Category: KDE

KDE: Run a command 0

KDE: “Run a command” on notification trigger

KDE had a feature a lot of people didn’t know about. You could run a command when a notification triggered. The feature wasn’t very well documented and nobody really blogged about it. However with the release of KDE Plasma 6, the feature was removed. I learned about it by accident, as it is tracked by Bug #481069. I really need the feature and I re-implemented...


AVIF (12/10/8-bit) image support for darktable

As I’m an amateur photographer, I’m using Open Source tools for developing my images. The software I use is called darktable. I think it is the best tool out there for editing RAW images. From time to time I contributed small code changes to darktable, mostly bug fixes. Now I nearly finished my first feature for darktable, support for the AVIF image format. For implementing...


Testing PAM modules and PAM-aware applications in the Matrix

Jakub Hrozek and I are proud to announce the first release of pam_wrapper. This tool allows you to either simplify testing PAM modules or your application using PAM to authenticate users. PAM (Pluggable Authentication Modules) is a layer of abstraction on top of Unix authentication. For testing PAM-aware applications we have written a simple PAM module called pam_matrix. If you plan to test a PAM...


uid_wrapper-1.2.0 released!

I’ve just released uid_wrapper-1.2.0, a testing tool to fake privilege separation! The new version correctly checks privileges when changing IDs and has a lot more tests! Learn more at


libssh is running in the Matrix now

Since I joined the libssh project we started to write tests to find regression and make development easier. This has been achieved using the a unit testing framework called cmocka which I maintain and develop. The problem is that to run these tests you need to modify the sshd configuration and setup a test user so that the tests can be successfully executed. This is...


cmocka 1.0

At the beginning of February I attended in Brno and the days before I had a hack week with Jakub Hrozek on cmocka. cmocka is a unit testing framework for C with support for mock objects. We already rewrote the test runner last year and it was time to finish it and add support for several different message output formats. You are able to...


resolv_wrapper 1.0.0 – the new cwrap tool

I’ve released a new preloadable wrapper named resolv_wrapper which can be used for nameserver redirection or DNS response faking. It can be used in testing environment to route DNS queries to a real nameserver separate from resolv.conf or fake one with simple config file. We tested it on Linux, FreeBSD and Solaris. It should work on other UNIX flavors too. You can download resolv_wrapper here.


A talk about cwrap at LinuxCon Europe

Next week is the LinuxCon Europe in Düsseldorf, Germany. I will be there and give a talk about cwrap, a set of tools to make client/server testing easy on a single machine. Testing network applications correctly is hard. This talk will demonstrate how to create a fully isolated network environment for client and server testing on a single host, complete with synthetic account information, hostname...


How to get real DNS resolving in ‘make test’?

As you might know I’m working (hacking) on Samba. Samba has a DNS implementation to easier integrate all the AD features. The problem is we would like to talk to the DNS server but /etc/resolv.conf points to a nameserver so your machine is correctly working in your network environment. For this Samba in our dns resolver library we implemented a way to setup a dns_hosts_file...


What is preloading?

by Jakub Hrozek and Andreas Schneider The LD_PRELOAD trick! Preloading is a feature of the dynamic linker (ld). It is a available on most Unix system and allows to load a user specified, shared library before all other shared libraries which are linked to an executable. Library pre-loading is most commonly used when you need a custom version of a library function to be called....