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  13  <h1>
  14      <a href="http://people.skolelinux.org/pere/blog/">Petter Reinholdtsen</a>
  15
  16  </h1>
  17
  18 </div>
  19
  20
  21     <h3>Entries tagged "nice free software".</h3>
  22
  23     <div class="entry">
  24       <div class="title">
  25         <a href="http://people.skolelinux.org/pere/blog/PlantUML_for_text_based_UML_diagram_modelling___nice_free_software.html">PlantUML for text based UML diagram modelling - nice free software</a>
  26       </div>
  27       <div class="date">
  28         25th March 2019
  29       </div>
  30       <div class="body">
  31         <p>As part of my involvement with the
  32 <a href="https://gitlab.com/OsloMet-ABI/nikita-noark5-core/">Nikita
  33 Noark 5 core project</a>, I have been proposing improvements to the
  34 API specification created by <a href="https://www.arkivverket.no/">The
  35 National Archives of Norway</a> and helped migrating the text from a
  36 version control system unfriendly binary format (docx) to Markdown in
  37 git.  Combined with the migration to a public git repository (on
  38 github), this has made it possible for anyone to suggest improvement
  39 to the text.</p>
  40
  41 <p>The specification is filled with UML diagrams.  I believe the
  42 original diagrams were modelled using Sparx Systems Enterprise
  43 Architect, and exported as EMF files for import into docx.  This
  44 approach make it very hard to track changes using a version control
  45 system.  To improve the situation I have been looking for a good text
  46 based UML format with associated command line free software tools on
  47 Linux and Windows, to allow anyone to send in corrections to the UML
  48 diagrams in the specification.  The tool must be text based to work
  49 with git, and command line to be able to run it automatically to
  50 generate the diagram images.  Finally, it must be free software to
  51 allow anyone, even those that can not accept a non-free software
  52 license, to contribute.</p>
  53
  54 <p>I did not know much about free software UML modelling tools when I
  55 started.  I have used dia and inkscape for simple modelling in the
  56 past, but neither are available on Windows, as far as I could tell.  I
  57 came across a nice
  58 <a href="https://modeling-languages.com/text-uml-tools-complete-list/">list
  59 of text mode uml tools</a>, and tested out a few of the tools listed
  60 there.  <a href="http://plantuml.com/">The PlantUML tool</a> seemed
  61 most promising.  After verifying that the packages
  62 <a href="https://tracker.debian.org/pkg/plantuml">is available in
  63 Debian</a> and found <a href="https://github.com/plantuml/plantuml">its
  64 Java source</a> under a GPL license on github, I set out to test if it
  65 could represent the diagrams we needed, ie the ones currently in
  66 <a href="https://github.com/arkivverket/noark5-tjenestegrensesnitt-standard/">the
  67 Noark 5 Tjenestegrensesnitt specification</a>.  I am happy to report
  68 that it could represent them, even thought it have a few warts here
  69 and there.</p>
  70
  71 <p>After a few days of modelling I completed the task this weekend.  A
  72 temporary link to the complete set of diagrams (original and from
  73 PlantUML) is available in
  74 <a href="https://github.com/arkivverket/noark5-tjenestegrensesnitt-standard/issues/76">the
  75 github issue discussing the need for a text based UML format</a>, but
  76 please note I lack a sensible tool to convert EMF files to PNGs, so
  77 the "original" rendering is not as good as the original was in the
  78 publised PDF.</p>
  79
  80 <p>Here is an example UML diagram, showing the core classes for
  81 keeping metadata about archived documents:</p>
  82
  83 <pre>
  84 @startuml
  85 skinparam classAttributeIconSize 0
  86
  87 !include media/uml-class-arkivskaper.iuml
  88 !include media/uml-class-arkiv.iuml
  89 !include media/uml-class-klassifikasjonssystem.iuml
  90 !include media/uml-class-klasse.iuml
  91 !include media/uml-class-arkivdel.iuml
  92 !include media/uml-class-mappe.iuml
  93 !include media/uml-class-merknad.iuml
  94 !include media/uml-class-registrering.iuml
  95 !include media/uml-class-basisregistrering.iuml
  96 !include media/uml-class-dokumentbeskrivelse.iuml
  97 !include media/uml-class-dokumentobjekt.iuml
  98 !include media/uml-class-konvertering.iuml
  99 !include media/uml-datatype-elektronisksignatur.iuml
 100
 101 Arkivstruktur.Arkivskaper "+arkivskaper 1..*" <-o "+arkiv 0..*" Arkivstruktur.Arkiv
 102 Arkivstruktur.Arkiv o--> "+underarkiv 0..*" Arkivstruktur.Arkiv
 103 Arkivstruktur.Arkiv "+arkiv 1" o--> "+arkivdel 0..*" Arkivstruktur.Arkivdel
 104 Arkivstruktur.Klassifikasjonssystem "+klassifikasjonssystem [0..1]" <--o "+arkivdel 1..*" Arkivstruktur.Arkivdel
 105 Arkivstruktur.Klassifikasjonssystem "+klassifikasjonssystem [0..1]" o--> "+klasse 0..*" Arkivstruktur.Klasse
 106 Arkivstruktur.Arkivdel "+arkivdel 0..1" o--> "+mappe 0..*" Arkivstruktur.Mappe
 107 Arkivstruktur.Arkivdel "+arkivdel 0..1" o--> "+registrering 0..*" Arkivstruktur.Registrering
 108 Arkivstruktur.Klasse "+klasse 0..1" o--> "+mappe 0..*" Arkivstruktur.Mappe
 109 Arkivstruktur.Klasse "+klasse 0..1" o--> "+registrering 0..*" Arkivstruktur.Registrering
 110 Arkivstruktur.Mappe --> "+undermappe 0..*" Arkivstruktur.Mappe
 111 Arkivstruktur.Mappe "+mappe 0..1" o--> "+registrering 0..*" Arkivstruktur.Registrering
 112 Arkivstruktur.Merknad "+merknad 0..*" <--* Arkivstruktur.Mappe
 113 Arkivstruktur.Merknad "+merknad 0..*" <--* Arkivstruktur.Dokumentbeskrivelse
 114 Arkivstruktur.Basisregistrering -|> Arkivstruktur.Registrering
 115 Arkivstruktur.Merknad "+merknad 0..*" <--* Arkivstruktur.Basisregistrering
 116 Arkivstruktur.Registrering "+registrering 1..*" o--> "+dokumentbeskrivelse 0..*" Arkivstruktur.Dokumentbeskrivelse
 117 Arkivstruktur.Dokumentbeskrivelse "+dokumentbeskrivelse 1" o-> "+dokumentobjekt 0..*" Arkivstruktur.Dokumentobjekt
 118 Arkivstruktur.Dokumentobjekt *-> "+konvertering 0..*" Arkivstruktur.Konvertering
 119 Arkivstruktur.ElektroniskSignatur -[hidden]-> Arkivstruktur.Dokumentobjekt
 120 @enduml
 121 </pre>
 122
 123 <p><a href="http://plantuml.com/class-diagram">The format</a> is quite
 124 compact, with little redundant information.  The text expresses
 125 entities and relations, and there is little layout related fluff.  One
 126 can reuse content by using include files, allowing for consistent
 127 naming across several diagrams.  The include files can be standalone
 128 PlantUML too.  Here is the content of
 129 <tt>media/uml-class-arkivskaper.iuml<tt>:</p>
 130
 131 <pre>
 132 @startuml
 133 class Arkivstruktur.Arkivskaper <Arkivenhet> {
 134   +arkivskaperID : string
 135   +arkivskaperNavn : string
 136   +beskrivelse : string [0..1]
 137 }
 138 @enduml
 139 </pre>
 140
 141 <p>This is what the complete diagram for the PlantUML notation above
 142 look like:</p>
 143
 144 <p><img width="80%" src="http://people.skolelinux.org/pere/blog/images/2019-03-25-noark5-plantuml-diagrameksempel.png"></p>
 145
 146 <p>A cool feature of PlantUML is that the generated PNG files include
 147 the entire original source diagram as text.  The source (with include
 148 statements expanded) can be extracted using for example
 149 <tt>exiftool</tt>.  Another cool feature is that parts of the entities
 150 can be hidden after inclusion.  This allow to use include files with
 151 all attributes listed, even for UML diagrams that should not list any
 152 attributes.</p>
 153
 154 <p>The diagram also show some of the warts.  Some times the layout
 155 engine place text labels on top of each other, and some times it place
 156 the class boxes too close to each other, not leaving room for the
 157 labels on the relationship arrows.  The former can be worked around by
 158 placing extra newlines in the labes (ie "\n").  I did not do it here
 159 to be able to demonstrate the issue.  I have not found a good way
 160 around the latter, so I normally try to reduce the problem by changing
 161 from vertical to horizontal links to improve the layout.</p>
 162
 163 <p>All in all, I am quite happy with PlantUML, and very impressed with
 164 how quickly its lead developer responds to questions.  So far I got an
 165 answer to my questions in a few hours when I send an email.  I
 166 definitely recommend looking at PlantUML if you need to make UML
 167 diagrams.  Note, PlantUML can draw a lot more than class relations.
 168 Check out the documention for a complete list. :)</p>
 169
 170 <p>As usual, if you use Bitcoin and want to show your support of my
 171 activities, please send Bitcoin donations to my address
 172 <b><a href="bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b">15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b</a></b>.</p>
 173
 174       </div>
 175       <div class="tags">
 176
 177
 178         Tags: <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/nice free software">nice free software</a>, <a href="http://people.skolelinux.org/pere/blog/tags/noark5">noark5</a>, <a href="http://people.skolelinux.org/pere/blog/tags/nuug">nuug</a>, <a href="http://people.skolelinux.org/pere/blog/tags/standard">standard</a>.
 179
 180
 181       </div>
 182     </div>
 183     <div class="padding"></div>
 184
 185     <div class="entry">
 186       <div class="title">
 187         <a href="http://people.skolelinux.org/pere/blog/Measuring_the_speaker_frequency_response_using_the_AUDMES_free_software_GUI___nice_free_software.html">Measuring the speaker frequency response using the AUDMES free software GUI - nice free software</a>
 188       </div>
 189       <div class="date">
 190         22nd October 2018
 191       </div>
 192       <div class="body">
 193         <p><img src="http://people.skolelinux.org/pere/blog/images/2018-10-22-audmes-measure-speakers.png" align="right" width="40%"/></p>
 194
 195 <p>My current home stereo is a patchwork of various pieces I got on
 196 flee markeds over the years.  It is amazing what kind of equipment
 197 show up there.  I've been wondering for a while if it was possible to
 198 measure how well this equipment is working together, and decided to
 199 see how far I could get using free software.  After trawling the web I
 200 came across an article from DIY Audio and Video on
 201 <a href="https://www.diyaudioandvideo.com/Tutorial/SpeakerResponseTesting/">Speaker
 202 Testing and Analysis</a> describing how to test speakers, and it listing
 203 several software options, among them
 204 <a href="https://sourceforge.net/projects/audmes/">AUDio MEasurement
 205 System (AUDMES)</a>.  It is the only free software system I could find
 206 focusing on measuring speakers and audio frequency response.  In the
 207 process I also found an interesting article from NOVO on
 208 <a href="http://novo.press/understanding-speaker-specifications-and-frequency-response/">Understanding
 209 Speaker Specifications and Frequency Response</a> and an article from
 210 ecoustics on
 211 <a href="https://www.ecoustics.com/articles/understanding-speaker-frequency-response/">Understanding
 212 Speaker Frequency Response</a>, with a lot of information on what to
 213 look for and how to interpret the graphs.  Armed with this knowledge,
 214 I set out to measure the state of my speakers.</p>
 215
 216 <p>The first hurdle was that AUDMES hadn't seen a commit for 10 years
 217 and did not build with current compilers and libraries.  I got in
 218 touch with its author, who no longer was spending time on the program
 219 but gave me write access to the subversion repository on Sourceforge.
