My Dell PowerEdge T105 server (as referenced in my previous post [1]) is now working. It has new memory (why replace just the broken DIMM when you can replace both) and a new BIOS (Dell released an “Urgent” update yesterday that fixes a problem with memory timing and Opteron CPUs). The BIOS update can be installed from a DOS executable (traditionally done from a floppy disk) or an i386 Linux executable. As I didn’t have a floppy drive in my new server I had to use Linux (not that I object to using Linux, but I’d rather have had the technician do it all for me). I used rescue mode from a Fedora 9 CD that was convenient, mounted a USB stick that I had used to store the BIOS update, and then ran it. The Dell service was quite good, on-site service and the problem was fixed approximately 27 hours after I called them. Replacing a couple of DIMMs is hardly a test of skill for the repair-man (unlike the time in Amsterdam when a Dell repair-man swapped a motherboard in a server with only 20 minutes of down-time). So I haven’t seen evidence of them doing anything really great, but getting someone on-site close to 24 hours after the report is quite decent, especially considering that I paid for the cheapest support that they offer. When I got it working I was a little surprised by the memory speed, I had hoped that a new 2GHz Opteron would perform similarly to an Intel E2160 and better than an old Pentium-D (see the results here [2]). Also the memtest86+ run took ages on the step of writing random numbers (I don’t recall ever seeing that step on previous runs, let alone having a system spend half an hour doing it). It seems that the CPU (Opteron 1212) doesn’t perform well for random number generation. In terms of actual operation all I’ve done so far is to install Debian. The process of installing Debian packages was quite fast (even with a RAID-1 reconstruction occurring at the same time) and the boot time is also very quick. The hard drive “rails” seemed a little flimsy. The way they attach to the drive is that they have screws that end in pins, so you screw them into plastic and the pins just sit in the holes in the drive where screws normally attach. I think that it would make more sense to have them not screw onto the plastic and instead screw onto the disk. Then if the plastic part that connects the two sides was to break it would still be usable. In fact they could just make the “rails” be separate rails as most other manufacturers do. One thing that surprised me was the lack of PS/2 keyboard and mouse ports. I had expected that such ports would last longer than serial ports and floppy drives. However my Dell has a power connector for a floppy drive and has a built-in serial port (with some BIOS support for management via a serial port - I have not investigated this because I always plan to use a keyboard and monitor). Of course I expect that most other machines will start shipping without PS/2 ports now and I will have to dispose of my stockpile of PS/2 keyboards and mouses. I generally like to keep a few on hand so that I can give friends and relatives a chance to try a selection and discover which type suits them the best. But I probably don’t need a dozen of them for that purpose. While a comment on my previous post noted that the floppy drive bay can be used for another disk, it seems that a disk is not going to fit in there easily. It looks like I might be able to install a disk there from the front if I unscrew the face-plate - but that’s more effort than I’m prepared to exert for testing the system (for production I will only have two disks). In terms of noise, the Dell seems considerably better than a NEC machine which was designed for desktop use. Of course it’s difficult to be certain as part of the noise is from hard disks and one of the disks I’ve installed in the Dell is a WD “Green” disk and the other may have newer technology to minimise noise. Also the mounting brackets for disks in a server may be better at damping vibrations than screwing a disk to the chassis of a desktop machine. Finally the NEC machine does seem to make more noise now than it used to, so maybe it would be best to compare after a few months use to allow for minor wear on the moving parts. I was initially going to run Debian/Etch on the machine. But as Debian didn’t recognise the built-in Ethernet card and the Xen kernel crashed when doing intensive disk IO I was forced to use CentOS. CentOS 5.1 didn’t start my DomU’s for some reason (which I never diagnosed) but CentOS 5.2 worked perfectly. Finally I was shocked when I realised that the Dell has no sound hardware! When the CentOS post-install program said that it couldn’t find a sound device I thought that meant that it didn’t support the hardware (it’s the sort of thing that sometimes happens when you get a new machine). But it actually has no sound support! It seems really strange that Dell design a desk-side server (which is quiet) and don’t include sound support. If nothing else then using something like randomsound to take input from the microphone line as a source of entropy is going to be useful on servers. While the seven USB ports initially seemed like a lot, being forced to use them for keyboard, mouse, and sound (if I end up using it on a desktop) means that there would only be four left.

• [1] http://etbe.coker.com.au/2008/06/26/dell-poweredge-t105/


• [2] http://doc.coker.com.au/computers/ram-speed-memtest86/

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Late last year, I spent some time disentangling aptitude's internal UI library and packaging it as a separate library, which I named cwidget. This article is the first in what will hopefully become a series describing the basic concepts and APIs of cwidget. It applies to the versions of cwidget currently available in Debian sid and lenny, 0.5.11-1 and 0.5.12-1. Autogenerated documentation of cwidget can be found here (but beware that as of this writing it is somewhat incomplete).

