- <div class="title"><a href="http://people.skolelinux.org/pere/blog/Making_battery_measurements_a_little_easier_in_Debian.html">Making battery measurements a little easier in Debian</a></div>
- <div class="date">15th March 2016</div>
- <div class="body"><p>Back in September, I blogged about
-<a href="http://people.skolelinux.org/pere/blog/The_life_and_death_of_a_laptop_battery.html">the
-system I wrote to collect statistics about my laptop battery</a>, and
-how it showed the decay and death of this battery (now replaced). I
-created a simple deb package to handle the collection and graphing,
-but did not want to upload it to Debian as there were already
-<a href="https://tracker.debian.org/pkg/battery-stats">a battery-stats
-package in Debian</a> that should do the same thing, and I did not see
-a point of uploading a competing package when battery-stats could be
-fixed instead. I reported a few bugs about its non-function, and
-hoped someone would step in and fix it. But no-one did.</p>
-
-<p>I got tired of waiting a few days ago, and took matters in my own
-hands. The end result is that I am now the new upstream developer of
-battery stats (<a href="https://github.com/petterreinholdtsen/battery-stats">available from github</a>) and part of the team maintaining
-battery-stats in Debian, and the package in Debian unstable is finally
-able to collect battery status using the <tt>/sys/class/power_supply/</tt>
-information provided by the Linux kernel. If you install the
-battery-stats package from unstable now, you will be able to get a
-graph of the current battery fill level, to get some idea about the
-status of the battery. The source package build and work just fine in
-Debian testing and stable (and probably oldstable too, but I have not
-tested). The default graph you get for that system look like this:</p>
-
-<p align="center"><img src="http://people.skolelinux.org/pere/blog/images/2016-03-15-battery-stats-graph-example.png" width="70%" align="center"></p>
-
-<p>My plans for the future is to merge my old scripts into the
-battery-stats package, as my old scripts collected a lot more details
-about the battery. The scripts are merged into the upstream
-battery-stats git repository already, but I am not convinced they work
-yet, as I changed a lot of paths along the way. Will have to test a
-bit more before I make a new release.</p>
-
-<p>I will also consider changing the file format slightly, as I
-suspect the way I combine several values into one field might make it
-impossible to know the type of the value when using it for processing
-and graphing.</p>
-
-<p>If you would like I would like to keep an close eye on your laptop
-battery, check out the battery-stats package in
-<a href="https://tracker.debian.org/pkg/battery-stats">Debian</a> and
-on
-<a href="https://github.com/petterreinholdtsen/battery-stats">github</a>.
-I would love some help to improve the system further.</p>
+ <div class="title"><a href="http://people.skolelinux.org/pere/blog/A_program_should_be_able_to_open_its_own_files_on_Linux.html">A program should be able to open its own files on Linux</a></div>
+ <div class="date"> 5th June 2016</div>
+ <div class="body"><p>Many years ago, when koffice was fresh and with few users, I
+decided to test its presentation tool when making the slides for a
+talk I was giving for NUUG on Japhar, a free Java virtual machine. I
+wrote the first draft of the slides, saved the result and went to bed
+the day before I would give the talk. The next day I took a plane to
+the location where the meeting should take place, and on the plane I
+started up koffice again to polish the talk a bit, only to discover
+that kpresenter refused to load its own data file. I cursed a bit and
+started making the slides again from memory, to have something to
+present when I arrived. I tested that the saved files could be
+loaded, and the day seemed to be rescued. I continued to polish the
+slides until I suddenly discovered that the saved file could no longer
+be loaded into kpresenter. In the end I had to rewrite the slides
+three times, condensing the content until the talk became shorter and
+shorter. After the talk I was able to pinpoint the problem –
+kpresenter wrote inline images in a way itself could not understand.
