We started producing shows as Today with a Techie 9 years, 4 months, 29 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 11 days.
Last time we looked at some basics about how TLS and SSL work, and saw that this is basically an application of the same technology used to encrypt e-mails. But we also noted that there are some problems with this approach. We need to recognize that in security there is never a permanent solution, and that vulnerabilities are constantly being discovered, and ideally then being fixed. Some of these may involve highly technical issues about cryptographic methods, but I think the largest category of issues is about the processes around the use of certificates. For more go to http://www.zwilnik.com/?page_id=686
tree - list contents of directories in a tree-like format.
tree [-adfghilnopqrstuvxACDFNS] [-L level [-R]] [-H baseHREF] [-T title] [-o filename] [--nolinks] [-P pattern] [-I pattern] [--inodes] [--device] [--noreport] [--dirsfirst] [--version] [--help] [--filelimit #] [directory ...]
Tree is a recursive directory listing program that produces a depth indented listing of files. Color is supported ala dircolors if the LS_COLORS environment variable is set, output is to a tty, and the -C flag is used. With no arguments, tree lists the files in the current directory. When directory arguments are given, tree lists all the files and/or directories found in the given directories each in turn. Upon completion of listing all files/directories found, tree returns the total number of files and/or directories listed.
By default, when a symbolic link is encountered, the path that the symbolic link refers to is printed after the name of the link in the format:
name -> real-path
If the '-l' option is given and the symbolic link refers to an actual directory, then tree will follow the path of the symbolic link as if it were a real directory.
The mystery of my pickup toolbox.
- Amps (what it's measured in)
- amount of water. (what i compare it to)
- voltage (what its measured in)
- pressure (what i compare it to)
- Ohms (what it's measured in)
- valve (what i compare it to)
Last Month's Shows
Mailing List discussions
Policy decisions surrounding HPR are taken by the community as a whole. This discussion takes place on the Mail List which is open to all HPR listeners and contributors. The discussions are open and available on the Gmane archive.
The main threads this month were:
- From: Charles Thayer
Date: 2015-02-01 03:59:07 UTC
Subject: HackerPublicRadio.com (squatter-occupied look-alike site): Domain Available?
- From: Patrick Dailey
Date: 2015-02-04 22:04:43 -0500
- From: Ivan Privaci
Date: 2015-02-08 21:23:54 -0500
Subject: I ain'tnt dead yet: quick question (well, a couple)
- From: Ivan Privaci
Date: 2015-02-09 19:14:56 -0500
Subject: "HPR Dodgers, in the 21th-and-a-half centuryyyyy....." (Future HPR features)
- From: Ken Fallon
Date: 2015-02-11 13:34:35 +0100
Subject: Wed 2015-04-01: hpr1738 Reserved: Open Systems Interconnection (OSI) model (ISO/IEC 7498-1).
- From: Ken Fallon
Date: 2015-02-12 15:08:12 +0100
Subject: Fwd: Cross-Promotional Opportunties
- From: "O'Brien, Kevin"
Date: 2015-02-12 14:03:18 -0500
Subject: Kudos for FOSDEM coverage
- From: lostnbronx
Date: 2015-02-12 15:31:56 -0700
Subject: Re: Cybrary Cross-Promotional Offer
- From: Ken Fallon
Date: 2015-02-14 15:05:04 +0100
- From: Ivan Privaci
Date: 2015-02-19 11:10:33 -0500
Subject: Minor website bug report
- From: Mike Ray
Date: 2015-02-19 21:09:49 UTC
Subject: Topic request
- From: Dave Morriss
Date: 2015-02-23 07:55:12 UTC
Subject: HPR Community News - next Saturday on 2015-02-28T18:00:00Z
- From: Fifty OneFifty
Date: 2015-02-25 01:58:02 -0600
Subject: Is anyone else having trouble submitting shows?
- From: Joshua Knapp
Date: 2015-02-26 09:03:38 -0800
Subject: Added some firewall rules and IDS to the server
Total messages this month: 63
Comments this month
There are 17 comments:
(2014-06-03) "How to Use Docker and Linux Containers"
- Windigo on 2015-02-16:"Creating a bridge interface"
(2014-11-10) "How I make coffee"
by Dave Morriss.
- 1093i3511 on 2015-02-19:"[no title]"
- Dave Morriss on 2015-02-20:"Rommelsbacher EKO 366/E"
(2015-01-14) "Theater of the Imagination: Part 06"
- Charles on 2015-02-27:"Patronage as an alternative to marketplaces?"
(2015-01-20) "Podcast recommendations"
by Thaj Sara.
- Mark Waters on 2015-02-03:"Thanks"
(2015-02-05) "FOSDEM 2015 Part 3 of 5"
by Ken Fallon.
- FiftyOneFifty on 2015-02-05:"Play dat funky music"
- Mike Ray on 2015-02-05:"Thanks for asking the right questions"
(2015-02-06) "Today with a Techie episode two thousand"
by Ken Fallon.