---

In this tutorial, I will walk through a simple program (hello.cc) that initializes cwidget, displays a simple message box, and then terminates the program when the user confirms the message. I assume a basic familiarity with C++. The first thing to do is to include the portions of cwidget that our program will use. Most importantly, we need the top level cwidget routines. These are the global routines that initialize cwidget, shut it down, and control its main loop (among other things).

#include <cwidget/toplevel.h>

cwidget comes with a collection of stock dialog boxes for things like displaying messages to the user. To access the routines that build these dialogs, we write:

#include <cwidget/dialogs.h>

All the symbols provided by the cwidget library are in the cwidget namespace. Using the full library name means that there's a reasonable chance that its names will not conflict with the names provided by other libraries; however, it's a real pain to type cwidget over and over. Since this is the only namespaced library we are using in this program, it's handy to define cw as an alias for cwidget:

namespace cw = cwidget;

Now we're ready to write the main routine. The first interaction of client code with the cwidget library is to initialize it. This will initialize the ncurses library and put the terminal into a mode suitable for a full-screen curses program.

cw::toplevel::init();

Next, we create a dialog box that will be displayed to the user. There are two things to note about this code:

1. cwidget is Unicode-aware and the ok() routine expects the message string to be a wide-character string. In this case, that means that we need to pass in a wide-character string (indicated by typing L in front of the string).
2. The second argument tells cwidget what to do when the ok button is pressed. The expression

     sigc::ptr_fun(cw::toplevel::exitmain);
   

   creates a slot using libsigc++. Briefly, a slot is a reference to a function or to a method of a class instance. When invoked, this particular slot will call cwidget::toplevel::exitmain(), which causes the main cwidget loop to exit. The slot is wrapped in cwidget::util::arg, a utility function that handles passing slots as optional arguments.

cw::widgets::widget_ref dialog =
    cw::dialogs::ok(L"Hello, world!",
                    cw::util::arg(sigc::ptr_fun(cw::toplevel::exitmain)));

Now that we have a widget, the next step is to arrange for it to appear on the terminal. In cwidget, control of the terminal is assigned to a single top-level widget: whatever it displays is what gets displayed on the terminal, and all user input is passed directly to it. In a real program this widget will typically manage a collection of sub-widgets and assign each one a screen region, but for now let's just display the dialog box we created:

cw::toplevel::settoplevel(dialog);

With everything initialized, we're ready to start the main loop. mainloop() will keep the display up-to-date and dispatch incoming events (for instance, keystrokes and mouse presses) until exitmain() is invoked.

cw::toplevel::mainloop();

When the user presses Enter or clicks on the Ok button in the dialog, exitmain() will be invoked by the binding that we set up earlier. Once this happens, we need to shut down cwidget in order to restore the terminal to its original state. If you skip this step, the terminal will be garbled and will not work properly when your program exits.

cw::toplevel::shutdown();

And that's it! To compile the program, change to the directory containing hello.cc and run:

$ g++ -o hello hello.cc $(pkg-config --cflags --libs cwidget)

Of course, you'll need to have the g++ and libcwidget-dev packages installed for this to work!

Yesterday, my friend Marc had to visit a court in Barcelona, after being accussed for an electoral penalty. Marc has always had a strong Catalan sentiment, and fights for the independence of his country from the French and Spanish states in as many ways he finds convenient. In this direction, he's been involved in countless activities promoting independence, in the Internet and in the streets. For now, he has to deal with living in the Spanish state, and recently this became a legal problem. Spain held parlamentary elections in March, and Marc was appointed to serve at one of the polling stations in Barcelona. Believing he had nothing to do with an election process to elect the Spanish parliament, he conciously refused to take his seat during that Sunday, infringing the Spanish electoral law. He presented his allegations to the officer, and refused to declare anything else. He now faces a fine ranging from 180 to 1800 or community work (which he would, again, object to perform). The officer told him that he's apparently the first Catalan to object like this, so what will happen next (besides he'll have to sit in court and see how it goes) is unprecedented. While Marc and I don't share many of our political views, I admire his dedication and his solid defence of his ideals. If I had been called to serve in a polling station last March, I would most probably have had my own personal debate on what to do, but suspect I would have ended going there to avoid creating these kind of situations, and would have had to participate in a process that I consider broken, unfair and undemocratic. I admire and support Marc for being stubborn enough to get this far. His case has had quite some echo in the Catalan blogsphere and some Catalan media like VilaWeb. Some people have started a campaign to collect money to help Marc pay the fine. The response so far has been surprisingly positive. Marc, molta sort i una abra ada!

