1 <?xml version=
"1.0" encoding=
"utf-8"?>
2 <rss version='
2.0' xmlns:lj='http://www.livejournal.org/rss/lj/
1.0/' xmlns:
atom=
"http://www.w3.org/2005/Atom">
4 <title>Petter Reinholdtsen
</title>
5 <description></description>
6 <link>http://people.skolelinux.org/pere/blog/
</link>
7 <atom:link href=
"http://people.skolelinux.org/pere/blog/index.rss" rel=
"self" type=
"application/rss+xml" />
10 <title>Web services for writing academic LaTeX papers as a team
</title>
11 <link>http://people.skolelinux.org/pere/blog/Web_services_for_writing_academic_LaTeX_papers_as_a_team.html
</link>
12 <guid isPermaLink=
"true">http://people.skolelinux.org/pere/blog/Web_services_for_writing_academic_LaTeX_papers_as_a_team.html
</guid>
13 <pubDate>Tue,
31 Oct
2017 21:
00:
00 +
0100</pubDate>
14 <description><p
>I was surprised today to learn that a friend in academia did not
15 know there are easily available web services available for writing
16 LaTeX documents as a team. I thought it was common knowledge, but to
17 make sure at least my readers are aware of it, I would like to mention
18 these useful services for writing LaTeX documents. Some of them even
19 provide a WYSIWYG editor to ease writing even further.
</p
>
21 <p
>There are two commercial services available,
<a
22 href=
"https://sharelatex.com
">ShareLaTeX
</a
> and
<a
23 href=
"https://overleaf.com
">Overleaf
</a
>. They are very easy to use.
24 Just start a new document, select which publisher to write for (ie
25 which LaTeX style to use), and start writing. Note, these two have announced their
26 intention to join forces, so soon it will only be one joint service.
27 I
've used both for different documents, and they work just fine.
28 While
<a href=
"https://github.com/sharelatex/sharelatex
">ShareLaTeX is
29 free software
</a
>, while the latter is not. According to
<a
30 href=
"https://www.overleaf.com/help/
17-is-overleaf-open-source
">a
31 announcement from Overleaf
</a
>, they plan to keep the ShareLaTeX code
32 base maintained as free software.
</p
>
34 But these two are not the only alternatives.
35 <a href=
"https://app.fiduswriter.org/
">Fidus Writer
</a
> is another free
36 software solution with
<a href=
"https://github.com/fiduswriter
">the
37 source available on github
</a
>. I have not used it myself. Several
38 others can be found on the nice
39 <a href=
"https://alternativeto.net/software/sharelatex/
">alterntiveTo
40 web service
</a
>.
42 <p
>If you like Google Docs or Etherpad, but would like to write
43 documents in LaTeX, you should check out these services. You can even
44 host your own, if you want to. :)
</p
>
50 <title>Locating IMDB IDs of movies in the Internet Archive using Wikidata
</title>
51 <link>http://people.skolelinux.org/pere/blog/Locating_IMDB_IDs_of_movies_in_the_Internet_Archive_using_Wikidata.html
</link>
52 <guid isPermaLink=
"true">http://people.skolelinux.org/pere/blog/Locating_IMDB_IDs_of_movies_in_the_Internet_Archive_using_Wikidata.html
</guid>
53 <pubDate>Wed,
25 Oct
2017 12:
20:
00 +
0200</pubDate>
54 <description><p
>Recently, I needed to automatically check the copyright status of a
55 set of
<a href=
"http://www.imdb.com/
">The Internet Movie database
56 (IMDB)
</a
> entries, to figure out which one of the movies they refer
57 to can be freely distributed on the Internet. This proved to be
58 harder than it sounds. IMDB for sure list movies without any
59 copyright protection, where the copyright protection has expired or
60 where the movie is lisenced using a permissive license like one from
61 Creative Commons. These are mixed with copyright protected movies,
62 and there seem to be no way to separate these classes of movies using
63 the information in IMDB.
</p
>
65 <p
>First I tried to look up entries manually in IMDB,
66 <a href=
"https://www.wikipedia.org/
">Wikipedia
</a
> and
67 <a href=
"https://www.archive.org/
">The Internet Archive
</a
>, to get a
68 feel how to do this. It is hard to know for sure using these sources,
69 but it should be possible to be reasonable confident a movie is
"out
70 of copyright
" with a few hours work per movie. As I needed to check
71 almost
20,
000 entries, this approach was not sustainable. I simply
72 can not work around the clock for about
6 years to check this data
75 <p
>I asked the people behind The Internet Archive if they could
76 introduce a new metadata field in their metadata XML for IMDB ID, but
77 was told that they leave it completely to the uploaders to update the
78 metadata. Some of the metadata entries had IMDB links in the
79 description, but I found no way to download all metadata files in bulk
80 to locate those ones and put that approach aside.
</p
>
82 <p
>In the process I noticed several Wikipedia articles about movies
83 had links to both IMDB and The Internet Archive, and it occured to me
84 that I could use the Wikipedia RDF data set to locate entries with
85 both, to at least get a lower bound on the number of movies on The
86 Internet Archive with a IMDB ID. This is useful based on the
87 assumption that movies distributed by The Internet Archive can be
88 legally distributed on the Internet. With some help from the RDF
89 community (thank you DanC), I was able to come up with this query to
90 pass to
<a href=
"https://query.wikidata.org/
">the SPARQL interface on
94 SELECT ?work ?imdb ?ia ?when ?label
97 ?work wdt:P31/wdt:P279* wd:Q11424.
101 ?work wdt:P577 ?when.
102 ?work rdfs:label ?label.
103 FILTER(LANG(?label) =
"en
").
106 </pre
></p
>
108 <p
>If I understand the query right, for every film entry anywhere in
109 Wikpedia, it will return the IMDB ID and The Internet Archive ID, and
110 when the movie was released and its English title, if either or both
111 of the latter two are available. At the moment the result set contain
112 2338 entries. Of course, it depend on volunteers including both
113 correct IMDB and The Internet Archive IDs in the wikipedia articles
114 for the movie. It should be noted that the result will include
115 duplicates if the movie have entries in several languages. There are
116 some bogus entries, either because The Internet Archive ID contain a
117 typo or because the movie is not available from The Internet Archive.
118 I did not verify the IMDB IDs, as I am unsure how to do that
119 automatically.
