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Hacker Public Radio

Your ideas, projects, opinions - podcasted.

New episodes Monday through Friday.

Welcome to HPR the Community Podcast Network

We started producing shows as Today with a Techie 9 years, 9 months, 24 days ago. Our shows are produced by listeners like you and can be on any topic that "are of interest to Hackers". If you listen to HPR then please consider contributing one show a year. If you record your show now it could be released in 14 days.

Latest Shows

hpr1823 :: Kansas Linux Fest 2015, March 21-22, Lawrence KS, Interview 2 of 2

Interview: Ryan Sipes, Organizer, Administrator, Coder, Innovator, Raconteur

Hosted by FiftyOneFifty on 2015-07-29 and released under a CC-BY-SA license.
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Ryan Sipes: KLF Organizer; Systems Administrator, Northeast Kansas Library System; Organizer of Lawrence (KS) Linux User Group; with Ikey Doherty, Ryan is a developer for Solus (formerly Evolve OS); a contributor to Vulcan text editor, written in Vala (Ryan's KLF talk, "How to Write a GTK/Gnome Application", was pretty much a tutorial in Vala)

Ryan's projects and employer

KLF related interviews with Ryan Sipes

Evolve OS related interviews

KLF sponsors:

The beers:

hpr1822 :: Some tips on using ImageMagick

ImageMagick is an amazing toolkit for manipulating images. Here's how I use it

Hosted by Dave Morriss on 2015-07-28 and released under a CC-BY-SA license.
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Some tips on using ImageMagick

I like to use images in HPR shows if I can. I have experimented with various ways of preparing them since I first started contributing, but I'm particularly impressed with what I am able to do using ImageMagick.

The ImageMagick system contains an enormous range of capabilities, enough for a whole series of shows. I thought I would talk about some of the features I use when preparing episodes to give you a flavour of what can be done.

I'm the rawest amateur when it comes to this kind of image manipulation. Just reading some of the ImageMagick documentation (see links) will show you what an enormous number of possibilities there are. I am only using a few in this episode.

I have prepared longer show notes and demonstrated some scripts to explain how I process images. These can be found here.

hpr1821 :: James Beard's Never-Fail Blender Hollandaise Sauce

Frank describes how to make perfect Hollandaise Sauce every time.

Hosted by Frank Bell on 2015-07-27 and released under a CC-BY-SA license.
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Frank describes James Beard's simple and almost infallible recipe for making Hollandaise sauce with a blender.
The recipe from the _Theory_and_Practice_of_Good_Cooking_, used copies of which can be readily found via a web search. According to Amazon.doc, new copies are also available. Frank's copy is a first edition dating from 1977, though it's been used too much to be a collector's item.


hpr1820 :: Kansas Linux Fest 2015, March 21-22, Lawrence KS, Interview 1 of 2

Interview Alex Juarez Rackspace Principal Enginneer

Hosted by FiftyOneFifty on 2015-07-24 and released under a CC-BY-SA license.
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From the LAMP Stack break-fix competition, to the breakfast buffet they funded on Sunday, the Rackspace crew presented their organization as the managed hosting company that puts the customer first, by making sure no customer has to wait in a long queue before taking to a human, and to staying on the line as long as it takes to make sure all problems are solved and all questions are answered. This kind of commitment to service naturally requires are larger number of people working tech support, and by the end of the weekend I think it was clear to everyone Rackspace was in Kansas to recruit. I was impressed when one of the Rackspace representatives told me, "We can teach people tech. We can't teach people to want to help other people". Rackspace dedicates a significant part of employee time to training and improving the skills of their help desk staff. If there is a drawback it's that when one shift is training, the other two are expected to pull extra hours to cover the third shift.

hpr1819 :: LibreOffice Tips: Horizontal Lists and Headless Operation

A workaround to create horizontal ordered lists in LibreOffice and run LO headless to convert files

Hosted by Jon Kulp on 2015-07-23 and released under a CC-BY-SA license.
Listen in ogg, spx, or mp3 format. Series: LibreOffice | Comments (0)

LibreOffice Tips: Horizontal Lists

One of these things is how to create horizontal lists in LibreOffice. This is something that I wanted to do, I think it was maybe a year ago that I was really trying to find out how to do this. What I mean by that is I wanted to be able to do in LibreOffice the equivalent of an in-line list in HTML and CSS. There's a way in CSS to tell the browser to display a series of list items in-line rather than vertically—and this is used all the time for footers and headers and things of that sort—and I wanted to be able to do that in LibreOffice because it would ease the process of creating the exams that I make in my classes, where I have a numbered list for all of the questions, and the answers for each question are also done in a numbered list but at the 2nd level—usually done with a, b, c and d, whereas the numbers of the questions are 1, 2, 3, 4, and so forth. What I wanted to be able to do was have the ordered list a, b, c, d spread out horizontally across the page without having to do it manually. So in other words I wanted to be able to type a word for an answer and then press enter, and instead of having it go into a new line, have it simply move over to the right a little bit with a new letter in place for the next item in the ordered list. I hope it's clear what I'm after here.

Anyway I never did find a way to do this. I searched online and there were a couple of other people who were interested in doing the same thing but they were all told this is impossible. Well, sort of. I found a workaround for this and it's not all that elegant but in a pinch it could work, and I don't think I would want to do it for an entire test but I thought it was kind of a cool way to do it.

So what you do his make up the ordered list just like usual. I have here on my computer right now opened a document with a single question, question no. 1. And then it has at the 2nd level of ordered list a series of 4 options: red, purple, green, and blue. And each one of these is in a font color of the same name, so that the word "Red" is red, the word "Purple" is in purple, "green" is in green. I do this because it makes it easier to see how these things move up and down. There are little buttons down at the bottom of the screen where if you click on the arrow up or the arrow down, it will move the list item up or down. So right now red is in the 1st position, but if I click the down arrow it will go down to the 2nd position and the one that was formally 2nd is now 1st. So purple and red have switched places.

I want to have this kind of flexibility going horizontally as well, and the way I found to do this was to use columns. I select the 4 items and then under the Format menu choose Columns and tell it I want 4 columns because I have 4 items, and I click OK and suddenly these things are distributed across the screen horizontally. Now if I click the up arrow, the item moves left and right!

The bad thing about using columns is that the columns are of uniform width, so they do not dynamically change according to the number of characters that are in the word the way it would do in HTML with CSS.

Headless Operation

To convert a Word .docx file to HTML, run the following command (LibreOffice must not be open in a graphical environment when you try to do this):

libreoffice --headless --convert-to html foobar.docx

To convert the same document to .odt format, run this command.

libreoffice --headless --convert-to odt foobar.docx


hpr1818 :: Review of HPR's Interview Recorder: Zoom H1

HPR has a digital recorder. You are welcome to use it for interviews at your next tech event.

Hosted by FiftyOneFifty on 2015-07-22 and released under a CC-BY-SA license.
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The Hacker Public Radio network owns a Zoom H1 digital voice recorder. If you are going to attend an open source event and think you would like to record interviews for Hacker Public Radio, make inquires to the mailing list and the correspondent with the recorder in their possession (currently FiftyOneFifty) will send it to you. This episode is a review of the devices features and how to use them.

Manufacturer page:

How to use the H1 as an USB Mic

hpr1817 :: Gathering Parts

NYbill talks about the process he goes through while starting an electronics project.

Hosted by NYbill on 2015-07-21 and released under a CC-BY-SA license.
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The web site that started this all:

Big Muff Pi:

Parts Distributors:

Hammond Box:

Joe Knows:

Picture of the gathered parts:

When I made the reference to "two red lips" regarding resistor colors I didn't quite explain what that meant. It was a way I learned, way back when, to remember which color was which number on a resistor. I hadn't thought about it in years. It used rhyming and references scheme to line the colors up with values.