- Mike Ray on 2015-02-06:"Such a parcel of rogues"
- FiftyOneFifty on 2015-02-06:"Thanks for the memories"
- Mikael on 2015-02-10:"Thank you, Ken"
- Epicanis on 2015-02-11:"Not what I was expecting..."
- JM on 2015-02-12:"great work!!"
(2015-02-10) "FOSDEM 2015 Part 5 of 5"
by Ken Fallon.
- borgu on 2015-02-11:"reactos moar!"
(2015-02-11) "Open Source CD Rippers"
- Ken Fallon on 2015-02-13:"K3b"
- Charles on 2015-02-25:"[no title]"
(2015-02-17) "A tour round my desktop"
- Marshal Mellow on 2015-02-22:"Good job"
(2015-02-20) "Windows Remote Desktop on GNU/Linux"
by Ken Fallon.
- johanv on 2015-02-26:"Nice!"
Our next topic is Cell Styles. If you are already familiar with Styles from Writer, think of Cell Styles as the equivalent of Writers Paragraph Styles. Just as a single Writer document can have a variety of Paragraph Styles applied to different paragraphs (e.g. Headings, Lists, Paragraphs), a single spreadsheet can have multiple Cell Styles. And the same arguments for using Styles also apply. If you have consistently used Cell Styles in your spreadsheet, you can update the appearance easily just by changing the Style instead of needing to go through the file looking for every cell that needs to be adjusted. And by using Styles you can apply a large number of formatting choices to many cells with just a few mouse clicks. So it really does pay to learn how to use Cell Styles.
Introduction to Vim
This is the start of the Vim Hints series.
As a Linux user there are many editors available to you. Which one you want to use depends on your needs and the amount of time you want to dedicate to learning how to use it.
One of the editors from the early days of Unix is vi, written in 1976. Contemporary with it is Emacs, also originating in 1976. However, it seemed to become the norm (in my experience anyway) that vi rather than Emacs was provided as standard with versions of Unix, and this has often continued into Linux.
I originally started using Unix around 1988 and found vi available to me. I learnt how to use it in a rudimentary way since I knew I'd find it on any Unix systems I came across.
Many derivatives and clones of vi have been created. The one which has become the most popular and available is Vim, the name of which is an acronym for Vi IMproved, created in 1991 by Bram Moolenaar. This is what I use, and I have not wanted to learn another editor since adopting it, even though I have experimented with several. This is the editor we will be looking at in this series.
What's the series about?
The thinking behind this series is:
- You may already be using Vim; there are features you may not be aware of that can be revealed here
- You may be using a different, simpler editor; you might want to use Vim and gain from its advanced features
Of course, you may prefer to learn Emacs instead. That's fine; you should choose the tool that best suits your needs. Both Emacs and Vim have quite steep learning curves, but the broad range of capabilities you gain from knowing either is considerable.
I am not an expert in Vim. In fact I am continuing to learn new Vim features on a regular basis. However, I have been using it for many years and would like to share some of what I have learnt.
Why use Vim?
With simpler editors you can move about a file, add, remove and change text and save the results. The editor might have syntax highlighting and some degree of knowledge of the programming language you are typing. You might have spell checking as well.
With Vim and other more advanced editors you have all of this and a lot more. You can perform global changes throughout a file, process many files at once, add plugins to the editor to change its behaviour, and so on. Also, there is a language behind the scenes which can be used to build extensions.
Usually, typing the command vi at the command line actually invokes vim. Vim runs in vi-compatible mode by default, which results in Vim enhancements being unavailable.
Vim uses a configuration file, which is called
.vimrc on Linux. (Vim will also run on Windows, OSX and other operating systems but we will not be covering these implementations in this series.) Vim also has a GUI interface invoked by the command
gvim, and it has its own configuration file
I you don't have a
.vimrc create one with
touch ~/.vimrc before you start. This will stop Vim running in vi-compatible mode. We will look at what the
.vimrc can be used to do later.
You can start Vim on its own without pointing at a file, but normally you use it to edit a file, which need not already exist. So, to create a new file called
testfile invoke Vim with the command:
Once running, Vim shows the contents of the file. All the lines on the screen where there is no content are marked with a tilde "~" character. If you are creating a file the first line on the screen will be blank, and last line will contain the name of the file followed by "[New File]" and some other details which we will examine later:
"testfile" [New File] 0,0-1 All
All the rest of the lines will contain a tilde.
Vim is a modal editor. The mode you usually start in is normal mode where you can move around the lines of the file and perform actions, but nothing you type is actually written to the file. In fact, the keys you type are actually editing commands. This is one of the features of Vim that causes problems for new users.
Since this is a new file there is not much you can do other than enter text, and to do this you need to switch to insert mode. Do this by pressing the i key. The message -- INSERT -- will appear on the bottom line of the screen. Now type some text, pressing the Enter key at the end of each line.
You might notice that in insert mode you can press the arrow keys and move back to text you have already typed. This is a Vim feature and was not available in the original vi editor.
