- wlug - list.wlug.org.nz

SSH -> getting the originating IP of a client using RDP
by Eric Light 24 Jul '15

24 Jul '15

Hey all This is a total edge case, but I thought it may be interesting to some. We have thin clients, which RDP to a Windows Terminal Server, through which users SSH (using PuTTY) into our Linux server. This isn't flexible (for good reasons which I won't go into here). However, to talk properly to our new EFTPOS units, we need to know the IP of the thin client. Of course, through SSH you only get the IP of the client, which is the Terminal Server. Here's how I fixed it: 1) Add the following line to /etc/ssh/sshd_config, and restarted ssh: * AcceptEnv CLIENTNAME* 2) Added the following to the Windows login script: * REG ADD HKCU\Software\SimonTatham\PuTTY\Sessions\DG\ /v Environment /d "CLIENTNAME="%CLIENTNAME% /f* 3) Result: * ~ $ env | grep CLIENTNAME CLIENTNAME=eric-lmde* >From there, we can do what we needed with the EFTPOS! Eric -------------------------------------------- Q: Why is this email five sentences or less? A: http://five.sentenc.es

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Troubleshooting Over The Phone
by Lawrence D'Oliveiro 23 Jul '15

23 Jul '15

I just helped someone unbork their Ubuntu system over the phone. It was reporting “disk full”, without being more specific than that. I got him to open up a terminal window, and use the “df” and “du” commands to narrow down the directory that was filling up the disk. Sometimes /tmp gets filled up with stuff, but in this case it was /var/lib/apt/lists/partial/. I have had an instance of high disk usage on that directory myself, a while back. I think it’s where apt keeps partially-downloaded repo index files, though I’m not sure why—is it to retry downloading the rest? But when the problem hits, it just seems to fill up with failed downloads. So I carefully led him up to executing the command “sudo rm /var/lib/apt/lists/partial/*”, and that cleared the problem. The main thing I was careful with was spelling out the commands phonetically, and getting him to read them back to me. But imagine having to do this with a GUI, over the phone. I don’t think I would even try...

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Why Debian Returned To FFmpeg
by Lawrence D'Oliveiro 23 Jul '15

23 Jul '15

<http://lwn.net/Articles/650816/> What impresses me about this is, even though the Debian package maintainer is also a libav developer, he “...in the end, could not bring himself to say that he was sure libav was the better choice.” With regard to the commit statistics, it seems like much of the activity in FFmpeg commits is wholesale copying of code from libav. But so what? If sticking with FFmpeg gives you the best of both worlds, why bother separately including packages for libav at all?

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meeting next Monday
by Peter Reutemann 22 Jul '15

22 Jul '15

Hi everyone We have a WLUG meeting coming up next Monday: "Ian Stewart will talk about the Linux Terminal Server Project (LTSP) and how to connect to it using thin clients and Raspberry Pi. Peter Reutemann will give the new Linux Mint release a quick spin." Details can be found here: http://www.meetup.com/WaikatoLinuxUsersGroup/events/223850397 Cheers, Peter -- Peter Reutemann Dept. of Computer Science University of Waikato, NZ +64 (7) 858-5174 http://www.cms.waikato.ac.nz/~fracpete/ http://www.data-mining.co.nz/

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On Being Pro-GPL
by Peter Reutemann 22 Jul '15

22 Jul '15

'Christopher Allan Webber, recently returned from OSCON, shares his thoughts on the GPL and why he dislikes people pitting one type of software license against another. He says, "I am not only pro-copyleft, I am also pro-permissive licensing. The difference between these is tactics: the first tactic is towards guaranteeing user freedom, the second tactic is toward pushing adoption. I am generally pro-freedom, but sometimes pushing adoption is important, especially if you're pushing standards and the like. But let's step back for a moment. One thing that's true is that over the last many years we've seen an explosion of free and open source software... at the same time that computers have become more locked down than ever before! How can this be? And notice... the rise of the arguments for permissive/lax licensing have grown simultaneously with this trend. ...The fastest way to develop software which locks down users for maximum monetary extraction is to use free software as a base. And this is where the anti-copyleft argument comes in, because copyleft may effectively force an entity to give back at this stage... and they might not want to. ... Copyleft's strings say, 'you can use my stuff, as long as you give back what you make from it.' But the proprietary differentiation strategy's strings say, 'I will use your stuff, and then add terms which forbid you to ever share or modify the things I build on top of it.' Don't be fooled: both attach strings. But which strings are worse?"' -- source: http://news.slashdot.org/story/15/07/21/2256243 Personally, I'm a pro-GPL person. Simply because I don't like software getting locked down and nothing flowing back to the community. Especially, when open source is so community centred. Cheers, Peter -- Peter Reutemann Dept. of Computer Science University of Waikato, NZ +64 (7) 858-5174 http://www.cms.waikato.ac.nz/~fracpete/ http://www.data-mining.co.nz/

