Category Archives: Tech

In mijn loopbaan als allround systeembeheerder heb ik bij verschillende organisaties voornamelijk vriendelijke en geduldige collega’s gehad. Toch zijn er bepaalde types gebruikers die overal terug te vinden zijn. Hieronder beschrijf ik er een paar. Ik twijfel er niet aan dat er voor systeembeheerders/helpdeskers soortgelijke lijsten zijn. De Wegloper: loopt weg als je aankomt om […]

Last week we had a spam issue when a user’s mail credentials were apparently guessed or stolen. (Our mail server doesn’t do two factor yet.) A lot of spam was sent from that useraccount. To monitor our relay server I wrote a script that checks for unusual amounts of mail being sent. It sends a […]

This is my ~/.tmux.conf file, for my own reference. For the right keyboard sequences to be passed on from PuTTY it might be necessary to set your keyboard to Xterm R6. Here’s the file.

Purpose: send all incoming mail to non-existing addresses to a central account. I added corrections, commentary and screenshots to the code I found at http://www.qtzar.com/dlyh-5mnlz8/. The code parts are licensed under the Apache 2.0 license. The non-code part of qtzar’s page is licensed under the Creative Commons Attribution 3.0 Unported (CC BY 3.0) license and […]

Testlab This article describes how to set up a virtual LAN with a virtual router and virtual computers. It is isolated from your physical LAN and meant to test setups with multiple computers in the same LAN. Intended audience This is for everyone who wants to experiment with networked servers isolated from their production network. […]

Here’s a script to track Twitter unfollowers. It it based on @sferik‘s excellent command-line Ruby Twitter client ‘t’. Visit its GitHub page for installation instructions; they’re pretty straightforward. The script is quick and dirty but easy to follow: it compares a new followers list to the previous list followers list and e-mails you the difference. […]

Here’s my personal documentation on Vi(m) in case I forget how I did it. Hope it helps someone. Running Debian Jessie and I want: – to make Vim the systemwide default editor; – to have syntax highlighting; – a nice colour scheme. For the colour scheme and syntax highlighting we need to install some additional […]

Here are some odd things I learned about scheduling jobs with cron. Define your PATH End in newline Log to syslog Set default shell Run every odd minute Mute output Mail to different address Example Define your PATH When running stuff from an interactive shell under your regular account you’re probably using the PATH variable. […]

To give my server a bit of personality I have it render words of wisdom everytime I log on to it through SSH. Also, show its uptime and any tunning tmux sessions. This is for Debian 8, I’m not sure about Red Hat or other distros. First install fortune and cowsay: Place the following commands […]

Following a rather radical pruning of my Twitter followings (people who I am following) my timeline has got both better and less exciting. So I wanted to follow some new people but not just random accounts. I have a list of ununfollowables: the followings I like best. Those people are probably good judges of the […]