0- Black - It's a "no" color, a zero
1- Brown - 'brow-one'
2- Red - Two red lips
3- Orange - Orange tree
4- Yellow - Yell for help
5- Green - a five dollar bill is green
6- Blue - Blue and sick
7- Violet - Violet heaven
8- Gray - Great
9- White - White wine

hpr1816 :: Visualising HPR tags

Using GraphViz to visualise the tags on HPR episodes

Hosted by Dave Morriss on 2015-07-20 and released under a CC-BY-SA license.
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As you know, HPR asks for tags to be added to the episodes we contribute. These are intended to be used to produce some kind of improved topic search at some point in the future.

I find it difficult to decide what tags to add to my shows, and I expect many people feel the same way about it. Should I use common tags like Linux or does that not differentiate it enough? How many tags should I add, should the words be plural or singular?

We have recently been asked to contribute to the task of adding tags to previous shows, so it's very much a hot topic at the moment.

In thinking about this I wondered if there was a way in which existing tags could be represented in a visual way to help with the process of choosing and rationalising tags. It was the type of thought that occurs to you in the shower or while out for a walk.

In my last job I occasionally used a package called GraphViz to generate graphical representations. I used it to generate a chart showing how the organisation (a university) was divided up into schools, departments, sections and so on in a hierarchical manner. I wondered if it could be used for this task.

I decided to use my currently preferred scripting language, Perl, and found there was a module which let me access GraphViz. I started putting together a script.

The script was created in an evening and is still rather rough. It performs a very simple query on the database to obtain the show numbers of shows with tags, their titles and their tags. It then uses a CSV parser to parse the tag list and builds a hash table indexed by tags, where the contents per tag are the show numbers that use this tag.

Having built this hash table it is used to generate GraphViz data by making each tag and each show number a node and joining them together.

Finally the script processes the graph to produce output in SVG format which is available to view.

Bear in mind that this is not a finished project - it may never be finished! The script may not be ideal. My understanding of GraphViz may be insufficient, and the rendering of the SVG may not be good (I got various results on different browsers).

However, you might find it interesting or even useful. Feedback on the idea is welcome.

hpr1815 :: 57 - LibreOffice Impress - Styles and Objects 2 - Drawing Object Styles

Drawing Object Styles and their use in LibreOffice Impress

Hosted by Ahuka on 2015-07-17 and released under a CC-BY-SA license.
Listen in ogg, spx, or mp3 format. Series: LibreOffice | Comments (0)

In the previous tutorial we looked at Presentation Styles, and I started with them because they were mostly similar to what we already covered in Writer when we looked at Paragraph styles. But Impress is a graphical product, so we need to wrap our heads around a different set of issues here. and that brings us to Drawing Object Styles.

For more go to

hpr1814 :: Custom Context Menus in GNU/Linux GUI File Managers

I describe how to add custom context menu items in the Nautilus and Thunar file managers.

Hosted by Jon Kulp on 2015-07-16 and released under a CC-BY-SA license.
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On Nautilus

On Nautilus you have to put your scripts into the Nautilus scripts folder, which on my system is located here:


You can either put copies of the scripts in there, or you can do like I did and make symlinks from the Nautilus scripts folder to your /home/bin folder. (I prefer to make symlinks instead of copying the files in there, just in case I make any changes to my scripts. If I have made a symlink instead of copying the file, then I only have to change original script and the symlink will automatically use the updated version.) Once you've done that, you right-click on a file and choose scripts then <yourscriptname> to run your script on the file.


On Thunar you don't have to put your scripts anywhere special. It actually handles custom actions much better than Nautilus, in my opinion. What you do is go to the Edit menu and choose Configure custom actions. Then you get a dialog box with two tabs. The first tab is where you can give your custom action a name and then tell it what command to run, and also tell it whether to apply the custom action only to the selected file, to all files in the directory, or to all selected files. On the other tab you choose the context in which this custom action will appear. You can select categories of files—like images, audio files, or text files, and so forth—or you can specify filetypes by extension, so that your custom action will only appear if you right click on a file that has the extension.