How to split a wallpaper for multiple monitors on GNU/Linux

So I wanted to split a 3840×1080 wallpaper in two halves for my dual monitor based KDE 4.10.5 setup. Obviously there are several applications that would do the job, but why bother when ImageMagick can do it with a one-liner. The “magick” is achieved by using a geometry argument:

What is the latest Skype for Business User-Agent string?

When using a client other than Skype for Business (formerly known as Lync) to connect with your Office 365 account, you’ll need to provide the Microsoft Lync servers with a user-agent string they recognize as an “acceptable” client. The reasoning behind this is surely to give you the best possible experience and not at all to lock out other messaging clients.

How to add failed logins from Logwatch as firewall rules using Iptables

Just for the record: collecting failed logins from Logwatch and feeding them to the firewall is by no means a viable strategy against brute force attacks or other intrusion attempts. There are better means to mitigate these kind of security concerns in real time.

BlueOnyx 5107R - make_sock: could not bind to address 0.0.0.0:80

Recently, I became aware that Apache’s access and error_log on a BlueOnyx 5107R server were both zero byte files. Restarting Apache to correct the issue resulted in the following error message:

(98) Address already in use: make_sock: could not bind to address 0.0.0.0:80
no listening sockets available, shutting down
Unable to open logs

Fixing the issue was a simple matter of issuing the following commands:

killall -9 httpd
service httpd start

It seems that during logrotate, Apache was not able to get new file handles to write to the new log files.

Arch Linux - Failed to start Verify integrity of password and group files

The shadow.service unit reported that it had failed and threw the following error message: “user ‘colord’: directory ‘/var/lib/colord’ does not exist”. I had no recollection of housing such a user, but by issuing the command below there was hard proof (image to the right) that colord was indeed a homeless user on my system, and her home was supposed to have been /var/lib/colord.

How to reverse a shortened URL with a single command on GNU/Linux

Remember that old saying: if you don’t know the source, don’t click it? With all these new URL shortening services, that advice seems to have been thrown out the window. As a result, evildoers are embracing the technology to disguise their malware sites behind shortened URLs.

This is obviously effective as an URL like hxxps://goo.gl/3BSi65 would have a much easier time getting past your spamfilter than say something like hxxp://h4x0r.tld/inject.aspx

Slackware ARM on the Raspberry Pi 2- 38 days later

Excited by the prospect of hosting my blog on the new Raspberry Pi 2, I decided lately to wave goodbye to the local datacenter and unleash a Slackware Linux box into the wild (full story here).

Everything went (mostly) without a hitch until I wanted to get back in sync with the Slackware-current tree. After applying the available updates and issuing a reboot, the system seemed operational and nothing from the logs gave any indication of imminent failure.

WordPress on Raspberry Pi 2 running Slackware ARM

Two weeks ago, I decided to move this blog from its old hosting and deploy it on a Raspberry Pi 2. The geek in me could no longer resist the urge to discover if a $35 worth computer could replace the need for commercial hosting. Besides, what a great opportunity to finally get my hands on Slackware’s official ARM port.

RPi2 setup:

Raspberry Pi 2 Model B
Raspberry Pi 2 Micro USB Power Cable 1.2A
MicroSDHC Ultra UHS-I 32GB

LAMP setup:

Slackware ARM current
Package series: a, ap, d, l, k, n (and a few from “x”).
Apache 2.4.12 (rebuilt)
MariaDB 5.5.40 (rebuilt)
PHP 5.4.40 with mod_proxy_fcgi and php-fpm (rebuilt)

Non stock packages:
Modsecurity 2.9.0
Fail2ban 0.9.1

Why use Slackware and not a hard float port?

A hardware floating-point unit you say, well I’d never heard of it.

VMware Player - Taking ownership of this virtual machine failed

After Windows 8.1 had performed an unscheduled reboot, I was greeted with the following error message when trying to start up a virtual machine in VMware Player:

This virtual machine appears to be in use.
If this virtual machine is not in use, press the “Take Ownership” button to obtain ownership of it. Otherwise, press the “Cancel” button to avoid damaging it.

VMware Player - Take ownership of Virtual Machine

VMware Player- Taking ownership failed.

Kane & Lynch: Dead Men - xlive.dll is missing from your computer

Trying to start the game Kane & Lynch: Dead Men from the Steam client on a default Windows 8.1 installation will not work. Furthermore, you’ll get no error message other than the obvious lack of the gameplay.

Kane and Lynch

Games for Windows Live- Kane & Lynch: Dead Men running on Steam.

As usual with these kinds of errors, a good starting point is to locate the actual game folder. From Steam’s Game library, right click on “Kane and Lynch: Dead Men” and select properties, then select the tab called “Local files” and finally click the button labeled “Browse local files”. You’ll now find yourself in the game directory. By trying to execute “kaneandlynch.exe” you’ll get an error message stating that “xlive.dll is missing from your computer”. Thankfully, Steam has already included the necessary libraries inside a folder named XLiveRedist which contains the installer package XLiveRedist01.02.0241.00.msi.

The OTRS Group axes the Windows installer

With the release of OTRS Help Desk 4, it seems that running OTRS on a native Windows environment for all intents and purposes is no longer viable. By killing off the Windows installer and recommending migration into the OTRS appliance, the OTRS Group seems to be subtly hinting that OTRS on Windows is dead in the water.

The OTRS Windows installer

The now unmaintaned OTRS Windows installer.

Switching to the OTRS appliance might be a good solution for some Windows installations, but in my case OTRS is configured with MS Active Directory as a customer and agent backend, and we’re relaying on IIS for single sign on. It might be possible to do a source based update and subsequently hack it all back together, but who really wants to travel down that road.

How to configure KMail with GPG on Slackware Linux 14.1

No additional software is required on a full Slackware 14.1 install.
Slackware 14.1 ships with KDE 4.10.5.

Prerequisites

If you don’t already have a key pair (secret and public key), then your first order of business is to create one. The preferrable option is to use the CLI with the command:

gpg --gen-key

KDE provides two graphical tools for working with GPG, namely KGpg and Kleopatra.  KGpg will walk you through the initial setup using an interactive wizard and subsequently create the needed key pair and config files (do not use Kleopatra for your initial setup).
If you’re importing an existing private key then make sure to change the default trust level afterwards.