</p
>
121 <p
>I wrote a small python script to extract the data set from Wikidata
122 and check if the XML metadata for the movie is available from The
123 Internet Archive, and after around
1.5 hour it produced a list of
2097
124 free movies and their IMDB ID. In total,
171 entries in Wikidata lack
125 the refered Internet Archive entry. I assume the
70 "disappearing
"
126 entries (ie
2338-
2097-
171) are duplicate entries.
</p
>
128 <p
>This is not too bad, given that The Internet Archive report to
129 contain
<a href=
"https://archive.org/details/feature_films
">5331
130 feature films
</a
> at the moment, but it also mean more than
3000
131 movies are missing on Wikipedia or are missing the pair of references
132 on Wikipedia.
</p
>
134 <p
>I was curious about the distribution by release year, and made a
135 little graph to show how the amount of free movies is spread over the
138 <p
><img src=
"http://people.skolelinux.org/pere/blog/images/
2017-
10-
25-verk-i-det-fri-filmer.png
"></p
>
140 <p
>I expect the relative distribution of the remaining
3000 movies to
141 be similar.
</p
>
143 <p
>If you want to help, and want to ensure Wikipedia can be used to
144 cross reference The Internet Archive and The Internet Movie Database,
145 please make sure entries like this are listed under the
"External
146 links
" heading on the Wikipedia article for the movie:
</p
>
149 * {{Internet Archive film|id=FightingLady}}
150 * {{IMDb title|id=
0036823|title=The Fighting Lady}}
151 </pre
></p
>
153 <p
>Please verify the links on the final page, to make sure you did not
154 introduce a typo.
</p
>
156 <p
>Here is the complete list, if you want to correct the
171
157 identified Wikipedia entries with broken links to The Internet
158 Archive:
<a href=
"http://www.wikidata.org/entity/Q1140317
">Q1140317
</a
>,
159 <a href=
"http://www.wikidata.org/entity/Q458656
">Q458656
</a
>,
160 <a href=
"http://www.wikidata.org/entity/Q458656
">Q458656
</a
>,
161 <a href=
"http://www.wikidata.org/entity/Q470560
">Q470560
</a
>,
162 <a href=
"http://www.wikidata.org/entity/Q743340
">Q743340
</a
>,
163 <a href=
"http://www.wikidata.org/entity/Q822580
">Q822580
</a
>,
164 <a href=
"http://www.wikidata.org/entity/Q480696
">Q480696
</a
>,
165 <a href=
"http://www.wikidata.org/entity/Q128761
">Q128761
</a
>,
166 <a href=
"http://www.wikidata.org/entity/Q1307059
">Q1307059
</a
>,
167 <a href=
"http://www.wikidata.org/entity/Q1335091
">Q1335091
</a
>,
168 <a href=
"http://www.wikidata.org/entity/Q1537166
">Q1537166
</a
>,
169 <a href=
"http://www.wikidata.org/entity/Q1438334
">Q1438334
</a
>,
170 <a href=
"http://www.wikidata.org/entity/Q1479751
">Q1479751
</a
>,
171 <a href=
"http://www.wikidata.org/entity/Q1497200
">Q1497200
</a
>,
172 <a href=
"http://www.wikidata.org/entity/Q1498122
">Q1498122
</a
>,
173 <a href=
"http://www.wikidata.org/entity/Q865973
">Q865973
</a
>,
174 <a href=
"http://www.wikidata.org/entity/Q834269
">Q834269
</a
>,
175 <a href=
"http://www.wikidata.org/entity/Q841781
">Q841781
</a
>,
176 <a href=
"http://www.wikidata.org/entity/Q841781
">Q841781
</a
>,
177 <a href=
"http://www.wikidata.org/entity/Q1548193
">Q1548193
</a
>,
178 <a href=
"http://www.wikidata.org/entity/Q499031
">Q499031
</a
>,
179 <a href=
"http://www.wikidata.org/entity/Q1564769
">Q1564769
</a
>,
180 <a href=
"http://www.wikidata.org/entity/Q1585239
">Q1585239
</a
>,
181 <a href=
"http://www.wikidata.org/entity/Q1585569
">Q1585569
</a
>,
182 <a href=
"http://www.wikidata.org/entity/Q1624236
">Q1624236
</a
>,
183 <a href=
"http://www.wikidata.org/entity/Q4796595
">Q4796595
</a
>,
184 <a href=
"http://www.wikidata.org/entity/Q4853469
">Q4853469
</a
>,
185 <a href=
"http://www.wikidata.org/entity/Q4873046
">Q4873046
</a
>,
186 <a href=
"http://www.wikidata.org/entity/Q915016
">Q915016
</a
>,
187 <a href=
"http://www.wikidata.org/entity/Q4660396
">Q4660396
</a
>,
188 <a href=
"http://www.wikidata.org/entity/Q4677708
">Q4677708
</a
>,
189 <a href=
"http://www.wikidata.org/entity/Q4738449
">Q4738449
</a
>,
190 <a href=
"http://www.wikidata.org/entity/Q4756096
">Q4756096
</a
>,
191 <a href=
"http://www.wikidata.org/entity/Q4766785
">Q4766785
</a
>,
192 <a href=
"http://www.wikidata.org/entity/Q880357
">Q880357
</a
>,
193 <a href=
"http://www.wikidata.org/entity/Q882066
">Q882066
</a
>,
194 <a href=
"http://www.wikidata.org/entity/Q882066
">Q882066
</a
>,
195 <a href=
"http://www.wikidata.org/entity/Q204191
">Q204191
</a
>,
196 <a href=
"http://www.wikidata.org/entity/Q204191
">Q204191
</a
>,
197 <a href=
"http://www.wikidata.org/entity/Q1194170
">Q1194170
</a
>,
198 <a href=
"http://www.wikidata.org/entity/Q940014
">Q940014
</a
>,
199 <a href=