Well, the gauntlet is down (BTW - desktop power integration. Cool!). The use case Ted talks about is actually quite interesting - we were at UDS last month, waiting on a SVN server that was apparently so slow we could have walked to it and copied stuff onto harddisk more quickly. (Really. No kidding). bzr was idling and blocked on network IO the whole time... kudos for the plugin Ted! For my response, may I present a new index format, (branch url) 70% smaller than bzr's current default, equally fast at most workloads, up to 20 times faster at others. I started this this week, and John jumped in in overlapping time periods, but I think it counts! Note that the perfromance wins are a component improvement - other things we haven't addressed yet can make the index improvements less visible. But several early adopters have told me that they see a 25-30% reduction in 'time bzr log > /dev/null' or other commands. To install: bzr branch http://bazaar.launchpad.net/~lifeless/+junk/bzr-index2 ~/.bazaar/plugins/index2 bzr branch https://bazaar.launchpad.net/~jameinel/+junk/pybloom ~/.bazaar/plugins/pybloom To use: cd <repository you want to experiment on> bzr upgrade --btree-plain (or --btree-rich-root for bzr-svn users). A version of this will be going to trunk soon, and it will be able to upgrade from any repository that you have that uses the plugin as long as you keep the plugin installed.

It’s been a looong time since I blogged here. Perhaps I should write more frequently so you won’t start thinking I died silently ;). I’m not dead. It’s just that I’ve started a company a couple of months ago and that does take a lot of my time. It’s pretty exciting, - as you can imagine - we’re using Debian everywhere and the team is great. I’ll write another blog-entry about that later. In the meanwhile, I’m on holydays for a week, and I plan to squash my TODO list:

• Backup Manager (a couple of bugs have to be fixed)
• Electricsheep (a new upstream release is available)
• My Perl modules deserve a couple of maintenance too, like Coat::Persistent

We currently have fifteen cats in the house. Only three of them are ours. When Sarah was contracting at Google, she started an informal, but company-endorsed trap/neuter/release program, because the basement of buildings 40-43 had a bit of a stray/feral cat infestation. Since she left Google, she's continued doing trappings on an on and off basis. She got a call a couple of days ago about a litter of kittens behind one of the other buildings, so she headed off last night with one of her crazy cat lady friends, and they proceeded to catch one of the kittens. She brought that home, and I went back with her, and the mother, which seems fairly feral, had been caught in a trap. The rest of the kittens seemed to have managed to secrete themselves away inside a generator behind the building. This morning, with some help from various facilities types, she managed to extract the other four kittens from the generator. So that put the mother plus five kittens in the spare room (in a large cage). At more or less the same time, Sarah got news of a litter of six kittens that need rescuing from down Gilroy way (some woman in a trailer park didn't seem to realise that boy cat + girl cat = kittens), so after grabbing the other four kittens this morning, she headed off to Gilroy to grab them. So the current plan is to get the mother cat of what we'll call the Google litter desexed on Tuesday and then release her back where she came from. Her five kittens are young enough (~8 weeks) that they can be socialised and won't be feral. The six Gilroy kittens are from non-feral parents, and are about 11 weeks old. All of the kittens are old enough to be desexed as well, but Sarah can't get them into Palo Alto Animal Services for desexing for a couple of weeks, so I suspect we're stuck with them in the interim, unless Sarah can find foster homes for them. To cap it off, we're going to Sacramento for the weekend, so we have to get one of our friends in the complex to take care of them all. The sad thing is the Gilroy Six seem to be in worse condition than the Google Five. They've got pretty poor coats, and seem to have some diarrhoea. Hopefully with a better diet they'll pick up. They're all very cute. The first one of the Google Five that Sarah caught last night is particularly cute. I expect Sarah will get some photos of them all up soon. If anyone is in the Bay Area is interested in a kitten, we've got them by the near-dozen.

