blog/archive/2023/01/01.rss

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   4                 <title>Petter Reinholdtsen - Entries from January 2023</title>
   5                 <description>Entries from January 2023</description>
   6                 <link>http://www.hungry.com/~pere/blog/</link>
   7
   8
   9         <item>
  10                 <title>Is the desktop recommending your program for opening its files?</title>
  11                 <link>http://www.hungry.com/~pere/blog/Is_the_desktop_recommending_your_program_for_opening_its_files_.html</link>
  12                 <guid isPermaLink="true">http://www.hungry.com/~pere/blog/Is_the_desktop_recommending_your_program_for_opening_its_files_.html</guid>
  13                 <pubDate>Sun, 29 Jan 2023 11:00:00 +0100</pubDate>
  14                 <description>&lt;p&gt;Linux desktop systems
  15 &lt;a href=&quot;https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html&quot;&gt;have
  16 standardized&lt;/a&gt; how programs present themselves to the desktop
  17 system.  If a package include a .desktop file in
  18 /usr/share/applications/, Gnome, KDE, LXDE, Xfce and the other desktop
  19 environments will pick up the file and use its content to generate the
  20 menu of available programs in the system.  A lesser known fact is that
  21 a package can also explain to the desktop system how to recognize the
  22 files created by the program in question, and use it to open these
  23 files on request, for example via a GUI file browser.&lt;/p&gt;
  24
  25 &lt;p&gt;A while back I ran into a package that did not tell the desktop
  26 system how to recognize its files and was not used to open its files
  27 in the file browser and fixed it.  In the process I wrote a simple
  28 debian/tests/ script to ensure the setup keep working.  It might be
  29 useful for other packages too, to ensure any future version of the
  30 package keep handling its own files.&lt;/p&gt;
  31
  32 &lt;p&gt;For this to work the file format need a useful MIME type that can
  33 be used to identify the format.  If the file format do not yet have a
  34 MIME type, it should define one and preferably also
  35 &lt;a href=&quot;https://www.iana.org/assignments/media-types/media-types.xhtml&quot;&gt;register
  36 it with IANA&lt;/a&gt; to ensure the MIME type string is reserved.&lt;/p&gt;
  37
  38 &lt;p&gt;The script uses the &lt;tt&gt;xdg-mime&lt;/tt&gt; program from xdg-utils to
  39 query the database of standardized package information and ensure it
  40 return sensible values.  It also need the location of an example file
  41 for xdg-mime to guess the format of.&lt;/p&gt;
  42
  43 &lt;pre&gt;
  44 #!/bin/sh
  45 #
  46 # Author: Petter Reinholdtsen
  47 # License: GPL v2 or later at your choice.
  48 #
  49 # Validate the MIME setup, making sure motor types have
  50 # application/vnd.openmotor+yaml associated with them and is connected
  51 # to the openmotor desktop file.
  52
  53 retval=0
  54
  55 mimetype=&quot;application/vnd.openmotor+yaml&quot;
  56 testfile=&quot;test/data/real/o3100/motor.ric&quot;
  57 mydesktopfile=&quot;openmotor.desktop&quot;
  58
  59 filemime=&quot;$(xdg-mime query filetype &quot;$testfile&quot;)&quot;
  60
  61 if [ &quot;$mimetype&quot; != &quot;$filemime&quot; ] ; then
  62     retval=1
  63     echo &quot;error: xdg-mime claim motor file MIME type is $filemine, not $mimetype&quot;
  64 else
  65     echo &quot;success: xdg-mime report correct mime type $mimetype for motor file&quot;
  66 fi
  67
  68 desktop=$(xdg-mime query default &quot;$mimetype&quot;)
  69
  70 if [ &quot;$mydesktopfile&quot; != &quot;$desktop&quot; ]; then
  71     retval=1
  72     echo &quot;error: xdg-mime claim motor file should be handled by $desktop, not $mydesktopfile&quot;
  73 else
  74     echo &quot;success: xdg-mime agree motor file should be handled by $mydesktopfile&quot;
  75 fi
  76
  77 exit $retval
  78 &lt;/pre&gt;
  79
  80 &lt;p&gt;It is a simple way to ensure your users are not very surprised when
  81 they try to open one of your file formats in their file browser.&lt;/p&gt;
  82
  83 &lt;p&gt;As usual, if you use Bitcoin and want to show your support of my
  84 activities, please send Bitcoin donations to my address
  85 &lt;b&gt;&lt;a href=&quot;bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b&quot;&gt;15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b&lt;/a&gt;&lt;/b&gt;.&lt;/p&gt;
  86 </description>
  87         </item>
  88
  89         <item>
  90                 <title>Opensnitch, the application level interactive firewall, heading into the Debian archive</title>
  91                 <link>http://www.hungry.com/~pere/blog/Opensnitch__the_application_level_interactive_firewall__heading_into_the_Debian_archive.html</link>
  92                 <guid isPermaLink="true">http://www.hungry.com/~pere/blog/Opensnitch__the_application_level_interactive_firewall__heading_into_the_Debian_archive.html</guid>
  93                 <pubDate>Sun, 22 Jan 2023 23:55:00 +0100</pubDate>
  94                 <description>&lt;p&gt;While reading a
  95 &lt;a href=&quot;https://sneak.berlin/20230115/macos-scans-your-local-files-now/&quot;&gt;blog
