Justin TV is a streaming service that uses the broken flash concept in order to allow you to view channels.

Unfortunately it's the only source of Arabic movies, series and shows.

I wrote a GStreamer source that retrieves the channel information and uses libRTMP to connect to the Justin streaming server. The rest is handled by GStreamer ;-)

If you want to watch http://www.justin.tv/ammartv for example, you simply do

The 2nd plugin is a Totem plugin that indirectly utilizes the GStreamer source.
Given a language code (ar or en or ...), it will download the list of channels in that language and shows them in Totem's side panel. One can then easily double click on a channel and simply watch it. I originally wanted to do the Totem plugin in python but the inability to do asynchronous callback based HTTP requests prevented me :-(

Be warned that the code is of course a bit buggy and needs a lot of cleanups, it's been years since I coded anything in Gtk and that Justin might find out and either block the source somehow or even change the protocol but let's wait until that happens ;-) read more

Having monitoring for dualstack connectivity in place helps a lot. Unfortunately in most cases we are running also services we want to offer dualstacked. In the past we just monitored in those cases IPv4 only or created a separate check for the same service on IPv6. This is a bit messy and I was looking for something to check services via IPv4 and IPv6. Digging my most boring search engine doesn t help much here. So I was talking with some people more involved into the core Icinga/Nagios stuff. Seems there is actually the best solution to use check_multi. As we have the command definition for check_multi_icinga already in place, I created a check_smtp_dualstack.cmd for monitoring a dualstacked SMTP service

command[ IPv4 ] = check_smtp -4 -H $HOSTADDRESS$
command[ IPv6 ] = check_smtp -6 -H $HOSTADDRESS6$
state [ CRITICAL ] = COUNT(CRITICAL) > 1
state [ WARNING ] = COUNT(WARNING) > 0 COUNT(CRITICAL) > 0
state [ UNKNOWN ] = COUNT(UNKNOWN) > 1 A simple SMTP service definition does the trick (don t forget address6 in host definition)

define service
use generic-service ; Name of service template to use
host_name localhost
service_description SMTP
check_command check_multi_icinga! check_smtp_dualstack.cmd !'-r 1+2+4+8
Okay .. that looks nice, but only at the first view. Imagining what we are actually running as service checks, it seems we just need for every unique service check a new cmd-file for check_multi as I didn t found a way to generalize the whole stuff yet. Does anybody know a way to pass commands for check_multi via service definitions? Something like:

define service
[...]
check_command check_multi_icinga! check_general_dualstack.cmd !'check_smtp -p 666 ! -r 1+2+4+8
[...]

Inspired by the interview series conducted by Raphael, I started a Norwegian interview series with people involved in the Debian Edu / Skolelinux community. This was so popular that I believe it is time to move to a more international audience. While Debian Edu and Skolelinux originated in France and Norway, and have most users in Europe, there are users all around the globe. One of those far away from me is Nigel Barker, a long time Debian Edu system administrator and contributor. It is thanks to him that Debian Edu is adjusted to work out of the box in Japan. I got him to answer a few questions, and am happy to share the response with you. :) Who are you, and how do you spend your days? My name is Nigel Barker, and I am British. I am married to Yumiko, and we have three lovely children, aged 15, 14 and 4(!) I am the IT Coordinator at Hiroshima International School, Japan. I am also a teacher, and in fact I spend most of my day teaching Mathematics, Science, IT, and Chemistry. I was originally a Chemistry teacher, but I have always had an interest in computers. Another teacher teaches primary school IT, but apart from that I am the only computer person, so that means I am the network manager, technician and webmaster, also, and I help people with their computer problems. I teach python to beginners in an after-school club. I am way too busy, so I really appreciate the simplicity of Skolelinux. How did you get in contact with the Skolelinux/Debian Edu project? In around 2004 or 5 I discovered the ltsp project, and set up a server in the IT lab. I wanted some way to connect it to our central samba server, which I was also quite poor at configuring. I discovered Edubuntu when it came out, but it didn't really improve my setup. I did various desperate searches for things like "school Linux server" and ended up in a document called "Drift" something or other. Reading there it became clear that Skolelinux was going to solve all my problems in one go. I was very excited, but apprehensive, because my previous attempts to install Debian had ended in failure (I used Mandrake for everything - ltsp, samba, apache, mail, ns...). I downloaded a beta version, had some problems, so subscribed to the Debian Edu list for help. I have remained subscribed ever since, and my school has run a Skolelinux network since Sarge. What do you see as the advantages of Skolelinux/Debian Edu? For me the integrated setup. This is not just the server, or the workstation, or the ltsp. Its all of them, and its all configured ready to go. I read somewhere in the early documentation that it is designed to be setup and managed by the Maths or Science teacher, who doesn't necessarily know much about computers, in a small Norwegian school. That describes me perfectly if you replace Norway with Japan. What do you see as the disadvantages of Skolelinux/Debian Edu? The desktop is fairly plain. If you compare it with Edubuntu, who have fun themes for children, or with distributions such as Mint, who make the desktop beautiful. They create a good impression on people who don't need to understand how to use any of it, but who might be important to the school. School administrators or directors, for instance, or parents. Even kids. Debian itself usually has ugly default theme settings. It was my dream a few years back that some kind of integration would allow Edubuntu to do the desktop stuff and Debian Edu the servers, but now I realise how impossible that is. A second disadvantage is that if something goes wrong, or you need to customise something, then suddenly the level of expertise required multiplies. For example, backup wasn't working properly in Lenny. It took me ages to learn how to set up my own server to do rsync backups. I am afraid of anything to do with ldap, but perhaps Gosa will help. Which free software do you use daily? Nowadays I only use Debian on my personal computers. I have one for studio work (I play guitar and write songs), running AV Linux (customised Debian) a netbook running Squeeze, and a bigger laptop still running Skolelinux Lenny workstation. I have a Tjener in my house, that's very useful for the family photos and music. At school the students only use Skolelinux. (Some teachers and the office still have windows). So that means we only use free software all day every day. Open office, The GIMP, Firefox/Iceweasel, VLC and Audacity are installed on every computer in school, irrespective of OS. We also have Koha on Debian for the library, and Apache, Moodle, b2evolution and Etomite on Debian for the www. The firewall is Untangle. Which strategy do you believe is the right one to use to get schools to use free software? Current trends are in our favour. Open source is big in industry, and ordinary people have heard of it. The spread of Android and the popularity of Apple have helped to weaken the impression that you have to have Microsoft on everything. People complain to me much less about file formats and Word than they did 5 years ago. The Edu aspect is also a selling point. This is all customised for schools. Where is the Windows-edu, or the Mac-edu? But of course the main attraction is budget.The trick is to convince people that the quality is not compromised when you stop paying and use free software instead. That is one reason why I say the desktop experience is a weakness. People are not impressed when their USB drive doesn't work, or their browser doesn't play flash, for example.

One of the best way to add SNMP support to an application is the use of AgentX protocol: an application can act as a subagent and handle requests from a master agent using AgentX protocol. The most widespread implementation for such a task is the one from Net-SNMP. TL;DR: An application asynchronously leveraging Net-SNMP AgentX implementation has many opportunities to get stuck when the master agent becomes temporarily unavailable. A mostly efficient workaround is to dedicate a master agent for AgentX and delegate MIB handling to a subagent.

Pinging the master agent Net-SNMP uses an event-based model. It also provides some synchronous functions but they are built on top of the asynchronous ones. It is shipped with its own event loop. Therefore, Net-SNMP AgentX protocol implementation seems a fine choice to add SNMP support to an event-based program, for example in Keepalived, a VRRP daemon and a monitoring daemon for LVS clusters. Unfortunately, an AgentX subagent is expected to check, at a regular interval, if the master agent is alive . This is handled automatically with Net-SNMP implementation as long as you call run_alarms() function which will call agentx_check_session():

/*
 * check a session validity for connectivity to the master agent.  If
 * not functioning, close and start attempts to reopen the session 
 */
void
agentx_check_session(unsigned int clientreg, void *clientarg)
 
    /* [...] */
    DEBUGMSGTL(("agentx/subagent", "checking status of session %p\n", ss));
    if (!agentx_send_ping(ss))  
        snmp_log(LOG_WARNING,
                 "AgentX master agent failed to respond to ping.  Attempting to re-register.\n");
        /*
         * master agent disappeared?  Try and re-register.
         * close first, just to be sure .
         */
        agentx_unregister_callbacks(ss);
        agentx_close_session(ss, AGENTX_CLOSE_TIMEOUT);
        /* [...] */
        if (main_session != NULL)  
            /* [...] */
            main_session = NULL;
            agentx_reopen_session(0, NULL);
         
        else  
            snmp_close(main_session);
            main_session = NULL;
         
      else  
        DEBUGMSGTL(("agentx/subagent", "session %p responded to ping\n",
                    ss));
     
 

This piece of code will end up calling (directly or indirectly) the following functions¹ which are using agentx_synch_response():

• agentx_send_ping()
• agentx_open_session()
• agentx_reopen_session()
• agentx_close_session()
• agentx_register()
• agentx_unregister()
• agentx_register_index()
• agentx_unregister_index()
• agentx_add_agentcaps()
• agentx_remove_agentcaps()

agentx_synch_response() will synchronously wait for an answer from the master agent. Your event-based program will just sit here doing nothing while this happens. For example, keepalived may be unable to send VRRP probes resulting in some serious havoc in your cluster. Functions prefixed by agentx_ are not part of NetSNMP API and could therefore be rewritten to do their work asynchronously. Unfortunately, talk is cheap. Moreover, there exists other deep paths that will block a subagent. For example, the low-level connection to the master agent (using TCP or a Unix socket, but not with UDP) will use a blocking connect() call. It seems quite difficult to fix this. Here are some (partial) workarounds:

• Call agentx_check_session() less often. The default interval is 15 seconds. Disabling it completely or using a very high value is not advised because this function is the only way to reestablish a connection to the master agent when it is, for example, restarted. Here is how to change the delay to 120 seconds:

  netsnmp_ds_set_int(NETSNMP_DS_APPLICATION_ID,
                     NETSNMP_DS_AGENT_AGENTX_PING_INTERVAL, 120);
  

• Don t call agentx_check_session() if we know the master agent is alive. For example, if it just sent us a new request, no need to ping it. I have written a patch implementing such a workaround. The ABI is left untouched, therefore, you only need to recompile Net-SNMP libraries.
• Use a lower timeout and no retry. By default, the timeout for synchronous requests is 1 second and a failed request will be retried 5 times. Because several synchronous functions are used in a row, you may be trapped for as long as 30 seconds with those settings. Here is how² to disable the retry mechanism and to set the timeout to a very low value:

  static int
  snmp_setup_session_cb(int majorID, int minorID,
                void *serverarg, void *clientarg)
   
      netsnmp_session *sess = serverarg;
      sess->timeout = ONE_SEC / 3;
      sess->retries = 0;
      return 0;
   
  void some_init_function()
   
      /* [...] */
      snmp_register_callback(SNMP_CALLBACK_LIBRARY,
         SNMP_CALLBACK_SESSION_INIT,
         snmp_setup_session_cb, NULL);
      /* [...] */
   
  

Unresponsive master agent Why is the master agent unresponsive? snmpd is also an event-based program and, trust me, there are a lot of places where it will become unresponsive. Here are two examples:

• When using the pass or the pass_persist directive, Net-SNMP will block until the delegated command outputs a complete line.

  /* var_extensible_pass() in agent/mibgroup/ucd-snmp/pass.c */
  /*
   * valid call.  Exec and get output 
   */
  if ((fd = get_exec_output(passthru)) != -1)  
      file = fdopen(fd, "r");
      if (fgets(buf, sizeof(buf), file) == NULL)  
          fclose(file);
          wait_on_exec(passthru);
          /* [...] */
          continue;
       
      /* [...] */
      fclose(file);
      wait_on_exec(passthru);
      /* [...] */
   
  

• DISMAN-PING-MIB implementation will just hang while pinging the remote host. If the host is down and you have requested 5 probes with a timeout of 1 second, snmpd will be unresponsive for 5 seconds. A similar problem exists with DISMAN-TRACEROUTE-MIB.

Minimal master agent More and more code is running in the main agent. You cannot expect it to not block. But we could add a minimal master agent to the mix: it will handle only a few MIB modules by itself while most MIB modules will be delagated to a complete agent running as a subagent. Your own subagent will connect to the minimal master agent. It is quite easy to turn snmpd into a subagent: just use -X flag. We should also disable unwanted MIB modules for each agent with -I flag. For the minimal master agent, we only enable some modules. All other modules³ will be served by snmpd acting as a subagent.

$ MODS="snmp_mib,sysORTable,usmConf,usmStats,usmUser,vacm_conf,vacm_context,vacm_vars"
$ snmpd -Lsd -Lf /dev/null -u snmp -g snmp \
>   -C -c /etc/snmp/snmpd.master.conf \
>   -p /var/run/snmpd.master.pid \
>   -I $MODS
$ snmpd -Lsd -Lf /dev/null -u snmp -g snmp \
>   -p /var/run/snmpd.pid -X \
>   -I -$MODS

Access control configuration should be placed in /etc/snmp/snmpd.master.conf, as well as master agentx directive. Other directives (like pass, pass_persist, load, sysname, ) in /etc/snmp/snmpd.conf. The minimal master agent is very unlikely to block and while the ground cause is still here, it is now very much mitigated. You may extend this solution by splicing snmpd into several subagents: one handling safe modules, one handling pass and pass_persist stuff and a last one for unsafe modules (like DISMAN-PING-MIB).