My Dell PowerEdge T105 server (as referenced in my previous post [1]) is now working. It has new memory (why replace just the broken DIMM when you can replace both) and a new BIOS (Dell released an “Urgent” update yesterday that fixes a problem with memory timing and Opteron CPUs). The BIOS update can be installed from a DOS executable (traditionally done from a floppy disk) or an i386 Linux executable. As I didn’t have a floppy drive in my new server I had to use Linux (not that I object to using Linux, but I’d rather have had the technician do it all for me). I used rescue mode from a Fedora 9 CD that was convenient, mounted a USB stick that I had used to store the BIOS update, and then ran it. The Dell service was quite good, on-site service and the problem was fixed approximately 27 hours after I called them. Replacing a couple of DIMMs is hardly a test of skill for the repair-man (unlike the time in Amsterdam when a Dell repair-man swapped a motherboard in a server with only 20 minutes of down-time). So I haven’t seen evidence of them doing anything really great, but getting someone on-site close to 24 hours after the report is quite decent, especially considering that I paid for the cheapest support that they offer. When I got it working I was a little surprised by the memory speed, I had hoped that a new 2GHz Opteron would perform similarly to an Intel E2160 and better than an old Pentium-D (see the results here [2]). Also the memtest86+ run took ages on the step of writing random numbers (I don’t recall ever seeing that step on previous runs, let alone having a system spend half an hour doing it). It seems that the CPU (Opteron 1212) doesn’t perform well for random number generation. In terms of actual operation all I’ve done so far is to install Debian. The process of installing Debian packages was quite fast (even with a RAID-1 reconstruction occurring at the same time) and the boot time is also very quick. The hard drive “rails” seemed a little flimsy. The way they attach to the drive is that they have screws that end in pins, so you screw them into plastic and the pins just sit in the holes in the drive where screws normally attach. I think that it would make more sense to have them not screw onto the plastic and instead screw onto the disk. Then if the plastic part that connects the two sides was to break it would still be usable. In fact they could just make the “rails” be separate rails as most other manufacturers do. One thing that surprised me was the lack of PS/2 keyboard and mouse ports. I had expected that such ports would last longer than serial ports and floppy drives. However my Dell has a power connector for a floppy drive and has a built-in serial port (with some BIOS support for management via a serial port - I have not investigated this because I always plan to use a keyboard and monitor). Of course I expect that most other machines will start shipping without PS/2 ports now and I will have to dispose of my stockpile of PS/2 keyboards and mouses. I generally like to keep a few on hand so that I can give friends and relatives a chance to try a selection and discover which type suits them the best. But I probably don’t need a dozen of them for that purpose. While a comment on my previous post noted that the floppy drive bay can be used for another disk, it seems that a disk is not going to fit in there easily. It looks like I might be able to install a disk there from the front if I unscrew the face-plate - but that’s more effort than I’m prepared to exert for testing the system (for production I will only have two disks). In terms of noise, the Dell seems considerably better than a NEC machine which was designed for desktop use. Of course it’s difficult to be certain as part of the noise is from hard disks and one of the disks I’ve installed in the Dell is a WD “Green” disk and the other may have newer technology to minimise noise. Also the mounting brackets for disks in a server may be better at damping vibrations than screwing a disk to the chassis of a desktop machine. Finally the NEC machine does seem to make more noise now than it used to, so maybe it would be best to compare after a few months use to allow for minor wear on the moving parts. One interesting feature is the Broadcom Gig-E port on the motherboard, it supports iSCSI as a boot protocol which is an interesting alternative to PXE, so if you have a server attached to a SAN via iSCSI you can use the same protocol for booting. There is a USB port inside the case (for permanently attached USB devices), however the USB boot option states that it is offering the option to boot from front USB ports - and it claims that no operating system is found on the USB stick that I use to boot my Thinkpad. The down-side is that the bnx2 module in the Debian/Etch kernel doesn’t seem to work with it. I want the machine to have three Ethernet ports, I have a two-port PCI card and if I can get the port on the motherboard to work then I’ll have enough. Otherwise I need to buy a PCIe Ethernet card (the machine only has one PCI slot). I ended up installing CentOS on the machine after the Debian/Etch Xen kernel started falling over on disk IO load (a problem I had seen on another Debian/Etch 64bit Xen machine). CentOS 5.1 supports the built-in Ethernet device, but didn’t work correctly with Xen (my DomU’s would just hang or abort). CentOS 5.2 is now working correctly.

• [1] http://etbe.coker.com.au/2008/06/26/dell-poweredge-t105/


• [2] http://doc.coker.com.au/computers/ram-speed-memtest86/

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One interesting aspect of the TED conference [1] is the fact that they only run one stream. There is one lecture hall with one presentation and everyone sees the same thing. This is considerably different to what seems to be the standard practice for Linux conferences (as implemented by LCA, OLS, and Linux Kongress) where there are three or more lecture halls with talks in progress at any time. At a Linux conference you might meet someone for lunch and start a conversation by asking “did you attend the lecture on X“, as there are more than two lecture halls the answer is most likely to be “no“, which then means that you have to describe the talk in question before talking about what you might really want to discuss (such as how a point made in the lecture in question might impact the work of the people you are talking two). In the not uncommon situation where there is an interesting implication of combining the work described in two lectures it might be necessary to summarise both lectures before describing the implication of combining the work. Now there are very good reasons for running multiple lecture rooms at Linux conferences. The range of topics is quite large and probably very few delegates will be interested in the majority of the talks. Usually the conference organisers attempt to schedule things to minimise the incidence of people missing talks that interest them, one common way of doing so is to have conference “streams”. Of course when you have for example a “networking” stream, a “security” stream, and a “virtualisation” stream then you will have problems when people are interested in the intersection of some of those areas (virtual servers do change things when you are working on network security). There seem some obvious comparisons between Planet installations (as aggregates of RSS feeds) and conferences (as aggregates of lectures). On Planet Debian [2] there has traditionally been a strong shared context with many blog posts referring to the same topics - where one person’s post has inspired others to write about similar topics. After some discussion (on blogs and by email) it was determined that there would be no policy for Planet Debian and that anyone who doesn’t want to read some of the content should filter the feed. Of course this means that the number of people who read (or at least skim) the entire feed will drop and therefore we lose the shared context. Planet Linux Australia [3] currently has a discussion about the issue of what types of content to aggregate. Michael Davies has just blogged a survey about what types of content to include [4]. I think it’s unfortunate that he decided to name the post after one blogger who’s feed is aggregated on that Planet as that will encourage votes on the specific posts written by that person rather than the general issue. But I think it’s much better to tailor a Planet to the interests of the people who read it than to include everything and encourage readers to read a sub-set. When similar issues were in discussion about Planet Debian I wrote about my ideas on the topic [5]. In summary I think that the Gentoo idea of having two Planet installations (one for the content which is most relevant and one for everything that is written by members) is a really good one. It’s also a good thing to have a semi-formal document about the type of content that is expected - this would be useful both for using a limited feed for people who go significantly off-topic and as a guideline for people who want to write posts that will be appreciated by the majority of the readers. Planet Ubuntu has a guideline, but it was not very formal last time I checked. Finally in regard to short posts, they generally don’t interest me much. If I want to get a list of hot URLs then I could go to any social media site to find some. I write a list post at most once a month, and I generally don’t include a URL in the list unless I have a comment to make about it. I always try to describe each page that I link to in enough detail that if the reader can’t view it then they at least have some idea of what it is about (no “this is cool” or “this sucks” links).

