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Xfce 4.12 not suspending on laptop-lid close

Linux

Xfce 4.12 as default in Ubuntu/Xubuntu 18.04 LTS did not suspend a laptop after closing the lid. In fact running xfce4-power-manager --quit ; xfce4-power-manager --no-daemon --debug showed that xfce4 wasn't seeing a laptop lid close event at all.

To the contrary acpi_listen nicely finds button/lid LID close and button/lid LID open events when folding the screen and opening it up again.

As so often the wonderful docs / community of Arch Linux to the rescue. This forum thread from 2015 received the correct answer in 2017:

Xfce4 basically recognizes systemd and thus disables its built-in power-management options for handling these "button events" (but doesn't tell you so in the config UI for power-manager). Systemd is configured to handle these events by default (/etc/systemd/logind.conf has HandleLidSwitch=suspend but for unknown reasons decides not to honor that).

So best is to teach Xfce4 to handle the events again as in pre-systemd times:

xfconf-query -c xfce4-power-manager -p /xfce4-power-manager/logind-handle-lid-switch -s false

Now the UI options will work again as intended and the laptop suspends on lid close and resumes on lid open.

Update:

07.01.19: Changed XFCE -> Xfce as per Corsac's suggestion in the comments below. Thank you!

Background info:

The name "XFCE" was originally an acronym for "XForms Common Environment", but since that time it has been rewritten twice and no longer uses the XForms toolkit. The name survived, but it is no longer capitalized as "XFCE", but rather as "Xfce". The developers' current stance is that the initialism no longer stands for anything specific. After noting this, the FAQ on the Xfce Wiki comments "(suggestion: X Freakin' Cool Environment)".

(quoted from Wikipedia's Xfce article also found in the Xfce docs FAQ).

Firefox asking to be made the default browser again and again

Linux

Firefox on Linux can develop the habit to (rather randomly) ask again and again to be made the default browser. E.g. when started from Thunderbird by clicking a link it asks but when starting from a shell all is fine.

The reason to this is often two (or more) .desktop entries competing with each other.

So, walkthrough: (GOTO 10 in case you are sure to have all the basics right)

update-alternatives --display x-www-browser
update-alternatives --display gnome-www-browser

should both show firefox for you. If not

update-alternatives --config <entry>

the entry to fix the preference on /usr/bin/firefox.

Check (where available)

exo-preferred-applications

that the "Internet Browser" is "Firefox".

Check (where available)

xfce4-mime-settings

that anything containing "html" points to Firefox (or is left at a non-user set default).

Check (where available)

xdg-settings get default-web-browser

that you get firefox.desktop. If not run

xdg-settings check default-web-browser firefox.desktop

If you are running Gnome, check

xdg-settings get default-url-scheme-handler http

and the same for https.

LABEL 10:

Run

sensible-editor ~/.config/mimeapps.list

and remove all entries that contain something like userapp-Firefox-<random>.desktop.

Run

find ~/.local/share/applications -iname "userapp-firefox*.desktop"

and delete these files or move them away.

Done.

Once you have it working again consider disabling the option for Firefox to check whether it is the default browser. Because it will otherwise create those pesky userapp-Firefox-<random>.desktop files again.

Configuring Linux is easy, innit?

Unbalanced volume (channels) on headset audio

Linux

I use a headset to make phone calls and when they are mono the great awesomeness of the Linux audio stack seems to change volume only on the active channel (e.g. the right channel). So when I listen to some music (stereo) afterwards the channels are not balanced anymore and one side is louder than the other. And this persists thanks to saving the preferences across reboots. Duh.

As usually checking Pulseaudio (pavucontrol) is useless, it shows balanced channels.

But checking Alsa (alsamixer) revealed the issue and alsamixer can fix this, too:

Step 1: run alsamixer in a terminal and select your headset after pressing [F6]:

Alsamixer: Select sound card

Step 2: Select the headset audio output with [<-] and [->] cursor keys:

Alsamixer: Unbalanced channels on the headset (left / right channel loudness are different)

Step 3: Press [b] to balance the left and right channels:

Alsamixer: Balanced channels (left / right channel loudness) again

Step 4: Press [Esc] to exit alsamixer which will keep the changed settings (... great choice of key, [q] raises the left channel's loundness ...).

Step 5: Save this setting by running sudo alsactl store which should update /var/lib/alsa/asound.state with the fixed settings so they persist across reboots.

Step 6: Enjoy music again :-).

If you need to script this, amixer is the tool to use, e.g. amixer -c 1 set "Headset" 36.
1 is the card number which you see in alsamixer, "Headset" is the channel name, also from alsamixer (which can contain blanks, hence the quotes around the name) and 36 is the desired loundness level for both channels. See the screenshots above where to find the data or run aplay -l to see the cards on your PC and amixer -c 1 (with your card id) to see the channels that (virtual, USB) sound card has.

Prevent Ubuntu from phoning home

Linux

Ubuntu unfortunately has decided again to implement another "phone home" feature, this time transferring your lsb_release information, CPU model and speed (from /proc/cpuinfo), uptime output, most of uname -a and curl version to a Ubuntu news web-service.

Here is the Launchpad bug report #1637800 introducing this ... web bug.

This thing runs both systemd-timer based (via /lib/systemd/system/motd-news.service and /lib/systemd/system/motd-news.timer) and on request when you log in (via /etc/update-motd.d/50-motd-news).

Ubuntu news on ssh login

There has even been a bug filed about the motd advertising HBO's Silicon Valley show.

To prevent this from running (it is enabled by default on Ubuntu 17.04 and may probably propagate down to earlier versions as well), edit /etc/default/motd-news to include

ENABLED=0

so

sed -i "s/ENABLED=1/ENABLED=0/" /etc/default/motd-news # run as root

for your automated installs.

Update:

02.07.2017: Dustin Kirkland responded to a YC "hacker news" mention of his motd spam. He mentions:

You're welcome to propose your own messages for merging, if you have a well formatted, informative message for Ubuntu users.
We'll be happy to review and include them in the future.

What could possibly go wrong?

Ubuntu Karmic 9.10 Bluetooth UMTS Dial-up (DUN)

Linux

Using a mobile phone's Bluetooth Dial-up network (DUN) to connect to the Internet (UMTS/GPRS) while on the road is quite convenient for me. Sadly so this is not supported out-of-the-box in Ubuntu Karmic 9.10 (Netbook Remix) as it uses Network-Manager to handle - well - network connections. And that is not quite there on Bluetooth managed devices yet.

While the default solution (rfcomm and Gnome-PPP) still works, it's ugly to set up. Sadly so, zillions of Ubuntu-Forum threads and blog entries still detail this solution - or the issues encountered with it along the way.

The much better solutions is using Blueman, an improved Gnome-Bluetooth primarily developed by Valmantas Palikša. It brings the right UDEV magic along to teach Network-Manager about the Bluetooth devices it handles.

Blueman Screenshot on Ubuntu Karmic 9.10 Netbook Edition

Just follow the steps on their downloads page to set up the Blueman PPA (Personal Package Archive) to get things working.

Kubuntu 9.10 (karmic) 64bit firefox java plugin

Linux

For some unknown reason the (K)Ubuntu developers did not update the Java plugin for firefox after jaunty (yet?).

The version that Karmic (9.10) pulls out of the multiverse repository is still jaunty's (9.04).

So when you try:

apt-get install sun-java6-plugin

you'll get something like

   Reading package lists... Done
   Building dependency tree
   Reading state information... Done
   Some packages could not be installed. This may mean that you have
   requested an impossible situation or if you are using the unstable
   distribution that some required packages have not yet been created
   or been moved out of Incoming.
   The following information may help to resolve the situation:
   
   The following packages have unmet dependencies:
     sun-java6-plugin: Depends: sun-java6-bin (= 6-15-1) but 6-16-0ubuntu1.9.04 is to be installed
   E: Broken packages

Duh.

Actually if you have the Java Runtime Environment (JRE, package name sun-java6-jre) installed all files needed are already present.
Just not put in the right place on the filesystem.

So, run:

sudo apt-get install sun-java6-jre   # install JRE if needed
sudo ln -s /usr/lib/jvm/java-6-sun/jre/lib/amd64/libnpjp2.so /usr/lib/mozilla/plugins/

This will install the JRE (if it's not already installed) and will symlink the firefox plugin for java in place so that it'll be found after a browser restart.

Fixing FreeNX / NoMachine NX keyboard glitches (e.g. ALTGr)

Linux

There is a add-on technology to X or VNC called NX by an Italian company called NoMachine. It's quite useful as it speeds up working on remote desktops via slow network connections (i.e. DSL pipes) substantially.

The libraries that implement NX are released under GPLv2 by that company. A server wrapping up the libraries' functionality is available as closed source from NoMachine or as a free product (GPLv2 again) by Fabian Franz, called FreeNX.

FreeNX itself is amazing as it is written in BASH (with a few helper functions in C). It's also able to mend some of the shortcomings of the NX architecture. E.g. stock NX requires a technical user called "nx" to able to ssh into the NX server with a public/private keypair. FreeNX can work around that for more secure set-ups.

One issue I bumped into quite regularly with Linux clients and Linux hosts from different distributions/localisations is that the keymaps are not compatible. This usually results in the ALTGr key not usable, so German keyboard users can't enter a pipe ("|"), tilde ("~") or a backslash ("\") character. Also the up and down keys are usually resulting in weird characters being pasted to the shell. Now all of that makes using a shell/terminal prompt quite interesting.

Continue reading "Fixing FreeNX / NoMachine NX keyboard glitches (e.g. ALTGr)"

Getting dual-screen (xinerama) to work with Matrox G450/550 graphics cards and Xorg 1.5

Gentoo

Gentoo finally decided to update Xorg to 1.5. Because this has very substantial changes against the previous version, some things break and there is a migration guide that you are nagged to read. After the upgrade I found that the Matrox card in one of my servers would not display xinerama anymore, i.e. I would get the same image on both screens only. This is the default behaviour for the stock Xorg mga driver. It needs a proprietary HALlib to get real dual-screen capabilities. Whilst there are a few unstable ebuilds for x11-drivers/xf86-video-mga none worked for me any better with Xinerama. The Gentoo Changelog is useless as usual. (Gentoo ebuild ChangeLogs tend to never really tell what is fixed, if you're lucky they reference a bug with a good description. But that's only if you're really lucky.)

Worse, that driver hasn't been updated by Matrox anymore since mammals took over the earth (figuratively ... 2005). This is the typical unmaintained-closed-source-drivers-make-hardware-obsolete-sooner-than-later story. Luckily the cards are quite widely used and clever people from the Open Source community have written guides (Tuxx-Home, Fkung) on how to dissect the proprietary driver and combine parts of it with the Open Source version so that it can be linked into recent X servers. Unfortunately because of the architectural changes in Xorg 1.5, following these guides will fail at the compile stage.

In the Matrox Forum of Alexander Griesser, the author of the first comprehensive Matrox driver install guide linked above, people currently mostly downgrade to previous Xorg versions to work around the issue.

But there is a better^Hworking solution already emerging :-P ...

Continue reading "Getting dual-screen (xinerama) to work with Matrox G450/550 graphics cards and Xorg 1.5"