"http://www.wikidata.org/entity/Q946863
">Q946863
</a
>,
200 <a href=
"http://www.wikidata.org/entity/Q172837
">Q172837
</a
>,
201 <a href=
"http://www.wikidata.org/entity/Q573077
">Q573077
</a
>,
202 <a href=
"http://www.wikidata.org/entity/Q1219005
">Q1219005
</a
>,
203 <a href=
"http://www.wikidata.org/entity/Q1219599
">Q1219599
</a
>,
204 <a href=
"http://www.wikidata.org/entity/Q1643798
">Q1643798
</a
>,
205 <a href=
"http://www.wikidata.org/entity/Q1656352
">Q1656352
</a
>,
206 <a href=
"http://www.wikidata.org/entity/Q1659549
">Q1659549
</a
>,
207 <a href=
"http://www.wikidata.org/entity/Q1660007
">Q1660007
</a
>,
208 <a href=
"http://www.wikidata.org/entity/Q1698154
">Q1698154
</a
>,
209 <a href=
"http://www.wikidata.org/entity/Q1737980
">Q1737980
</a
>,
210 <a href=
"http://www.wikidata.org/entity/Q1877284
">Q1877284
</a
>,
211 <a href=
"http://www.wikidata.org/entity/Q1199354
">Q1199354
</a
>,
212 <a href=
"http://www.wikidata.org/entity/Q1199354
">Q1199354
</a
>,
213 <a href=
"http://www.wikidata.org/entity/Q1199451
">Q1199451
</a
>,
214 <a href=
"http://www.wikidata.org/entity/Q1211871
">Q1211871
</a
>,
215 <a href=
"http://www.wikidata.org/entity/Q1212179
">Q1212179
</a
>,
216 <a href=
"http://www.wikidata.org/entity/Q1238382
">Q1238382
</a
>,
217 <a href=
"http://www.wikidata.org/entity/Q4906454
">Q4906454
</a
>,
218 <a href=
"http://www.wikidata.org/entity/Q320219
">Q320219
</a
>,
219 <a href=
"http://www.wikidata.org/entity/Q1148649
">Q1148649
</a
>,
220 <a href=
"http://www.wikidata.org/entity/Q645094
">Q645094
</a
>,
221 <a href=
"http://www.wikidata.org/entity/Q5050350
">Q5050350
</a
>,
222 <a href=
"http://www.wikidata.org/entity/Q5166548
">Q5166548
</a
>,
223 <a href=
"http://www.wikidata.org/entity/Q2677926
">Q2677926
</a
>,
224 <a href=
"http://www.wikidata.org/entity/Q2698139
">Q2698139
</a
>,
225 <a href=
"http://www.wikidata.org/entity/Q2707305
">Q2707305
</a
>,
226 <a href=
"http://www.wikidata.org/entity/Q2740725
">Q2740725
</a
>,
227 <a href=
"http://www.wikidata.org/entity/Q2024780
">Q2024780
</a
>,
228 <a href=
"http://www.wikidata.org/entity/Q2117418
">Q2117418
</a
>,
229 <a href=
"http://www.wikidata.org/entity/Q2138984
">Q2138984
</a
>,
230 <a href=
"http://www.wikidata.org/entity/Q1127992
">Q1127992
</a
>,
231 <a href=
"http://www.wikidata.org/entity/Q1058087
">Q1058087
</a
>,
232 <a href=
"http://www.wikidata.org/entity/Q1070484
">Q1070484
</a
>,
233 <a href=
"http://www.wikidata.org/entity/Q1080080
">Q1080080
</a
>,
234 <a href=
"http://www.wikidata.org/entity/Q1090813
">Q1090813
</a
>,
235 <a href=
"http://www.wikidata.org/entity/Q1251918
">Q1251918
</a
>,
236 <a href=
"http://www.wikidata.org/entity/Q1254110
">Q1254110
</a
>,
237 <a href=
"http://www.wikidata.org/entity/Q1257070
">Q1257070
</a
>,
238 <a href=
"http://www.wikidata.org/entity/Q1257079
">Q1257079
</a
>,
239 <a href=
"http://www.wikidata.org/entity/Q1197410
">Q1197410
</a
>,
240 <a href=
"http://www.wikidata.org/entity/Q1198423
">Q1198423
</a
>,
241 <a href=
"http://www.wikidata.org/entity/Q706951
">Q706951
</a
>,
242 <a href=
"http://www.wikidata.org/entity/Q723239
">Q723239
</a
>,
243 <a href=
"http://www.wikidata.org/entity/Q2079261
">Q2079261
</a
>,
244 <a href=
"http://www.wikidata.org/entity/Q1171364
">Q1171364
</a
>,
245 <a href=
"http://www.wikidata.org/entity/Q617858
">Q617858
</a
>,
246 <a href=
"http://www.wikidata.org/entity/Q5166611
">Q5166611
</a
>,
247 <a href=
"http://www.wikidata.org/entity/Q5166611
">Q5166611
</a
>,
248 <a href=
"http://www.wikidata.org/entity/Q324513
">Q324513
</a
>,
249 <a href=
"http://www.wikidata.org/entity/Q374172
">Q374172
</a
>,
250 <a href=
"http://www.wikidata.org/entity/Q7533269
">Q7533269
</a
>,
251 <a href=
"http://www.wikidata.org/entity/Q970386
">Q970386
</a
>,
252 <a href=
"http://www.wikidata.org/entity/Q976849
">Q976849
</a
>,
253 <a href=
"http://www.wikidata.org/entity/Q7458614
">Q7458614
</a
>,
254 <a href=
"http://www.wikidata.org/entity/Q5347416
">Q5347416
</a
>,
255 <a href=
"http://www.wikidata.org/entity/Q5460005
">Q5460005
</a
>,
256 <a href=
"http://www.wikidata.org/entity/Q5463392
">Q5463392
</a
>,
257 <a href=
"http://www.wikidata.org/entity/Q3038555
">Q3038555
</a
>,
258 <a href=
"http://www.wikidata.org/entity/Q5288458
">Q5288458
</a
>,
259 <a href=
"http://www.wikidata.org/entity/Q2346516
">Q2346516
</a
>,
260 <a href=
"http://www.wikidata.org/entity/Q5183645
">Q5183645
</a
>,
261 <a href=
"http://www.wikidata.org/entity/Q5185497
">Q5185497
</a
>,
262 <a href=
"http://www.wikidata.org/entity/Q5216127
">Q5216127
</a
>,
263 <a href=
"http://www.wikidata.org/entity/Q5223127
">Q5223127
</a
>,
264 <a href=
"http://www.wikidata.org/entity/Q5261159