---

1. agentx_reopen_session() will call agentx_close_session() and agentx_open_session(). agentx_register() and the following functions will be called by those two functions.
2. NETSNMP_DS_AGENT_AGENTX_TIMEOUT and NETSNMP_DS_AGENT_AGENTX_RETRIES variables are only used by the master agent, not by a subagent.
3. Use snmpd -Dmib_init -H to get the list of modules. You may want to add smux module to the master agent.

What is it? Last month I started what I am calling the LUV Hardware Library. It s a briefcase full of computer parts that are free to LUV members which I plan to bring to all LUV meetings [1]. The issue is that there is a lot of hardware which has no great value to people and is often excess to requirements but which is still somewhat expensive or difficult to obtain and thus transferring it from the people who don t need it to people who do provides a significant benefit to the recipient but no real cost to the donor. Currently my briefcase has a range of different types of DIMM, some PCI cards, some assorted cables, a laptop SATA disk, and a bunch of other random things. Most of the stuff has been in my spare parts pile for a year or two, but some of it has been donated by other people. What we Need The next thing we need is more packaging, anti-static bags for RAM and PCI cards, sealable bags for screws, and some way of storing motherboard batteries. In terms of hardware that can be donated one thing that would be really useful is SATA disks. I m sure that there are lots of people who have upgraded the storage of their computer and kept the old drive with no real chance of using it. But there are lots of people who need such disks, for example I ve been giving away a bunch of P4 systems which lack disks and are not cabled for IDE disks a supply of SATA disks would make them a lot more usable. Also any other random electronic stuff is of interest, including non-Linux things such as mobile phones (but only if not network locked). If you have something that s big or heavy to donate then contact me via email first. Other Options Computerbank does great work in rebuilding old PCs and selling them cheaply to worthy people [2], but most of the spare hardware I get is below the minimum specs that they will accept. I m not planning to compete with Computerbank in any way, I just want to provide a useful service to LUV members who want to upgrade their PC for free. I encourage other people to do the same at other LUG meetings!

• [1] http://luv.asn.au/
• [2] http://www.computerbank.org.au/

Related posts:

1. Donating old Hardware On a recent visit to my local e-waste disposal place...
2. Giving Away Hardware For the last few years I have been actively seeking...
3. Shelf-life of Hardware Recently I ve been having some problems with hardware dying. Having...

Released a few hours ago, here is the monthly report of DPL activities for February 2012.

---

Howdy, dear Project Members,
here's another round of updates about what has happened in DPL land, this time during February 2012. Highlights Quit a bit of highlights for this month:

• The first item is not pleasant but important. Early February I've submitted to the attention of the Technical Committee the upload of multi-arch enabled dpkg to the archive. The Technical Committee quickly reached a decision. Shortly afterwards an upload to experimental has happened and discussions on -devel ensued. Please help out with testing.
• Thanks to IBM and OSUOSL we have some new fairly capable (virtual) machines for powerpc* ports. See the announcement for more info. In particular, please note the call for powerpc64 porters. If you're interested in contributing to such a port, please get in touch with DSA.
• Google Summer of Code project is up again. As usual, it is a good chance to get some work done and, more importantly, to let students who are passionate about Free Software discover Debian. I've delegated the task of GSoC admins --- thanks Ana, Gergely, and Sukhbir! A call for project proposals has already been sent out; there isn't much time left, so please hurry up and drop your ideas to the wiki page and contact the soc-coordination mailing list.
• A couple of important discussions have been going on on -project. The first is the old "trademark vs DFSG" discussion. I've posted there results from legal advice that I've sought on the matter, based on your suggestions. Then, I've posted a proposal on how to deal with trademarks issues in the archive.
• The second discussion is about Debian affiliation with OSI. We've been approached by OSI about that, as I've summarized on -project. Helped by the feedback received, I've decided to go ahead with affiliation and I'm now discussing with OSI representative the next steps.
• The long running work on software patent issues in the archive has been concluded publishing a policy on the matter. We now have a contact point and legal advice with whom we can discuss specific issues if/when they arise; hopefully that would help us to discriminate actual issues in the archive (if any) from the vast amount of FUD in the area.

Talks, interviews, and the like

• Following up Debian related talks at FOSDEM, I've been interviewed, together with Lars Wirzenius and Wookey, for The Register.
• I've took part at a FOSDEM panel session on comparing the organization of local user groups, ambassadors, and the like. We've mostly to learn from others in this area, but I've took the change to summarize what we currently have in a slide deck.

Sprints Plenty of sprints related news!

• DSA and the Groupware team will be holding sprints later on in March, while DAM / FrontDesk are having one right now co-located with the BSP in Moenchengladbach
• the video team sent out a report for their sprint back in November
• debbugs (AKA bugs.debian.org) hackers are organizing a sprint to get people interested in contributing to the code base up to speed. If you're, drop a line in the thread

It would be amazing to have an average of one sprint per month for 2012, and we're on good track for it. If you want to help, organize one for your team as documented on the wiki. Legal stuff

• Thanks to SPI, we've established contacts with the owners of debian.eu, domain we believe we legitimately own. As a first step they've set up HTTP redirection from debian.eu to debian.org (instead of a computer hardware shop, as it was before) and we're now discussing actual transfer of domain ownership to a Debian Trusted Organization.
• We've contacted the Japanese trademark office to transfer the "debian" trademark there to SPI. Thanks to the previous owners (all Debian developers or contributors) for agreeing to the move. Now "only" a nasty pile of paperwork remains to be done.

Appointments In addition to the GSoC admins delegation (see above), I've agreed with former secretary Kurt Roeckx to reappoint him as a secretary for another year. Many thanks, Kurt! Miscellaneous

• We have been invited to attend the OpenStack summit in April and have a presence there, free of charge. Loic Dachary, active member of the OpenStack packaging team in Debian, has agreed to go and represent Debian there. Thanks a lot to Stefano Maffulli for the invitation and to Loic for his availability!
• We are in the process of joining as a project, instead of relying on individual maintainers as in the past the ISC forum to get access to embargoed vulnerability information for important pieces of software such as BIND and DHCP. They've kindly offered us membership free of charge. I've submitted a draft of the membership agreement to SPI and I'm waiting for their decision.
• Steady progress on the front of periodic budget reports, thanks to the work of Martin Michlmayr. We've discussed at length during FOSDEM and agreed on procedures to query the state of Debian finances that work for both auditors and the DPL. Martin has also set up a shared ledger repository and already checked in into it a lot of money transactions for the past few years not from all trusted organizations yet, though. Have faith, we'll get there

Happy Debian hacking.