 220 The end result is that now the code build on Linux and is capable of
 221 saving and loading the collected frequency response data in CSV
 222 format.  The application is quite nice and flexible, and I was able to
 223 select the input and output audio interfaces independently.  This made
 224 it possible to use a USB mixer as the input source, while sending
 225 output via my laptop headphone connection.  I lacked the hardware and
 226 cabling to figure out a different way to get independent cabling to
 227 speakers and microphone.</p>
 228
 229 <p>Using this setup I could see how a large range of high frequencies
 230 apparently were not making it out of my speakers.  The picture show
 231 the frequency response measurement of one of the speakers.  Note the
 232 frequency lines seem to be slightly misaligned, compared to the CSV
 233 output from the program.  I can not hear several of these are high
 234 frequencies, according to measurement from
 235 <a href="http://freehearingtestsoftware.com">Free Hearing Test
 236 Software</a>, an freeware system to measure your hearing (still
 237 looking for a free software alternative), so I do not know if they are
 238 coming out out the speakers.  I thus do not quite know how to figure
 239 out if the missing frequencies is a problem with the microphone, the
 240 amplifier or the speakers, but I managed to rule out the audio card in my
 241 PC by measuring my Bose noise canceling headset using its own
 242 microphone.  This setup was able to see the high frequency tones, so
 243 the problem with my stereo had to be in the amplifier or speakers.</p>
 244
 245 <p>Anyway, to try to role out one factor I ended up picking up a new
 246 set of speakers at a flee marked, and these work a lot better than the
 247 old speakers, so I guess the microphone and amplifier is OK.  If you
 248 need to measure your own speakers, check out AUDMES.  If more people
 249 get involved, perhaps the project could become good enough to
 250 <a href="https://bugs.debian.org/910876">include in Debian</a>?  And if
 251 you know of some other free software to measure speakers and amplifier
 252 performance, please let me know.  I am aware of the freeware option
 253 <a href="https://www.roomeqwizard.com/">REW</a>, but I want something
 254 that can be developed also when the vendor looses interest.</p>
 255
 256 <p>As usual, if you use Bitcoin and want to show your support of my
 257 activities, please send Bitcoin donations to my address
 258 <b><a href="bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b">15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b</a></b>.</p>
 259
 260       </div>
 261       <div class="tags">
 262
 263
 264         Tags: <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/nice free software">nice free software</a>.
 265
 266
 267       </div>
 268     </div>
 269     <div class="padding"></div>
 270
 271     <div class="entry">
 272       <div class="title">
 273         <a href="http://people.skolelinux.org/pere/blog/youtube_dl_for_nedlasting_fra_NRK_med_undertekster___nice_free_software.html">youtube-dl for nedlasting fra NRK med undertekster - nice free software</a>
 274       </div>
 275       <div class="date">
 276         28th April 2018
 277       </div>
 278       <div class="body">
 279         <p>I <a href="https://no.wikipedia.org/wiki/VHS">VHS-kassettenes</a>
 280 tid var det rett frem å ta vare på et TV-program en ønsket å kunne se
 281 senere, uten å være avhengig av at programmet ble sendt på nytt.
 282 Kanskje ønsket en å se programmet på hytten der det ikke var
 283 TV-signal, eller av andre grunner ha det tilgjengelig for fremtidig
 284 fornøyelse.  Dette er blitt vanskeligere med introduksjon av
 285 digital-TV og webstreaming, der opptak til harddisk er utenfor de
 286 flestes kontroll hvis de bruker ufri programvare og bokser kontrollert
 287 av andre.  Men for NRK her i Norge, finnes det heldigvis flere fri
 288 programvare-alternativer, som jeg har
 289 <a href="http://people.skolelinux.org/pere/blog/Hvordan_enkelt_laste_ned_filmer_fra_NRK.html">skrevet</a>
 290 <a href="http://people.skolelinux.org/pere/blog/Hvordan_enkelt_laste_ned_filmer_fra_NRK_med_den__nye__l_sningen.html">om</a>
 291 <a href="http://people.skolelinux.org/pere/blog/Nedlasting_fra_NRK__som_Matroska_med_undertekster.html">før</a>.
 292 Så lenge kilden for nedlastingen er lovlig lagt ut på nett (hvilket
 293 jeg antar NRK gjør), så er slik lagring til privat bruk også lovlig i
 294 Norge.</p>
 295
 296 <p>Sist jeg så på saken, i 2016, nevnte jeg at
 297 <a href="https://rg3.github.com/youtube-dl/">youtube-dl</a> ikke kunne
 298 bake undertekster fra NRK inn i videofilene, og at jeg derfor
 299 foretrakk andre alternativer.  Nylig oppdaget jeg at dette har endret
 300 seg.  Fordelen med youtube-dl er at den er tilgjengelig direkte fra
 301 Linux-distribusjoner som <a href="https://www.debian.org/">Debian</a>
 302 og <a href="https://www.ubuntu.com/">Ubuntu</a>, slik at en slipper å
 303 finne ut selv hvordan en skal få dem til å virke.</p>
 304
 305 <p>For å laste ned et NRK-innslag med undertekster, og få den norske
 306 underteksten pakket inn i videofilen, så kan følgende kommando
 307 brukes:</p>
 308
 309 <p><pre>
 310 youtube-dl --write-sub --sub-format ttml \
 311   --convert-subtitles srt --embed-subs \
 312   https://tv.nrk.no/serie/ramm-ferdig-gaa/MUHU11000316/27-04-2018
 313 </pre></p>
 314
 315 <p>URL-eksemplet er dagens toppsak på tv.nrk.no.  Resultatet er en
 316 MP4-fil med filmen og undertekster som kan spilles av med VLC.  Merk
 317 at VLC ikke viser frem undertekster før du aktiverer dem.  For å gjøre
 318 det, høyreklikk med musa i fremviservinduet, velg menyvalget for
 319 undertekst og så norsk språk.  Jeg testet også '--write-auto-sub',
 320 men det kommandolinjeargumentet ser ikke ut til å fungere, så jeg
 321 endte opp med settet med argumentlisten over, som jeg fant i en
 322 feilrapport i youtube-dl-prosjektets samling over feilrapporter.</p>
 323
 324 <p>Denne støtten i youtube-dl gjør det svært enkelt å lagre
 325 NRK-innslag, det være seg nyheter, filmer, serier eller dokumentater,
 326 for å ha dem tilgjengelig for fremtidig referanse og bruk, uavhengig
 327 av hvor lenge innslagene ligger tilgjengelig hos NRK.  Så får det ikke
 328 hjelpe at NRKs jurister mener at det er
 329 <a href="http://people.skolelinux.org/pere/blog/Best___ikke_fortelle_noen_at_streaming_er_nedlasting___.html">vesensforskjellig
 330 å legge tilgjengelig for nedlasting og for streaming</a>, når det rent
 331 teknisk er samme sak.</p>
 332
 333 <p>Programmet youtube-dl støtter også en rekke andre nettsteder, se
 334 prosjektoversikten for
 335 <a href="http://rg3.github.io/youtube-dl/supportedsites.html">en
 336 komplett liste</a>.</p>
 337
 338       </div>
 339       <div class="tags">
 340
 341
 342         Tags: <a href="http://people.skolelinux.org/pere/blog/tags/multimedia">multimedia</a>, <a href="http://people.skolelinux.org/pere/blog/tags/nice free software">nice free software</a>, <a href="http://people.skolelinux.org/pere/blog/tags/norsk">norsk</a>, <a href="http://people.skolelinux.org/pere/blog/tags/video">video</a>, <a href="http://people.skolelinux.org/pere/blog/tags/web">web</a>.
 343
 344
 345       </div>
 346     </div>
 347     <div class="padding"></div>
 348
 349     <div class="entry">
 350       <div class="title">
 351         <a href="http://people.skolelinux.org/pere/blog/Oolite__a_life_in_space_as_vagabond_and_mercenary___nice_free_software.html">Oolite, a life in space as vagabond and mercenary - nice free software</a>
 352       </div>
 353       <div class="date">
 354         11th December 2016
 355       </div>
 356       <div class="body">
 357         <p align="center"><img width="70%" src="http://people.skolelinux.org/pere/blog/images/2016-12-11-nice-oolite.png"/></p>
 358
 359 <p>In my early years, I played
 360 <a href="http://wiki.alioth.net/index.php/Classic_Elite">the epic game
 361 Elite</a> on my PC.  I spent many months trading and fighting in
 362 space, and reached the 'elite' fighting status before I moved on.  The
 363 original Elite game was available on Commodore 64 and the IBM PC
 364 edition I played had a 64 KB executable.  I am still impressed today
 365 that the authors managed to squeeze both a 3D engine and details about
 366 more than 2000 planet systems across 7 galaxies into a binary so
 367 small.</p>
 368
 369 <p>I have known about <a href="http://www.oolite.org/">the free
 370 software game Oolite inspired by Elite</a> for a while, but did not
 371 really have time to test it properly until a few days ago.  It was
 372 great to discover that my old knowledge about trading routes were
 373 still valid.  But my fighting and flying abilities were gone, so I had
 374 to retrain to be able to dock on a space station.  And I am still not
 375 able to make much resistance when I am attacked by pirates, so I
 376 bougth and mounted the most powerful laser in the rear to be able to
 377 put up at least some resistance while fleeing for my life. :)</p>
 378
 379 <p>When playing Elite in the late eighties, I had to discover
 380 everything on my own, and I had long lists of prices seen on different
 381 planets to be able to decide where to trade what.  This time I had the
 382 advantages of the
 383 <a href="http://wiki.alioth.net/index.php/Main_Page">Elite wiki</a>,
 384 where information about each planet is easily available with common
 385 price ranges and suggested trading routes.  This improved my ability
 386 to earn money and I have been able to earn enough to buy a lot of
 387 useful equipent in a few days.  I believe I originally played for
 388 months before I could get a docking computer, while now I could get it
 389 after less then a week.</p>
 390
 391 <p>If you like science fiction and dreamed of a life as a vagabond in
 392 space, you should try out Oolite.  It is available for Linux, MacOSX
 393 and Windows, and is included in Debian and derivatives since 2011.</p>
 394
 395 <p>As usual, if you use Bitcoin and want to show your support of my
 396 activities, please send Bitcoin donations to my address
 397 <b><a href="bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b">15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b</a></b>.</p>
 398
 399       </div>
 400       <div class="tags">
 401
 402
 403         Tags: <a href="http://people.skolelinux.org/pere/blog/tags/debian">debian</a>, <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/nice free software">nice free software</a>.