">Q5261159
</a
>,
265 <a href=
"http://www.wikidata.org/entity/Q1300759
">Q1300759
</a
>,
266 <a href=
"http://www.wikidata.org/entity/Q5521241
">Q5521241
</a
>,
267 <a href=
"http://www.wikidata.org/entity/Q7733434
">Q7733434
</a
>,
268 <a href=
"http://www.wikidata.org/entity/Q7736264
">Q7736264
</a
>,
269 <a href=
"http://www.wikidata.org/entity/Q7737032
">Q7737032
</a
>,
270 <a href=
"http://www.wikidata.org/entity/Q7882671
">Q7882671
</a
>,
271 <a href=
"http://www.wikidata.org/entity/Q7719427
">Q7719427
</a
>,
272 <a href=
"http://www.wikidata.org/entity/Q7719444
">Q7719444
</a
>,
273 <a href=
"http://www.wikidata.org/entity/Q7722575
">Q7722575
</a
>,
274 <a href=
"http://www.wikidata.org/entity/Q2629763
">Q2629763
</a
>,
275 <a href=
"http://www.wikidata.org/entity/Q2640346
">Q2640346
</a
>,
276 <a href=
"http://www.wikidata.org/entity/Q2649671
">Q2649671
</a
>,
277 <a href=
"http://www.wikidata.org/entity/Q7703851
">Q7703851
</a
>,
278 <a href=
"http://www.wikidata.org/entity/Q7747041
">Q7747041
</a
>,
279 <a href=
"http://www.wikidata.org/entity/Q6544949
">Q6544949
</a
>,
280 <a href=
"http://www.wikidata.org/entity/Q6672759
">Q6672759
</a
>,
281 <a href=
"http://www.wikidata.org/entity/Q2445896
">Q2445896
</a
>,
282 <a href=
"http://www.wikidata.org/entity/Q12124891
">Q12124891
</a
>,
283 <a href=
"http://www.wikidata.org/entity/Q3127044
">Q3127044
</a
>,
284 <a href=
"http://www.wikidata.org/entity/Q2511262
">Q2511262
</a
>,
285 <a href=
"http://www.wikidata.org/entity/Q2517672
">Q2517672
</a
>,
286 <a href=
"http://www.wikidata.org/entity/Q2543165
">Q2543165
</a
>,
287 <a href=
"http://www.wikidata.org/entity/Q426628
">Q426628
</a
>,
288 <a href=
"http://www.wikidata.org/entity/Q426628
">Q426628
</a
>,
289 <a href=
"http://www.wikidata.org/entity/Q12126890
">Q12126890
</a
>,
290 <a href=
"http://www.wikidata.org/entity/Q13359969
">Q13359969
</a
>,
291 <a href=
"http://www.wikidata.org/entity/Q13359969
">Q13359969
</a
>,
292 <a href=
"http://www.wikidata.org/entity/Q2294295
">Q2294295
</a
>,
293 <a href=
"http://www.wikidata.org/entity/Q2294295
">Q2294295
</a
>,
294 <a href=
"http://www.wikidata.org/entity/Q2559509
">Q2559509
</a
>,
295 <a href=
"http://www.wikidata.org/entity/Q2559912
">Q2559912
</a
>,
296 <a href=
"http://www.wikidata.org/entity/Q7760469
">Q7760469
</a
>,
297 <a href=
"http://www.wikidata.org/entity/Q6703974
">Q6703974
</a
>,
298 <a href=
"http://www.wikidata.org/entity/Q4744
">Q4744
</a
>,
299 <a href=
"http://www.wikidata.org/entity/Q7766962
">Q7766962
</a
>,
300 <a href=
"http://www.wikidata.org/entity/Q7768516
">Q7768516
</a
>,
301 <a href=
"http://www.wikidata.org/entity/Q7769205
">Q7769205
</a
>,
302 <a href=
"http://www.wikidata.org/entity/Q7769988
">Q7769988
</a
>,
303 <a href=
"http://www.wikidata.org/entity/Q2946945
">Q2946945
</a
>,
304 <a href=
"http://www.wikidata.org/entity/Q3212086
">Q3212086
</a
>,
305 <a href=
"http://www.wikidata.org/entity/Q3212086
">Q3212086
</a
>,
306 <a href=
"http://www.wikidata.org/entity/Q18218448
">Q18218448
</a
>,
307 <a href=
"http://www.wikidata.org/entity/Q18218448
">Q18218448
</a
>,
308 <a href=
"http://www.wikidata.org/entity/Q18218448
">Q18218448
</a
>,
309 <a href=
"http://www.wikidata.org/entity/Q6909175
">Q6909175
</a
>,
310 <a href=
"http://www.wikidata.org/entity/Q7405709
">Q7405709
</a
>,
311 <a href=
"http://www.wikidata.org/entity/Q7416149
">Q7416149
</a
>,
312 <a href=
"http://www.wikidata.org/entity/Q7239952
">Q7239952
</a
>,
313 <a href=
"http://www.wikidata.org/entity/Q7317332
">Q7317332
</a
>,
314 <a href=
"http://www.wikidata.org/entity/Q7783674
">Q7783674
</a
>,
315 <a href=
"http://www.wikidata.org/entity/Q7783704
">Q7783704
</a
>,
316 <a href=
"http://www.wikidata.org/entity/Q7857590
">Q7857590
</a
>,
317 <a href=
"http://www.wikidata.org/entity/Q3372526
">Q3372526
</a
>,
318 <a href=
"http://www.wikidata.org/entity/Q3372642
">Q3372642
</a
>,
319 <a href=
"http://www.wikidata.org/entity/Q3372816
">Q3372816
</a
>,
320 <a href=
"http://www.wikidata.org/entity/Q3372909
">Q3372909
</a
>,
321 <a href=
"http://www.wikidata.org/entity/Q7959649
">Q7959649
</a
>,
322 <a href=
"http://www.wikidata.org/entity/Q7977485
">Q7977485
</a
>,
323 <a href=
"http://www.wikidata.org/entity/Q7992684
">Q7992684
</a
>,
324 <a href=
"http://www.wikidata.org/entity/Q3817966
">Q3817966
</a
>,
325 <a href=
"http://www.wikidata.org/entity/Q3821852
">Q3821852
</a
>,
326 <a href=
"http://www.wikidata.org/entity/Q3420907
">Q3420907
</a
>,
327 <a href=
"http://www.wikidata.org/entity/Q3429733
">Q3429733
</a
>,
328 <a href=
"http://www.wikidata.org/entity/Q774474
">Q774474
</a
></p
>
333 <title>A one-way wall on the border?
