Category: Software

Posts

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09 April Jens Grassel / Software

Quite some time ago I started noticing that the mouse in dosbox was starting to “jump” occasionally. But since I don’t get to play games quite often I ignored and filed it under “possibly driver issues”.

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27 March Jens Grassel / Software

This is an updated version of my previous guide and reflects the latests changes in the scala ecosystem. So if you would like to use neovim for your Scala development work flow then this guide will get you started.

Because ENSIME is dead and gone we will use the metals language server for Scala.

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27 March Jens Grassel / Bücher / Software
Unser Buch “Come out and Play” über Webentwicklung mit Scala, Scala.js, Akka und dem Play Framework ist fertig. Die finale Version kann bei LeanPub erworben werden.
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09 February Jens Grassel / Bücher / Software
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21 December Jens Grassel / Software

Das Thema Datensicherung (Backup) ist ein großes und jeder, der sich ernsthafter mit Computertechnik beschäftigt, sollte damit Berührung gehabt haben. Im Guten wie im Schlechten. ;-)

In dieser kleinen Anleitung möchte ich kurz beschreiben wie man mit wenig Aufwand in die Lage versetzt wird die Snapshots von ZFS zu nutzen, um verschlüsselte Sicherungen auf eine externe Festplatte zu ziehen.

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12 September Jens Grassel / Software

If you would like to use neovim for their Scala development workflow then this guide may get you started.

It is possible to simply edit the source files but some configuration and plugins will make your workflow way more productive. This includes using projects like ENSIME, SBT and several plugins for neovim.

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17 July Jens Grassel / Software

Because there are way to many options for git to remember it is feasible to have a template file for the .gitconfig which is usually located in the home directory.

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02 July Jens Grassel / Software

If you’re upgrading your FreeBSD installation to 11.2-RELEASE please ensure that you disable custom kernel modules first. The usual suspects are the nvidia driver and the virtualbox kernel module.

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08 June Jens Grassel / Software

In some cases you may need the sources (kernel source) for your FreeBSD installation. However if you did not select the source package in the installer it will not be installed.

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20 November Jens Grassel / Software

If you’re running confluence behind a reverse proxy then you might stumble upon an issue that prevents firefox from working correctly. Strange bugs will hapen like clicking on “add a new page” resulting in endless loading loops.

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03 November Jens Grassel / Software

If you work with sbt (or activator) and want to restrict the resolvers to the ones that you choose then you might get frustrated that overriding the resolvers setting does not suffice.

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05 October Jens Grassel / Software

If you happen to use the fine postgres extension for slick named slick-pg then you might stumble into an issue where the compiler complains about missing implicits for column types that should be provided by slick-pg if you override the api method of the custom postgres driver.

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03 June Jens Grassel / Software
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10 May Jens Grassel / Software
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10 May Jens Grassel / Software

If you upgrade cups on your FreeBSD installation or maybe you install some foomatic packages this may lead to the removal of the cups-filters package. In some cases this package is needed for your printer to work correctly.

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16 December Jens Grassel / Software

The prompt of lftp can be configured in the config file via the set prompt directive. A while ago I found a prompt on the internet but forgot where, here it is:

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12 November Jens Grassel / Software
If you search in Windows 10 then by default search results from the web (Bing) are included. To disable that just click on the settings icon after you opened the search dialog. There you can disable Cortana and afterwards disable web results.
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10 November Jens Grassel / Software

The start menu of Windows 10 displays some stuff from the internet by default. If you find this annoying like me then feel free to follow this guide to fix that.

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20 September Jens Grassel / Software
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15 September Jens Grassel / Software
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12 September Jens Grassel / Software

Nach einer neuerlichen Umstellung des Onlinebankings hatte ich nach über einem Jahrzehnt reibungslosen Ablaufs Probleme die HBCI-Verbindung neu einzurichten.

Es stellte sich heraus, daß man entgegen der Empfehlung der Bank sowohl den Benutzernamen als auch die Kundennummer angeben mußte. Letztere mußte dabei einem bestimmten Format genügen (siehe unten):

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03 September Jens Grassel / Software

A simple shell script that jumps into a given directory (or a default one) and updates all git repos in there. Additionally it checks if an upstream remote exists. If that is the case it fetches the upstream changes.

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25 June Jens Grassel / Software

From time to time you have to update your SSL keys and certificates. In some cases you may have a mixed infrastructure e.g. “normal” http servers and tomcat or other java based servers. In the latter case you’ll have to import your shiny new certificate and key into your java keystore.

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13 June Jens Grassel / Software
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08 June Jens Grassel / Software

I needed not to chain promises but to resolve a whole bunch of them together. The documentation was sparse so it took me a while to stumble upon the solution (Ember.RSVP.all). In case you need something like that here it is.