---

PS as usual, the boring day-to-day activity log is available at master:/srv/leader/news/bits-from-the-DPL.*

If you ever used filelight or baobab you probably know how useful they are. If you didn't, then you missed a lot on how you can spot (and fix) where your disk space is wasted.

With my recent attempt to upgrade to GNOME 3 which, because of its innate property to be useless and counter-productive, actually made me to use Xfce4 with a mix of GNOME aplications (since Xfce lacks a few functionalities here and there), I ran into all sorts of problems.

As a side note, Xfce4 is quite decent, but if you like some icons on your panels to be left aligned and some right aligned, you should know that you can add a Separator item to the panel, right click on it -> Properties and tick the Expand* check box. And if you also set the Transparent style, it will look nice, too.

Back to the topic. With my mix of Xfce and Gnome apps, I configured my top panel to contain a Free Space Checker for my /home file system and today it alerted me that I was low on disk space, so I started baobab to check what I can clean up.

When I found a possible suspect, I wanted to open the directory with a file browser, but, instead, Totem was started and started trying to queue all the files in the offending directory. The problem is that one way or another, Totem (or VLC) was configured to be the default handler for directories instead of the file manager.

The solution is simple, open with an editor the file ~/.local/share/applications/mimeapps.list and search for the line starting with inode/directory= and you'll see something like:

inode/directory=nautilus-folder-handler.desktop;baobab-usercreated.desktop;vlc-usercustom.desktop;

Remove the offending part, vlc-usercustom.desktop;, save the file and try again to open that directory from baobab. If you are double-lucky :P and now it opens with Totem, you will have to remove a reference to a "totem-usercustom.desktop;" or something of that sort. Now, on my system, that line looks like this:

inode/directory=nautilus-folder-handler.desktop;baobab-usercreated.desktop;

And now it works as expected**

* I suppose it's called like that in English, I have my desktop in Romanian
** Except that I would like it to start my desktop preferred file manager, not Nautilus, but that's another issue.

This is my monthly summary of my Debian related activities. If you re among the people who made a donation to support my work (384.14 , thanks everybody!), then you can learn how I spent your money. Otherwise it s just an interesting status update on my various projects. Dpkg and multiarch The month started with a decision of the technical committee which allowed me to proceed with an upload of a multiarch dpkg even if Guillem had not yet finished his review (and related changes). Given this decision, Guillem made the experimental upload himself. I announced the availability of this test version and invited people to test it. This lead to new discussions on debian-devel. We learned in those discussions that Guillem changed his mind about the possibility of sharing (identical) files between multiple Multi-Arch: same packages, and that he dropped that feature. But if this point of the multiarch design had been reverted, it would mean that we had to update again all library packages which had already been updated for multi-arch. The discussions mostly stalled at this point with a final note of Guillem explaining that there was a tension between convenience and doing the right things every time that we discuss far-reaching changes. After a few weeks (and a helpful summary from Russ Allbery), Guillem said that he remained unconvinced but that he put back the feature. He also announced that he s close to having completed the work and that he would push the remaining parts of the multiarch branch to master this week (with the 1.16.2 upload planned next week). That s it for the summary. Obviously I participated in the discussions but I didn t do much besides this I have a mandate to upload a multiarch dpkg to sid but I did not want to make use of it while those discussions remained pretty unconclusive. Also Guillem made it pretty clear that the multiarch implementation was buggy , not right and not finished and that he had reworked code fixing at least some of the issues since he never shared that work in progress, I also had no way to help even just by reviewing what he s doing. We also got a few multiarch bug reports, but I couldn t care to get them fixed since Guillem clearly held a lock on the codebase having done many private changes it s not quite like this that I expect to collaborate on a free software project but life is full of surprises! I ll be relieved once this story is over. In the mean time, I have added one new thing on my TODO list since I made a proposal to handle bin-nmu changelogs and it s something that could also fix #440094. Misc dpkg stuff After a discussion with Guillem, we agreed that copyright notices should only appear in the sources and not in manual pages or --version output, both of which are translated and cause useless work to translators when updated. Guillem already had some code to do it for --version strings, and I took care of the changes for the manual pages. I merged some minor documentation updates, fixed a bug with a missing manpage. Later I discovered that some recent changes lead to the loss of all the translated manual pages. I suggested an improvement to dh_installman to fix this (and even prepared a patch). In the end, Guillem opted for another way of installing translated manual pages. Triggered by a discussion on debian-devel, I added a new entry to my TODO list: implementing dpkg-maintscript-helper rm_conffile_if_owner to deal with the case where a conffile is taken over by another package which might (or might not) be installed. Misc packaging At the start of the month, I packaged quilt 0.51. The number of Debian specific patches is slowly getting down. With version 0.51, we dropped 5 patches and introduced a new one. Later in the month I submitted 4 supplementary patches upstream which have been accepted for version 0.60. This new version (just released, I will package it soon) is an important milestone since it s the first version without any C code (Debian had this for a long time but we were carrying an intrusive patch for this). Upstream developer Jean Delvare worked on this and based his work on our patch, but he went further to make it much more efficient. Besides quilt, I also uploaded dh-linktree 0.2 (minor doc update), sql-ledger 2.8.36 (new upstream version), logidee-tools 1.2.12 (minor fixes) and publican 2.8-2 (to fix release critical bug #660795). Debian Consultants The Debian Project Leader is working on federating Debian Companies. As the owner of Freexian SARL, I was highly interested in it since Freexian contributes to Debian, offers support for Debian and has a strategic interest in Debian . There s only one problem, you need to have at least 2 Debian developers on staff but I have no employees (it s me only). I tried to argue that I have already worked with multiple Debian developers (as contractors) when projects were too big for me alone (or when I did not have enough time). Alas this argument was not accepted. Instead, and since our fearless leader is never afraid to propose compromises, he suggested me (and MJ Ray who argued something similar than me) to try to bring life to the Debian Consultants list which (in his mind) would be more appropriate for one-man companies like mine. I accepted to help animate the list, and on his side, he s going to promote both the Debian Companies and the Debian Consultants lists. In any case, the list has seen some traffic lately and you re encouraged to join if you re a freelancer offering services around Debian. The most promising thing is that James Bromberger offered to implement a real database of consultants instead of the current static page. Book update We made quite some progress this month. There s only one chapter left to translate. I thus decided to start with proofreading. I made a call for volunteers and I submitted one (different) chapter to 5 proofreaders. The liberation campaign made a nice leap forwards thanks to good coverage on barrapunto.com. We have reached 80% while we were only at 72% at the start of the month (thanks to the 113 new supporters!). There s thus less than 5000 EUR to raise before the book gets published under a free license. Looking at the progression in the past months, this is unlikely to be completed on time for the release of the book in April. It would be nice though so please share the news around you. Speaking of the book s release, I m slowly preparing it. Translating docbook files is not enough, I must be able to generate HTML, ePub and PDF versions of the book. I m using Publican for most formats, but for the PDF version Publican is moving away of fop and the replacement (webkit-based) is far from being satisfactory to generate a book ready for print. So I plan to use dblatex and get Publican to support dblatex as a backend. I have hired Beno t Guillon, the upstream author of dblatex, to fix some annoying bugs and to improve it to suit my needs for the book (some results are already in the upstream CVS repository). I m also working with a professional book designer to get a nice design. I have also started to look for a Python Django developer to build the website that I will use to commercialize the book. The website will have a larger goal than just this though ( helping to fund free software developers ) but in free software it s always good to start with your own case. Hopefully everything will be ready in April. I m working hard to meet that deadline (you might have noticed that my blog has been relatively quiet in the last month ). Thanks See you next month for a new summary of my activities.