 404
 405
 406       </div>
 407     </div>
 408     <div class="padding"></div>
 409
 410     <div class="entry">
 411       <div class="title">
 412         <a href="http://people.skolelinux.org/pere/blog/Coz_can_help_you_find_bottlenecks_in_multi_threaded_software___nice_free_software.html">Coz can help you find bottlenecks in multi-threaded software - nice free software</a>
 413       </div>
 414       <div class="date">
 415         11th August 2016
 416       </div>
 417       <div class="body">
 418         <p>This summer, I read a great article
 419 "<a href="https://www.usenix.org/publications/login/summer2016/curtsinger">coz:
 420 This Is the Profiler You're Looking For</a>" in USENIX ;login: about
 421 how to profile multi-threaded programs.  It presented a system for
 422 profiling software by running experiences in the running program,
 423 testing how run time performance is affected by "speeding up" parts of
 424 the code to various degrees compared to a normal run.  It does this by
 425 slowing down parallel threads while the "faster up" code is running
 426 and measure how this affect processing time.  The processing time is
 427 measured using probes inserted into the code, either using progress
 428 counters (COZ_PROGRESS) or as latency meters (COZ_BEGIN/COZ_END).  It
 429 can also measure unmodified code by measuring complete the program
 430 runtime and running the program several times instead.</p>
 431
 432 <p>The project and presentation was so inspiring that I would like to
 433 get the system into Debian.  I
 434 <a href="https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=830708">created
 435 a WNPP request for it</a> and contacted upstream to try to make the
 436 system ready for Debian by sending patches.  The build process need to
 437 be changed a bit to avoid running 'git clone' to get dependencies, and
 438 to include the JavaScript web page used to visualize the collected
 439 profiling information included in the source package.
 440 But I expect that should work out fairly soon.</p>
 441
 442 <p>The way the system work is fairly simple.  To run an coz experiment
 443 on a binary with debug symbols available, start the program like this:
 444
 445 <p><blockquote><pre>
 446 coz run --- program-to-run
 447 </pre></blockquote></p>
 448
 449 <p>This will create a text file profile.coz with the instrumentation
 450 information.  To show what part of the code affect the performance
 451 most, use a web browser and either point it to
 452 <a href="http://plasma-umass.github.io/coz/">http://plasma-umass.github.io/coz/</a>
 453 or use the copy from git (in the gh-pages branch).  Check out this web
 454 site to have a look at several example profiling runs and get an idea what the end result from the profile runs look like.  To make the
 455 profiling more useful you include &lt;coz.h&gt; and insert the
 456 COZ_PROGRESS or COZ_BEGIN and COZ_END at appropriate places in the
 457 code, rebuild and run the profiler.  This allow coz to do more
 458 targeted experiments.</p>
 459
 460 <p>A video published by ACM
 461 <a href="https://www.youtube.com/watch?v=jE0V-p1odPg">presenting the
 462 Coz profiler</a> is available from Youtube.  There is also a paper
 463 from the 25th Symposium on Operating Systems Principles available
 464 titled
 465 <a href="https://www.usenix.org/conference/atc16/technical-sessions/presentation/curtsinger">Coz:
 466 finding code that counts with causal profiling</a>.</p>
 467
 468 <p><a href="https://github.com/plasma-umass/coz">The source code</a>
 469 for Coz is available from github.  It will only build with clang
 470 because it uses a
 471 <a href="https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55606">C++
 472 feature missing in GCC</a>, but I've submitted
 473 <a href="https://github.com/plasma-umass/coz/pull/67">a patch to solve
 474 it</a> and hope it will be included in the upstream source soon.</p>
 475
 476 <p>Please get in touch if you, like me, would like to see this piece
 477 of software in Debian.  I would very much like some help with the
 478 packaging effort, as I lack the in depth knowledge on how to package
 479 C++ libraries.</p>
 480
 481       </div>
 482       <div class="tags">
 483
 484
 485         Tags: <a href="http://people.skolelinux.org/pere/blog/tags/debian">debian</a>, <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/nice free software">nice free software</a>.
 486
 487
 488       </div>
 489     </div>
 490     <div class="padding"></div>
 491
 492     <div class="entry">
 493       <div class="title">
 494         <a href="http://people.skolelinux.org/pere/blog/Creepy__visualise_geotagged_social_media_information___nice_free_software.html">Creepy, visualise geotagged social media information - nice free software</a>
 495       </div>
 496       <div class="date">
 497         24th January 2016
 498       </div>
 499       <div class="body">
 500         <p>Most people seem not to realise that every time they walk around
 501 with the computerised radio beacon known as a mobile phone their
 502 position is tracked by the phone company and often stored for a long
 503 time (like every time a SMS is received or sent).  And if their
 504 computerised radio beacon is capable of running programs (often called
 505 mobile apps) downloaded from the Internet, these programs are often
 506 also capable of tracking their location (if the app requested access
 507 during installation).  And when these programs send out information to
 508 central collection points, the location is often included, unless
 509 extra care is taken to not send the location.  The provided
 510 information is used by several entities, for good and bad (what is
 511 good and bad, depend on your point of view).  What is certain, is that
 512 the private sphere and the right to free movement is challenged and
 513 perhaps even eradicated for those announcing their location this way,
 514 when they share their whereabouts with private and public
 515 entities.</p>
 516
 517 <p align="center"><img width="70%" src="http://people.skolelinux.org/pere/blog/images/2016-01-24-nice-creepy-desktop-window.png"></p>
 518
 519 <p>The phone company logs provide a register of locations to check out
 520 when one want to figure out what the tracked person was doing.  It is
 521 unavailable for most of us, but provided to selected government
 522 officials, company staff, those illegally buying information from
 523 unfaithful servants and crackers stealing the information.  But the
 524 public information can be collected and analysed, and a free software
 525 tool to do so is called
 526 <a href="http://www.geocreepy.com/">Creepy or Cree.py</a>.  I
 527 discovered it when I read
 528 <a href="http://www.aftenposten.no/kultur/Slik-kan-du-bli-overvaket-pa-Twitter-og-Instagram-uten-a-ane-det-7787884.html">an
 529 article about Creepy</a> in the Norwegian newspaper Aftenposten i
 530 November 2014, and decided to check if it was available in Debian.
 531 The python program was in Debian, but
 532 <a href="https://tracker.debian.org/pkg/creepy">the version in
 533 Debian</a> was completely broken and practically unmaintained.  I
 534 uploaded a new version which did not work quite right, but did not
 535 have time to fix it then.  This Christmas I decided to finally try to
 536 get Creepy operational in Debian.  Now a fixed version is available in
 537 Debian unstable and testing, and almost all Debian specific patches
 538 are now included
 539 <a href="https://github.com/jkakavas/creepy">upstream</a>.</p>
 540
 541 <p>The Creepy program visualises geolocation information fetched from
 542 Twitter, Instagram, Flickr and Google+, and allow one to get a
 543 complete picture of every social media message posted recently in a
 544 given area, or track the movement of a given individual across all
 545 these services.  Earlier it was possible to use the search API of at
 546 least some of these services without identifying oneself, but these
 547 days it is impossible.  This mean that to use Creepy, you need to
 548 configure it to log in as yourself on these services, and provide
 549 information to them about your search interests.  This should be taken
 550 into account when using Creepy, as it will also share information
 551 about yourself with the services.</p>
 552
 553 <p>The picture above show the twitter messages sent from (or at least
 554 geotagged with a position from) the city centre of Oslo, the capital
 555 of Norway.  One useful way to use Creepy is to first look at
 556 information tagged with an area of interest, and next look at all the
 557 information provided by one or more individuals who was in the area.
 558 I tested it by checking out which celebrity provide their location in
 559 twitter messages by checkout out who sent twitter messages near a
 560 Norwegian TV station, and next could track their position over time,
 561 making it possible to locate their home and work place, among other
 562 things.  A similar technique have been
 563 <a href="http://www.buzzfeed.com/maxseddon/does-this-soldiers-instagram-account-prove-russia-is-covertl">used
 564 to locate Russian soldiers in Ukraine</a>, and it is both a powerful
 565 tool to discover lying governments, and a useful tool to help people
 566 understand the value of the private information they provide to the
 567 public.</p>
 568
 569 <p>The package is not trivial to backport to Debian Stable/Jessie, as
 570 it depend on several python modules currently missing in Jessie (at
 571 least python-instagram, python-flickrapi and
 572 python-requests-toolbelt).</p>
 573
 574 <p>(I have uploaded
 575 <a href="https://screenshots.debian.net/package/creepy">the image to
 576 screenshots.debian.net</a> and licensed it under the same terms as the
 577 Creepy program in Debian.)</p>
 578
 579       </div>
 580       <div class="tags">
 581
 582
 583         Tags: <a href="http://people.skolelinux.org/pere/blog/tags/debian">debian</a>, <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/nice free software">nice free software</a>.
 584
 585
 586       </div>
 587     </div>
 588     <div class="padding"></div>
 589
 590     <div class="entry">
 591       <div class="title">
 592         <a href="http://people.skolelinux.org/pere/blog/OpenALPR__find_car_license_plates_in_video_streams___nice_free_software.html">OpenALPR, find car license plates in video streams - nice free software</a>
 593       </div>
 594       <div class="date">
 595         23rd December 2015
 596       </div>
 597       <div class="body">
 598         <p>When I was a kid, we used to collect "car numbers", as we used to
 599 call the car license plate numbers in those days.  I would write the
 600 numbers down in my little book and compare notes with the other kids
 601 to see how many region codes we had seen and if we had seen some
 602 exotic or special region codes and numbers.  It was a fun game to pass
 603 time, as we kids have plenty of it.</p>
 604
 605 <p>A few days I came across
 606 <a href="https://github.com/openalpr/openalpr">the OpenALPR
 607 project</a>, a free software project to automatically discover and
 608 report license plates in images and video streams, and provide the
 609 "car numbers" in a machine readable format.  I've been looking for
 610 such system for a while now, because I believe it is a bad idea that the
 611 <a href="https://en.wikipedia.org/wiki/Automatic_number_plate_recognition">automatic
 612 number plate recognition</a> tool only is available in the hands of
 613 the powerful, and want it to be available also for the powerless to
 614 even the score when it comes to surveillance and sousveillance.  I
 615 discovered the developer
 616 <a href="https://bugs.debian.org/747509">wanted to get the tool into
 617 Debian</a>, and as I too wanted it to be in Debian, I volunteered to
 618 help him get it into shape to get the package uploaded into the Debian
 619 archive.</p>
 620
 621 <p>Today we finally managed to get the package into shape and uploaded
 622 it into Debian, where it currently
 623 <a href="https://ftp-master.debian.org//new/openalpr_2.2.1-1.html">waits
 624 in the NEW queue</a> for review by the Debian ftpmasters.</p>
 625
 626 <p>I guess you are wondering why on earth such tool would be useful
 627 for the common folks, ie those not running a large government
 628 surveillance system?  Well, I plan to put it in a computer on my bike
 629 and in my car, tracking the cars nearby and allowing me to be notified
 630 when number plates on my watch list are discovered.  Another use case
 631 was suggested by a friend of mine, who wanted to set it up at his home
 632 to open the car port automatically when it discovered the plate on his
 633 car.  When I mentioned it perhaps was a bit foolhardy to allow anyone
 634 capable of placing his license plate number of a piece of cardboard to
 635 open his car port, men replied that it was always unlocked anyway.  I
 636 guess for such use case it make sense.  I am sure there are other use
 637 cases too, for those with imagination and a vision.</p>
 638
 639 <p>If you want to build your own version of the Debian package, check
 640 out the upstream git source and symlink ./distros/debian to ./debian/
 641 before running "debuild" to build the source.  Or wait a bit until the
 642 package show up in unstable.</p>
 643
 644       </div>
 645       <div class="tags">
 646
 647
 648         Tags: <a href="http://people.skolelinux.org/pere/blog/tags/debian">debian</a>, <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/nice free software">nice free software</a>.
 649
 650
 651       </div>
 652     </div>
 653     <div class="padding"></div>
 654
 655     <div class="entry">
 656       <div class="title">
 657         <a href="http://people.skolelinux.org/pere/blog/listadmin__the_quick_way_to_moderate_mailman_lists___nice_free_software.html">listadmin, the quick way to moderate mailman lists - nice free software</a>
 658       </div>
 659       <div class="date">
 660         22nd October 2014
 661       </div>
 662       <div class="body">
 663         <p>If you ever had to moderate a mailman list, like the ones on
 664 alioth.debian.org, you know the web interface is fairly slow to
 665 operate.  First you visit one web page, enter the moderation password
 666 and get a new page shown with a list of all the messages to moderate
 667 and various options for each email address.  This take a while for
 668 every list you moderate, and you need to do it regularly to do a good
 669 job as a list moderator.  But there is a quick alternative,
 670 <a href="http://heim.ifi.uio.no/kjetilho/hacks/#listadmin">the
 671 listadmin program</a>.  It allow you to check lists for new messages
 672 to moderate in a fraction of a second.  Here is a test run on two
 673 lists I recently took over:</p>
 674
 675 <p><blockquote><pre>
 676 % time listadmin xiph
 677 fetching data for pkg-xiph-commits@lists.alioth.debian.org ... nothing in queue
 678 fetching data for pkg-xiph-maint@lists.alioth.debian.org ... nothing in queue
 679
 680 real    0m1.709s
 681 user    0m0.232s
 682 sys     0m0.012s
 683 %
 684 </pre></blockquote></p>
 685
 686 <p>In 1.7 seconds I had checked two mailing lists and confirmed that
 687 there are no message in the moderation queue.  Every morning I
 688 currently moderate 68 mailman lists, and it normally take around two
 689 minutes.  When I took over the two pkg-xiph lists above a few days
 690 ago, there were 400 emails waiting in the moderator queue.  It took me
 691 less than 15 minutes to process them all using the listadmin
 692 program.</p>
 693
 694 <p>If you install
 695 <a href="https://tracker.debian.org/pkg/listadmin">the listadmin
 696 package</a> from Debian and create a file <tt>~/.listadmin.ini</tt>
 697 with content like this, the moderation task is a breeze:</p>
 698
 699 <p><blockquote><pre>
 700 username username@example.org
 701 spamlevel 23
 702 default discard
 703 discard_if_reason "Posting restricted to members only. Remove us from your mail list."
 704
 705 password secret
 706 adminurl https://{domain}/mailman/admindb/{list}
 707 mailman-list@lists.example.com
 708
 709 password hidden
 710 other-list@otherserver.example.org
 711 </pre></blockquote></p>
 712
 713 <p>There are other options to set as well.  Check the manual page to
 714 learn the details.</p>
 715
 716 <p>If you are forced to moderate lists on a mailman installation where
 717 the SSL certificate is self signed or not properly signed by a
 718 generally accepted signing authority, you can set a environment
 719 variable when calling listadmin to disable SSL verification:</p>
 720
 721 <p><blockquote><pre>
 722 PERL_LWP_SSL_VERIFY_HOSTNAME=0 listadmin
 723 </pre></blockquote></p>
 724
 725 <p>If you want to moderate a subset of the lists you take care of, you
 726 can provide an argument to the listadmin script like I do in the
 727 initial screen dump (the xiph argument).  Using an argument, only
 728 lists matching the argument string will be processed.  This make it
 729 quick to accept messages if you notice the moderation request in your
 730 email.</p>
 731
 732 <p>Without the listadmin program, I would never be the moderator of 68
 733 mailing lists, as I simply do not have time to spend on that if the
 734 process was any slower. The listadmin program have saved me hours of
 735 time I could spend elsewhere over the years.  It truly is nice free
 736 software.</p>
 737
 738 <p>As usual, if you use Bitcoin and want to show your support of my
 739 activities, please send Bitcoin donations to my address
 740 <b><a href="bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b">15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b</a></b>.</p>
 741
 742 <p>Update 2014-10-27: Added missing 'username' statement in
 743 configuration example.  Also, I've been told that the
 744 PERL_LWP_SSL_VERIFY_HOSTNAME=0 setting do not work for everyone.  Not
 745 sure why.</p>
 746
 747       </div>
 748       <div class="tags">
 749
 750
 751         Tags: <a href="http://people.skolelinux.org/pere/blog/tags/debian">debian</a>, <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/nice free software">nice free software</a>.
 752
 753
 754       </div>
 755     </div>
 756     <div class="padding"></div>
 757
 758     <div class="entry">
 759       <div class="title">
 760         <a href="http://people.skolelinux.org/pere/blog/S3QL__a_locally_mounted_cloud_file_system___nice_free_software.html">S3QL, a locally mounted cloud file system - nice free software</a>
 761       </div>
 762       <div class="date">
 763          9th April 2014
 764       </div>
 765       <div class="body">
 766         <p>For a while now, I have been looking for a sensible offsite backup
 767 solution for use at home.  My requirements are simple, it must be
 768 cheap and locally encrypted (in other words, I keep the encryption
 769 keys, the storage provider do not have access to my private files).
 770 One idea me and my friends had many years ago, before the cloud
 771 storage providers showed up, was to use Google mail as storage,
 772 writing a Linux block device storing blocks as emails in the mail
 773 service provided by Google, and thus get heaps of free space.  On top
 774 of this one can add encryption, RAID and volume management to have
 775 lots of (fairly slow, I admit that) cheap and encrypted storage.  But
 776 I never found time to implement such system.  But the last few weeks I
 777 have looked at a system called
 778 <a href="https://bitbucket.org/nikratio/s3ql/">S3QL</a>, a locally
 779 mounted network backed file system with the features I need.</p>
 780
 781 <p>S3QL is a fuse file system with a local cache and cloud storage,
 782 handling several different storage providers, any with Amazon S3,
 783 Google Drive or OpenStack API.  There are heaps of such storage
 784 providers.  S3QL can also use a local directory as storage, which
 785 combined with sshfs allow for file storage on any ssh server.  S3QL
 786 include support for encryption, compression, de-duplication, snapshots
 787 and immutable file systems, allowing me to mount the remote storage as
 788 a local mount point, look at and use the files as if they were local,
 789 while the content is stored in the cloud as well.  This allow me to
 790 have a backup that should survive fire.  The file system can not be
 791 shared between several machines at the same time, as only one can
 792 mount it at the time, but any machine with the encryption key and
 793 access to the storage service can mount it if it is unmounted.</p>
 794
 795 <p>It is simple to use.  I'm using it on Debian Wheezy, where the
 796 package is included already.  So to get started, run <tt>apt-get
 797 install s3ql</tt>.  Next, pick a storage provider.  I ended up picking
 798 Greenqloud, after reading their nice recipe on
 799 <a href="https://greenqloud.zendesk.com/entries/44611757-How-To-Use-S3QL-to-mount-a-StorageQloud-bucket-on-Debian-Wheezy">how
 800 to use S3QL with their Amazon S3 service</a>, because I trust the laws
 801 in Iceland more than those in USA when it come to keeping my personal
 802 data safe and private, and thus would rather spend money on a company
 803 in Iceland.  Another nice recipe is available from the article
 804 <a href="http://www.admin-magazine.com/HPC/Articles/HPC-Cloud-Storage">S3QL
 805 Filesystem for HPC Storage</a> by Jeff Layton in the HPC section of
 806 Admin magazine.  When the provider is picked, figure out how to get
 807 the API key needed to connect to the storage API.  With Greencloud,
 808 the key did not show up until I had added payment details to my
 809 account.</p>
 810
 811 <p>Armed with the API access details, it is time to create the file
 812 system.  First, create a new bucket in the cloud.  This bucket is the
 813 file system storage area.  I picked a bucket name reflecting the
 814 machine that was going to store data there, but any name will do.
 815 I'll refer to it as <tt>bucket-name</tt> below.  In addition, one need
 816 the API login and password, and a locally created password.  Store it
 817 all in ~root/.s3ql/authinfo2 like this:
 818
 819 <p><blockquote><pre>
 820 [s3c]
 821 storage-url: s3c://s.greenqloud.com:443/bucket-name
 822 backend-login: API-login
 823 backend-password: API-password
 824 fs-passphrase: local-password
 825 </pre></blockquote></p>
 826
 827 <p>I create my local passphrase using <tt>pwget 50</tt> or similar,
 828 but any sensible way to create a fairly random password should do it.
 829 Armed with these details, it is now time to run mkfs, entering the API
 830 details and password to create it:</p>
 831
 832 <p><blockquote><pre>
 833 # mkdir -m 700 /var/lib/s3ql-cache
 834 # mkfs.s3ql --cachedir /var/lib/s3ql-cache --authfile /root/.s3ql/authinfo2 \
 835   --ssl s3c://s.greenqloud.com:443/bucket-name
 836 Enter backend login:
 837 Enter backend password:
 838 Before using S3QL, make sure to read the user's guide, especially
 839 the 'Important Rules to Avoid Loosing Data' section.