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06 June Jens Grassel / Software
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03 June Jens Grassel / Software

If you spin up a 32bit guest system within vagrant using the virtualbox provider, setting the number of cpus is not enough. Meaning that the following won’t do:

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02 June Jens Grassel / Software
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20 May Jens Grassel / Software
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12 February Jens Grassel / Software

If you’re not using gnome or xfce but have some gtk apps installed then you could always set your theme preferences via ~/.gtkrc-2.0 like this:

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10 February Jens Grassel / Software
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08 February Jens Grassel / Software
At least on my Nexus 4 (made by LG) I have to press the following keys: Power + Volume Down Within the bootloader you can switch entries with the volume keys and select one with the power key. This can be helpful if your android doesn’t start anymore.
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05 February Jens Grassel / Software
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14 June Jens Grassel / Software
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12 June Jens Grassel / Software
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10 June Jens Grassel / Software
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08 June Jens Grassel / Software

To prevent the log files of a rails application to grow without limit you should setup log rotation. There are several ways to do this. Here is a simple solution using logrotate.

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05 June Jens Grassel / Software

If you want to mirror a svn repository via git there is a nice little gem called svn2git available that provides easy setup. Updating your repository is done via svn2git --rebase.

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02 June Jens Grassel / Software

Sometimes you have to rebuild ports due to a library update. But if there are vulnerabilities known for that ports then make will bail out with an error message and refuse to build the port. Instead it gives you the advice to update or deinstall the port which is good advice but sometimes just not possible.

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01 June Jens Grassel / Software
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28 May Jens Grassel / Software

If you are using lighttpd to host several php applications via virtual hosts and are using the newrelic php monitoring service then you’ll have noticed that setting the php application name per virtual host does not seem possible at first.

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26 May Jens Grassel / Software
Besides the consolas font which is a splendid developer font I do like the terminus font for console and terminals. If I’m stuck on a windows box I usually ssh via putty into linux or bsd boxes. Since the terminus font project does provide an installer for windows you can easily download, install and use it in your terminal session.
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24 May Jens Grassel / Software
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22 May Jens Grassel / Software

If you’re running a non web app on the github api you can simply get the auth token for it (if you have configured in your account under applications of course) by running the following curl command.

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20 May Jens Grassel / Software

If you encounter an too many open files exception you usually edit /etc/security/limits.conf and increase the value. But on Ubuntu (10.04 LTS at least) this is ignored!

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18 May Jens Grassel / Software
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15 May Jens Grassel / Software
If you run into an error while trying to compile the py-cairo port complaining it can’t find the python headers, you need to rebuild your python port with pth support disabled.
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09 May Jens Grassel / Software
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03 May Jens Grassel / Software
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08 April Jens Grassel / Software
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05 April Jens Grassel / Software
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05 March Jens Grassel / Software
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02 March Jens Grassel / Software

Since some time it seems to be somewhat impossible to install the ruby-debug gem into your rails app. The error message will most likely look similar to this one:

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01 March Jens Grassel / Software
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15 June Jens Grassel / Software
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14 June Jens Grassel / Software
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13 June Jens Grassel / Software

If you run MySQL you probably use the innodb storage engine because it provides a number of advantages over MyIsam.

The official documentation recommends giving 50-80% of your ram to innodb_buffer_pool_size which can easily go above 10 gb because ram is cheap nowadays. The same documentation recommends settings innodb_log_file_size to 25% of innodb_buffer_pool_size meaning this can easily be 2 or more gb.

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12 June Jens Grassel / Software
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11 June Jens Grassel / Software

If you are using heroku you probably ran into some issues with rake assets:precompile. When using active admin bringing it’s assets into your app can also be quite tricky.

The method of precompiling your assets yourself and adding them to your git repository works for sure but it isn’t really best practice.

Another way to get the needed assets to be compiled is as follows:

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10 June Jens Grassel / Software
If you’re using cucumber you should be carefully examining your tests to make sure you’re really writing acceptance tests and not integration tests. While you can certainly write integration tests in cucumber that is mostly a waste of time because these are easier and faster to write with rspec and capybara. However I find cucumber a nice tool for the implementation of acceptance tests.
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09 June Jens Grassel / Software
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08 June Jens Grassel / Software

Sometimes you’ll want or have to split a git repository into two. This is usually a sign of not thinking forward enough but hey sh.. happens. If your repository is structured in a way that you just need a subdirectory of it into a new repository you can follow the steps below.

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07 June Jens Grassel / Software

If you are using lighttpd as webserver and host drupal websites you probably have used some lua script and mod_magnet to get clean urls. Recent versions of lighttpd (1.4.26+) are able to handle rewrites better through the url.rewrite-if-not-file command. The config for your [virtual] server should look like this:

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06 June Jens Grassel / Software

To write unit tests for your javascript code you can use a testing framework like JSTestDriver which is able to run under TeamCity.

Usage and configuration instructions for JSTestDriver are available on their website. For integration with TeamCity you’ll have to write an ant build file. But to be able to run browsers on your build agent machine you’ll have to use Xvfb. The test task in your ant file should look like the one below:

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05 June Jens Grassel / Software
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04 June Jens Grassel / Software

Sometimes you’ll want to remove all ruby gems from your system. This is very easy (at least under unix like operating systems). Just issue the following command:

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03 June Jens Grassel / Software
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02 June Jens Grassel / Software

The zsh contains a very usefull extension called zmv. You can load it via autoload -U zmv. The man page is located under zshcontrib. A very usefull flag is -n which does not execute the command but prints the command that would be executed. Use this if you are unsure about your patterns.

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01 June Jens Grassel / Software