• [1] http://www.ted.com/


• [2] http://planet.debian.org/


• [3] http://planet.linux.org.au/


• [4] http://www.michaeldavies.org/weblog/tech/linux-australia/mikal-blather-poll.html


• [5] http://etbe.coker.com.au/2008/04/21/purpose-of-planet-debian/

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or ^C doesn’t kill processes, SIGINT does On the LUV mailing list recently, the perils of tty handling when booting with “init=/bin/bash” came up, and somebody asked why running ‘ping’ (without remembering to run stty or openvt first) will result in you having to reboot. i.e. “why doesn’t ^C work in emergency mode”? I wrote a fairly detailed, but comprehensible to a novice, answer and a friend suggested i should have written it as a blog post - which was the point of me setting up a blog in the first place. So here’s a slightly edited version of it: > Couldn’t you just open another console, run “top” and find the PID for
> ping and kill it? Or ps aux grep ping and kill it? Is a reboot the
> only way to kill a ping where ^C is not available? there’s nothing special about ^C except that by long convention it is mapped to the interrupt signal aka intr aka SIGINT. So, ^C itself doesn’t kill a program, the fact that it generates an interrupt signal does. If you’ve rebooted for emergency maintenance (e.g. “init=/bin/bash” on the LILO or GRUB command line) then all you get is ONE instance of /bin/bash. Nothing else is running and nothing else has been run (because you’ve overriden the usual init with /bin/bash). No setup has been done on the terminal, and no other virtual terminals have been opened. The emergency environment is minimal (and deliberately so - you asked for it, you got it). It’s up to you to do whatever is needed to set up the environment so that you can do the required maintenance/repair work. So if you run ping *before* remembering to set up the terminal (’stty sane’) then ^C doesn’t work because ^C doesn’t generate SIGINT so there’s no way of telling ping to quit, and if you haven’t opened another virtual terminal with openvt (aka “open” - it got renamed some time ago) then there is no other shell available to run top or ps or kill. BTW, it’s not just ping. You’ll see the same problem in the same environment with ANY program that runs continuously until it gets a signal to terminate it. ping’s just the most obvious and common example. Most programs, especially simple programs like ping, don’t have a ^C handler. They don’t need one. They have a signal handler which, amongst other things, handles SIGINT however it’s generated - it can be generated by pressing ^C in a normal tty environment, or by sending the program a SIGINT (e.g. “kill -2″). That, BTW, is a core difference between a SIGTERM (just plain ‘kill’ or ‘kill -15′) and SIGKILL (’kill -9′). SIGTERM is usually handled by the program by setting up a signal handler for it, and it voluntarily terminates when it receives the signal (usually cleaning up, closing files, etc before it does so). If the program hasn’t set up a handler for SIGTERM then the default action is to just terminate. A program can set up a handler which does nothing on SIGTERM, which effectively just ignores the signal. SIGKILL is handled by the kernel and it just kills the process immediately - it can not be blocked or intercepted by the program. (By common convention, SIGHUP or ‘kill -1′ tells a long running daemon process to just reload it’s config files. It’s also generated when the tty that the program is running on is terminated - e.g. you log out or the modem hangs up or the ssh session dies, hence the name “HUP” aka “HANGUP”. That’s why you need to use something like nohup or screen if you want a program to continue running after you log out) In a way, ‘kill’ is a bit of a misnomer. It’s actually a generic tool for sending signals to running processes, but the default action for most of those signals is to terminate the program. Here’s a list of the signals which can be sent.