  96 post claiming MacOS X recently started scanning local files and
  97 reporting information about them to Apple&lt;/a&gt;, even on a machine where
  98 all such callback features had been disabled, I came across a
  99 description of the Little Snitch application for MacOS X.  It seemed
 100 like a very nice tool to have in the tool box, and I decided to see if
 101 something similar was available for Linux.&lt;/p&gt;
 102
 103 &lt;p&gt;It did not take long to find
 104 &lt;a href=&quot;https://github.com/evilsocket/opensnitch&quot;&gt;the OpenSnitch
 105 package&lt;/a&gt;, which has been in development since 2017, and now is in
 106 version 1.5.0.  It has had a
 107 &lt;a href=&quot;https://bugs.debian.org/909567&quot;&gt;request for Debian
 108 packaging&lt;/a&gt; since 2018, but no-one completed the job so far.  Just
 109 for fun, I decided to see if I could help, and I was very happy to
 110 discover that
 111 &lt;a href=&quot;https://github.com/evilsocket/opensnitch/issues/304&quot;&gt;upstream
 112 want a Debian package too&lt;/a&gt;.&lt;/p&gt;
 113
 114 &lt;p&gt;After struggling a bit with getting the program to run, figuring
 115 out building Go programs (and a little failed detour to look at eBPF
 116 builds too - help needed), I am very happy to report that I am
 117 sponsoring upstream to maintain the package in Debian, and it has
 118 since this morning been waiting in NEW for the ftpmasters to have a
 119 look.  Perhaps it can get into the archive in time for the Bookworm
 120 release?&lt;/p&gt;
 121
 122 &lt;p&gt;As usual, if you use Bitcoin and want to show your support of my
 123 activities, please send Bitcoin donations to my address
 124 &lt;b&gt;&lt;a href=&quot;bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b&quot;&gt;15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b&lt;/a&gt;&lt;/b&gt;.&lt;/p&gt;
 125 </description>
 126         </item>
 127
 128         <item>
 129                 <title>LinuxCNC MQTT publisher component</title>
 130                 <link>http://www.hungry.com/~pere/blog/LinuxCNC_MQTT_publisher_component.html</link>
 131                 <guid isPermaLink="true">http://www.hungry.com/~pere/blog/LinuxCNC_MQTT_publisher_component.html</guid>
 132                 <pubDate>Sun, 8 Jan 2023 19:30:00 +0100</pubDate>
 133                 <description>&lt;p&gt;I watched &lt;a href=&quot;https://yewtu.be/watch?v=jmKUV3aNLjk&quot;&gt;a 2015
 134 video from Andreas Schiffler&lt;/a&gt; the other day, where he set up
 135 &lt;a href=&quot;https://linuxcnc.org/&quot;&gt;LinuxCNC&lt;/a&gt; to send status
 136 information to the MQTT broker IBM Bluemix.  As I also use MQTT for
 137 graphing, it occured to me that a generic MQTT LinuxCNC component
 138 would be useful and I set out to implement it.  Today I got the first
 139 draft limping along and submitted as
 140 &lt;a href=&quot;https://github.com/LinuxCNC/linuxcnc/pull/2253&quot;&gt;a patch to the
 141 LinuxCNC project&lt;/a&gt;.&lt;/p&gt;
 142
 143 &lt;p&gt;The simple part was setting up the MQTT publishing code in Python.
 144 I already have set up other parts submitting data to my Mosquito MQTT
 145 broker, so I could reuse that code.  Writing a LinuxCNC component in
 146 Python as new to me, but using existing examples in the code
 147 repository and the extensive documentation, this was fairly straight
 148 forward.  The hardest part was creating a automated test for the
 149 component to ensure it was working.  Testing it in a simulated
 150 LinuxCNC machine proved very useful, as I discovered features I needed
 151 that I had not thought of yet, and adjusted the code quite a bit to
 152 make it easier to test without a operational MQTT broker
 153 available.&lt;/p&gt;
 154
 155 &lt;p&gt;The draft is ready and working, but I am unsure which LinuxCNC HAL
 156 pins I should collect and publish by default (in other words, the
 157 default set of information pieces published), and how to get the
 158 machine name from the LinuxCNC INI file.  The latter is a minor
 159 detail, but I expect it would be useful in a setup with several
 160 machines available.  I am hoping for feedback from the experienced
 161 LinuxCNC developers and users, to make the component even better
 162 before it can go into the mainland LinuxCNC code base.&lt;/p&gt;
 163
 164 &lt;p&gt;Since I started on the MQTT component, I came across
 165 &lt;a href=&quot;https://yewtu.be/watch?v=Bqa2grG0XtA&quot;&gt;another video from Kent
 166 VanderVelden&lt;/a&gt; where he combine LinuxCNC with a set of screen glasses
 167 controlled by a Raspberry Pi, and it occured to me that it would
 168 be useful for such use cases if LinuxCNC also provided a REST API for
 169 querying its status.  I hope to start on such component once the MQTT
 170 component is working well.&lt;/p&gt;
 171
 172 &lt;p&gt;As usual, if you use Bitcoin and want to show your support of my
 173 activities, please send Bitcoin donations to my address
 174 &lt;b&gt;&lt;a href=&quot;bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b&quot;&gt;15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b&lt;/a&gt;&lt;/b&gt;.&lt;/p&gt;
 175 </description>
 176         </item>
 177
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 179 </rss>