this, I thought Collabora was a small company. But as I looked more into it, I discovered that's not longer the case, there's many more people than I imagined working there (here!), and was delighted to see I knew many of them, and many other are well known members of the major Free Sofware communities. I'll be joining the sysadmin team to work closely with Jo Shields. See you tomorrow, folks. :) This opportunity to work from home is godsend, given the third bit of change that'll be happening soon: sometime in late September, Maria and I should join the ranks of first-time parents, following the baby boom wave surrounding us. While you can imagine we're really happy about this, we're also freaking out because this is going to happen in just two months and a half, and weeks go by really fast lately. So yeah, being able to be at home with this really small baby will be a big bonus for the incredible experience we're about to enjoy. We've been both busy with other stuff, but during the summer we should be focusing on preparing the baby's arrival. There's a whole lot to do! Expect my Debian and other Free Software activities to get a hit, of course. :) If I am normally sleep-deprived, this is going to be the next level.

Debian Med: Debian Med Bits: Report from LSM Geneva by Andreas Tille

In this report from LSM 2012 in Geneva I will report about
  1. Medical imaging using Debian
  2. Debian Med packaging workshop
  3. Integration of VistA into Debian
  4. Other interesting talks
Medical imaging using Debian There were about 10 attendees basically upstream developers of medical imaging software. The talk got some attention and the message to include even more medical imaging software into Debian was well percived. Thanks to Mathieu Malaterre there was some live demonstration which was way easier for him as a medical imaging expert than it would have been for me.
Debian Med packaging workshop Due to my advertising in the talk yesterday three students (two of them from one medical imaging project, one from an other project) attended the workshop. Thanks to Axel Beckert who helped me out surviving the challenge to walk on unexplored ground.

The idea of the workshop was to ask the attendees to name a package of their own and just package this. Because two of the attendees were upstream developers of CreaTools we decided to go on for packaging this. After circumeventing some pitfalls in the beginning it went rather smoothly and after about 2.5 hours we were able to commit some initial packaging to the Debian Med Git repository which comes quite close to a ready package (perhaps some split into a library and a development package needs to be done and for sure testing is needed).
Quoting Frederic Cervenansky, upstream of CreaTools
Thanks for your work. Your workshop was very interesting and didactic: a relevant discussion between Claire and me for the future of Creatools has emerged from the difficulties you encountered to package creatools. I will try, before the end of the month, to fully package creatools. And for sure, I will contact the debian-med mailing list.
Integration of VistA into Debian I had the good chance to directly address some issues of Claudio Zaugg the speaker in the talk Implementing open source Health Information Systems in Low- and Middle Income Countries a practical review directly before mine. It turned out that by using Debian packaged software might help simplifying the issues they had in supporting health care workers in Low- and Middle Income Countries.
My talk was partly repeating some basic ideas about Debian Med from the talk on Monday because the audience was completely different. Than I tried to explain in detail how we tried hard to establish good contacts to upstream developers and why this is essential to finalise the goal to include hospital information systems straight into Debian any by doing so open the doors of hospitals for large scale Debian installations.
There is also video recording of this talk. Other interesting talks OpenEMR, a multi-language free open source electronic health record for international use Just discussed the packaging of OpenEMR which is prepared for Debian Med as it can be seen on our tasks page. The contact to the creator of some inofficial package will be established to finalise this task.
OpenFovea : when open-source and biophysical research get married Just another target for Debian Med popped up in this talk to further enhance Debian Med in covering all issues of medical care on one hand and on the other hand helping upstream authors to distribute their code
more effectively.
Collaborative software development for nanoscale physics The talk would have fit very nicely into the Debian Science workshop at ESRF (European Synchrotron Radiation Facility) in Grenoble because it was about ETRF (European Theoretical Radiation Facility). At previous LSM events I had just talked with Yann and the work to include their software into Debian is on its way.
Free software and High Performance Computing This talk was not directly connected to my Debian work but I simply enjoyed to see how "two people" had a really entertaining talk about Top 500 computers. Vittoria, you made my last day at LSM.