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Open Document Format 1.2 Becomes ISO/IEC Standard
by Lawrence D'Oliveiro 21 Jul '15

21 Jul '15

Only four years after its creation, ODF 1.2, the native format for the current version of LibreOffice, has been officially accepted as ISO/IEC standard 26300:2015 <https://blog.documentfoundation.org/2015/07/17/open-document-format-odf-1-2…>. By the way, if you try downloading the specs from the links on that page, you will be confronted by copyright warnings forcing you to click an “accept” button. You can get the same thing from here <http://www.oasis-open.org/committees/tc_home.php?wg_abbrev=office#technical> without the nonsense.

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Fwd: Re: Customs Minister Wants Right To Demand Passwords From Device Users
by Chris O'Halloran 20 Jul '15

20 Jul '15

On Tue, 14 Jul 2015 12:59:12 +1200, Lawrence D'Oliveiro <ldo(a)geek-central.gen.nz> wrote: > I would say this relevant to everybody in New Zealand or visiting New > Zealand, Linux user or not. > > “Powers that would require a person to provide a password or access > to > their electronic device will be useless if their material is instead > stored online, Customs Minister Nicky Wagner admits. It's interesting in the sense that normally you're not obliged to say anything that might incriminate yourself. David Bain didn't have to give his version of events.

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Customs Minister Wants Right To Demand Passwords From Device Users
by Lawrence D'Oliveiro 19 Jul '15

19 Jul '15

I would say this relevant to everybody in New Zealand or visiting New Zealand, Linux user or not. “Powers that would require a person to provide a password or access to their electronic device will be useless if their material is instead stored online, Customs Minister Nicky Wagner admits. However, Ms Wagner insists such a change to legislation is necessary and will still enable Customs to catch people with illegal material.” <http://www.nzherald.co.nz/politics/news/article.cfm?c_id=280&objectid=11480…>

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ARM Support Comes To SUSE Linux Enterprise Server
by Peter Reutemann 16 Jul '15

16 Jul '15

"SUSE announced partner program expansion to include support for 64-bit ARM server processors. This expansion makes available to partners a version of SUSE Linux Enterprise 12 that allows them to develop, test and deliver products to the market using 64-bit ARM chips. To simplify partner access, SUSE has also implemented support for ARM and AArch64 into its openSUSE Build Service. This allows the community to build packages against real 64-bit ARM hardware and the SUSE Linux Enterprise 12 binaries." -- source: http://linux.slashdot.org/story/15/07/15/1720216 Cheers, Peter -- Peter Reutemann Dept. of Computer Science University of Waikato, NZ +64 (7) 858-5174 http://www.cms.waikato.ac.nz/~fracpete/ http://www.data-mining.co.nz/

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What the GNOME Desktop Gets Right and KDE Gets Wrong
by Peter Reutemann 14 Jul '15

14 Jul '15

'Eric Griffith at Phoronix has provided a fresh perspective on the KDE vs. GNOME desktop debate after exclusively using GNOME for the past week while being a longtime KDE user. He concluded his five-page editorial (which raises some valid points throughout) by saying, "Gnome feels like a product. It feels like a singular experience. When you use it, it feels like it is complete and that everything you need is at your fingertips. It feels like the Linux desktop. ... In KDE, it's just some random-looking window popup that any application could have created. ... KDE doesn't feel like cohesive experience. KDE doesn't feel like it has a direction its moving in, it doesn't feel like a full experience. KDE feels like its a bunch of pieces that are moving in a bunch of different directions, that just happen to have a shared toolkit beneath them." However, with the week over and despite his criticism, he's back to using KDE.' -- source: http://tech.slashdot.org/story/15/07/13/1548237 Cheers, Peter -- Peter Reutemann Dept. of Computer Science University of Waikato, NZ +64 (7) 858-5174 http://www.cms.waikato.ac.nz/~fracpete/ http://www.data-mining.co.nz/