</title>
334 <link>http://people.skolelinux.org/pere/blog/A_one_way_wall_on_the_border_.html
</link>
335 <guid isPermaLink=
"true">http://people.skolelinux.org/pere/blog/A_one_way_wall_on_the_border_.html
</guid>
336 <pubDate>Sat,
14 Oct
2017 22:
10:
00 +
0200</pubDate>
337 <description><p
>I find it fascinating how many of the people being locked inside
338 the proposed border wall between USA and Mexico support the idea. The
339 proposal to keep Mexicans out reminds me of
340 <a href=
"http://www.history.com/news/
10-things-you-may-not-know-about-the-berlin-wall
">the
341 propaganda twist from the East Germany government
</a
> calling the wall
342 the “Antifascist Bulwark” after erecting the Berlin Wall, claiming
343 that the wall was erected to keep enemies from creeping into East
344 Germany, while it was obvious to the people locked inside it that it
345 was erected to keep the people from escaping.
</p
>
347 <p
>Do the people in USA supporting this wall really believe it is a
348 one way wall, only keeping people on the outside from getting in,
349 while not keeping people in the inside from getting out?
</p
>
354 <title>Generating
3D prints in Debian using Cura and Slic3r(-prusa)
</title>
355 <link>http://people.skolelinux.org/pere/blog/Generating_3D_prints_in_Debian_using_Cura_and_Slic3r__prusa_.html
</link>
356 <guid isPermaLink=
"true">http://people.skolelinux.org/pere/blog/Generating_3D_prints_in_Debian_using_Cura_and_Slic3r__prusa_.html
</guid>
357 <pubDate>Mon,
9 Oct
2017 10:
50:
00 +
0200</pubDate>
358 <description><p
>At my nearby maker space,
359 <a href=
"http://sonen.ifi.uio.no/
">Sonen
</a
>, I heard the story that it
360 was easier to generate gcode files for theyr
3D printers (Ultimake
2+)
361 on Windows and MacOS X than Linux, because the software involved had
362 to be manually compiled and set up on Linux while premade packages
363 worked out of the box on Windows and MacOS X. I found this annoying,
364 as the software involved,
365 <a href=
"https://github.com/Ultimaker/Cura
">Cura
</a
>, is free software
366 and should be trivial to get up and running on Linux if someone took
367 the time to package it for the relevant distributions. I even found
368 <a href=
"https://bugs.debian.org/
706656">a request for adding into
369 Debian
</a
> from
2013, which had seem some activity over the years but
370 never resulted in the software showing up in Debian. So a few days
371 ago I offered my help to try to improve the situation.
</p
>
373 <p
>Now I am very happy to see that all the packages required by a
374 working Cura in Debian are uploaded into Debian and waiting in the NEW
375 queue for the ftpmasters to have a look. You can track the progress
377 <a href=
"https://qa.debian.org/developer.php?email=
3dprinter-general%
40lists.alioth.debian.org
">the
378 status page for the
3D printer team
</a
>.
</p
>
380 <p
>The uploaded packages are a bit behind upstream, and was uploaded
381 now to get slots in
<a href=
"https://ftp-master.debian.org/new.html
">the NEW
382 queue
</a
> while we work up updating the packages to the latest
383 upstream version.
</p
>
385 <p
>On a related note, two competitors for Cura, which I found harder
386 to use and was unable to configure correctly for Ultimaker
2+ in the
387 short time I spent on it, are already in Debian. If you are looking
388 for
3D printer
"slicers
" and want something already available in
390 <a href=
"https://tracker.debian.org/pkg/slic3r
">slic3r
</a
> and
391 <a href=
"https://tracker.debian.org/pkg/slic3r-prusa
">slic3r-prusa
</a
>.
392 The latter is a fork of the former.
</p
>
397 <title>Mangler du en skrue, eller har du en skrue løs?
</title>
398 <link>http://people.skolelinux.org/pere/blog/Mangler_du_en_skrue__eller_har_du_en_skrue_l_s_.html
</link>
399 <guid isPermaLink=
"true">http://people.skolelinux.org/pere/blog/Mangler_du_en_skrue__eller_har_du_en_skrue_l_s_.html
</guid>
400 <pubDate>Wed,
4 Oct
2017 09:
40:
00 +
0200</pubDate>
401 <description>Når jeg holder på med ulike prosjekter, så trenger jeg stadig ulike
402 skruer. Det siste prosjektet jeg holder på med er å lage
403 <a href=
"https://www.thingiverse.com/thing:
676916">en boks til en
404 HDMI-touch-skjerm
</a
> som skal brukes med Raspberry Pi. Boksen settes
405 sammen med skruer og bolter, og jeg har vært i tvil om hvor jeg kan
406 få tak i de riktige skruene. Clas Ohlson og Jernia i nærheten har
407 sjelden hatt det jeg trenger. Men her om dagen fikk jeg et fantastisk
408 tips for oss som bor i Oslo.