 840 Enter encryption password:
 841 Confirm encryption password:
 842 Generating random encryption key...
 843 Creating metadata tables...
 844 Dumping metadata...
 845 ..objects..
 846 ..blocks..
 847 ..inodes..
 848 ..inode_blocks..
 849 ..symlink_targets..
 850 ..names..
 851 ..contents..
 852 ..ext_attributes..
 853 Compressing and uploading metadata...
 854 Wrote 0.00 MB of compressed metadata.
 855 # </pre></blockquote></p>
 856
 857 <p>The next step is mounting the file system to make the storage available.
 858
 859 <p><blockquote><pre>
 860 # mount.s3ql --cachedir /var/lib/s3ql-cache --authfile /root/.s3ql/authinfo2 \
 861   --ssl --allow-root s3c://s.greenqloud.com:443/bucket-name /s3ql
 862 Using 4 upload threads.
 863 Downloading and decompressing metadata...
 864 Reading metadata...
 865 ..objects..
 866 ..blocks..
 867 ..inodes..
 868 ..inode_blocks..
 869 ..symlink_targets..
 870 ..names..
 871 ..contents..
 872 ..ext_attributes..
 873 Mounting filesystem...
 874 # df -h /s3ql
 875 Filesystem                              Size  Used Avail Use% Mounted on
 876 s3c://s.greenqloud.com:443/bucket-name  1.0T     0  1.0T   0% /s3ql
 877 #
 878 </pre></blockquote></p>
 879
 880 <p>The file system is now ready for use.  I use rsync to store my
 881 backups in it, and as the metadata used by rsync is downloaded at
 882 mount time, no network traffic (and storage cost) is triggered by
 883 running rsync.  To unmount, one should not use the normal umount
 884 command, as this will not flush the cache to the cloud storage, but
 885 instead running the umount.s3ql command like this:
 886
 887 <p><blockquote><pre>
 888 # umount.s3ql /s3ql
 889 #
 890 </pre></blockquote></p>
 891
 892 <p>There is a fsck command available to check the file system and
 893 correct any problems detected.  This can be used if the local server
 894 crashes while the file system is mounted, to reset the "already
 895 mounted" flag.  This is what it look like when processing a working
 896 file system:</p>
 897
 898 <p><blockquote><pre>
 899 # fsck.s3ql --force --ssl s3c://s.greenqloud.com:443/bucket-name
 900 Using cached metadata.
 901 File system seems clean, checking anyway.
 902 Checking DB integrity...
 903 Creating temporary extra indices...
 904 Checking lost+found...
 905 Checking cached objects...
 906 Checking names (refcounts)...
 907 Checking contents (names)...
 908 Checking contents (inodes)...
 909 Checking contents (parent inodes)...
 910 Checking objects (reference counts)...
 911 Checking objects (backend)...
 912 ..processed 5000 objects so far..
 913 ..processed 10000 objects so far..
 914 ..processed 15000 objects so far..
 915 Checking objects (sizes)...
 916 Checking blocks (referenced objects)...
 917 Checking blocks (refcounts)...
 918 Checking inode-block mapping (blocks)...
 919 Checking inode-block mapping (inodes)...
 920 Checking inodes (refcounts)...
 921 Checking inodes (sizes)...
 922 Checking extended attributes (names)...
 923 Checking extended attributes (inodes)...
 924 Checking symlinks (inodes)...
 925 Checking directory reachability...
 926 Checking unix conventions...
 927 Checking referential integrity...
 928 Dropping temporary indices...
 929 Backing up old metadata...
 930 Dumping metadata...
 931 ..objects..
 932 ..blocks..
 933 ..inodes..
 934 ..inode_blocks..
 935 ..symlink_targets..
 936 ..names..
 937 ..contents..
 938 ..ext_attributes..
 939 Compressing and uploading metadata...
 940 Wrote 0.89 MB of compressed metadata.
 941 #
 942 </pre></blockquote></p>
 943
 944 <p>Thanks to the cache, working on files that fit in the cache is very
 945 quick, about the same speed as local file access.  Uploading large
 946 amount of data is to me limited by the bandwidth out of and into my
 947 house.  Uploading 685 MiB with a 100 MiB cache gave me 305 kiB/s,
 948 which is very close to my upload speed, and downloading the same
 949 Debian installation ISO gave me 610 kiB/s, close to my download speed.
 950 Both were measured using <tt>dd</tt>.  So for me, the bottleneck is my
 951 network, not the file system code.  I do not know what a good cache
 952 size would be, but suspect that the cache should e larger than your
 953 working set.</p>
 954
 955 <p>I mentioned that only one machine can mount the file system at the
 956 time.  If another machine try, it is told that the file system is
 957 busy:</p>
 958
 959 <p><blockquote><pre>
 960 # mount.s3ql --cachedir /var/lib/s3ql-cache --authfile /root/.s3ql/authinfo2 \
 961   --ssl --allow-root s3c://s.greenqloud.com:443/bucket-name /s3ql
 962 Using 8 upload threads.
 963 Backend reports that fs is still mounted elsewhere, aborting.
 964 #
 965 </pre></blockquote></p>
 966
 967 <p>The file content is uploaded when the cache is full, while the
 968 metadata is uploaded once every 24 hour by default.  To ensure the
 969 file system content is flushed to the cloud, one can either umount the
 970 file system, or ask S3QL to flush the cache and metadata using
 971 s3qlctrl:
 972
 973 <p><blockquote><pre>
 974 # s3qlctrl upload-meta /s3ql
 975 # s3qlctrl flushcache /s3ql
 976 #
 977 </pre></blockquote></p>
 978
 979 <p>If you are curious about how much space your data uses in the
 980 cloud, and how much compression and deduplication cut down on the
 981 storage usage, you can use s3qlstat on the mounted file system to get
 982 a report:</p>
 983
 984 <p><blockquote><pre>
 985 # s3qlstat /s3ql
 986 Directory entries:    9141
 987 Inodes:               9143
 988 Data blocks:          8851
 989 Total data size:      22049.38 MB
 990 After de-duplication: 21955.46 MB (99.57% of total)
 991 After compression:    21877.28 MB (99.22% of total, 99.64% of de-duplicated)
 992 Database size:        2.39 MB (uncompressed)
 993 (some values do not take into account not-yet-uploaded dirty blocks in cache)
 994 #
 995 </pre></blockquote></p>
 996
 997 <p>I mentioned earlier that there are several possible suppliers of
 998 storage.  I did not try to locate them all, but am aware of at least
 999 <a href="https://www.greenqloud.com/">Greenqloud</a>,
1000 <a href="http://drive.google.com/">Google Drive</a>,
1001 <a href="http://aws.amazon.com/s3/">Amazon S3 web serivces</a>,
1002 <a href="http://www.rackspace.com/">Rackspace</a> and
1003 <a href="http://crowncloud.net/">Crowncloud</A>.  The latter even
1004 accept payment in Bitcoin.  Pick one that suit your need.  Some of
1005 them provide several GiB of free storage, but the prize models are
1006 quite different and you will have to figure out what suits you
1007 best.</p>
1008
1009 <p>While researching this blog post, I had a look at research papers
1010 and posters discussing the S3QL file system.  There are several, which
1011 told me that the file system is getting a critical check by the
1012 science community and increased my confidence in using it.  One nice
1013 poster is titled
1014 "<a href="http://www.lanl.gov/orgs/adtsc/publications/science_highlights_2013/docs/pg68_69.pdf">An
1015 Innovative Parallel Cloud Storage System using OpenStack’s SwiftObject
1016 Store and Transformative Parallel I/O Approach</a>" by Hsing-Bung
1017 Chen, Benjamin McClelland, David Sherrill, Alfred Torrez, Parks Fields
1018 and Pamela Smith.  Please  have a look.</p>
1019
1020 <p>Given my problems with different file systems earlier, I decided to
1021 check out the mounted S3QL file system to see if it would be usable as
1022 a home directory (in other word, that it provided POSIX semantics when
1023 it come to locking and umask handling etc).  Running
1024 <a href="http://people.skolelinux.org/pere/blog/Testing_if_a_file_system_can_be_used_for_home_directories___.html">my
1025 test code to check file system semantics</a>, I was happy to discover that
1026 no error was found.  So the file system can be used for home
1027 directories, if one chooses to do so.</p>
1028
1029 <p>If you do not want a locally file system, and want something that
1030 work without the Linux fuse file system, I would like to mention the
1031 <a href="http://www.tarsnap.com/">Tarsnap service</a>, which also
1032 provide locally encrypted backup using a command line client.  It have
1033 a nicer access control system, where one can split out read and write
1034 access, allowing some systems to write to the backup and others to
1035 only read from it.</p>
1036
1037 <p>As usual, if you use Bitcoin and want to show your support of my
1038 activities, please send Bitcoin donations to my address
1039 <b><a href="bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b">15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b</a></b>.</p>
1040
1041       </div>
1042       <div class="tags">
1043
1044
1045         Tags: <a href="http://people.skolelinux.org/pere/blog/tags/debian">debian</a>, <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/nice free software">nice free software</a>, <a href="http://people.skolelinux.org/pere/blog/tags/personvern">personvern</a>, <a href="http://people.skolelinux.org/pere/blog/tags/sikkerhet">sikkerhet</a>.
1046
1047
1048       </div>
1049     </div>
1050     <div class="padding"></div>
1051
1052     <div class="entry">
1053       <div class="title">
1054         <a href="http://people.skolelinux.org/pere/blog/ReactOS_Windows_clone___nice_free_software.html">ReactOS Windows clone - nice free software</a>
1055       </div>
1056       <div class="date">
1057          1st April 2014
1058       </div>
1059       <div class="body">
1060         <p>Microsoft have announced that Windows XP reaches its end of life
1061 2014-04-08, in 7 days.  But there are heaps of machines still running
1062 Windows XP, and depending on Windows XP to run their applications, and
1063 upgrading will be expensive, both when it comes to money and when it
1064 comes to the amount of effort needed to migrate from Windows XP to a
1065 new operating system.  Some obvious options (buy new a Windows
1066 machine, buy a MacOSX machine, install Linux on the existing machine)
1067 are already well known and covered elsewhere.  Most of them involve
1068 leaving the user applications installed on Windows XP behind and
1069 trying out replacements or updated versions. In this blog post I want
1070 to mention one strange bird that allow people to keep the hardware and
1071 the existing Windows XP applications and run them on a free software
1072 operating system that is Windows XP compatible.</p>
1073
1074 <p><a href="http://www.reactos.org/">ReactOS</a> is a free software
1075 operating system (GNU GPL licensed) working on providing a operating
1076 system that is binary compatible with Windows, able to run windows
1077 programs directly and to use Windows drivers for hardware directly.
