Author Archives: admin

Viewing package changelogs with yum

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To quickly review the latest changes to an rpm package, there’s a handy plugin for yum called yum-changelog. It’s part of the Fedora repository and can be installed by invoking The usage is quite self-explanatory, but here a a few useful examples anyway: To list the whole changelog history of a package, run To list the changelog of a specific… Read more »

Updating STK500 firmware

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Unfortunately, Atmel does not ship a hex file for their STK500 development system that could be used to update the firmware using 3rd party tools like avrdude. Instead, an encrypted ebn-file comes with the latest Atmel Studio. The tools that is used to flash the firmware onto the ATmega8535 is a bit dull, though. Preparing serial connection First, hook up… Read more »

Re-enabling KDE touch pad

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As I wrote in an earlier post, the ambient light button on HP EliteBooks is per default mapped to switch off the touch pad. Since it’s placed right next to the function keys that increase or decrease the screen brightness, it happens quite often that the key is hit by accident. If you’re running KDE, hitting Fn+F11 not only switches… Read more »

Fixing HP EliteBook ambient button

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The button that is supposed to toggle the ambient light sensor on HP EliteBooks 8440p and 8460p per default switches off the touch pad. That is because Fn+F11 (scancode 0x33), which is the ambient light button, is incorrectly mapped to KEY_TOUCHPAD_OFF (keycode 193) in kernel. To remap the scancode to another keycode, you can use setkeycodes. An appropriate choice for… Read more »

C/C++ compound binary logic operations

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I’ve always had trouble reading and understanding compound binary operations fluently. Whenever they appear in a piece of code, I have to decode them to actually understand what they are doing. This is mainly due to the fact that I infrequently work close to hardware were heavy bit manipulation is a daily occurrence. I won’t bother you with the truth… Read more »

Accessing PL2303 USB serial adapter as non-root user

If you plug the PL2303 USB to serial adapter (or any other FTDI-like USB adapter) into your USB port, udev creates a /dev/ttyUSBX device with limited read and write permissions (0660 per default). Usually, only the root user and a specific group can access the device at all . To access the device as a regular user, you can either… Read more »

How to label a partition

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Labelling a partition can be quite handy, especially for partitions on usb drives that usually get auto-mounted to a folder that corresponds to their label. Usually the label is set when the partition is created. If the label is not explicitly specified, it is usually auto-generated. To change the label, there are a couple of tools available: ext2/ext3/ext4 partitions You… Read more »

Inserting arbitrary unicode characters to kwrite

While you can normally insert arbitrary unicode characters to any X11 application using Ctrl-Shift-u and four hex digits, it doesn’t work in kwrite or kate. Instead you’d have to press F7 to switch to command line and type in For example, to get the degree symbol (Unicode: U+00B0) you’d type in ‘char 176’ (176 being 0xB0 converted do decimal).

Search for a package containing a certain file

Assumed you want to find the package that contains the shared object libGLU.so.1, e.g. because a binary is dynamically linked against it, and ldd tells you that the shared library requirements are not met. On Fedora (or any yum-type os) you’d run and yum would tell you, that mesa-libGLU comes with /usr/lib64/libGLU.so.1 which could fulfill your need (could because you… Read more »