409 <a href=
"http://www.zachskruer.no/
">Zachariassen Jernvare AS
</a
> i
410 <a href=
"http://www.openstreetmap.org/?mlat=
59.93421&mlon=
10.76795#map=
19/
59.93421/
10.76795">Hegermannsgate
411 23A på Torshov
</a
> har et fantastisk utvalg, og åpent mellom
09:
00 og
412 17:
00. De selger skruer, muttere, bolter, skiver etc i løs vekt, og
413 så langt har jeg fått alt jeg har lett etter. De har i tillegg det
414 meste av annen jernvare, som verktøy, lamper, ledninger, etc. Jeg
415 håper de har nok kunder til å holde det gående lenge, da dette er en
416 butikk jeg kommer til å besøke ofte. Butikken er et funn å ha i
417 nabolaget for oss som liker å bygge litt selv. :)
</p
>
422 <title>Visualizing GSM radio chatter using gr-gsm and Hopglass
</title>
423 <link>http://people.skolelinux.org/pere/blog/Visualizing_GSM_radio_chatter_using_gr_gsm_and_Hopglass.html
</link>
424 <guid isPermaLink=
"true">http://people.skolelinux.org/pere/blog/Visualizing_GSM_radio_chatter_using_gr_gsm_and_Hopglass.html
</guid>
425 <pubDate>Fri,
29 Sep
2017 10:
30:
00 +
0200</pubDate>
426 <description><p
>Every mobile phone announce its existence over radio to the nearby
427 mobile cell towers. And this radio chatter is available for anyone
428 with a radio receiver capable of receiving them. Details about the
429 mobile phones with very good accuracy is of course collected by the
430 phone companies, but this is not the topic of this blog post. The
431 mobile phone radio chatter make it possible to figure out when a cell
432 phone is nearby, as it include the SIM card ID (IMSI). By paying
433 attention over time, one can see when a phone arrive and when it leave
434 an area. I believe it would be nice to make this information more
435 available to the general public, to make more people aware of how
436 their phones are announcing their whereabouts to anyone that care to
439 <p
>I am very happy to report that we managed to get something
440 visualizing this information up and running for
441 <a href=
"http://norwaymakers.org/osf17
">Oslo Skaperfestival
2017</a
>
442 (Oslo Makers Festival) taking place today and tomorrow at Deichmanske
443 library. The solution is based on the
444 <a href=
"http://people.skolelinux.org/pere/blog/Easier_recipe_to_observe_the_cell_phones_around_you.html
">simple
445 recipe for listening to GSM chatter
</a
> I posted a few days ago, and
446 will show up at the stand of
<a href=
"http://sonen.ifi.uio.no/
">Åpen
447 Sone from the Computer Science department of the University of
448 Oslo
</a
>. The presentation will show the nearby mobile phones (aka
449 IMSIs) as dots in a web browser graph, with lines to the dot
450 representing mobile base station it is talking to. It was working in
451 the lab yesterday, and was moved into place this morning.
</p
>
453 <p
>We set up a fairly powerful desktop machine using Debian
454 Buster/Testing with several (five, I believe) RTL2838 DVB-T receivers
455 connected and visualize the visible cell phone towers using an
456 <a href=
"https://github.com/marlow925/hopglass
">English version of
457 Hopglass
</a
>. A fairly powerfull machine is needed as the
458 grgsm_livemon_headless processes from
459 <a href=
"https://tracker.debian.org/pkg/gr-gsm
">gr-gsm
</a
> converting
460 the radio signal to data packages is quite CPU intensive.
</p
>
462 <p
>The frequencies to listen to, are identified using a slightly
463 patched scan-and-livemon (to set the --args values for each receiver),
464 and the Hopglass data is generated using the
465 <a href=
"https://github.com/petterreinholdtsen/IMSI-catcher/tree/meshviewer-output
">patches
466 in my meshviewer-output branch
</a
>. For some reason we could not get
467 more than four SDRs working. There is also a geographical map trying
468 to show the location of the base stations, but I believe their
469 coordinates are hardcoded to some random location in Germany, I
470 believe. The code should be replaced with code to look up location in
471 a text file, a sqlite database or one of the online databases
473 <a href=
"https://github.com/Oros42/IMSI-catcher/issues/
14">the github
474 issue for the topic
</a
>.
476 <p
>If this sound interesting, visit the stand at the festival!
</p
>
481 <title>Easier recipe to observe the cell phones around you
</title>
482 <link>http://people.skolelinux.org/pere/blog/Easier_recipe_to_observe_the_cell_phones_around_you.html
</link>
483 <guid isPermaLink=
"true">http://people.skolelinux.org/pere/blog/Easier_recipe_to_observe_the_cell_phones_around_you.html
</guid>
484 <pubDate>Sun,
24 Sep
2017 08:
30:
00 +
0200</pubDate>
485 <description><p
>A little more than a month ago I wrote
486 <a href=
"http://people.skolelinux.org/pere/blog/Simpler_recipe_on_how_to_make_a_simple__7_IMSI_Catcher_using_Debian.html
">how
487 to observe the SIM card ID (aka IMSI number) of mobile phones talking
488 to nearby mobile phone base stations using Debian GNU/Linux and a
489 cheap USB software defined radio
</a
>, and thus being able to pinpoint
490 the location of people and equipment (like cars and trains) with an
491 accuracy of a few kilometer. Since then we have worked to make the
492 procedure even simpler, and it is now possible to do this without any
493 manual frequency tuning and without building your own packages.
</p
>
495 <p
>The
<a href=
"https://tracker.debian.org/pkg/gr-gsm
">gr-gsm
</a
>
496 package is now included in Debian testing and unstable, and the
497 IMSI-catcher code no longer require root access to fetch and decode
498 the GSM data collected using gr-gsm.
</p
>
500 <p
>Here is an updated recipe, using packages built by Debian and a git
501 clone of two python scripts:
</p
>
505 <li
>Start with a Debian machine running the Buster version (aka
508 <li
>Run
'<tt
>apt install gr-gsm python-numpy python-scipy
509 python-scapy
</tt
>' as root to install required packages.
</li
>
511 <li
>Fetch the code decoding GSM packages using
'<tt
>git clone
512 github.com/Oros42/IMSI-catcher.git
</tt
>'.
</li
>
514 <li
>Insert USB software defined radio supported by GNU Radio.
</li
>
516 <li
>Enter the IMSI-catcher directory and run
'<tt
>python
517 scan-and-livemon
</tt
>' to locate the frequency of nearby base
518 stations and start listening for GSM packages on one of them.
</li
>
520 <li
>Enter the IMSI-catcher directory and run
'<tt
>python
521 simple_IMSI-catcher.py
</tt
>' to display the collected information.
</li
>
525 <p
>Note, due to a bug somewhere the scan-and-livemon program (actually
526 <a href=
"https://github.com/ptrkrysik/gr-gsm/issues/
336">its underlying
527 program grgsm_scanner
</a
>) do not work with the HackRF radio. It does
528 work with RTL
8232 and other similar USB radio receivers you can get
530 (
<a href=
"https://www.ebay.com/sch/items/?_nkw=rtl+
2832">for example
531 from ebay
</a
>), so for now the solution is to scan using the RTL radio
532 and only use HackRF for fetching GSM data.
</p
>
534 <p
>As far as I can tell, a cell phone only show up on one of the
535 frequencies at the time, so if you are going to track and count every
536 cell phone around you, you need to listen to all the frequencies used.