Francois Marier: Browsing privacy and ad blocking on Android

On the desktop, I usually rely on Privoxy to strip out ads, tracking resources and other privacy-invading elements. So I was looking for an equivalent solution on Android. Firefox 10 With the current version of Firefox for Android, you can simply install the Adblock Plus extension and it will filter most undesirable elements from webpages. Unfortunately, that extension is not yet available for the latest Firefox Beta, so I had to find another solution. Android Adblock It turns out that there is an Open Source proxy similar to Privoxy (though much more limited in functionality) available for Android: Adblock (also available on the F-Droid Free Software market). However, its default configuration really doesn't block much and so you'll probably want to import a new blocklist as soon as you install it. I used a combination of the Easylist and EasyPrivacy blocklists. Configuring Fennec to use a proxy Unlike its desktop cousin, Firefox for Android (also called Fennec) doesn't expose proxy settings in the user interface. Instead, you have to open the about:config page and configure the following settings manually: 

network.proxy.http = localhost
network.proxy.http_port = 8080
network.proxy.ssl = localhost
network.proxy.ssl_port = 8080
network.proxy.type = 1
Once you're done, test your connection by going into the AdBlock application and turning the proxy off. Then switch back to Firefox and go to a new website. You should get an error message telling you that the proxy is blocking connections. That means it's successfully using your proxy to talk to other websites and not connecting to them directly. (It might also be possible to set this up in the default Android browser or in the Chrome for Android Beta, but I haven't been able to find how. Feel free to leave a comment if you know how it's done.) Bonus tips While you're at it, I highly recommend you turn on the Do Not Track feature in Firefox. Some large sites (like Twitter) have recently committed to turning off individual tracking on web requests which contain this new privacy header. Also, if you want to help move the mobile web away from a WebKit monoculture (remember how bad the Internet Explorer 6 monoculture was for the web?), then please consider joining the Mobile Testdrivers team and help us make Firefox rock on Android!

Steve Langasek: For those who care about my foot

Sitting in the airport during a layover on my way back from DebConf is one of the few times of year that time and motivation come together and routinely lead me to blog. Each year's DebConf has been special in its own way. This year at DebConf 12, in addition to the usual routine of catching up with all my far-away Debian friends, and of making new Debian friends in a country I've never been before, I got a special treat: my first opportunity to experience the practice of medicine in a foreign country. Last Saturday after arriving in Managua, I discovered that the very pretty paving stones making up the hotel walkway were also very slippery when wet, and the thin rubber strips that had been helpfully put in place to make them less slippery did not measurably succeed in doing so. So as it was raining that afternoon (as it does nearly every afternoon this time of year in Nicaragua), I slipped, and made the critical error of not falling. Instead, I stopped my slide - as it happens, by using the big toe of my left foot as if it were a roller skate brake. I don't recommend this, particularly if, as in my case, you already had it on your todo list to consult a podiatrist after DebConf regarding an ongoing feeling of weakness in precisely that part of precisely that foot. So while everything seemed fine the next day, Monday I woke up early with excruciating pain in my foot which, having forgotten about the incident two days prior, seemed to come from nowhere. After favoring the foot for another day and trying to keep the pain at bay using just OTC drugs, by Tuesday my foot was quite swollen and a source of concern. So I visited the clinic on the university campus, where the doctor diagnosed me with a dropped arch plus cellulitis due to bacteria entering through some invisible cut. Conclusion: university campus clinics are equally useless the world over. But at least in addition to pointlessly prescribing antibiotics, the doctor also prescribed some anti-inflammatory drugs to help bring the swelling down. Nevertheless, my questionable mobility kept both me and Patty from attending the day trip on Wednesday, which was a real shame as I had been keen to climb a volcano that day with my fellow Debian Developers (which in the end didn't happen for anyone, but that's a story for someone else's blog). Instead I took it easy for the day at the hotel, together with a few others who had opted not to attend the day trip, catching up on email and other work and hoping matters would improve. But by the end of the day the swelling was as bad as ever, if not worse, and I had no idea what was going on. Was it broken? Was something dislocated? And so I decided that the following day I would go to the hospital. The nearest hospital, as given in the DebConf local information page, is the Hospital Militar. It's a strange sort of thing as an American who remembers the 1980s to be seeking medical care from a facility operated by the Nicaraguan military; but accompanied by Fitoria, my native escort from the local team I had nothing to worry about; and besides, as a frequent international traveler I long ago learned the secret truth that people are people everywhere, no matter what flag they were born under. The highlight of the hospital visit was definitely when a member of the hospital staff, in full military uniform, shooed me towards a chair instead of standing to talk to her because "every patient has the right to sit, no matter what country they're in". After six x-rays and a doctor's consult, the conclusion was that it's probably not a broken bone and that it will probably clear up in just a couple of days with an even-better anti-inflammatory prescription and taking care of it by not walking on it. And indeed, my foot was already feeling better by Friday and aside from a little tenderness is now just about 100%. There are plenty of other entries on Planet Debian talking about the conference itself, and I don't think I have much to add to what's already been said there. But as for Nicaragua, I can conclude that it must be one of the best countries in the world to break your foot in - between the help of the hotel staff, the top-notch medical professionals, and above all the support of the DebConf local team (with a very big thank you again to Fitoria!), this is one brand of socialized medicine I can appreciate.