1078 The project goal is for Windows user to keep their existing machines,
1079 drivers and software, and gain the advantages from user a operating
1080 system without usage limitations caused by non-free licensing.  It is
1081 a Windows clone running directly on the hardware, so quite different
1082 from the approach taken by <a href="http://www.winehq.org/">the Wine
1083 project</a>, which make it possible to run Windows binaries on
1084 Linux.</p>
1085
1086 <p>The ReactOS project share code with the Wine project, so most
1087 shared libraries available on Windows are already implemented already.
1088 There is also a software manager like the one we are used to on Linux,
1089 allowing the user to install free software applications with a simple
1090 click directly from the Internet.  Check out the
1091 <a href="http://www.reactos.org/screenshots">screen shots on the
1092 project web site</a> for an idea what it look like (it looks just like
1093 Windows before metro).</p>
1094
1095 <p>I do not use ReactOS myself, preferring Linux and Unix like
1096 operating systems.  I've tested it, and it work fine in a virt-manager
1097 virtual machine.  The browser, minesweeper, notepad etc is working
1098 fine as far as I can tell.  Unfortunately, my main test application
1099 is the software included on a CD with the Lego Mindstorms NXT, which
1100 seem to install just fine from CD but fail to leave any binaries on
1101 the disk after the installation.  So no luck with that test software.
1102 No idea why, but hope someone else figure out and fix the problem.
1103 I've tried the ReactOS Live ISO on a physical machine, and it seemed
1104 to work just fine.  If you like Windows and want to keep running your
1105 old Windows binaries, check it out by
1106 <a href="http://www.reactos.org/download">downloading</a> the
1107 installation CD, the live CD or the preinstalled virtual machine
1108 image.</p>
1109
1110       </div>
1111       <div class="tags">
1112
1113
1114         Tags: <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/nice free software">nice free software</a>, <a href="http://people.skolelinux.org/pere/blog/tags/reactos">reactos</a>.
1115
1116
1117       </div>
1118     </div>
1119     <div class="padding"></div>
1120
1121     <div class="entry">
1122       <div class="title">
1123         <a href="http://people.skolelinux.org/pere/blog/Video_DVD_reader_library___python_dvdvideo___nice_free_software.html">Video DVD reader library / python-dvdvideo - nice free software</a>
1124       </div>
1125       <div class="date">
1126         21st March 2014
1127       </div>
1128       <div class="body">
1129         <p>Keeping your DVD collection safe from scratches and curious
1130 children fingers while still having it available when you want to see a
1131 movie is not straight forward.  My preferred method at the moment is
1132 to store a full copy of the ISO on a hard drive, and use VLC, Popcorn
1133 Hour or other useful players to view the resulting file.  This way the
1134 subtitles and bonus material are still available and using the ISO is
1135 just like inserting the original DVD record in the DVD player.</p>
1136
1137 <p>Earlier I used dd for taking security copies, but it do not handle
1138 DVDs giving read errors (which are quite a few of them).  I've also
1139 tried using
1140 <a href="http://people.skolelinux.org/pere/blog/Ripping_problematic_DVDs_using_dvdbackup_and_genisoimage.html">dvdbackup
1141 and genisoimage</a>, but these days I use the marvellous python library
1142 and program
1143 <a href="http://bblank.thinkmo.de/blog/new-software-python-dvdvideo">python-dvdvideo</a>
1144 written by Bastian Blank.  It is
1145 <a href="http://packages.qa.debian.org/p/python-dvdvideo.html">in Debian
1146 already</a> and the binary package name is python3-dvdvideo. Instead
1147 of trying to read every block from the DVD, it parses the file
1148 structure and figure out which block on the DVD is actually in used,
1149 and only read those blocks from the DVD.  This work surprisingly well,
1150 and I have been able to almost backup my entire DVD collection using
1151 this method.</p>
1152
1153 <p>So far, python-dvdvideo have failed on between 10 and
1154 20 DVDs, which is a small fraction of my collection.  The most common
1155 problem is
1156 <a href="https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=720831">DVDs
1157 using UTF-16 instead of UTF-8 characters</a>, which according to
1158 Bastian is against the DVD specification (and seem to cause some
1159 players to fail too).  A rarer problem is what seem to be inconsistent
1160 DVD structures, as the python library
1161 <a href="https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=723079">claim
1162 there is a overlap between objects</a>.  An equally rare problem claim
1163 <a href="https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=741878">some
1164 value is out of range</a>.  No idea what is going on there.  I wish I
1165 knew enough about the DVD format to fix these, to ensure my movie
1166 collection will stay with me in the future.</p>
1167
1168 <p>So, if you need to keep your DVDs safe, back them up using
1169 python-dvdvideo. :)</p>
1170
1171       </div>
1172       <div class="tags">
1173
1174
1175         Tags: <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/multimedia">multimedia</a>, <a href="http://people.skolelinux.org/pere/blog/tags/nice free software">nice free software</a>, <a href="http://people.skolelinux.org/pere/blog/tags/opphavsrett">opphavsrett</a>, <a href="http://people.skolelinux.org/pere/blog/tags/video">video</a>.
1176
1177
1178       </div>
1179     </div>
1180     <div class="padding"></div>
1181
1182     <div class="entry">
1183       <div class="title">
1184         <a href="http://people.skolelinux.org/pere/blog/Free_Timetabling_Software___nice_free_software.html">Free Timetabling Software - nice free software</a>
1185       </div>
1186       <div class="date">
1187          7th July 2012
1188       </div>
1189       <div class="body">
1190         <p>Included in <a href="http://www.skolelinux.org/">Debian Edu /
1191 Skolelinux</a> is a large collection of end user and school specific
1192 software.  It is one of the packages not installed by default but
1193 provided in the Debian archive for schools to install if they want to,
1194 is a system to automatically plan the school time table using
1195 information about available teachers, classes and rooms, combined with
1196 the list of required courses and how many hours each topic should
1197 receive.  The software is
1198
1199 <a href="http://lalescu.ro/liviu/fet/">named FET</a>, and it provide a
1200 graphical user interface to input the required information, save the
1201 result in a fairly simple XML format, and generate time tables for
1202 both teachers and students.  It is available both for
1203 <a href="http://lalescu.ro/liviu/fet/download.html">Linux, MacOSX and
1204 Windows</a>.</p>
1205
1206 <p>This is <a href="http://lalescu.ro/liviu/fet/features.html">the
1207 feature list</a>, liftet from the project web site:</p>
1208
1209 <p><ul>
1210
1211   <li>FET is free software, licensed under the GNU GPL v2 or later.
1212     You can freely use, copy, modify and redistribute it </li>
1213
1214   <li>Localized to en_US (US English, default), ar (Arabic), ca
1215     (Catalan), da (Danish), de (German), el (Greek), es (Spanish), fa
1216     (Persian), fr (French), gl (Galician), he (Hebrew), hu
1217     (Hungarian), id (Indonesian), it (Italian), lt (Lithuanian), mk
1218     (Macedonian), ms (Malay), nl (Dutch), pl (Polish), pt_BR
1219     (Brazilian Portuguese), ro (Romanian), ru (Russian), si (Sinhala),
1220     sk (Slovak), sr (Serbian), tr (Turkish), uk (Ukrainian), uz
1221     (Uzbek) and vi (Vietnamese) (incompletely for some languages)
1222     </li>
1223
1224   <li>Fully automatic generation algorithm, allowing also
1225     semi-automatic or manual allocation</li>
1226
1227   <li>Platform independent implementation, allowing running on
1228     GNU/Linux, Windows, Mac and any system that Qt supports </li>
1229
1230   <li>Flexible modular XML format for the input file, allowing editing
1231     with an XML editor or by hand (besides FET interface)</li>
1232
1233   <li>Import/export from CSV format</li>
1234
1235   <li>The resulted timetables are exported into HTML, XML and CSV
1236     formats </li>
1237
1238   <li>Flexible students structure, organized into sets: years, groups
1239     and subgroups. FET allows overlapping years and groups and
1240     non-overlapping subgroups. You can even define individual students
1241     (as separate sets)</li>
1242
1243   <li>Each constraint has a weight percentage, from 0.0% to 100.0%
1244     (but some special constraints are allowed to have only 100% weight
1245     percentage)</li>
1246
1247   <li>Limits for the algorithm (all these limits can be increased on
1248     demand, as a custom version, because this would require a bit more
1249     memory):
1250     <ul>
1251       <li>Maximum total number of hours (periods) per day: 60</li>
1252       <li>Maximum number of working days per week: 35</li>
1253       <li>Maximum total number of teachers: 6000</li>
1254       <li>Maximum total number of sets of students: 30000</li>
1255       <li>Maximum total number of subjects: 6000</li>
1256       <li>Virtually unlimited number of activity tags</li>
1257       <li>Maximum number of activities: 30000</li>
1258       <li>Maximum number of rooms: 6000</li>
1259       <li>Maximum number of buildings: 6000</li>
1260       <li>Possibility of adding multiple teachers and
1261           students sets for each activity.  (it is possible
1262           also to have no teachers or no students sets for an
1263           activity)</li>
1264       <li>Virtually unlimited number of time constraints</li>
1265       <li>Virtually unlimited number of space constraints</li>
1266     </ul></li>
1267
1268   <li>A large and flexible palette of time constraints:
1269     <ul>
1270       <li>Break periods</li>
1271       <li>For teacher(s):
1272         <ul>
1273           <li>Not available periods</li>
1274           <li>Max/min days per week</li>
1275           <li>Max gaps per day/week</li>
1276           <li>Max hours daily/continuously</li>
1277           <li>Min hours daily</li>
1278           <li>Max hours daily/continuously with an activity tag</li>
1279
1280           <li>Respect working in an hourly interval a max number of
1281             days per week</li>
1282         </ul></li>
1283       <li>For students (sets):
1284         <ul>
1285           <li>Not available periods</li>
1286           <li>Begins early (specify max allowed beginnings at second hour)</li>
1287           <li>Max gaps per day/week</li>
1288           <li>Max hours daily/continuously</li>
1289           <li>Min hours daily</li>
1290           <li>Max hours daily/continuously with an activity tag</li>
1291
1292           <li>Respect working in an hourly interval a max number of
1293             days per week</li>
1294         </ul></li>
1295       <li>For an activity or a set of activities/subactivities:
1296         <ul>
1297           <li>A single preferred starting time</li>
1298           <li>A set of preferred starting times</li>
1299           <li>A set of preferred time slots</li>
1300           <li>Min/max days between them</li>
1301           <li>End(s) students day</li>
1302           <li>Same starting time/day/hour</li>
1303           <li>Occupy max time slots from selection (a complex and
1304             flexible constraint, useful in many situations)</li>
1305           <li>Consecutive, ordered, grouped (for 2 or 3 (sub)activities)</li>
1306           <li>Not overlapping</li>
1307           <li>Max simultaneous in selected time slots</li>
1308           <li>Min gaps between a set of (sub)activities</li>
1309         </ul></li>
1310     </ul></li>
1311
1312   <li>A large and flexible palette of space constraints:
1313     <ul>
1314       <li>Room not available periods</li>
1315       <li>For teacher(s):
1316         <ul>
1317           <li>Home room(s)</li>
1318           <li>Max building changes per day/week</li>
1319           <li>Min gaps between building changes</li>
1320         </ul>
1321       </li>
1322
1323       <li>For students (sets):
1324         <ul>
1325           <li>Home room(s)</li>
1326           <li>Max building changes per day/week</li>
1327           <li>Min gaps between building changes</li>
1328         </ul>
1329       </li>
1330       <li>Preferred room(s):
1331         <ul>
1332           <li>For a subject</li>
1333           <li>For an activity tag</li>
1334           <li>For a subject and an activity tag</li>
1335           <li>Individually for a (sub)activity</li>
1336         </ul>
1337       </li>
1338
1339       <li>For a set of activities:
1340         <ul>
1341           <li>Occupy a maximum number of different rooms</li>
1342         </ul>
1343       </li>
1344     </ul>
1345   </li>
1346 </ul></p>
1347
1348 <p>I have not used it myself, as I am not involved in time table
1349 planning at a school, but it seem to work fine when I test it.  If you
1350 need to set up your schools time table, and is tired of doing it
1351 manually, check it out.