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Speed-Ups, Small Fixes Earn Good Marks From Ars For Mint 17.2
by Peter Reutemann 13 Jul '15

13 Jul '15

'Ars Technica reviews the newest release from Linux MInt -- version 17.2, offered with either the Cinnamon desktop, or the lighter-weight MATE, which feels like what Gnome 2 might feel in an alternate universe where Gnome 3 never happened. Reviewer Scott Gilbertson has mostly good things to say about either variety, and notes a few small drawbacks, too. The nits seem to be minor ones, though they might bite some people more than others: Mint, based on Ubuntu deep down, is almost perfectly compatible with Ubuntu packages, but not every one, and this newest version of Mint ships with the 3.16 kernel of Ubuntu 14.04, which means slightly less advanced hardware support. (Gilbertson notes, though, that going with 3.16 means Mint may be the ideal distro if you want to avoid systemd.) "This release sees the Cinnamon developers focusing on some of what are sometimes call "paper cut" fixes, which just means there's been a lot of attention to the details, particularly the small, but annoying problems. For example, this release adds a new panel applet called "inhibit" which temporarily bans all notifications. It also turns off screen locking and stops any auto dimming you have set up, making it a great tool for when you want to watch a video or play a game." More "paper cut" fixes include improved multi-panel options, graphics-refresh tweaks, a way to restart the Cinnamon desktop without killing the contents of a session, graphics-refresh tweaks, and other speed-ups that make this release "noticeably snappier than its predecessor on the same hardware."' -- source: http://linux.slashdot.org/story/15/07/12/1720236 Cheers, Peter -- Peter Reutemann Dept. of Computer Science University of Waikato, NZ +64 (7) 858-5174 http://www.cms.waikato.ac.nz/~fracpete/ http://www.data-mining.co.nz/

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Question - ping -f
by Eric Light 13 Jul '15

13 Jul '15

Hi guys I'm investigating a flaky printer, and was running ping -f to see when it went down. I got the following: PING prn37.forlongs.local (10.7.140.37) 56(84) bytes of data. ..................................................... ..................................................... ..................................................... .......E............................................. ... what the heck is the 'E'? I can't find it in the man pages. Eric -------------------------------------------- Q: Why is this email five sentences or less? A: http://five.sentenc.es

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Automatically enabling numlock in an X11 session, *without* a window manager
by Eric Light 12 Jul '15

12 Jul '15

I just spent a whole day on this, so I wanted to share it with some people who would understand the struggle. -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- The Scenario:You have some remote users who need to securely access your application, delivered in plaintext over SSH. To do this, they get a thin client delivered to them, fully set up. However, most of these users have very limited computer knowledge, so they need the application to be as simple and responsive as possible. The Solution: The thin client needn’t have Windows on it. Also Windows is slow (wimpy thin clients), prone to fickleness (“have you tried turning it off and on again?”), and insecure (no antivirus or even security updates are installed on the thin clients). In fact, these users are so limited they shouldn’t even have a window manager at all. No need to resize, copy & paste, or multitask – a single application window would be ample. So let’s install just a plain edition of Debian, then run sudo apt-get install xinit, to get the barest of essential graphical libraries. The Challenge: Set up our thin clients, based on a Linux install, such that it boots quietly and quickly, automatically logs in as the user, waits for the network, and launches a Putty window. When the user quits Putty, they should only have two options: launch a new Putty session, or shutdown the computer. The Yak: Because there’s no window manager, every Putty window is launched in its’ own session. A new X11 session has number lock disabled by default. The standard answer for controlling numlock, a program named “numlockx”, works just fine – however, because there’s no window manager, you can only send a single command to the X11 session. Thus, you can *either* turn on NumLock, *or *you can launch Putty. Shaving the Yak: 1) Create the file ~/putty This file contains the lines: numlockx on & putty -load {your saved session} 2) Launch the file with: xinit ~/putty $* -- The End: Now you can set up your silent boot (/etc/sysctl.conf -> kernel.printk), your automatic login (/etc/system/system/getty(a)tty1.service.d/autologin.conf), and your auto-start locked-down profile (~/.profile) with other tutorials available on the internet. (PS they boot in about ten seconds, and our guinea pig testers love them) Eric