$ kill -l
 1) SIGHUP	 2) SIGINT	 3) SIGQUIT	 4) SIGILL
 5) SIGTRAP	 6) SIGABRT	 7) SIGBUS	 8) SIGFPE
 9) SIGKILL	10) SIGUSR1	11) SIGSEGV	12) SIGUSR2
13) SIGPIPE	14) SIGALRM	15) SIGTERM	16) SIGSTKFLT
17) SIGCHLD	18) SIGCONT	19) SIGSTOP	20) SIGTSTP
21) SIGTTIN	22) SIGTTOU	23) SIGURG	24) SIGXCPU
25) SIGXFSZ	26) SIGVTALRM	27) SIGPROF	28) SIGWINCH
29) SIGIO	30) SIGPWR	31) SIGSYS	34) SIGRTMIN
35) SIGRTMIN+1	36) SIGRTMIN+2	37) SIGRTMIN+3	38) SIGRTMIN+4
39) SIGRTMIN+5	40) SIGRTMIN+6	41) SIGRTMIN+7	42) SIGRTMIN+8
43) SIGRTMIN+9	44) SIGRTMIN+10	45) SIGRTMIN+11	46) SIGRTMIN+12
47) SIGRTMIN+13	48) SIGRTMIN+14	49) SIGRTMIN+15	50) SIGRTMAX-14
51) SIGRTMAX-13	52) SIGRTMAX-12	53) SIGRTMAX-11	54) SIGRTMAX-10
55) SIGRTMAX-9	56) SIGRTMAX-8	57) SIGRTMAX-7	58) SIGRTMAX-6
59) SIGRTMAX-5	60) SIGRTMAX-4	61) SIGRTMAX-3	62) SIGRTMAX-2
63) SIGRTMAX-1	64) SIGRTMAX

See the man pages for init(8), kill(1), and especially signal(7) for more info on this topic. Syndicated from Craig Sanders' Errata: Tech Notes and Miscellaneous Thoughts Introduction to Linux Signals 101

So I am giving a talk this Friday at the University and here is the English introduction to my talk/paper and below is the Portuguese one. It starts at 9 am in Porto Alegre, Brazil and is being streamed. *O Departamento de P s-Gradua o da Antropologia e a Associa o Software Livre.org ...

Who knew that rants at Starbucks could be the subject of a seemingly interesting lingustic article.

Using OpenStreetMap maps with gpsdrive Here's how I made it:

1. wget http://download.geofabrik.de/osm/europe/italy.osm.bz2
2. bunzip2 italy.osm.bz2 (this might not be needed)
3. setup mapnik; the instructions for sid worked on my lenny/testing system.
4. osm2pgsql -c /store/italy.osm (you should not use -m with gpsdrive)
5. start gpsdrive and turn on mapnik mode. Originally it did not work for me, until I deleted ~/.gpsdrive/osm.xml.

This makes gpsdrive not only more useful, but also completely Free.

From Tuesday thingers, via Jules Jones:

Here is the Top 100 Most Popular Books on LibraryThing. Bold what you own, italicize what you’ve read. Star what you liked. Star multiple times what you loved!

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I just uploaded belpic 2.6.0-4, with a few minor changes, and one major one. The minor changes are, first, a fix to beid-register-pkcs11.html so that it tries to install libbeidpkcs11.so.2, rather than just the .so file, into iceweasel; otherwise you have to install the -dev package (or manually install the library, or change the .html file) to be able to use beid in your browser. Second, there were some typo fixes of which a bugreport had been open embarrasingly long. Oops. The major change, however, is the fact that the debian packages now no longer have support for OpenCT as an alternative to PC/SC Lite. This isn't actually supported by the belpic upstream; and while the Debian packages did include support for such cardreaders, I do have a feeling that it was causing some problems. So why did I include it in the first place, you ask? Well, because my very own cardreader wasn't supported by PC/SC Lite. You see, when I originally packaged the eID software back in 2004, most people didn't have an eID yet, let alone a cardreader; and the fairly common ACR38U-based smartcard readers that are thrown to people's heads these days were nowhere to be found yet. So, I googled for a smartcard manufacturer, found Gemplus who claimed Linux support for (at least some of) their models, found the distributor for Belgium, and ordered a smartcardreader. It did work with Linux allright—but OpenCT, only. Only later on did I find that belpic expects PC/SC Lite. In itself, this was no problem; the first versions of belpic (up to and including 2.3.13) did have the OpenCT and other reader drivers still compiled in, anyway; only with 2.5 and later did Zetes choose to remove them. That's when I started patching, and that's when I discovered that problems began... So, anyway. No more mr nice guy OpenCT. I needed to do my tax declaration, and since it'd been a while since I last tried to do some belpic stuff (since before the move, actually), I discovered that I couldn't find my cardreader anymore. So, I bought me a proper ACR38U-based one, and did my tax declarations before doing the upload. How's that for testing? In any case, if anyone beside me was using the OpenCT bits in belpic, they're now out of luck. Go get yourself an ACR38U-based reader—they're only 15ish, anyway...

I've been working hard on a new project for the last couple of months, which I'm glad to be able to share with you now. For the impatient: today my company Control Yourself, Inc. is launching Identi.ca, a new microblogging service. (There's a press release on the Control Yourself site). Users can post short messages about themselves to Identi.ca, which are then broadcast to friends in their social network using instant messages (IM), RSS feeds, and the Web. The difference between Identi.ca and other services like Twitter, Jaiku, or Pownce is that it is Open Source software. I tried to meet the requirements of the Open Service Definition -- Free Software and Free Data. In the same spirit, Identi.ca supports open standards like OpenID and OpenMicroBlogging, to integrate with other Web sites and services. A little background: in March of this year, I was privileged to take part in a summit at the Free Software Foundation about open network services. The summit brought together a number of people involved in Open Source and Open Content to discuss problems with "software as a service" and how to solve them. More and more, people are depending on Web sites and other network services "in the cloud" to do much of their computing tasks. Examples: using Yahoo! Maps instead of a desktop mapping application, or using Google Docs instead of Microsoft Word. Software-as-a-service can be extremely convenient -- data on remote servers stays up-to-date, software gets updated regularly, and you can use different computers or mobile devices to get at the same data. The sacrifice, however, is user autonomy. If you decide that Google Docs doesn't work the way you want, you can't tinker with the software and fix it. If you want to share a map on your Web site, you need Yahoo!'s permission. If you want to use a new social networking site, you have to re-enter all your personal data and re-invite all your friends. The data and code belong to someone else, and they're hidden behind servers that you, the user, aren't allowed to touch. There aren't a lot of clear answers to this. But our loosely-organized summit group is moving forward to promote and support Free/Open Network Services. These are Web sites (or other services) that use Free/Open Source software (with the source available) and provide Open Content data (except for data that users mark as private). There are a lot of them popping up -- like OpenStreetMap and Wikipedia. Others are close on the software side, although the data side is a little less clear -- like Wordpress.com, Reddit, or LiveJournal. After the summit, I wanted to try to see what I could do personally to further this mission. I think several of the sites I work on now -- like Vinismo and Keiki -- would qualify. But I also wanted to break some new ground and challenge people's assumptions about software services. And the services I was using, and getting invited to, the most were microblogging sites. Clearly that was the area to dig into further. To do it, I started Laconica, the software underlying Identi.ca. It's AGPL'd PHP using MySQL as a backend -- probably the most accessible platform on the planet right now. I used lots of existing libraries to make development easier, and I hired a great designer (Montreal's Marie-Claude Doyon) to give the site a professional look. Almost as important as the Open Source and Open Content is the distributed nature of Identi.ca. I designed an open protocol called OpenMicroBlogging, based on OAuth, to make it easy for users on one Laconica server to subscribe to notices by users on another server. I hope this will make the service more robust, develop a rich and diverse social network, and stimulate innovation. Because in the end, that's the Internet that we all want to be part of. As a society we rejected "walled gardens" like AOL, Compuserve, and MSN in the early 90s in favor of the distributed, open nature of the World Wide Web. And I think that the new walled gardens like Facebook and Google, need to be replaced with open protocols and standards. Will Open Network Services be the basis of "Web 3.0", the next stage of Web culture? I truly think so, but that's still an open question. People have been using Identi.ca for a few weeks now, although I've asked that folks wait until the software was more mature before posting public links. Today I'm lifting that embargo and asking friends and colleagues to join and participate in the conversation. I hope that people who are sympathetic with the ideals of Identi.ca will take the time to blog about it, invite their friends, and start using the site regularly. And of course I'd love to get feedback on bugs, requested features, and ideas for the future. Please also subscribe to me on the site -- see http://identi.ca/evan -- so I can see who's out there. There are still so many standard services on the Web that I'd like to see open sourced, open content, and distributed -- advertising, storage, image and file sharing, comments, portal pages, social news, social bookmarks, search engines. There's a real business potential for taking the lead in these areas, and I hope more people jump in.

Recently the number of open bugs that I had submitted hit 100. I had completely lost track of which bugs I was interested in, which ones needed my attention, etc. so I started developing a prototype tool to try and help me keep track of it all. I've called it "debgtd", after getting things done, the self-improvement method which has proven very popular in IT culture. The current prototype will import the list of bugs that you have submitted from the BTS and let you display them sorted either by severity or package name. You can "sleep" a bug if it does not require your attention at present (e.g. awaiting maintainer feedback), or "ignore" it if you no longer want to keep track of it (e.g. you've stopped using the package in question). Double-clicking a row invokes your system's default X web browser on the bug page. This is enough at the moment to help me work through my backlog, although once I've done that I have ambitious plans for encoding more workflow into it (such as waking sleeping bugs up on events etc.). Try it out and see what you think: : code and a more rambling explanation of plans for the tool are available here. It's written in python and uses pygtk for the UI.