1352
1353 A quick summary on how to use it can be found in
1354 <a href="http://marvelsoft.co.in/wp/2012/03/generate-timetable-for-state-cbse-icse-igcse-schools-free/">a
1355 blog post from MarvelSoft</a>.  If you find FET useful, please provide
1356 a recipe for the Debian Edu project in the
1357 <a href="http://wiki.debian.org/DebianEdu#Howtos">Debian Edu HowTo
1358 section</a>.</p>
1359
1360       </div>
1361       <div class="tags">
1362
1363
1364         Tags: <a href="http://people.skolelinux.org/pere/blog/tags/debian edu">debian edu</a>, <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/nice free software">nice free software</a>.
1365
1366
1367       </div>
1368     </div>
1369     <div class="padding"></div>
1370
1371     <p style="text-align: right;"><a href="nice free software.rss"><img src="http://people.skolelinux.org/pere/blog/xml.gif" alt="RSS Feed" width="36" height="14" /></a></p>
1372     <div id="sidebar">
1373
1374
1375
1376 <h2>Archive</h2>
1377 <ul>
1378
1379 <li>2019
1380 <ul>
1381
1382 <li><a href="http://people.skolelinux.org/pere/blog/archive/2019/01/">January (4)</a></li>
1383
1384 <li><a href="http://people.skolelinux.org/pere/blog/archive/2019/02/">February (3)</a></li>
1385
1386 <li><a href="http://people.skolelinux.org/pere/blog/archive/2019/03/">March (3)</a></li>
1387
1388 <li><a href="http://people.skolelinux.org/pere/blog/archive/2019/05/">May (2)</a></li>
1389
1390 <li><a href="http://people.skolelinux.org/pere/blog/archive/2019/06/">June (5)</a></li>
1391
1392 <li><a href="http://people.skolelinux.org/pere/blog/archive/2019/07/">July (2)</a></li>
1393
1394 </ul></li>
1395
1396 <li>2018
1397 <ul>
1398
1399 <li><a href="http://people.skolelinux.org/pere/blog/archive/2018/01/">January (1)</a></li>
1400
1401 <li><a href="http://people.skolelinux.org/pere/blog/archive/2018/02/">February (5)</a></li>
1402
1403 <li><a href="http://people.skolelinux.org/pere/blog/archive/2018/03/">March (5)</a></li>
1404
1405 <li><a href="http://people.skolelinux.org/pere/blog/archive/2018/04/">April (3)</a></li>
1406
1407 <li><a href="http://people.skolelinux.org/pere/blog/archive/2018/06/">June (2)</a></li>
1408
1409 <li><a href="http://people.skolelinux.org/pere/blog/archive/2018/07/">July (5)</a></li>
1410
1411 <li><a href="http://people.skolelinux.org/pere/blog/archive/2018/08/">August (3)</a></li>
1412
1413 <li><a href="http://people.skolelinux.org/pere/blog/archive/2018/09/">September (3)</a></li>
1414
1415 <li><a href="http://people.skolelinux.org/pere/blog/archive/2018/10/">October (5)</a></li>
1416
1417 <li><a href="http://people.skolelinux.org/pere/blog/archive/2018/11/">November (2)</a></li>
1418
1419 <li><a href="http://people.skolelinux.org/pere/blog/archive/2018/12/">December (4)</a></li>
1420
1421 </ul></li>
1422
1423 <li>2017
1424 <ul>
1425
1426 <li><a href="http://people.skolelinux.org/pere/blog/archive/2017/01/">January (4)</a></li>
1427
1428 <li><a href="http://people.skolelinux.org/pere/blog/archive/2017/02/">February (3)</a></li>
1429
1430 <li><a href="http://people.skolelinux.org/pere/blog/archive/2017/03/">March (5)</a></li>
1431
1432 <li><a href="http://people.skolelinux.org/pere/blog/archive/2017/04/">April (2)</a></li>
1433
1434 <li><a href="http://people.skolelinux.org/pere/blog/archive/2017/06/">June (5)</a></li>
1435
1436 <li><a href="http://people.skolelinux.org/pere/blog/archive/2017/07/">July (1)</a></li>
1437
1438 <li><a href="http://people.skolelinux.org/pere/blog/archive/2017/08/">August (1)</a></li>
1439
1440 <li><a href="http://people.skolelinux.org/pere/blog/archive/2017/09/">September (3)</a></li>
1441
1442 <li><a href="http://people.skolelinux.org/pere/blog/archive/2017/10/">October (5)</a></li>
1443
1444 <li><a href="http://people.skolelinux.org/pere/blog/archive/2017/11/">November (3)</a></li>
1445
1446 <li><a href="http://people.skolelinux.org/pere/blog/archive/2017/12/">December (4)</a></li>
1447
1448 </ul></li>
1449
1450 <li>2016
1451 <ul>
1452
1453 <li><a href="http://people.skolelinux.org/pere/blog/archive/2016/01/">January (3)</a></li>
1454
1455 <li><a href="http://people.skolelinux.org/pere/blog/archive/2016/02/">February (2)</a></li>
1456
1457 <li><a href="http://people.skolelinux.org/pere/blog/archive/2016/03/">March (3)</a></li>
1458
1459 <li><a href="http://people.skolelinux.org/pere/blog/archive/2016/04/">April (8)</a></li>
1460
1461 <li><a href="http://people.skolelinux.org/pere/blog/archive/2016/05/">May (8)</a></li>
1462
1463 <li><a href="http://people.skolelinux.org/pere/blog/archive/2016/06/">June (2)</a></li>
1464
1465 <li><a href="http://people.skolelinux.org/pere/blog/archive/2016/07/">July (2)</a></li>
1466
1467 <li><a href="http://people.skolelinux.org/pere/blog/archive/2016/08/">August (5)</a></li>
1468
1469 <li><a href="http://people.skolelinux.org/pere/blog/archive/2016/09/">September (2)</a></li>
1470
1471 <li><a href="http://people.skolelinux.org/pere/blog/archive/2016/10/">October (3)</a></li>
1472
1473 <li><a href="http://people.skolelinux.org/pere/blog/archive/2016/11/">November (8)</a></li>
1474
1475 <li><a href="http://people.skolelinux.org/pere/blog/archive/2016/12/">December (5)</a></li>
1476
1477 </ul></li>
1478
1479 <li>2015
1480 <ul>
1481
1482 <li><a href="http://people.skolelinux.org/pere/blog/archive/2015/01/">January (7)</a></li>
1483
1484 <li><a href="http://people.skolelinux.org/pere/blog/archive/2015/02/">February (6)</a></li>
1485
1486 <li><a href="http://people.skolelinux.org/pere/blog/archive/2015/03/">March (1)</a></li>
1487
1488 <li><a href="http://people.skolelinux.org/pere/blog/archive/2015/04/">April (4)</a></li>
1489
1490 <li><a href="http://people.skolelinux.org/pere/blog/archive/2015/05/">May (3)</a></li>
1491
1492 <li><a href="http://people.skolelinux.org/pere/blog/archive/2015/06/">June (4)</a></li>
1493
1494 <li><a href="http://people.skolelinux.org/pere/blog/archive/2015/07/">July (6)</a></li>
1495
1496 <li><a href="http://people.skolelinux.org/pere/blog/archive/2015/08/">August (2)</a></li>
1497
1498 <li><a href="http://people.skolelinux.org/pere/blog/archive/2015/09/">September (2)</a></li>
1499
1500 <li><a href="http://people.skolelinux.org/pere/blog/archive/2015/10/">October (9)</a></li>
1501
1502 <li><a href="http://people.skolelinux.org/pere/blog/archive/2015/11/">November (6)</a></li>
1503
1504 <li><a href="http://people.skolelinux.org/pere/blog/archive/2015/12/">December (3)</a></li>
1505
1506 </ul></li>
1507
1508 <li>2014
1509 <ul>
1510
1511 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/01/">January (2)</a></li>
1512
1513 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/02/">February (3)</a></li>
1514
1515 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/03/">March (8)</a></li>
1516
1517 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/04/">April (7)</a></li>
1518
1519 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/05/">May (1)</a></li>
1520
1521 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/06/">June (2)</a></li>
1522
1523 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/07/">July (2)</a></li>
1524
1525 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/08/">August (2)</a></li>
1526
1527 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/09/">September (5)</a></li>
1528
1529 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/10/">October (6)</a></li>
1530
1531 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/11/">November (3)</a></li>
1532
1533 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/12/">December (5)</a></li>
1534
1535 </ul></li>
1536
1537 <li>2013
1538 <ul>
1539
1540 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/01/">January (11)</a></li>
1541
1542 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/02/">February (9)</a></li>
1543
1544 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/03/">March (9)</a></li>
1545
1546 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/04/">April (6)</a></li>
1547
1548 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/05/">May (9)</a></li>
1549
1550 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/06/">June (10)</a></li>
1551
1552 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/07/">July (7)</a></li>
1553
1554 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/08/">August (3)</a></li>
1555
1556 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/09/">September (5)</a></li>
1557
1558 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/10/">October (7)</a></li>
1559
1560 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/11/">November (9)</a></li>
1561
1562 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/12/">December (3)</a></li>
1563
1564 </ul></li>
1565
1566 <li>2012
1567 <ul>
1568
1569 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/01/">January (7)</a></li>
1570
1571 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/02/">February (10)</a></li>
1572
1573 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/03/">March (17)</a></li>
1574
1575 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/04/">April (12)</a></li>
1576
1577 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/05/">May (12)</a></li>
1578
1579 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/06/">June (20)</a></li>
1580
1581 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/07/">July (17)</a></li>
1582
1583 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/08/">August (6)</a></li>
1584
1585 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/09/">September (9)</a></li>
1586
1587 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/10/">October (17)</a></li>
1588
1589 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/11/">November (10)</a></li>
1590
1591 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/12/">December (7)</a></li>
1592
1593 </ul></li>
1594
1595 <li>2011
1596 <ul>
1597
1598 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/01/">January (16)</a></li>
1599
1600 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/02/">February (6)</a></li>
1601