+Eventually that bug was fixed and kpresenter ended up being a great
+program to make slides. The point I'm trying to make is that we
+expect a program to be able to load its own data files, and it is
+embarrassing to its developers if it can't.</p>
+
+<p>Did you ever experience a program failing to load its own data
+files from the desktop file browser? It is not a uncommon problem. A
+while back I discovered that the screencast recorder
+gtk-recordmydesktop would save an Ogg Theora video file the KDE file
+browser would refuse to open. No video player claimed to understand
+such file. I tracked down the cause being <tt>file --mime-type</tt>
+returning the application/ogg MIME type, which no video player I had
+installed listed as a MIME type they would understand. I asked for
+<a href="http://bugs.gw.com/view.php?id=382">file to change its
+behavour</a> and use the MIME type video/ogg instead. I also asked
+several video players to add video/ogg to their desktop files, to give
+the file browser an idea what to do about Ogg Theora files. After a
+while, the desktop file browsers in Debian started to handle the
+output from gtk-recordmydesktop properly.</p>
+
+<p>But history repeats itself. A few days ago I tested the music
+system Rosegarden again, and I discovered that the KDE and xfce file
+browsers did not know what to do with the Rosegarden project files
+(*.rg). I've reported <a href="http://bugs.debian.org/825993">the
+rosegarden problem to BTS</a> and a fix is commited to git and will be
+included in the next upload. To increase the chance of me remembering
+how to fix the problem next time some program fail to load its files
+from the file browser, here are some notes on how to fix it.</p>
+
+<p>The file browsers in Debian in general operates on MIME types.
+There are two sources for the MIME type of a given file. The output from
+<tt>file --mime-type</tt> mentioned above, and the content of the
+shared MIME type registry (under /usr/share/mime/). The file MIME
+type is mapped to programs supporting the MIME type, and this
+information is collected from
+<a href="https://www.freedesktop.org/wiki/Specifications/desktop-entry-spec/">the
+desktop files</a> available in /usr/share/applications/. If there is
+one desktop file claiming support for the MIME type of the file, it is
+activated when asking to open a given file. If there are more, one
+can normally select which one to use by right-clicking on the file and
+selecting the wanted one using 'Open with' or similar. In general
+this work well. But it depend on each program picking a good MIME
+type (preferably
+<a href="http://www.iana.org/assignments/media-types/media-types.xhtml">a
+MIME type registered with IANA</a>), file and/or the shared MIME
+registry recognizing the file and the desktop file to list the MIME
+type in its list of supported MIME types.</p>
+
+<p>The <tt>/usr/share/mime/packages/rosegarden.xml</tt> entry for
+<a href="http://www.freedesktop.org/wiki/Specifications/shared-mime-info-spec">the
+Shared MIME database</a> look like this:</p>
+
+<p><blockquote><pre>
+<?xml version="1.0" encoding="UTF-8"?>
+<mime-info xmlns="http://www.freedesktop.org/standards/shared-mime-info">
+ <mime-type type="audio/x-rosegarden">
+ <sub-class-of type="application/x-gzip"/>
+ <comment>Rosegarden project file</comment>
+ <glob pattern="*.rg"/>
+ </mime-type>
+</mime-info>
+</pre></blockquote></p>
+
+<p>This states that audio/x-rosegarden is a kind of application/x-gzip
+(it is a gzipped XML file). Note, it is much better to use an
+official MIME type registered with IANA than it is to make up ones own
+unofficial ones like the x-rosegarden type used by rosegarden.</p>
+
+<p>The desktop file of the rosegarden program failed to list
+audio/x-rosegarden in its list of supported MIME types, causing the
+file browsers to have no idea what to do with *.rg files:</p>
+
+<p><blockquote><pre>
+% grep Mime /usr/share/applications/rosegarden.desktop
+MimeType=audio/x-rosegarden-composition;audio/x-rosegarden-device;audio/x-rosegarden-project;audio/x-rosegarden-template;audio/midi;
+X-KDE-NativeMimeType=audio/x-rosegarden-composition
+%
+</pre></blockquote></p>
+
+<p>The fix was to add "audio/x-rosegarden;" at the end of the
+MimeType= line.</p>
+
+<p>If you run into a file which fail to open the correct program when
+selected from the file browser, please check out the output from
+<tt>file --mime-type</tt> for the file, ensure the file ending and
+MIME type is registered somewhere under /usr/share/mime/ and check
+that some desktop file under /usr/share/applications/ is claiming
+support for this MIME type. If not, please report a bug to have it
+fixed. :)</p>
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