March LUG – Kindling

Somewhere out over the North Sea I took off my jacket, leaned back, and sipped on my beer. My jacket has a nice big inside pocket and, if I take the cover of my kindle, it fits perfectly in the pocket. It’s a perfect fit. I mean, you wouldn’t know it was there …

A few days later I dug out my kindle and noticed the display was suffering from a split personality. The bottom half was telling me to switch it on, while the top half was still showing three little birds, outside my window, singing a sweet song. Oh dear. After a visit to the University of Google it became apparent to me that this problem is not uncommon. Weird, but not uncommon. Weird because you can run your finger across the screen and feel nothing; no cracks no blemishes. But it’s clearly broke. It may be silky smooth on the outside but it hides a shattered interior.

The forums on Amazon buzz with feel-good stories of customers phoning Amazon and getting great trade-in deals on their ‘just out of warranty’ kindles. My Kindle was not just out of warranty, it was exceedingly, comfortably and generously out of warranty, and had been for a couple of years. Still worth a try …

Well that didn’t go anywhere useful. Nice chap all the same, and together across the ether we visited the Amazon website where we discussed the nice shiny new kindles and he advised me that I could ‘buy’ one, at the price shown. Apparently bears also go to the bathroom in the woods. Ok, let’s go to ebay.

Aha … Now we’re cooking … This looks just the chap. A couple of days later a huge ball of bubble-wrap arrives at work, and somewhere inside, is a shiny new kindle screen. And there’s even a link to their Youtube video, yeah, well whatever. Why watch a youtube video when it’s NELUG night, and, well, you can run linux on a kindle can’t you? Apparently.

Durham - kindle - nelug -- Tue 19 Mar 2013 21-23-04 GMT_640x480

Richard takes the kindle to bits

That evening I turned up with a broken kindle, a new screen, and a random selection of small screwdrivers. I dumped them on the table and headed for the bar. A few minutes later I returned with my drink to find surgery was already underway. In the time it takes to say “a pint of Black Sheep please” Richard had prised open the cover, removed the battery, and was poking at various bits of the kindle’s anatomy with professional interest.

I made a perfunctory pretense of watching the instruction video on youtube but the Nelug hive mind was working quite well without it. With the new screen fitted re-assembly was, as they say, simply the reverse of disassembly. I stuck to the Black Sheep while Richard stuck to the screwdriver and, despite some frisky screws that had decided to go for a wander and wanted to live somewhere else for a while, it all ended well.

Mission Accomplished

The broken screen on the left with the repaired Kindle on the right

LUG meeting report, 18 September 2012

Much fun was had learning about the difference between BIOS and UEFI booting, with the help of a Fedora 17 live USB: booting a BIOS system with this gives you syslinux, but a UEFI laptop loaded GRUB with a broken set of configurations. A few internet searches told us this was a known problem, and we were able to fix the UEFI booting.

We also spent some time diagnosing CUPS and wireless driver problems, and discussing the implications of Google’s recent announcement that is supporting OAuth 2.0 authentication for several of its APIs.

A Brief Introduction To Regular Expressions

What is a Regular Expression?

Purpose

A regular expression is a flexible way of defining patterns of text. It is a formal language which is interpreted by a regular expression engine (which might be part of an application or a programming language) that parses input text and compares it to the regular expression, and then performs operations on text that matches the regular expression.

Common uses of regular expressions include:

  • Matching text
  • Substituting text
  • Extracting text

Syntax

The basic syntax of a regular expression is /pattern/flags. The main part is the text pattern description, and the flags control the behaviour of the regular expression engine.

Different regular expression engines support different features, and also slightly vary in their syntax. After a overview of general regexp syntax we will look at some common applications and languages and how they support regular expressions.

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Durham Linux User Group

We are in the process of updating this site… Apologies if the content you were looking for is no longer here… If you want to help, please get in touch.

You can join the mailing list by going to http://mailman.lug.org.uk/mailman/listinfo/durham

Meetings are held in Durham (In the bar at Durham Rowing Club – See the location page).

We meet on the 3rd Tuesday of every month, from around 19:30, until around 22:30

Book review: ‘Digital Audio Essentials: A Comprehensive Guide to Creating, Recording, Editing, and Sharing Music and Other Audio’

Book cover
Title: Digital Audio Essentials: A Comprehensive Guide to Creating, Recording, Editing, and Sharing Music and Other Audio
Author: Bruce Fries, Marty Fries
Price: £24.95
Publisher: O’Reilly
Published: May 2005
Reviewed by: Dougie Nisbet
Review date: October 2006
Rating: 4/5

Overview

This book presents itself an interesting challenge in that it attempts to present a comprehensive guide to digital audio in a book that isn’t the size of a brick. The authors do this successfully and the book is a worthwhile read. Continue reading

Book review: ’802.11 Wireless Networks: The Definitive Guide (Second Edition)’

Book cover
Title: 802.11 Wireless Networks: The Definitive Guide (Second Edition)
Author: Matthew S. Gast
Price: £31.95
Publisher: O’Reilly
Published: April 2005
Reviewed by: Martin Ward
Review Date: December 2005
Rating: 5/5

Calling your book “The Definitive Guide” sets the bar high at the start, and Gast does well to live up to his title and provide virtually everything you need to know about 802.11 networking.

If you are a wardriver looking for plans to make antennae out of Pringles cans, then you won’t find them here (but they are readily available on the Internet!) If you need to set up a wireless network of any size, or are just curious about how they actually work, then this is the book for you. Continue reading

Net booting a diskless Sun3 from a Linux server

My system consists of a Linux server (basically Slackware-3.6 but with kernel 2.2.10 and various other irrelevant package upgrades) and 2 Sun3′s, only one of which is ever in use at any given time (thus they use the same swap partition on the server – later).

The Sun3′s are diskless and hence boot from the Linux box, and mount all filesystems from it. The Sun’s run NetBSD 1.3.2 largely because the Sun 3 port of Linux was not very stable or mature when I set things up.
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Linux firewalls

Linux Firewalls

What is a firewall?

  • A firewall is a controlled gateway between one network and another (i.e. an intranet and the internet).
  • It is not a universal panacea for computer security. You must follow other good security practices.

Why Firewalls?

  • You cannot trust everyone. Some people take pleasure in hacking into machines. Not all are malicious but some are!
  • Your computer holds private/confidential data an you have a duty to protect it.
  • You want to limit access from within your private network to specific external information/services (i.e. not mpeg3′s)
  • You want to monitor/record traffic for audit/security purposes. Beware of privacy laws!

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Configuring Email Systems

NELUG, 7/6/2000

Eddy Younger (eddy@shofar.uklinux.net)

Software Components of the Email System

There are principally three classes of software components involved in transfering a mail message from the sender to the recipient:

  1. MUA – mail user agent, used to read, compose and post mail.
  2. MTA – mail transport agent. MTA’s at the source and destination hosts (and possibly also intermediate hosts) pass the messages from one to another
  3. MDA – mail delivery agent. At the ultimate destination host, the MDA receives the message from the local MTA and delivers it to its ultimate destination, usually the recipient’s mailbox file.

In the modern world almost all email transport is achieved using SMTP – the Simple Mail Transport Protocol – or its Extended variant ESMTP. MTA’s speak to each other in (E)SMTP. You can send mail without using a MUA if you wanted to, by talking SMTP directly to the MTA, and it used to be possible to do all kinds of nefarious things by doing so, though thankfully most mail servers are much more secure in these days of Skript Kiddies and Spam.

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