Christian Perrier: Combined runs in MGA

Not sure if that will work as I expect, but here as my runs in the city of Managua, combined in one single map, thanks to OpenRunner: <script src="http://www.openrunner.com/orservice/inorser-script.php?key=mykey&amp;ser=S03&amp;id=1802807&amp;w=500&amp;h=350&amp;hp=128&amp;k=5&amp;m=0&amp;pa=0&amp;c=0&amp;ts=1342329989" type="text/javascript"></script>

14 July 2012

Christian Perrier: Debconf 12 work

As already written, even though it seems, I didn't spend my time running at Debconf12. Or eating cheese... Or (tentatively) hiking volcanoes... Or helping people to kill each other with socks... Or drinking beers... Not *only* all of these (some of them at the same time, though hiking a volcano while eating cheese and drinking beers is not particularly easy)....but also some Debian work. So, I uploaded a backport of samba to squeeze backports and our squeeze users should now have the same samba version than wheezy ones. I also stopped several cronjobs on i18n.debian.net and moved some material there as links have been (or should be) moved to the brand new i18n.debian.org (and its alias l10n.debian.org). I did a major cleanup in tasksel, committed several fixes, proposed others for review (mostly to Joey Hess). All this in preparation for a soon-to-come upload, probably after D-I beta1 which has been prepared by Cyril Brulebois while he was.....not attending Debconf12.. I also followed the integration of Sorina Sandu's work on netcfg for link detection and network ESSID choice in Debian Installer. Sorina is doing well in her GSOC work, because she's clearly someone with great capabilities who we will, I hope, be able to keep contributing to Debian. We can also thank the mentoring work of Gaudenz Steinlin to guide Sorina through D-I's arcanes. I also went through the current status of debconf translation completeness in testing for the 7 languages that target 100% (Czech, German, Spanish, French, Portuguese, Russian, Swedish). Here, the point is mostly taking care that fixes are either: I can we have good chances to achieve this goal for at least 6 of these 7 languages (Czech might be more tricky as several translations are not yet made). Finally, I also did most of my regular Debian work (which usually takes 1-2 hours every day)...and bits of my paid work (sorry for those people who I shared the table at breakfast, but that was my only common time window with my team at work). So, well, quite productive weeks, once again.

Jonathan Carter: Debconf 12 Managua, Nicaragua


It s the last day of Debconf 12 in Managua, it s the first ever Decbonf I ve attended and it has been just awesome.

There s so much I could talk about and it would take forever to put down, but here s a few highlights for me:
  • My first time in Nicaragua and also Central America! First time I ve ever seen a vulcano!
  • The Bits from the DPL talk was great, Zack pretty much hit several nails on the head of why I love the Debian project so much
  • The Debian Cheese and Wine party was off the wall, the food and the drinks were awesome and it was a lot of fun
  • I ve been attending some of the Debconf organising sessions, I was considering getting a few people together so that we could put in a bit for Sherbrooke for 2016, but then I learned that a bunch of people are already getting together to put a bid together for Montr al in 2014, so I ll get involved with that instead. Stefano and I have also been talking about a hypothetical Debconf in 2018 or 2020 in Cape Town or Stellenbosch. As much as we want a Debconf in Africa, neither of us will have time to organise a team for that in the short term. I m hoping that being involved in the Montr al bid (and hopefully an event) will give me good experience for the Cape Town one.
  • The day trip in the middle of the week was great. I just spent the whole day lying in a hammock, drinking beer and staring at the ocean. I think I needed that.
  • The Debian key signing party was good, I got my key signed by more than 20 Debian contributors this week.
  • The sessions and BoFs were great. I learned a lot about the Debian project this week and filled up a few gaps in my knowledge.
  • I got involved with the video team and played camera man for a few sessions for the live video feeds. It was surprisingly fun. I took some photos too during the week but my camera is really awful, I need to get a new one by the next Debconf.
  • The people of Nicaragua are awesome. Everyone here is so friendly and helpful, it turned
  • There s probably too much other things to mention and I ll never get a blog entry out if I even try, but thanks to everyone who made this Debconf possible, even Pollito.