When you have finished entering text, press the Esc key to exit from insert mode. Now you can move around in normal mode, but remember that the keys you press are now commands not data to be entered into the file.
To move around in normal mode use the arrow keys or the home row keyboard keys: k to move up, j to move down, h to move left and l to move right.
This brings us to the last mode we'll look at: command mode. To enter this mode press the : (colon) key in normal mode. This moves the cursor to the last line of the screen, which starts with the colon you just typed. Here you can enter another class of commands. This time, we'll just look at how you can save the file and exit Vim.
Saving the file is achieved with the w command, and to exit from Vim the q command is used. These can be typed together, so :wq writes the file and exits.
If you were to use :q on its own, having entered data into Vim, this would not work. Vim prevents you from throwing away your work this way. If you really meant to quit without saving then the q must be followed by an exclamation mark ("!"). So :q! lets you exit Vim without saving.
Summary so far
- Vim usually starts in normal mode
- Arrow keys or h, j, k and l for left, down, up and right for navigation in normal mode
- i enters insert mode
- Esc exits from insert mode and reverts to normal mode
- : in normal mode enters command mode
- :w in normal mode writes the file
- :wq in normal mode writes and exits
- :q in normal mode exits but only if nothing was changed or added
- :q! in normal mode exits regardless of any changes
- I was wrong about the contents of the last line of the Vim screen in the audio. The notes have been corrected.
- Wikipedia page for vi http://en.wikipedia.org/wiki/Vi
- Wikipedia page for Emacs http://en.wikipedia.org/wiki/Emacs
- Wikipedia page for Vim http://en.wikipedia.org/wiki/Vim_(text_editor)
- Wikipedia page for Bram Moolenaar http://en.wikipedia.org/wiki/Bram_Moolenaar
- Learning the vi and Vim Editors, 7th Edition, by Arnold Robbins, Elbert Hannah, Linda Lamb. http://shop.oreilly.com/product/9780596529833.do
- vi and Vim Editors Pocket Reference, 2nd Edition, by Arnold Robbins. Available to buy or as a free PDF. http://it-ebooks.info/book/144/
- A Byte of Vim, by Swaroop C H. Available as a free PDF. http://www.swaroopch.com/notes/vim/
- The Vim Tutorial and Reference, by Steve Oualline. Available as a free PDF. http://www.oualline.com/vim-book.html
Free Software Law Expert Aaron Williamson held a brilliant talk on the history of internet surveillance in the USA at FOSDEM 2015. After the Paris terror attacks, many politicians want to increase surveillance. British Prime Minister David Cameron wants to read all our emails - even the encrypted ones. Is this the only answer to terror attacks? Aaron has a very strong opinion on this.
Mathias Kirschner, Free Software Foundation Europe
Matthias is the Vicepresident of the Free Software Foundation Europe. In our interview at Fosdem 2015, he explains the work and the goal of the foundation and how they do lobbying for Free Software in parliaments and government bodies.
Torproject - nos ognions
A member of nos-ognions.net, which is part of the Tor project, explains about exit nodes, transparency and surveillance.
Back in the summer of 2014 I started going to the Surrey Linux User Group.
I was asked to give a short presentation about Linux accessibility and how, although I am totally blind, I still write code and muck about with Linux.
I was then asked to give the same presentation at the Portsmouth LUG.
This time I made it more comprehensive and took more kit.
So I take this opportunity to give my version of the "What's in my bag" shows that some folks have been doing. As I am unemployed, like a lot of blind folks, I have been unable to justify this before now because I don't lug an interesting collection of stuff to and from work.
Here's a simple bullet list about the crate and it's contents:
- The crate is a 35 litre capacity 'Really Useful Box'
- First in were 2 Dell Latitude D630 (64-bit) laptops
- Next in was a Dell Inspiron (32-bit) laptop, clunky and slow
- The three laptops were sandwhiched between 3-ply layers of bubble-wrap
- Next in was a Seika 40-cell refreshable Braille display
- Next was a clear polycarbonate, zip-up pencil case stuffed with audio leads
- Then a 'Mesh' Bluetooth and line-in external speaker
- And a Braun external speaker/FM radio/micro-SD boom-box
- A four-way mains power splitter
- The three AC adaptors for the laptops
- On the top of the box, because it was too wide to go in, was a USB keyboard
- Mobile phone charging battery 'brick', for the Raspberry Pi
- A Raspberry Pi, a Banana Pi and some Arduino bits and pieces
Here's what I demonstrated with two of the laptops:
- Trisquel Linux and accessibility in the Gnome desktop with Orca
- Accessibility in the console with Debian and the Braille display on the Inspiron
The second Latitude was with me so I could get some sighted help with BIOS settings.
My thanks have to go to Tony Wood for the lift to and from both of these accessibility presentations. I could not have done either, especially the Portsmouth one without his help.
Thanks also to Lisi, the coordinator of the Portsmouth LUG and to the folks of that LUG for their enthusiasm.
Here's the link to the HPR show about my Raspberry Pi tts code fix: