Category Archives: tweaking

Using KDE systray notifications from bash scripts

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I just improved my Extract audio script to show a system notification when it’s finished. In the meantime I also have a “convert to mp3″ script which proves useful if you don’t care about the original audio stream and/or you target a platform with limited decoding abilities:

ffmpeg -i %u -acodec libmp3lame -ar 44100 -ab 160k %u.mp3

To popup a KDE4 system tray notification at the end of the encoding process, simply add the following:

kdialog --passivepopup 'Finished converting %u' 3

The last value simply specifies the timeout in seconds. To chain the commands together, use a semicolon, so it also executes when the encode fails.

Using your EID on opensuse 12.1

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In Belgium you can use your EID to login onto the federal portal for using electronic services, for example, for filing tax return. Installation instructions are provided for Windows, Mac and (Ubuntu) Linux. This is what I had to do to get it working on opensuse 12.1 on a Dell Precision M4600.

Installation

smartcard reader

Since the M4600 is a fairly new model, I had to upgrade my pcsc/ccid package to the latest version. It seems the M4600 comes with a Broadcom Corp 5880 smartcard reader which is connected through USB (internally).

Add the chipcard repo:

sudo zypper ar -r http://download.opensuse.org/repositories/security:/chipcard/openSUSE_12.1/security:chipcard.repo

and “switch system packages” in Yast. You should have installed at least the following packages: pcsc-lite, libpcsclite1 and libpth20.

Depending on your smartcard reader, you need a different pcsc plugin package. The Broadcom 5880 smartcard reader is supported through the ccid driver. This means we have to install the pcsc-ccid package from the chipcard repo.

eid middleware

Add the following repo by Pascal Bleser:

sudo zypper ar -r http://download.opensuse.org/repositories/home:/pbleser:/belgium-eid/openSUSE_12.1/home:pbleser:belgium-eid.repo

and install the eid-mw package. I also noticed the eid-mw-firefox package in this repo, but it did not seem to work in my case, possibly because I’m using 64-bit firefox.

configuring firefox

  • Install the belgium eid firefox add-on.
  • Trust Belgium Certificate Authority: Edit menu -> Preferences -> Advanced -> Encryption -> View Certificates -> Authorities -> Belgium root CA2 -> Edit trust -> check all checkboxes
I’m not sure whether the firefox add-on is really needed. Afterwards I uninstalled it and it kept working.

Troubleshooting

smartcard reader

  • check in /var/log/messages which device you have
  • most devices are connected through usb protocol. Check your usb device list:
    lsusb -v
  • google the device or check the device compatibility lists of the pcsc-<driver> packages. You can find the ccid device list here.
  • if you have a pccard interface for your reader, check whether the device is installed with:
    pccardctl ls
  • install the pcsc-tools and perl-pcsc package to have access to some smartcard reader analysis tools. Running the pcsc_scan tool should yield similar output like this:
  • If you get a segfault when loading the pcsc-ccid driver, for example:
    pcscd[3228]: segfault at 0 ip 00007f98bec38121 sp 00007fff2e806208 error 4 in libc-2.14.1.so[7f98bebb8000+187000]
    check whether you updated your portable thread library with the one in the chipcard repo (package name is libpth20)
  • be sure to be using all the packages from the chipcard repo by using the “switch system packages”.
  • firmware upgrade as suggested here, was not necessary. Read the whole thread to find out why a ccid upgrade was actually necessary.

eid middleware

The government created an application eid-viewer which you can use to read some public data from your EID. It’s a java-based app so you need a java JRE to run it:

java -jar eid-viewer-4.0.4-146_tcm227-178503.jar

You can obtain it from this page under the catory “other”.

firefox

Although I installed this add-on, I don’t believe it is needed. I did have trouble the first time I signed in: it succeeded, but redirected me to a page where I would again need to choose whether I wanted to sign on with EID or password. I closed firefox, and tried again, this time it just worked. You can surf to this test page to test whether everything is configured correctly.

Add new harddisk on the fly

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So you have this linux box and you want to add an extra harddrive without having to reboot it. The key command we’re looking for, is a way to rescan the scsi bus. This can be achived by rewriting some values in the /sys synthetic filesystem:

echo "- - -" > /sys/class/scsi_host/host#/scan

Replace the digit for the scsi host as appropiate.

If everything went well, you should get output on the console indicating it detected a new hard drive.

Disabling hibernation on windows 7 and why Dirt 2 shows no replay

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Yesterday I made this awesome flying finish in Colin McRae Dirt 2 and wanted to view the replay only to realize: there is no replay? That sounded impossible and today, after missing another fine opportunity, I decided to go to the bottom of this. :)

Turned out Dirt 2 automatically disables the replay functionality behind your back when there is insufficient free space on your OS partition! That’s right:

  • I have Dirt 2 installed on a partition with 15 GB free space, but that doesn’t matter.
  • It requires 2GB to save a replay!
  • I does not inform the player when it gets turned off (it used to work in the beginning).
  • There is no visual indication whatsoever, that the replay functionality uberhaupt exists but is disabled! It is surgically removed from the gui instead of just a disabled button, for example.

IMO, this is just another example of why consolisation of excellent PC games like CMR is BAD. Anyway, don’t let me go there, let’s focus on hibernation in win 7. :)

So I have a 20GB partition for Wintendo 7, but with only 1GB free that does not seem to cut it. Turns out about 6.5GB is taken by the hibernation file (I have 8GB RAM) which I don’t use. So, how to disable that in windows 7? Open a command prompt as administrator and type:

powercfg.exe /hibernate off

That’s all.

Getting mic to work with NVidia VT1708S

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Ever since I installed opensuse 11.3, I hadn’t used my mic/headset. Today I decided to fool a bit around in Ardour, but somehow my mic didn’t work. And alas, I made a classic beginner’s mistake: “the solution has to be difficult because it does not work out of the box”.

I tried the standard stuff like trying out all input sources, adding hidden channels, etc. but when that didn’t help I was quickly diving into custom .asoundrc configuration, arecord/aplay sysinfo scripts, probing kernel modules, looking into alsa upgrade scripts and the like.. :)

Until I had an epiphany while reading random forum post words. I had been adding the “hidden” channels to my mixer which indeed included “mic” and “front mic” with accompanying boost controls. I noticed a few others which I threw in as well for good measure. I neglected them though, as I didn’t feel interested in enabling “smart” 5.1 or IEC958 2, whatever that was. But then I suddenly remembered: motherboards come with configurable audio backpanels, so this wasn’t really about enabling a fancy audioprocessing feature but rather switching between the 5.1 and standard audio panel, duh!

Apparently, the 5.1 was enabled by default, so “muting” it solved my problem!

Btw, in case you wonder: the HDA NVidia VT1708S chipset is actually a HDA Intel chipset with VIA codec, hence the VTxxxx name. To keep things intesting. ;)

Configuring numlock indicator in KDE4

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My brother has this really neat wireless keyboard with built-in trackball for his mediacenter. There is only one downside: it doesn’t have a numerical keypad and you never really know if the numlock is on or off. I think it is off at boot, but after turning it on and logging on, it is off again, unless you did a reboot.. or something like that.. Anyway, since it can be quite a challenge to enter passwords correctly, I started looking for a numlock plasmoidish solution.

First thing that turned up in the searches was the Keyboard Status applet. However, in the comments someone rightfully asks why it doesn’t use the keystate DataEngine. Great idea, because this is already packaged with vanilla kde. So I started searching for a general LED plasmoid which I could connect any datasource to using some mapping. No such luck. But then I wondered: why would someone write a plasma DataEngine and then not use it? :) There must be some existing plasmoid! It turned out to be the Key State plasmoid which is currently hosted at gitorious.

Since it is a javascript plasmoid, you can install it as follows:

git clone git://gitorious.org/keystate/keystate.git
plasmapkg -i keystate

Done! It should now be in the list when adding plasmoids under the name “Key State”. You can configure a custom color for each special key. There are some advanced options as well which I didn’t try out. Here is what it looks like:

Key State plasmoid

A simple rectangle shows my numlock is active. I know, nothing fancy but it’s all we need and it does the job! Thank you Martin Blumenstingl. :)

Tip of the day: boot your computer using keyboard

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About a year ago, I assembled a new main rig. I put (almost) all hard drives I had into it with the idea to make a “global backup”. This meant I had to leave my super-silencing case open until the backup was done. However, a year later, I’m still “in the process”. ;)

dsc01173.JPG

Since I also removed my front panel for some eSata modding, I have to turn my computer on using a pointy device aka “nail” (on the corner of the white table above). After doing that for a year, every day, knowing that my motherboard supports booting by key stroke, I decided to turn that feature on yesterday. Pressing spacebar boots my computer now. You should try it too, you’ll be surprised how much satisfaction it gives. :)

Flushing the dns cache

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As we all know, under windows we can flush the DNS cache with

ipconfig /flushdns

But what is the linux equivalent command? It is so obvious, yet I somehow keep forgetting it. :)
Under linux, the standard way to have a daemon reload its configuration, is sending a SIGHUP signal. In case of the name service cache daemon (nscd), this implies flushing its cache!
So you could use the following command to flush the DNS cache if you’re using nscd:

pkill -1 nscd