537 To listen to several frequencies, use the --numrecv argument to
538 scan-and-livemon to use several receivers. Further, I am not sure if
539 phones using
3G or
4G will show as talking GSM to base stations, so
540 this approach might not see all phones around you. I typically see
541 0-
400 IMSI numbers an hour when looking around where I live.
</p
>
543 <p
>I
've tried to run the scanner on a
544 <a href=
"https://wiki.debian.org/RaspberryPi
">Raspberry Pi
2 and
3
545 running Debian Buster
</a
>, but the grgsm_livemon_headless process seem
546 to be too CPU intensive to keep up. When GNU Radio print
'O
' to
547 stdout, I am told there it is caused by a buffer overflow between the
548 radio and GNU Radio, caused by the program being unable to read the
549 GSM data fast enough. If you see a stream of
'O
's from the terminal
550 where you started scan-and-livemon, you need a give the process more
551 CPU power. Perhaps someone are able to optimize the code to a point
552 where it become possible to set up RPi3 based GSM sniffers? I tried
553 using Raspbian instead of Debian, but there seem to be something wrong
554 with GNU Radio on raspbian, causing glibc to abort().
</p
>
559 <title>Datalagringsdirektivet kaster skygger over Høyre og Arbeiderpartiet
</title>
560 <link>http://people.skolelinux.org/pere/blog/Datalagringsdirektivet_kaster_skygger_over_H_yre_og_Arbeiderpartiet.html
</link>
561 <guid isPermaLink=
"true">http://people.skolelinux.org/pere/blog/Datalagringsdirektivet_kaster_skygger_over_H_yre_og_Arbeiderpartiet.html
</guid>
562 <pubDate>Thu,
7 Sep
2017 21:
35:
00 +
0200</pubDate>
563 <description><p
>For noen dager siden publiserte Jon Wessel-Aas en bloggpost om
564 «
<a href=
"http://www.uhuru.biz/?p=
1821">Konklusjonen om datalagring som
565 EU-kommisjonen ikke ville at vi skulle få se
</a
>». Det er en
566 interessant gjennomgang av EU-domstolens syn på snurpenotovervåkning
567 av befolkningen, som er klar på at det er i strid med
568 EU-lovgivingen.
</p
>
570 <p
>Valgkampen går for fullt i Norge, og om noen få dager er siste
571 frist for å avgi stemme. En ting er sikkert, Høyre og Arbeiderpartiet
573 <a href=
"http://people.skolelinux.org/pere/blog/Datalagringsdirektivet_gj_r_at_Oslo_H_yre_og_Arbeiderparti_ikke_f_r_min_stemme_i__r.html
">denne
574 gangen heller
</a
>. Jeg har ikke glemt at de tvang igjennom loven som
575 skulle pålegge alle data- og teletjenesteleverandører å overvåke alle
576 sine kunder. En lov som er vedtatt, og aldri opphevet igjen.
</p
>
578 <p
>Det er tydelig fra diskusjonen rundt grenseløs digital overvåkning
579 (eller
"Digital Grenseforsvar
" som det kalles i Orvellisk nytale) at
580 hverken Høyre og Arbeiderpartiet har noen prinsipielle sperrer mot å
581 overvåke hele befolkningen, og diskusjonen så langt tyder på at flere
582 av de andre partiene heller ikke har det. Mange av
583 <a href=
"https://data.holderdeord.no/votes/
1301946411e
">de som stemte
584 for Datalagringsdirektivet i Stortinget
</a
> (
64 fra Arbeiderpartiet,
585 25 fra Høyre) er fortsatt aktive og argumenterer fortsatt for å radere
586 vekk mer av innbyggernes privatsfære.
</p
>
588 <p
>Når myndighetene demonstrerer sin mistillit til folket, tror jeg
589 folket selv bør legge litt innsats i å verne sitt privatliv, ved å ta
590 i bruk ende-til-ende-kryptert kommunikasjon med sine kjente og kjære,
591 og begrense hvor mye privat informasjon som deles med uvedkommende.
592 Det er jo ingenting som tyder på at myndighetene kommer til å være vår
594 <a href=
"http://people.skolelinux.org/pere/blog/How_to_talk_with_your_loved_ones_in_private.html
">Det
595 er mange muligheter
</a
>. Selv har jeg litt sans for
596 <a href=
"https://ring.cx/
">Ring
</a
>, som er basert på p2p-teknologi
597 uten sentral kontroll, er fri programvare, og støtter meldinger, tale
598 og video. Systemet er tilgjengelig ut av boksen fra
599 <a href=
"https://tracker.debian.org/pkg/ring
">Debian
</a
> og
600 <a href=
"https://launchpad.net/ubuntu/+source/ring
">Ubuntu
</a
>, og det
601 finnes pakker for Android, MacOSX og Windows. Foreløpig er det få
602 brukere med Ring, slik at jeg også bruker
603 <a href=
"https://signal.org/
">Signal
</a
> som nettleserutvidelse.
</p
>
608 <title>Simpler recipe on how to make a simple $
7 IMSI Catcher using Debian
</title>
609 <link>http://people.skolelinux.org/pere/blog/Simpler_recipe_on_how_to_make_a_simple__7_IMSI_Catcher_using_Debian.html
</link>
610 <guid isPermaLink=
"true">http://people.skolelinux.org/pere/blog/Simpler_recipe_on_how_to_make_a_simple__7_IMSI_Catcher_using_Debian.html
</guid>
611 <pubDate>Wed,
9 Aug
2017 23:
59:
00 +
0200</pubDate>
612 <description><p
>On friday, I came across an interesting article in the Norwegian
613 web based ICT news magazine digi.no on
614 <a href=
"https://www.digi.no/artikler/sikkerhetsforsker-lagde-enkel-imsi-catcher-for-
60-kroner-na-kan-mobiler-kartlegges-av-alle/
398588">how
615 to collect the IMSI numbers of nearby cell phones
</a
> using the cheap
616 DVB-T software defined radios. The article refered to instructions
617 and
<a href=
"https://www.youtube.com/watch?v=UjwgNd_as30
">a recipe by
618 Keld Norman on Youtube on how to make a simple $
7 IMSI Catcher
</a
>, and I decided to test them out.
</p
>
620 <p
>The instructions said to use Ubuntu, install pip using apt (to
621 bypass apt), use pip to install pybombs (to bypass both apt and pip),
622 and the ask pybombs to fetch and build everything you need from
623 scratch. I wanted to see if I could do the same on the most recent
624 Debian packages, but this did not work because pybombs tried to build
625 stuff that no longer build with the most recent openssl library or
626 some other version skew problem. While trying to get this recipe
627 working, I learned that the apt-
>pip-
>pybombs route was a long detour,
628 and the only piece of software dependency missing in Debian was the
629 gr-gsm package. I also found out that the lead upstream developer of
630 gr-gsm (the name stand for GNU Radio GSM) project already had a set of
631 Debian packages provided in an Ubuntu PPA repository. All I needed to
632 do was to dget the Debian source package and built it.
</p
>
634 <p
>The IMSI collector is a python script listening for packages on the
635 loopback network device and printing to the terminal some specific GSM
636 packages with IMSI numbers in them. The code is fairly short and easy
637 to understand. The reason this work is because gr-gsm include a tool
638 to read GSM data from a software defined radio like a DVB-T USB stick
639 and other software defined radios, decode them and inject them into a
640 network device on your Linux machine (using the loopback device by
641 default). This proved to work just fine, and I
've been testing the
642 collector for a few days now.
</p
>
644 <p
>The updated and simpler recipe is thus to
</p
>
648 <li
>start with a Debian machine running Stretch or newer,
</li
>
650 <li
>build and install the gr-gsm package available from
651 <a href=
"http://ppa.launchpad.net/ptrkrysik/gr-gsm/ubuntu/pool/main/g/gr-gsm/
">http://ppa.launchpad.net/ptrkrysik/gr-gsm/ubuntu/pool/main/g/gr-gsm/
</a
>,
</li
>
653 <li
>clone the git repostory from
<a href=
"https://github.com/Oros42/IMSI-catcher
">https://github.com/Oros42/IMSI-catcher
</a
>,
</li
>
655 <li
>run grgsm_livemon and adjust the frequency until the terminal
656 where it was started is filled with a stream of text (meaning you
657 found a GSM station).
</li
>
659 <li
>go into the IMSI-catcher directory and run
'sudo python simple_IMSI-catcher.py
' to extract the IMSI numbers.
</li
>
663 <p
>To make it even easier in the future to get this sniffer up and
664 running, I decided to package
665 <a href=
"https://github.com/ptrkrysik/gr-gsm/
">the gr-gsm project
</a
>
666 for Debian (
<a href=
"https://bugs.debian.org/
871055">WNPP
667 #
871055</a
>), and the package was uploaded into the NEW queue today.
668 Luckily the gnuradio maintainer has promised to help me, as I do not
669 know much about gnuradio stuff yet.
</p
>
671 <p
>I doubt this
"IMSI cacher
" is anywhere near as powerfull as
672 commercial tools like
673 <a href=
"https://www.thespyphone.com/portable-imsi-imei-catcher/
">The
674 Spy Phone Portable IMSI / IMEI Catcher
</a
> or the
675 <a href=
"https://en.wikipedia.org/wiki/Stingray_phone_tracker
">Harris
676 Stingray
</a
>, but I hope the existance of cheap alternatives can make
677 more people realise how their whereabouts when carrying a cell phone
678 is easily tracked. Seeing the data flow on the screen, realizing that
679 I live close to a police station and knowing that the police is also
680 wearing cell phones, I wonder how hard it would be for criminals to
681 track the position of the police officers to discover when there are
682 police near by, or for foreign military forces to track the location
683 of the Norwegian military forces, or for anyone to track the location
684 of government officials...
</p
>
686 <p
>It is worth noting that the data reported by the IMSI-catcher
687 script mentioned above is only a fraction of the data broadcasted on
688 the GSM network. It will only collect one frequency at the time,
689 while a typical phone will be using several frequencies, and not all
690 phones will be using the frequencies tracked by the grgsm_livemod
691 program. Also, there is a lot of radio chatter being ignored by the
692 simple_IMSI-catcher script, which would be collected by extending the
693 parser code. I wonder if gr-gsm can be set up to listen to more than
694 one frequency?
</p
>
699 <title>Norwegian Bokmål edition of Debian Administrator
's Handbook is now available
</title>
700 <link>http://people.skolelinux.org/pere/blog/Norwegian_Bokm_l_edition_of_Debian_Administrator_s_Handbook_is_now_available.html
</link>
701 <guid isPermaLink=
"true">http://people.skolelinux.org/pere/blog/Norwegian_Bokm_l_edition_of_Debian_Administrator_s_Handbook_is_now_available.html
</guid>
702 <pubDate>Tue,
25 Jul
2017 21:
10:
00 +
0200</pubDate>
703 <description><p align=
"center
"><img align=
"center
" src=
"http://people.skolelinux.org/pere/blog/images/
2017-
07-
25-debian-handbook-nb-testprint.png
"/
></p
>
705 <p
>I finally received a copy of the Norwegian Bokmål edition of
706 "<a href=
"https://debian-handbook.info/
">The Debian Administrator
's
707 Handbook
</a
>". This test copy arrived in the mail a few days ago, and
708 I am very happy to hold the result in my hand. We spent around one and a half year translating it. This paperbook edition
709 <a href=
"https://debian-handbook.info/get/#norwegian
">is available
710 from lulu.com
</a
>. If you buy it quickly, you save
25% on the list
711 price. The book is also available for download in electronic form as
712 PDF, EPUB and Mobipocket, as can be
713 <a href=
"https://debian-handbook.info/browse/nb-NO/stable/
">read online
714 as a web page
</a
>.
</p
>
716 <p
>This is the second book I publish (the first was the book
717 "<a href=
"http://free-culture.cc/
">Free Culture
</a
>" by Lawrence Lessig
719 <a href=
"http://www.lulu.com/shop/lawrence-lessig/free-culture/paperback/product-
22440520.html
">English
</a
>,
720 <a href=
"http://www.lulu.com/shop/lawrence-lessig/culture-libre/paperback/product-
22645082.html
">French
</a
>
722 <a href=
"http://www.lulu.com/shop/lawrence-lessig/fri-kultur/paperback/product-
22441576.html
">Norwegian
723 Bokmål
</a
>), and I am very excited to finally wrap up this
725 "<a href=
"http://www.lulu.com/shop/rapha%C3%ABl-hertzog-and-roland-mas/h%C3%A5ndbok-for-debian-administratoren/paperback/product-
23262290.html
">Håndbok
726 for Debian-administratoren
</a
>" will be well received.
</p
>
projects / homepage.git / blob