GNU parallel is an amazing command line tool for executing jobs in parallel using one or more machines. It has a lot of features and therefore a lot of options. Fortunately the manual page is full of examples.

This article describes very well how to exploit the linux-kernel with recursive memory-structures in virtual filesystems.

I tried to compile nvidia's 367.35 driver on the newest Linux kernel 4.7-rc7 but I just got a bunch of compiler errors. It seems to be some kind of problem with the radix_tree-empty()-function. I found a patch for this problem here.

apt-fast is a shellscript wrapper for apt-get and aptitude that can drastically improve apt download times by downloading packages in parallel, with multiple connections per package.

I found this very nice article about pack/unpack with ruby.

Today is sysadmin-day: Special thanks to all system administrators: you do a great job!

Most linux-users know $OLDPWD. It's an environment variable to get the recently used directory. Sometimes it would be nice to remember more visited directories. In such cases pushd and popd would be a good choice..

Most common shells do have a directory stack. By looking in the man-page of bash I found the following description of the DIRSTACK:

This article explains how to use sysrq for emergency reboots or shutdowns.

Today I inserted another sim card in  my fairphone 2. I want to use LTE with this card, but I wasn't able to configure 4G/3G/2G. 2G was selected and the button was disabled. So I just had 2G. The other card worked as expected and I was able to choose 4G/3G/2G. This bothered me the whole day.

In the evening I figured out how to fix the problem: