Author: rolfje

Print posters on a regular printer with Excel.

2014-05-15 rolfje No Comments

I recently needed to print out a big schematic diagram of the RX/TX board of a Kenwood TS50 Transceiver. This did not fit on a single piece of paper. Instead of downloading all kinds of crappy tools or uploading the image to some “free” site which is going to use it for whatever they think justifies their definition of “free”, I found out you can do this in Excel. Here’s how:

Make sure the image you want to print out as a poster has a decent resolution
Open Excel (maybe this will work in LibreOffice too, I haven’t tested, let me know)
Drag the image into a new worksheet so that it is top-left of the sheet.
Open the “Print preview” (the little icon in the bottom left of the window)
Resize the image so that it covers more than one page, up to the number of pages you’d like the poster to be. Your screen should now look somewhat like this:
Optional: Adjust the page margins.
Print.

After this, you’ll be gluing the pages together, but I think you already figured that out beforehand.

Have fun!

Fun, Workshop

Open a port in OSX Mavericks’ Firewall

2014-05-10 rolfje 10 Comments

The new firewall in Mavericks is great. For the common user. For a developer, not so much. If you are a Java developer like me, and you just need to open one port (say, 8080) so that the web application you’re working on is accessable from another computer, you can’t. I disabled the Firewall altogether for a few days, but it didn’t feel right.

I googled around and to make a long story short, here’s how to open port 8080 on any interface to any application on your OSX Mavericks installation in 3 steps:

sudo vim /etc/pf.conf

Then add the following lines at the end of the file:

# Open port 8080 for TCP on all interfaces pass in proto tcp from any to any port 8080

Test (and, according to the documentation, load) your edits with:

sudo pfctl -vnf /etc/pf.conf

Reboot.

(I have found at least 5 pieces of voodoo to make the Firewall restart and reload, but none of them seemed to work reliably, so pardon the reboot)

You can close it by commenting out the lines in pf.conf and reboot again. If anybody knows of an easier way to do this, preferably in one terminal command, and without rebooting, let me know.

Hope this helps.

Software

There’s life without Google. Or iCloud. Or Facebook.

2014-03-08 rolfje 5 Comments

Regular readers of this blog already know that I am not using dropbox, and I was an Evernote user, but recently decided it became to dangerous and replaced it with my own scripts. I had an interesting discussion on Twitter which made me decide to show you how I run my digital life without the help of Google, Facebook, Dropbox, Whatsapp or iCloud, and still be able to have all the functionality these services offer.

The search was hard and sometimes I need to reconsider some of the choices, but the last few years the selection of products was very stable and the setup has worked flawlessly. Searching for a secure replacement for Whatsapp or Google? It’s in here.

Software

Replace Evernote with Spidernote

2014-03-02 rolfje 8 Comments

In the past I have used Evernote extensively, it really helped me in my research for this blog and keeping track of meeting notes, todo lists and even making pictures of whiteboards at work searchable. As a product, there is no note taking app that can beat Evernote. But there is a little problem that has become a deal breaker for me, and that is basically the NSA and the way Americans, and particularly the American government seems to think about people’s privacy and online security.

Evernote is an American company, which sadly has to comply with whatever ridiculous request by the U.S. government to turn over data of innocent people all over the world (yes, even outside the U.S. border, I know, it’s amazing). This, combined with the fact that Evernote clearly can not use zero-knowledge encryption because of the services it provides, makes that all the data you and I put into Evernote are at NSA’s fingertips at all times. If you find that as scary as I do, and you have a Mac, there is a way to solve this.

Software

From the Finder to the Shell (and back)

2013-12-20 rolfje No Comments

A quick tip for OSX users out there who frequently need to open a Terminal window for the current location in the finder, or the other way around:

Go2Shell and Back

Install the free application from the App Store: Go2Shell. It will give you an icon on the toolbar of your Finder, and pressing it will open a Terminal window and automatically change it’s directory to match the Finder’s location.

The other way around is easier; you can already do that on any Mac. Simply type “open .” (that’s the word “open”, followed by a space and a period). This command will open a Finder window for the directory location your Terminal window is in.

Bonus tip: Also check the “open -t [filename]” command, it will open your system’s default text editor with the given file.

Apple, Software

Anonimatron: Quick Start

2013-11-03 rolfje 18 Comments

After reading my last blogpost on Anonimatron, you must have asked yourself “Great, but how do I actually use Anonimatron to de-personalize my database”? I tried my best to make basic Anonimatron configuration as self-explanatory as possible, just start it without any command line arguments and it will tell you.

Less adventurous or in a big hurry? This blogpost will show how simple it is to install and configure Anonimatron on an example MySQL database.

Read More “Anonimatron: Quick Start” »

Software

Anonimatron: Overview

2013-10-31 rolfje No Comments

In every software project, there comes a time where a bug pops up, nobody knows how to reproduce it, and somebody says “I know, let’s test this against a copy of the production database”. Even with the best intentions, once production data leaves the production machine with all its safeguards it becomes really hard to do access control on that data.

Most of the time, it’s not even needed to have that data. Developers just need a data set which resembles the production scenario close enough. Some brave souls have mixed succes with data generators, but those generators usually are tedious to maintain and die a slow death under the pressure of the daily grind.

In some ambitious projects automated integration testcases are built on top of the data which was inserted by the data generators. As the generators die, so die the tests. If you recognize this pattern, Anonimatron might be the answer for you.

Read More “Anonimatron: Overview” »

Software

iOS7 hidden features

2013-09-28 rolfje 2 Comments

If you’ve just installed iOS7 and like it as much as I do, you are probably interested in all the new features of it, and where to find them. On behalf of Apple, I’ll be happy to point out where all those neat new features are, and share my happiness about this wonderful new magical market-leading mobile OS.

Non-Java Binary Dependencies in Maven

2013-07-18 rolfje 9 Comments

Suppose you have a Java Server application, and some of the runtime binaries in that application are external to your application. Generated image files, compiled Silverlight components in your pages, or resource files which are managed by an external team.

Much like the jar files used by your application, these external binaries can be seen as dependencies, with versions. This blogpost assumes your project is built with Maven 2, because the real world isn’t always a greenfield project.

Because Maven is designed around jar file dependencies, and a lot of it’s internal decisions are based on file extensions, it looks like this problem can not be tackled with Maven. But there is a way to do this. It will decouple your sub-projects and make version and dependency management much better.

Software

How big is 5 Zettabyte?

2013-06-23 rolfje 3 Comments

Since the interview of Edward Snowden with the Guardian, the discussion about privacy and companies storing and sharing unencrypted private data is picking up. Particularly Americans are worried about what it does for their National security and their private data. But that’s actually a naive thought, given the NSA stores worldwide data.

In a recent coverage on theblaze.com (a rather tabloid-looking news station in the U.S.), the interviewers are shocked to see that the NSA spies on “every American”.

This is a limited view of the world and failing to see the importance of spying on people outside the U.S., but lets start with technical side of things first. What data are they storing and how big is their hard-disk?

Read More “How big is 5 Zettabyte?” »

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