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For some time, we use Pootle as online translation tool for phpMyAdmin. It is indeed great tool, but somehow we seem to be hitting more and more issues with it and I feel it really won't fit nicely once we will want to support translations on two divergent branches. Also it's code base is not something easy to understand so that I would be able to fix bugs myself without major effort. So this is when I started to look for alternatives. Unfortunately there is nothing I could find what would work in way I want. I've looked at Transifex, Translatewiki, Crowdin and others whose names I've forgotten and I still haven't found what I'm looking for. The key feature I want from such system is full integration with git. This means that whatever is changed should be committed to local git branch and merging translations back should be as easy as merging remote branch. I've hacked such thing into Pootle (in quite dirty way), so this is basically workflow we have right now and I'm pretty much happy with that. Another thing (which seems to be existing in some tools) is support for simultaneous translation of more branches - if same string exists in more branches, it should be translated in all of them. And last but not least, it should support import of po files allowing users offline translation. Thinking about this I'm starting to thing that it should be pretty easy to implement something what I want using existing pieces of software without major effort. I'll probably start to play with Django, translate-tookit and GitPython to see if I can come up with something working reasonably well in few days... PS: Anybody working on updated GitPython packages for Debian, looks like I will need them soon :-).

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The Debian/Ubuntu games team recently organised a half-day screenshots party for creating screenshots for all the games that are available in Debian/Ubuntu. Unfortunately, only 5 people participated in the screenshots party, I had hoped that we would get more folks turn up. Only one of those was not already involved in the games team and that one person found out via our spam on the #debian-mentors IRC channel. This means that most of our promotion of the event was ineffective. Hopefully for future games parties we can improve this, please let us know if you have any ideas about that. We also had 7 other people on the channel during the party lurking, discussing and or working on other things, in particular Ben Armstrong was working on a games live CD. Over the 7 hours of the party, we uploaded 100 screenshots for 40 different packages. Of the packages, 2 are available only in Debian (auralquiz, cutechess), one is available only in Ubuntu (plasma-widget-tictactoe) and the rest are available in both. I think we got quite a bit done for such a small group. Some of us could not resist filing some bugs on packages that had issues preventing or delaying us from taking screenshots. I also suggested to one maintainer that his package (acm4) be removed from Debian, since it is obsoleted by acm and unusable. If you want to play some games, check out goplay, which is a tool for browsing available games using debtags that displays screenshots from the games-thumbnails package, which has just been updated with the screenshots created during the party. goplay needs some more development, if you would like to help out with that, you would be most welcome. If you are interested to see our screenshots, they are all on the screenshots.debian.net website and the packages are auralquiz, cardstories, londonlaw, cube2font, ardentryst, cutechess, pianobooster, emacs-chess, xye, flare, tmw, garden-of-coloured-lights, flight-of-the-amazon-queen, geekcode, glpeces, fofix, unknown-horizons, klickety, polygen, tictactoe, xscreensaver-screensaver-dizzy, goban-original-games, xjokes, mudlet, xabacus, xtux-client, connectagram, crystalspace, pescetti, purity-ng, qstat, slashem, sudoku, minetest, xscavenger, plasma-widget-tictactoe, xbomb, xfrisk, xpilot-ng and xsok.

SQLAlchemy, MySQL and sql_mode=traditional As everyone should know, by default MySQL is an embarassing stupid toy:

mysql> create table foo (val integer not null);
Query OK, 0 rows affected (0.03 sec)
mysql> insert into foo values (1/0);
ERROR 1048 (23000): Column 'val' cannot be null
mysql> insert into foo values (1);
Query OK, 1 row affected (0.00 sec)
mysql> update foo set val=1/0 where val=1;
Query OK, 1 row affected, 1 warning (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 1
mysql> select * from foo;
+-----+
  val  
+-----+
    0  
+-----+
1 row in set (0.00 sec)

Luckily, you can tell it to stop being embarassingly stupid:

mysql> set sql_mode="traditional";
Query OK, 0 rows affected (0.00 sec)
mysql> update foo set val=1/0 where val=0;
ERROR 1365 (22012): Division by 0

(There is an even better sql mode you can choose, though: it is called "Install PostgreSQL") Unfortunately, I've been hired to work on a project that relies on the embarassing stupid behaviour of MySQL, so I cannot set sql_mode=traditional globally or the existing house of cards will collapse. Here is how you set it session-wide with SQLAlchemy 0.6.x: it took me quite a while to find out:

import sqlalchemy.interfaces
# Without this, MySQL will silently insert invalid values in the
# database, causing very long debugging sessions in the long run
class DontBeSilly(sqlalchemy.interfaces.PoolListener):
    def connect(self, dbapi_con, connection_record):
        cur = dbapi_con.cursor()
        cur.execute("SET SESSION sql_mode='TRADITIONAL'")
        cur = None
engine = create_engine(..., listeners=[DontBeSilly()])

Why does it take all that effort is beyond me. I'd have expected this to be turned on by default, possibly with a switch that insane people could use to turn it off.

Also this year the Debian Project is running a booth at Chemnitzer Linux-Tage. Unfortunately this year we are lacking a bit manpower compared to the last years. Actually we have 6 persons at our wiki without knowing how much time everybody will be present at the booth. It would be really cool, if we can prevent us from having a D j vu.
So if you want to visit one of the best community focused OpenSource events in germany and can invest some time helping to run our booth, have a look into the report from last year and the organization wiki. If you feel you want to be part of this enjoyable event, please get in touch with me. As the registration for the booth is closing on 28th February, don t wait too long! ;)

Our society is one that is pretty well defined by timeliness. TV programs start at a precise time, down to the second. Schools have elaborate timekeeping systems. Even church services are carefully timed. We know how fast we re going, and our GPS or phones tell us when we ll get there. And we re pretty confident that we will, in fact, get there. Somehow this doesn t apply to our pickup. This pickup, in case you re wondering, is a thing of stories, shall we say. After a particularly frustrating experience with it one week (oh yes, the battle extended several days), I likened it to the Greek gods. And Terah had a good laughing fit when I began a sentence with The reason there s a towel connecting the brake pedal to the steering wheel But I guess the thrifty side of me won out, and somewhere along the line, I relented. My brother fixed up the carburetor. I got it a new battery. The flat tire is repaired. The starter broke, and I got it replaced. And I even got an oil change. Fancy, I know. So today, when I needed to take some backbreaking junk off the yard, I was hoping the pickup would work. I hadn t driven it in months, and any manner of catastrophe could have struck it in that time. So I was mildly relieved when it started on the 6th try. That is, quite seriously, quite the improvement, and shows how skilled a mechanic my brother is. The speedometer, of course, isn t working. The odometer stupidly reads 21531 or something like that (it was only a 5-digit odometer, broke long ago, so who knows how many miles it really has.) And I like to keep things like grease and heavy ancient air conditioners (one of the things I was hauling) away from my watch, so I wasn t wearing it. The result: I have no idea what time it is, how fast I m going, when I ll get there, IF I ll get there, or all those things. I set out, and made it a good half mile before it died as I was rounding a corner at the bottom of the hill. Always a great place for a finicky old stick-shift vehicle to die, right? Anyhow, a few random adjustments to the choke later, and the thing sputtered then roared (and I do mean roared) back to life. A little lurching up the hill and I was back on my way. Now, I was stuck there in the middle of the road, but it was a country road, so I d have probably had a good hour to get it fixed before worrying about blocking anybody s way. My first stop: my great uncle s place. He has a scrap metal for charity project going on. He is looking for old motors, air conditioners, dehumidifiers, etc. He takes them apart, separates out the metals, sells them, and donates the result to MCC, a world relief agency. I knew I had an old dehumidifier in the basement, and thought I remembered seeing an old window air conditioner in the elevator. That thing is probably the single heaviest object I have ever moved without help. I have a bandaid to prove it. It was way too heavy to carry, so I kind of rolled it, side to side, from the side of the elevator on to the pickup. If you were watching, you d have heard me making struggling noises, followed by BANG rattle rattle rattle pause struggling noises . BANG rattle rattle rattle as I rolled it along the ground, and waited for the internal bits to settle after each quarter turn. So anyway, eventually I got it to the pickup, and then had the sickening realization: I have no way to get this thing up there. Oops. I eventually placed it on top of an old tire rim, balanced it there as I knelt down, and somehow still not quite sure how managed to lift the entire thing a few feet until I could get some leverage to shove it onto the pickup. I later commented to my dad that it was a Chrysler brand air conditioner, somewhat to my surprise, and he said that it was probably my great-grandpa s. That was a surprise. Anyhow, back to the pickup. I drove down the few miles to my great grandpa s place, not really knowing how fast I was going. I smelled the familiar smells of the old pickup: exhaust fumes, oil on hot surfaces it shouldn t be on, a touch of hot antifreeze. You never have any doubt about whether the engine is running. It was sort of nice to not know, or particularly care, how fast I was going, or what time it was. Sometimes I d idly wonder, but you know, it didn t really matter and there wasn t a thing I could do about it anyhow. I got to uncle s place, unloaded the junk sorta dropped the air conditioner off the back of the pickup with a terrific BANG, then rolled it all the way to his trailer and got back in. On to town. I hadn t put gas in the pickup in a few years, and I suspected it was getting low. (The gas gauge, you guessed it, doesn t work right either.) Plus we had some large recyclables built up and it was time to get rid of them. And for that, I had to drive on the highway a ways. The speed limit there is 65MPH. I have no idea how fast I was going, but it wasn t 65. Maybe it was 45. I got passed a lot, but nobody looked particularly surprised that a pickup that looks like mine wasn t going 65. Partway there, I smelled a different smoke smell. Not an oil smoke, but more of a grassy or wood smoke. Hmm, I thought. That s odd. Hope it s not coming from the pickup. I didn t really see smoke anywhere else, so I just drove on until I couldn t smell it anymore. I unloaded the recyclables, then went to the gas station. As the pump readout neared $50, I decided: 1) the gas tank really was pretty empty, and 2) I just can t put more gas in it anymore. That would be more than the truck s worth. So I drove home. The drive home was into the wind. My face got pretty cold I always drive with the windows open to prevent carbon monoxide poisoning (remember the fumes?) I got home and prepared to pack up the pickup close the windows, replace the bungee cord holding the brake pedal up, etc. I then thought I d have a look under the hood to see if there was anything, well, on fire. Nope, but there was a packrat nest that fell down as soon as the wind hit it. Source of grassy-smelling smoke identified. It s amazing what difference simple lack of knowledge makes sometimes. Not knowing what time it is or how fast I m going means I don t have to worry about those things. I wonder how society has changed simply because accurate and cheap watches are available. I kind of like driving the old truck. It s a bit of an adventure, a bit of a challenge, a bit of randomness, and a bit of an escape from the normal and predictable. Not a bad deal for a $75 vehicle.

A little while ago, we ran into memory problems on mahara.org. It turned out to be due to the GD library having issues with large (as in height and width, not file size) images.

What we discovered is that the PHP memory limit (which is set to a fairly low value) only applies to actual PHP code, not C libraries like GD that are called from PHP. It's not obvious what PHP libraries are implemented as external C calls, which fall outside of the control of the interpreter, but anything that sounds like it's using some other library is probably not in PHP and is worth looking at.

To put a cap on the memory usage of Apache, we set process limits for the main Apache process and all of its children using ulimit.

Unfortunately, the limit we really wanted to change (resident memory or "-m") isn't implemented in the Linux kernel. So what we settled on was to limit the total virtual memory that an Apache process (or sub-process) can consume using "ulimit -v".

On a Debian box, this can be done by adding this to the bottom of /etc/default/apache2:

ulimit -v 1048576

for a limit of 1GB of virtual memory.

You can ensure that it works by setting it first to a very low value and then loading one of your PHP pages and seeing it die with some kind of malloc error.

I'm curious to know what other people do to prevent runaway Apache processes.

To use an SSH agent, one usually has to:

1. launch the agent;
2. add his key to it.

The first step can be automated in the desktop or shell startup script (this is a typical use case for login shell-only startup scripts, by the way), but the second one cannot if your private key is protected by a passphrase.Opportunistic key loading GNOME Keyring includes an SSH agent which has an interesting feature I call opportunistic key loading : it asks for the passphrase to decrypt the private key the first time it is needed. This feature mimics the behaviour of PGP agents, and eliminates the second step I previously mentioned. Question Do you know if there exists another SSH agent able to do opportunistic key loading?