At the last two meetings of LUV [1] I’ve given away old hardware. This month I gave away a bunch of old PCI and AGP video cards, a heap of PC power cables, and some magnets (which I received for free because they were in defective toys that could seriously injure or kill children). One new member was particularly happy that at the first meeting he attended he received some free hardware (I hope it works - most of that stuff hasn’t been tested for over a year and I expect that some would fail). Also there was another guy giving away hardware, so I might have started a trend of giving away unused hardware at meetings (he was giving away some new stuff in the original boxes, mostly USB and firewire cables). For a long time (many years) at LUV meetings there have been free text books given away. One member reviews books and then gives them away after he has read them. At the meeting Ralph Becket gave a presentation on the Mercury functional language. It was interesting to note that Mercury can give performance that is close to C (within 80%) on LZW compression (which is apparently used as a benchmark for comparing languages). Given the number of reasonably popular languages which don’t give nearly that level of performance I think that this is quite a good result. After the meeting Richard Keech demonstrated his electric car. It’s a Hyundai Getz which has had the engine replaced by an electric motor but which still uses the manual gearbox. Richard did a bit of driving around with various LUV members as passengers to demonstrate what the car can do. Unfortunately I didn’t get a chance to be involved in that, so I’ll have to do so next time I meet him. One thing to note is that Richard’s car was not built that way by Hyundai, it was a custom conversion job. The down-side to this of course is that it would have cost significantly more than a vehicle with the same technology that was manufactured. One design trade-off is that Richard had batteries installed in the place for a spare tire. Last year the RACV magazine published a letter I wrote suggesting that small cars should be designed without a spare tire and that owners of such cars should rely on the RACV to support them if they get a flat tire [2], my option has not changed in the last year, I still think that cars which are driven in urban areas don’t really need spare tires so I don’t think that Richard is losing anything in this regard. The motor driving Richard’s car runs on three-phase AC and a solid-state inverter is used to convert 185V DC to about the same voltage at three phase AC (I didn’t write notes so I’m running from memory). Apparently on long drives the inverter gets cooler rather than hotter - I had expected that there would be enough inefficiency in the process of converting DC to AC that it would get hot. In a previous conversation Richard told me that he can drive his car 75Km on one charge and that it takes him 8 hours to charge when using an Australian mains (240V) plug rated at 10A. When designing such a vehicle it would be trivial to make it use a 20A plug for a 4 hour charge or even a two-phase plug for even shorter charging (I’m sure that Richard could have requested these options if he wanted them). But an 8 hour charge allows the vehicle to be completely charged during a working day and the use of the most common type of plug (the type used in every home and office) means that it can be charged almost anywhere (the standard mains circuit used in Australia is rated at 15A so special wiring is needed for a 20A socket). There is such a power point mounted on the outside of my house not too far from where a visitor could park their car. I anticipate that in a few years time it will not be uncommon for people who visit me to charge their car during their visit. Richard’s ratio of an hour of charge to almost 10Km of driving means that someone who visits for dinner could get enough charge into their car to allow for 30Km of driving before they leave. 30Km is about the driving distance to go from my house to a location on the other side of the city that is just outside the main urban area, so probably at least half of Melbourne’s population lives within a 30Km driving distance from my house. Not that I expect friends to arrive at my house with their car battery almost flat, but it does make it easier to plan a journey if you know that at point A you will be able to get enough charge to get you to point B. I think it’s a good thing to have members of LUGs give things away to other people and to demonstrate technology that is of wide interest. I hope to see more of it.

• [1] http://www.luv.asn.au/


• [2] http://etbe.coker.com.au/2007/03/02/spare-tires/

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I am in the process of packing my stuff for my holidays. Tomorrow, I will fly to Istanbul to attend GUADEC 2008. Because GUADEC does not start before the 7th, it will give me some time to roam around Istanbul itself and do some sightseeing, probably with some of the Collabora guys. I’m flying on July 3 at 12:00 (+0200) from Schiphol with KLM (flight KL 1615) and arrive at Istanbul Atat rk International Airport at 16:20 (+0300). I’ll return on July 13 at 17:15 (+0300), again with KLM (flight KL 1616), and land on Schiphol at 19:55 (+0200). In Istanbul I will be staying in the Saint Sophia Hotel in Sultanahmet. I’m looking forward to it, although it doesn’t feel like holidays to me yet. I should have an Internet connection over there, and probably Jaiku via cell phone will work fine too. So I will keep you up-to-date. It is also clear that I will be skipping DebConf this year. This is unfortunate, because I wanted to work with the Debian/Ruby team to advance some of our goals. However, I’m happy to catch at least one free software conference.

As of 09:53am CEST today, I am officially available for hire starting mid-August, and looking for a job. I’m going to enjoy some time off in the nice, sunny weather we’ve got here these days and I’ll have some time again to try and add proper support for the Intel Macs to d-i. Not that bad after all.