1602 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/03/">March (6)</a></li>
1603
1604 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/04/">April (7)</a></li>
1605
1606 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/05/">May (3)</a></li>
1607
1608 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/06/">June (2)</a></li>
1609
1610 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/07/">July (7)</a></li>
1611
1612 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/08/">August (6)</a></li>
1613
1614 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/09/">September (4)</a></li>
1615
1616 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/10/">October (2)</a></li>
1617
1618 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/11/">November (3)</a></li>
1619
1620 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/12/">December (1)</a></li>
1621
1622 </ul></li>
1623
1624 <li>2010
1625 <ul>
1626
1627 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/01/">January (2)</a></li>
1628
1629 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/02/">February (1)</a></li>
1630
1631 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/03/">March (3)</a></li>
1632
1633 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/04/">April (3)</a></li>
1634
1635 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/05/">May (9)</a></li>
1636
1637 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/06/">June (14)</a></li>
1638
1639 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/07/">July (12)</a></li>
1640
1641 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/08/">August (13)</a></li>
1642
1643 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/09/">September (7)</a></li>
1644
1645 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/10/">October (9)</a></li>
1646
1647 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/11/">November (13)</a></li>
1648
1649 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/12/">December (12)</a></li>
1650
1651 </ul></li>
1652
1653 <li>2009
1654 <ul>
1655
1656 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/01/">January (8)</a></li>
1657
1658 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/02/">February (8)</a></li>
1659
1660 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/03/">March (12)</a></li>
1661
1662 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/04/">April (10)</a></li>
1663
1664 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/05/">May (9)</a></li>
1665
1666 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/06/">June (3)</a></li>
1667
1668 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/07/">July (4)</a></li>
1669
1670 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/08/">August (3)</a></li>
1671
1672 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/09/">September (1)</a></li>
1673
1674 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/10/">October (2)</a></li>
1675
1676 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/11/">November (3)</a></li>
1677
1678 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/12/">December (3)</a></li>
1679
1680 </ul></li>
1681
1682 <li>2008
1683 <ul>
1684
1685 <li><a href="http://people.skolelinux.org/pere/blog/archive/2008/11/">November (5)</a></li>
1686
1687 <li><a href="http://people.skolelinux.org/pere/blog/archive/2008/12/">December (7)</a></li>
1688
1689 </ul></li>
1690
1691 </ul>
1692
1693
1694
1695 <h2>Tags</h2>
1696 <ul>
1697
1698  <li><a href="http://people.skolelinux.org/pere/blog/tags/3d-printer">3d-printer (16)</a></li>
1699
1700  <li><a href="http://people.skolelinux.org/pere/blog/tags/amiga">amiga (1)</a></li>
1701
1702  <li><a href="http://people.skolelinux.org/pere/blog/tags/aros">aros (1)</a></li>
1703
1704  <li><a href="http://people.skolelinux.org/pere/blog/tags/bankid">bankid (4)</a></li>
1705
1706  <li><a href="http://people.skolelinux.org/pere/blog/tags/betalkontant">betalkontant (8)</a></li>
1707
1708  <li><a href="http://people.skolelinux.org/pere/blog/tags/bitcoin">bitcoin (11)</a></li>
1709
1710  <li><a href="http://people.skolelinux.org/pere/blog/tags/bootsystem">bootsystem (17)</a></li>
1711
1712  <li><a href="http://people.skolelinux.org/pere/blog/tags/bsa">bsa (2)</a></li>
1713
1714  <li><a href="http://people.skolelinux.org/pere/blog/tags/chrpath">chrpath (2)</a></li>
1715
1716  <li><a href="http://people.skolelinux.org/pere/blog/tags/debian">debian (168)</a></li>
1717
1718  <li><a href="http://people.skolelinux.org/pere/blog/tags/debian edu">debian edu (158)</a></li>
1719
1720  <li><a href="http://people.skolelinux.org/pere/blog/tags/debian-handbook">debian-handbook (4)</a></li>
1721
1722  <li><a href="http://people.skolelinux.org/pere/blog/tags/digistan">digistan (11)</a></li>
1723
1724  <li><a href="http://people.skolelinux.org/pere/blog/tags/dld">dld (17)</a></li>
1725
1726  <li><a href="http://people.skolelinux.org/pere/blog/tags/docbook">docbook (26)</a></li>
1727
1728  <li><a href="http://people.skolelinux.org/pere/blog/tags/drivstoffpriser">drivstoffpriser (4)</a></li>
1729
1730  <li><a href="http://people.skolelinux.org/pere/blog/tags/english">english (407)</a></li>
1731
1732  <li><a href="http://people.skolelinux.org/pere/blog/tags/fiksgatami">fiksgatami (23)</a></li>
1733
1734  <li><a href="http://people.skolelinux.org/pere/blog/tags/fildeling">fildeling (14)</a></li>
1735
1736  <li><a href="http://people.skolelinux.org/pere/blog/tags/freeculture">freeculture (34)</a></li>
1737
1738  <li><a href="http://people.skolelinux.org/pere/blog/tags/freedombox">freedombox (9)</a></li>
1739
1740  <li><a href="http://people.skolelinux.org/pere/blog/tags/frikanalen">frikanalen (20)</a></li>
1741
1742  <li><a href="http://people.skolelinux.org/pere/blog/tags/h264">h264 (20)</a></li>
1743
1744  <li><a href="http://people.skolelinux.org/pere/blog/tags/intervju">intervju (42)</a></li>
1745
1746  <li><a href="http://people.skolelinux.org/pere/blog/tags/isenkram">isenkram (16)</a></li>
1747
1748  <li><a href="http://people.skolelinux.org/pere/blog/tags/kart">kart (22)</a></li>
1749
1750  <li><a href="http://people.skolelinux.org/pere/blog/tags/kodi">kodi (4)</a></li>
1751
1752  <li><a href="http://people.skolelinux.org/pere/blog/tags/ldap">ldap (9)</a></li>
1753
1754  <li><a href="http://people.skolelinux.org/pere/blog/tags/lego">lego (4)</a></li>
1755
1756  <li><a href="http://people.skolelinux.org/pere/blog/tags/lenker">lenker (8)</a></li>
1757
1758  <li><a href="http://people.skolelinux.org/pere/blog/tags/lsdvd">lsdvd (2)</a></li>
1759
1760  <li><a href="http://people.skolelinux.org/pere/blog/tags/ltsp">ltsp (1)</a></li>
1761
1762  <li><a href="http://people.skolelinux.org/pere/blog/tags/mesh network">mesh network (8)</a></li>
1763
1764  <li><a href="http://people.skolelinux.org/pere/blog/tags/multimedia">multimedia (42)</a></li>
1765
1766  <li><a href="http://people.skolelinux.org/pere/blog/tags/nice free software">nice free software (12)</a></li>
1767
1768  <li><a href="http://people.skolelinux.org/pere/blog/tags/noark5">noark5 (17)</a></li>
1769
1770  <li><a href="http://people.skolelinux.org/pere/blog/tags/norsk">norsk (307)</a></li>
1771
1772  <li><a href="http://people.skolelinux.org/pere/blog/tags/nuug">nuug (196)</a></li>
1773
1774  <li><a href="http://people.skolelinux.org/pere/blog/tags/offentlig innsyn">offentlig innsyn (37)</a></li>
1775
1776  <li><a href="http://people.skolelinux.org/pere/blog/tags/open311">open311 (2)</a></li>
1777
1778  <li><a href="http://people.skolelinux.org/pere/blog/tags/opphavsrett">opphavsrett (73)</a></li>
1779
1780  <li><a href="http://people.skolelinux.org/pere/blog/tags/personvern">personvern (109)</a></li>
1781
1782  <li><a href="http://people.skolelinux.org/pere/blog/tags/raid">raid (2)</a></li>
1783
1784  <li><a href="http://people.skolelinux.org/pere/blog/tags/reactos">reactos (1)</a></li>
1785
1786  <li><a href="http://people.skolelinux.org/pere/blog/tags/reprap">reprap (11)</a></li>
1787
1788  <li><a href="http://people.skolelinux.org/pere/blog/tags/rfid">rfid (3)</a></li>
1789
1790  <li><a href="http://people.skolelinux.org/pere/blog/tags/robot">robot (12)</a></li>
1791
1792  <li><a href="http://people.skolelinux.org/pere/blog/tags/rss">rss (1)</a></li>
1793
1794  <li><a href="http://people.skolelinux.org/pere/blog/tags/ruter">ruter (7)</a></li>
1795
1796  <li><a href="http://people.skolelinux.org/pere/blog/tags/scraperwiki">scraperwiki (2)</a></li>
1797
1798  <li><a href="http://people.skolelinux.org/pere/blog/tags/sikkerhet">sikkerhet (56)</a></li>
1799
1800  <li><a href="http://people.skolelinux.org/pere/blog/tags/sitesummary">sitesummary (4)</a></li>
1801
1802  <li><a href="http://people.skolelinux.org/pere/blog/tags/skepsis">skepsis (5)</a></li>
1803
1804  <li><a href="http://people.skolelinux.org/pere/blog/tags/standard">standard (66)</a></li>
1805
1806  <li><a href="http://people.skolelinux.org/pere/blog/tags/stavekontroll">stavekontroll (6)</a></li>
1807
1808  <li><a href="http://people.skolelinux.org/pere/blog/tags/stortinget">stortinget (12)</a></li>
1809
1810  <li><a href="http://people.skolelinux.org/pere/blog/tags/surveillance">surveillance (56)</a></li>
1811
1812  <li><a href="http://people.skolelinux.org/pere/blog/tags/sysadmin">sysadmin (4)</a></li>
1813
1814  <li><a href="http://people.skolelinux.org/pere/blog/tags/usenix">usenix (2)</a></li>
1815
1816  <li><a href="http://people.skolelinux.org/pere/blog/tags/valg">valg (9)</a></li>
1817
1818  <li><a href="http://people.skolelinux.org/pere/blog/tags/verkidetfri">verkidetfri (15)</a></li>
1819
1820  <li><a href="http://people.skolelinux.org/pere/blog/tags/video">video (73)</a></li>
1821
1822  <li><a href="http://people.skolelinux.org/pere/blog/tags/vitenskap">vitenskap (4)</a></li>
1823
1824  <li><a href="http://people.skolelinux.org/pere/blog/tags/web">web (42)</a></li>
1825
1826 </ul>
1827
1828
1829     </div>
1830     <p style="text-align: right">
1831  Created by <a href="http://steve.org.uk/Software/chronicle">Chronicle v4.6</a>
1832 </p>
1833
1834   </body>
1835 </html>