I switched from Google Reader to Liferea a while back. I was mostly happy with the functionality of Reader but I don't really want my reading history to be recorded or my feed list to be vulnerable to the whim of Google's inscrutable abuse department. I'm still using Liferea but unfortunately it has a lot of problems. Yes I do have bug numbers:

• Calls sync() many times while refreshing feeds (#623619). This is probably related to use of SQLite and not properly batching writes. I work around this by using 'eatmydata' to nullify those calls, but that's not ideal.
• The UI thread also blocks on feed updates. Together with the previous bug, this can make it unresponsive for minutes while updating feeds (#542276).
• It often leaks memory and other resources when I play embedded video (#660593).
• There is no progress or 'busy' indicator for the browser (#660595).
• Error/prompt callbacks are not handled (#660597) - for example, if I follow a link that happens to lead to a PDF, nothing happens.
• There is no progress indicator for downloading 'enclosed' files (typically podcast episodes), and errors are simply ignored (#660599).
• While updating feeds, it may reset the item pane back to the summary (#660602).

So, I'm looking for an alternative again. My requirements are:

1. MAY be a desktop or web application.
2. If it's a web application, it MUST be reasonably secure, e.g. it must not be written in PHP.
3. If it's a web application, it MUST allow for multiple independent users on the same server.
4. If it's a desktop application, it MUST embed a browser engine (presumably Gecko or WebKit) so I can follow links without having to switch windows.
5. MUST support organisation of feeds by folders or tags, including combined item lists.
6. MUST keep track of which items have been read.
7. MUST support a global 'unread items' list. SHOULD only remove items from this list when I refresh it, not as soon as I move away from an item.
8. SHOULD support a three-pane (folder/list/item) view or something similar. Google Reader's list view with expanding items is perhaps even better, though it means links must be opened in a separate tab.
9. SHOULD support folder and item navigation by keyboard.
10. SHOULD have some way to flag/bookmark items for later attention.
11. If it's a desktop application, it SHOULD have some sort of download manager to support podcasts.

A few people have been using the license-count tool that I wrote to analyze the breakdown of licenses in Debian and draw some conclusions. Unfortunately, some of those conclusions can't be drawn from the output of this specific tool (which doesn't make them wrong, just unproven). So here are a few cautions. license-count was written for a specific purpose: to see how many references there are to a particular license in Debian so that we had some facts behind our discussion of whether to include it in common-licenses. It was not written to classify packages into particular categories, only to find out how many copies of a license we could save by adding it to common-licenses. This means that using it to determine how much software in Debian is covered by a particular license fails in the following ways:

1. license-count numbers cannot be added. Since the goal is to find every reference to a given license, each package is not classified as under one and only one license. If a package has material under the GPL, the LGPL, and the GFDL, it will add one to each of those counts. This means that you cannot determine, from its output, questions like "how many packages are covered under one of the GPL family of licenses?" You will double- or treble-count packages when you add the numbers together.
2. license-count counts any reference, not just "important" ones. If the license is referenced in debian/copyright, that counts, since the goal is to see how many packages might benefit from being able to reference it in common-licenses. This may not be the license that the package is under, just some small portion of the package. For example, all of my packages that use Autotools add to the GPL count because I include all the source code licensing statements, including the statements for libtool and the Automake helper scripts, which say that the files can be released under either the GPL or the license of the including package. These packages are generally under a BSD-style license (or in some cases the Apache 2.0 license), not under the GPL, but since the reproduced license text has a reference to the GPL, license-count adds one to the GPL column for each of those binary packages. For most purposes for counting GPL-covered software, these are false positives. I don't know how many people are as complete in documenting license statements as I am, but just the binary packages that I maintain probably count for at least 50 false positives because of this alone.
3. license-count numbers include dual-licensing. Whether this matters for your analysis or not depends on what question you're asking, of course. If you're asking whether the package is covered under a copyleft license, including the thousands of packages that are dual-licensed under the Artistic license and the GPL may be okay, since the Artistic license is a sort of copyleft (although it allows you to avoid the copyleft requirement by renaming executables, providing the originals, and documenting your changes). But, for example, one of my packages is dual-licensed under a BSD-style license and the GPL (for reasons that aren't worth getting into). This package is not covered by copyleft under any reasonable definition of the term, but license-count will count it as a package using the GPL.

In order to draw interesting conclusions like "how much software in Debian is protected by copyleft," I'm afraid that you'd have to write a much more sophisticated tool than license-count.

<style type="text/css"> @import "/pub/special-css/venk.css"; </style> My friend Venkatesh, pictured above, is going to bike four thousand miles, all the way across the continental US, from Baltimore to Portland. He's doing it to raise money for the Ulman Cancer Fund for Young Adults. I'm writing this because I want you to donate money to his cause. He's a DragonFly BSD developer, loves bikes, and your donation could make a big difference. I first met Venkatesh through the Johns Hopkins computer club, an ACM chapter. I was the head of the club, and he had just started his career at Hopkins. He was looking for advice on running Brickwiki, the LEGO encyclopedia. Quickly, I became his friend; in that time, I've learned the following things about him.

• He is friendly!
• He believes in science; beyond just writing sharp code, he likes to ask questions.
• He is melodramatically attracted to the power and complexity of biology. (The above quote about cancer are his words.)
• He wants to do something to make cancer less of a killer.

In the years since I graduated from Hopkins, I've been impressed by Venkatesh's ongoing curiosity and contributions to open source projects like DragonFly. I'm honored to have this chance to help him bike across the country for a good cause. Here is a quick word about the 4K for cancer effort:

Since 2002, groups of college students have undertaken a 70 day, 4000+ mile summer bike ride across the United States with the goal of offering hope, inspiration and support to cancer communities along the way. This past summer was our 10th year of cycling across the country as 76 volunteers rode along three different routes: Baltimore to San Francisco, Baltimore to Portland, and Baltimore to Seattle. Our riders raised a combined $476,000 to support organizations and individuals in the fight against cancer.

His fundraising goal is $5,000. Anything from $5 to $500 is a donation to an organization that helps young adult cancer surviers and their families get access to information and support resources. Can you help?

The new RcppArmadillo release 0.2.35 now supports the Rcpp::Rcout output stream device. Based on a contributed Rcpp patch by Jelper Ypma, the Rcpp::Rcout output stream gets redirected to R's buffered output. In other words, R's own output and that eminating from C++ code using Rcpp::Rcout are now both in sync. This avoids a stern warning from Section 5.6 in the Writing R Extensions manual:

Using C++ iostreams, as in this example, is best avoided. There is no guarantee that the output will appear in the R console, and indeed it will not on the R for Windows console. Use R code or the C entry points (*note Printing) for all I/O if at all possible.

and does in fact provide exactly what is recommended: the same entry points R itself uses. Below is a sample program, once again using the wonderful inline package to compile, load and link C++ code into R from a simple text variable submitted to the cxxfunction. What is shown in R code to load the package, the definition of the C++ code as assigned to a variable src and the creation of the dynamically-loadaded R function called fun which contains the code from we compiled, link and load via a single call to cxxfunction() given src.

library
library(inline)
src <- '
  Rcpp::Rcout << "Armadillo version: " << arma::arma_version::as_string() << std::endl;
  // directly specify the matrix size (elements are uninitialised)
  arma::mat A(2,3);
  // .n_rows = number of rows    (read only)
  // .n_cols = number of columns (read only)
  Rcpp::Rcout << "A.n_rows = " << A.n_rows << std::endl;
  Rcpp::Rcout << "A.n_cols = " << A.n_cols << std::endl;
  // directly access an element (indexing starts at 0)
  A(1,2) = 456.0;
  A.print("A:");
  // scalars are treated as a 1x1 matrix,
  // hence the code below will set A to have a size of 1x1
  A = 5.0;
  A.print("A:");
  // if you want a matrix with all elements set to a particular value
  // the .fill() member function can be used
  A.set_size(3,3);
  A.fill(5.0);
  A.print("A:");
  arma::mat B;
  // endr indicates "end of row"
  B << 0.555950 << 0.274690 << 0.540605 << 0.798938 << arma::endr
    << 0.108929 << 0.830123 << 0.891726 << 0.895283 << arma::endr
    << 0.948014 << 0.973234 << 0.216504 << 0.883152 << arma::endr
    << 0.023787 << 0.675382 << 0.231751 << 0.450332 << arma::endr;
  // print to the cout stream
  // with an optional string before the contents of the matrix
  B.print("B:");
  // the << operator can also be used to print the matrix
  // to an arbitrary stream (cout in this case)
  Rcpp::Rcout << "B:" << std::endl << B << std::endl;
  // save to disk
  B.save("B.txt", arma::raw_ascii);
  // load from disk
  arma::mat C;
  C.load("B.txt");
  C += 2.0 * B;
  C.print("C:");
  // submatrix types:
  //
  // .submat(first_row, first_column, last_row, last_column)
  // .row(row_number)
  // .col(column_number)
  // .cols(first_column, last_column)
  // .rows(first_row, last_row)
  Rcpp::Rcout << "C.submat(0,0,3,1) =" << std::endl;
  Rcpp::Rcout << C.submat(0,0,3,1) << std::endl;
  // generate the identity matrix
  arma::mat D = arma::eye<arma::mat>(4,4);
  D.submat(0,0,3,1) = C.cols(1,2);
  D.print("D:");
  // transpose
  Rcpp::Rcout << "trans(B) =" << std::endl;
  Rcpp::Rcout << trans(B) << std::endl;
  // maximum from each column (traverse along rows)
  Rcpp::Rcout << "max(B) =" << std::endl;
  Rcpp::Rcout << max(B) << std::endl;
  // maximum from each row (traverse along columns)
  Rcpp::Rcout << "max(B,1) =" << std::endl;
  Rcpp::Rcout << max(B,1) << std::endl;
  // maximum value in B
  Rcpp::Rcout << "max(max(B)) = " << max(max(B)) << std::endl;
  // sum of each column (traverse along rows)
  Rcpp::Rcout << "sum(B) =" << std::endl;
  Rcpp::Rcout << sum(B) << std::endl;
  // sum of each row (traverse along columns)
  Rcpp::Rcout << "sum(B,1) =" << std::endl;
  Rcpp::Rcout << sum(B,1) << std::endl;
  // sum of all elements
  Rcpp::Rcout << "sum(sum(B)) = " << sum(sum(B)) << std::endl;
  Rcpp::Rcout << "accu(B)     = " << accu(B) << std::endl;
  // trace = sum along diagonal
  Rcpp::Rcout << "trace(B)    = " << trace(B) << std::endl;
  Rcpp::Rcout << std::endl;
'
fun <- cxxfunction(signature(), body=src, plugin="RcppArmadillo")
setwd("/tmp")                           # adjust on other OSs
fun()                                   # output to stdout
sink("rcpparma.log.txt")                # start 'sink' to output to file
fun()                                   # no output to screen
sink()                                  # stop 'sink'

We then switch to a temporary directory (as the example code, taken from one of the two examples in Conrad's Armadillo sources, creates a temporary file) and run the new function. To demontrate how it does in fact now mesh perfectly with R, we create an output 'sink' (which catches all output) and re-run. This simple example demonstrated how we can use the new Rcout output stream from Rcpp to have dynamically-loaded C++ code cooperate more cleanly with the (buffered) R output. It also demontrated some of the nice features in Armadillo which we bring to R via RcppArmadillo.

Now that Rcpp 0.9.10 is released and on CRAN, other packages can take advantage of a small change needed to make use of the quasi-output stream Rcpp::Rcout. So the new release 0.2.35 of RcppArmadillo does just that---and input/output from Armadillo, the wonderful linear algebra / math library for C++ written chiefly by Conrad Sanderson now comes through in a coordinated buffered fashion. As as std::cout is no longer used by default, the R CMD check no longer flags this. There are two more bugfixes in the releases for issues noticed by attentive RcppArmadillo users. Teo Guo Ci spotted a missing semicolon when C++0x code was activated, and Gershon Bialer suggested a fix for an issue plagueing users of the jurassic g++ 4.2.1 compiler which Apple forces on users of OS X. We thank Martin Renner for testing these fixes. The NEWS entry below summarises the changes.

0.2.35  2012-02-17
    o   Upgraded to Armadillo release 2.4.3
          * Support for ARMA_DEFAULT_OSTREAM using Rcpp::Rcout added
    o   Minor bug fix release improving corner cases affecting builds:
          * Missing semicolon added in Mat_meat (when in C++0x mode), with
            thanks to Teo Guo Ci 
          * Armadillo version vars now instantiated in RcppArmadillo.cpp
            which helps older g++ versions, with thanks to Gershon Bialer
          * Thanks also to Martin Renner for testing these changes
          * Unit tests output fallback directory changed per Brian Ripley's
            request to not ever use /tmp
          * Minor update to version numbers in RcppArmadillo-package.Rd

Courtesy of CRANberries, there is also a diffstat reports for 0.2.35 relative to 0.2.34 As always, more detailed information is on the RcppArmadillo page. Questions, comments etc should go to the rcpp-devel mailing list off the R-Forge page.