Rudy Godoy: svn changelist

Not few times I ve come upon the situation where I m working over a Subversion working copy locally and I wanted to commit bits of what I ve already baked and ready to go. Odds are that there s only one file not belonging to such changeset but mostly there are many files scattered around. This situation, I learned, can be managed with a lot more flexibility and fun.
svn changelist is a nice tool for such situation. svn changelist allows you to create a list of files I want to do something with meaning that you can use the changelist on your usual svn operations, read commit, remove, etc. Let s suppose you start with a project myapp, then you start creating three files A, B and C.
dragon% touch A B C
dragon% ls -lh
total 0
-rw-r--r-- 1 rudy rudy 0 Jul 13 20:16 A
-rw-r--r-- 1 rudy rudy 0 Jul 13 20:16 B
-rw-r--r-- 1 rudy rudy 0 Jul 13 20:16 C dragon% svn add A B C
A A
A B
A C
dragon% svn ci "first commit of A, B and C" .
Adding A
Adding B
Adding C
Transmitting file data ...
Committed revision 1.
 Now we want to edit A and add few pieces of text. Then edit B also.
dragon% echo "This file looks empty, so let's put some text inside it" > A
dragon%
dragon% echo "I'm afraid this one also is empty. Just in case" >> B
 Now, I need to work on this C file and that implies touching B also. I don t want to commit the changes I ve already made since I haven t made up my mind about them.
dragon% echo "C is a nice name for a source file, but this one doesn't look like one does it?" > C
dragon% echo "I'm going to add few lines to B too" >> B
dragon% svn st
M A
M B
M C
 So, let s suppose I m ready to hit the key and commit the 2nd revision. But I m not done on A, so I want to commit just B and C the way they are now. Here svn changelist enters the arena. I can create a changelist for the two files and do several tasks related to them. Let s see.
dragon% svn changelist mylist B C
Path 'B' is now a member of changelist 'mylist'.
Path 'C' is now a member of changelist 'mylist'.
 Now I have a changelist named mylist that I can do operations with. For instance,
dragon% svn st
M A --- Changelist 'mylist':
M B
M C
dragon% svn diff --changelist mylist
Index: B
===================================================================
--- B (revision 1)
+++ B (working copy)
@@ -0,0 +1,2 @@
+I'm afraid this one also is empty. Just in case
+I'm going to add few lines to B too
Index: C
===================================================================
--- C (revision 1)
+++ C (working copy)
@@ -0,0 +1 @@
+C is a nice name for a source file, but this one doesn't look like one does it?
 Now let s commit the list.
dragon% svn ci -m "Comitting files from the mylist changelist" --changelist mylist
Sending B
Sending C
Transmitting file data ..
Committed revision 2.
dragon% svn st
M A
 Now that I ve committed the files, the changelist mylist vanishes from our working copy. I cannot do any new operations with it. Few things you have to consider when using svn changelist.
changelist s are created in a one-time list, that means you cannot add another file to an existing list. If I type svn changelist mylist A it will define the changelist mylist to have just one member, A. It will not add A to the existing member files, B and C. Now, you are free to remove any file from an existing changelist using svn changelist mylist --remove B, for our previous example. That will make the changelist shrink to just have one element, C. You can also have as many changelists as you want, and member files can be associated to each one of them. Use case for that could be a diff over specific files. For this test project it almost makes no difference using this feature, but when you have lots of file sitting modified on your working copy, this feature will keep your hair on it s place, and maybe save the day. svn changelist is available since Subversion 1.5.

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