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Quote Of The Week
by Lawrence D'Oliveiro 11 Jul '15

11 Jul '15

“I have the greatest respect for mathematicians, but we need a national conversation about their claims about the division by zero problem.” -- Matt Blaze >From this report <http://www.theregister.co.uk/2015/07/08/crap_crypto_enforcement_laws_coming…> on how various sectors of the US Government seem intent on re-fighting the “crypto wars” of the 1990s. Tip to those in power: the laws of nature haven’t changed since then. (And if it isn’t clear, Matt Blaze is one of those who is fully aware of that!)

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Customizing The Compose Key
by Lawrence D'Oliveiro 09 Jul '15

09 Jul '15

The Compose key <http://wiki.wlug.org.nz/ComposeKey> is probably the best way of typing less common characters available on any OS. It lets you use mnemonic sequences that actually bear some relationship to the character you are trying to enter, instead of having to remember numeric codes. You will find there a list of the characters that I found most useful, though the complete set will be in the Compose file for your chosen locale. You can even add your own compose sequences. This tutorial for KDE <https://userbase.kde.org/Tutorials/ComposeKey/en> covers the procedure. Basically, you create a file “.XCompose” in your home directory, include a system Compose file to inherit the standard sequences, and put in extra compose-key definitions using the same syntax as the system Compose files. I had got this far, but then was baffled as to why KDE seemed to pay no attention whatsoever to my custom compose-key sequences. It turns out you need to define additional environment variables to get Qt/KDE- and GTK-based apps to use the X11 input method that actually reads the .XCompose file. Put these in your .bashrc: export GTK_IM_MODULE=xim export QT_IM_MODULE=xim and when you logout and login again, it should all work. For example, in my .XCompose, I have the line <Multi_key> <p> <i> which lets me type compose-p-i to produce “π”.

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Ah, The Memories...
by Lawrence D'Oliveiro 09 Jul '15

09 Jul '15

In the wake of the latest round of Microsoft’s layoffs, it seems apropos to remember the time they held a mock funeral for their competition at the time of the Windows Phone 7 launch: <http://appleinsider.com/articles/10/09/10/microsoft_employees_hold_funeral_…>. “Research firm Gartner predicted ... Nokia Symbian and Google Android [would be] first and second with 30.2 percent and 29.6 percent [market share] respectively [in 2014].” Did anybody notice any Symbian phones still on sale? Android had more like 80%...

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Debian To Switch From Libav Back To ffmpeg
by Lawrence D'Oliveiro 09 Jul '15

09 Jul '15

I’ve been using FFmpeg for years. I always built it from source, because I was aware that prebuilt distro packages were 1) well behind the latest development tree, and 2) likely to leave out features because of patent issues. So I hardly noticed the whole Libav fork issue <https://lwn.net/Articles/433347/>. I was dimly aware that my Debian system had these “libav” packages on it, that looked and behaved just like FFmpeg in everything but name. But I hardly ever used them—not directly. Then, last year, I found out a bit more about what really happened <https://lwn.net/Articles/607591/>, and why Debian went with the fork. Can you say “conflict of interest”? (Well, that’s how it looks like to me.) So now, Debian has officially decided to return to the original FFmpeg project <http://lwn.net/Articles/650495/>.

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your dishwasher is starting to discuss Sartre with you
by Ian Young 08 Jul '15

08 Jul '15

OK, vague relevance but it is Linus speaking, my excuse. http://www.theinquirer.net/inquirer/news/2416607/linux-founder-says-you-mus…

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BBC Micro Bit
by Ian Young 07 Jul '15

07 Jul '15

Stop me if you already are fully briefed on this -- I'd never heard of it. http://www.bbc.com/news/technology-33409311

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Amazon's New SSL/TLS Implementation In 6,000 Lines of Code
by Peter Reutemann 01 Jul '15

01 Jul '15

'Amazon has announced a new library called "s2n," an open source implementation of SSL/TLS, the cryptographic security protocols behind HTTPS, SSH, SFTP, secure SMTP, and many others. Weighing in at about 6k lines of code, it's just a little more than 1% the size of OpenSSL, which is really good news in terms of security auditing and testing. OpenSSL isn't going away, and Amazon has made clear that they will continue to support it. Notably, s2n does not provide all the additional cryptographic functions that OpenSSL provides in libcrypto, it only provides the SSL/TLS functions. Further more, it implements a relatively small subset of SSL/TLS features compared to OpenSSL.' -- source: http://it.slashdot.org/story/15/07/01/0214248 Cheers, Peter -- Peter Reutemann Dept. of Computer Science University of Waikato, NZ +64 (7) 858-5174 http://www.cms.waikato.ac.nz/~fracpete/ http://www.data-mining.co.nz/

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GMT Versus UTC
by Lawrence D'Oliveiro 01 Jul '15

01 Jul '15

It still seems to be common among groups outside the computing and scientific worlds to talk about “GMT” rather than “UTC”. The trouble with “GMT” is that it doesn’t seem to be clearly defined; it might or might not differ from UTC by up to 0.9 seconds. The (unadjusted) time reference defined by an official collection of atomic clocks worldwide is called “TAI”. This pays no heed to the slowing rotation of the Earth. Astronomers prefer a time reference called “UT1”, which is based on the actual rotation of the Earth (subject to some time-averaging, I think). The definition of “UTC” comes from TAI, adjusted by applying leap seconds. These accumulate as needed so as to keep UTC within 0.9 seconds of UT1, and we are currently up to 36 of them. That is, at 0:00:00 UTC today, TAI was actually 0:00:36. The trouble with GMT is that it is not officially clear whether it is the same as UT1, or the same as UTC. Given that it was originally defined at the Greenwich Observatory, which was (is?) run by astronomers, one would think they would make it the same as UT1. But the practical fact is, our usual everyday timekeeping is based on standard time zones, which are all defined as whole-second (indeed, whole multiples of a half-hour) offsets from UTC.

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How Long Can A Filename Be?
by Lawrence D'Oliveiro 01 Jul '15

01 Jul '15

Allowed length of an individual file/directory name: ldo(a)theon:~> getconf NAME_MAX / 255 Allowed length of a full path name: ldo(a)theon:~> getconf PATH_MAX / 4096 The answers can be filesystem-specific; here “/” is an ext3 filesystem. But on my /home, which is ext4, I get the same numbers.

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Reuters: Samsung won’t give up on Tizen OS, plans more phones this year
by Peter Reutemann 01 Jul '15

01 Jul '15

'Samsung still loves its home-grown operating system. A report from Reuters says the company is planning more Tizen phones for 2015, and they'll come in at "varying prices."' -- source: http://arstechnica.com/gadgets/2015/06/reuters-samsung-wont-give-up-on-tize… Cheers, Peter -- Peter Reutemann Dept. of Computer Science University of Waikato, NZ +64 (7) 858-5174 http://www.cms.waikato.ac.nz/~fracpete/ http://www.data-mining.co.nz/

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So How Did Your Leap-Second Go?
by Lawrence D'Oliveiro 01 Jul '15

01 Jul '15

At noon today NZ time, an extra second was inserted into UTC, the time kept by the world’s atomic clocks. The time that was one second before midnight UTC (one second before noon NZST) became two seconds before intead: after 23:59:59 UTC came 23:59:60 UTC, before ticking over to 0:00:00 UTC. The previous time this happened, three years ago, several Linux-based systems malfunctioned. No word yet on how this one went... <http://lwn.net/Articles/648313/>

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Doing For Video What PulseAudio Did For Audio
by Lawrence D'Oliveiro 01 Jul '15

01 Jul '15

Pinos is a project to allow better handling of video input across multiple applications. Pinos will make it easier to switch cameras in applications and for the same camera source to be used by multiple apps simultaneously, there will be support for multiple types of video inputs, GStreamer integration, and some audio support. Pinos should allow better screencasting within GNOME 3, video support for desktop sandboxes, and many other potential use-cases. In an email, Christian mentioned why it didn't end up being called PulseVideo over name squatting. <http://phoronix.com/scan.php?page=news_item&px=Fedora-Pinos-Announced>

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