Readers sound off.


Better Method of Last Resort

There is a better “method of last resort” than the one mentioned in Kyle Rankin's excellent article in the March 2009 issue titled, “When Disaster Strikes: Hard Drive Crashes”.

If you can't mount a ddrescue image, but need to retrieve documents, photographs, PDF files and so on, you can use a nifty program called foremost. It is available for most *nix platforms, and on Windoze via cygwin. foremost scans through a hard drive image, mountable or not, and looks for recognizable file headers. It understands more than 20 popular file headers, including jpg, pdf, doc, xml and so on. When it finds these files, it dumps them out as usable files. It is truly a thing of beauty. The first time you use it, you will just sit back in amazement. For example, if you have a hard drive image named my_hd_image.dd that was made with one of the dd utilities, you could execute the following command:

~$  foremost -t all -i my_hd_image.dd

After the command executes, a subdirectory will be created that has all of the recovered files, organized neatly by file type. On Ubuntu, you can get foremost by typing:

~$  sudo apt-get install foremost

This tool is also excellent for recovering deleted files from USB drives and more. Enjoy! Love your magazine!


Wow, great tip. Thanks!—Ed.

Cool Project

I wanted to put in another plug for all the authors of LJ and say that you guys and gals do a bang-up job. I recently renewed my subscription, not for one but two years. It is the highlight of my month to find it in the mailbox.

Compliments aside, I have a neat suggestion. I have been scanning forums, journals and search engines for a way to utilize a laptop as a more-or-less standalone DVD player for our vehicle. I know that the logical thing to do would be to use the laptop as a laptop, but I am wanting to get a little more “geeky” and see if I could ceiling-mount something like a 12" unit, link it into the car stereo system through an auxiliary channel and use it as a media server—and even get a wireless mouse/keyboard to “pimp up my ride” a little bit. The thing is, I would like it to be easy to use for my seven- and/or five-year-old and non-techy spouse.

Thanks again to all contributors. I appreciate your knowledge and philosophy.

Dean Anderson

Thanks for the compliments. Regarding your car-puter, um, AWESOME! That's a cool project if I've ever heard one. It might be worth investing in touchscreen technology and something like XBMC. Your kids would be able to manage things by tapping. (And, my wife just made it very clear to ME that I'm not allowed to try such a thing with our minivan, so you'll have to keep us posted.)—Ed.


Regarding the LJ Web article “What's the Tweeting Protocol?” by Doc Searls (www.linuxjournal.com/content/whats-tweeting-protocol), is LJ ever going to create a social blog for Linux users to come together and work on rallying up new users and clients for Linux as a better and more adaptable OS? Love the mag and its articles.

C Anaman

We always are interested in how best to take over the world. Unfortunately, we still haven't figured out the secret sauce for making it take off. Please don't hesitate to drop us suggestions; we're always open to ideas.—Ed.

Misery Loves Company

I work for an agency of the California State government. Our agency is going open source as much as possible. Our programmers even slap the GPL on everything they make at work. We have Linux servers and use MySQL, Apache and nginx, among other open-source applications. There's really only one major hurdle stopping us from putting Linux on the desktop: specialized applications. For example, there's an application that allows a judge to click on case characteristics, and the app then spits out everything the judge is supposed to tell the jury before the trial begins. The laws that govern what judges are supposed to tell juries change quarterly; therefore, we receive quarterly updates.

Unfortunately, like many of our other specialized applications, it doesn't work on Wine. There are no open-source or even commercial Linux programs that do the same thing.

I've thought of virtual machines, but that still requires us to purchase Windows licenses, as would dual-booting or terminal services/Citrix.

I am hoping that as Linux advocates and experts, you could suggest a strategy that would allow Linux on the desktop at our organization given our circumstances.

Toby Richards

I deal with this every day working at a school district. You're absolutely correct that a few proprietary applications are tough to deal with. So far, the best way I've managed to handle it is with a single Windows terminal server accessed remotely via rdesktop. You don't need to pay for the CAL for the Linux machine, but you still do need to pay for the server and TSCALs. I think, ultimately, the best hope will be as programmers continue to move their applications to Web-based alternatives. I think that will truly level the playing field on the desktop.

Thanks again for the question, and although I'm not much help, perhaps misery loves company.—Ed.

My Carbon Footprint Is Doing Just Fine, Thank You

In James Gray's “Go Green, Save Green with Linux” article in the April 2008 issue, and again in a response to that article in the April 2009 Letters section titled “Ouch!”, we continue to be misled into believing that carbon dioxide is a deadly poison. This is irresponsible journalism, or journalism without research to back up the statements. Carbon dioxide is, in fact, an essential ingredient to life on this planet. It produces oxygen that we breathe through a process called photosynthesis, and without carbon dioxide, we would suffocate. Additionally, the whole “carbon footprint” scam is simply a fraud designed by fear-mongers whose aim is to introduce a “carbon tax” against your “carbon footprint”; it's all the same scam as the global warming myth, and it's simply political fear mongering. If you research it, the carbon dioxide output from humans is miniscule compared to the carbon dioxide output from the earth itself. For us to believe that we are having an impact on global temperatures via our carbon dioxide output is absolutely absurd. Please, LJ, let's all stop perpetuating these myths. Don't get me wrong; I'm all for conservation of energy and all the benefits from that, but let's get our facts straight. Thanks.


James Gray replies: Thanks for writing. You are completely correct that carbon dioxide is essential to life on Earth. For the record, nowhere did I say that it is a deadly poison. However, I do contend that an imbalance of carbon dioxide in the atmosphere appears to have an effect on our global climate patterns. On one level, it is simple physics. Carbon dioxide is one of many greenhouse gases that trap heat in the lower atmosphere, enabling life to exist. Logically, if more carbon dioxide exists in the atmosphere—and we are filling it with around 30 gigatons of a gas every year—more heat will be trapped. However, this is not something I pulled out of a hat. It is called the Theory of Global Climate Change. To learn about the theory, I have read documents, such as the “Climate Change 2007: Synthesis Report” from the Intergovernmental Panel on Climate Change (IPCC). The IPCC, which recently won the Nobel Peace Prize for its work, summarizes the scientific findings of climatologists around the world. This report states: “Warming of the climate system is unequivocal, as is now evident from observations of increases in global air and ocean temperatures, widespread melting of snow, ice and rising average sea level.” Regarding causes, the report says: “Global GHG [greenhouse gas] emissions due to human activities have grown since pre-industrial times, with an increase of 70% between 1970 and 2004....Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic [that is, human-caused] GHG concentrations.” Read the full document at www.ipcc.ch/pdf/assessment-report/ar4/syr/ar4_syr_spm.pdf.

I'm curious how you've determined that a scientific theory—one supported by huge amounts of empirical data and having near unanimous consensus among climatologists—is a “myth”. Are you a climatologist who has collected his own data? Do you reject other scientific theories, such as plate tectonics, the Big Bang or relativity? Or do you just reject those that are inconvenient to you?

I periodically write about the Theory of Global Climate Change because I care about the planet I will leave to my descendants, and I am fascinated by the wonders of nature. I also will stridently advocate for a carbon tax, because such tools are the only effective way to change human behavior. I think that if you do your homework, you will find yourself on the same team—the one that is informed by today's best science and advocates for prevention today in order to avoid a future climate catastrophe.

Poor Little Nerd Boy

I have been watching your videos on YouTube for quite some time now, and I have become so interested in Linux, I have installed it on my PS3. (I know you're thinking, how can you be poor if you own a PS3? Well, the answer for that is my friend sold me his for $30, because he got a 360.) Anyway, I have sent you an e-mail because I really would like to get a fully functional Ubuntu Linux computer of some sort. I was wondering if you could send me one of your test laptops that you receive? My parents tell me that I should get a job to earn the money for one, but sadly, I am not old enough for a job, so I became desperate and have turned to you. I don't expect to be e-mailed back, but it would make my day if you would reply.


Sadly, we don't get to keep most of the products we review. That said, if a fully functional Linux machine is really something you want, it might be worth checking with the local schools or government buildings. Often, last year's models are either given away or sold for very good prices. If you draft a convincing letter to the right administrator at a local school district, you might be surprised with the response you get. Good luck!—Ed.

Keep On Keeping On

Today I got a letter saying that Dr. Dobbs, the other magazine I'm subscribed to, ceased as a standalone monthly magazine. I hope you're not planning to do the same. LJ is the main/only source of information I have on Linux, and I certainly would miss not receiving it anymore. Keep up the good work!


We certainly don't plan to go anywhere! If you now have more in your subscription budget, perhaps you could get a subscription to Linux Journal for someone else. (Shameless plug?) Also, don't forget to stop by our Web site. We have tons of additional content there as well.—Ed.


I'm right behind Fritz Mehner's desire [see the March 2009 Letters section] to make scripting more elegant and efficient wherever possible.

Fritz's letter drew my attention to a problem with the example for loop at the end of the Tech Tip referred to by him (LJ, December 2008, page 56), which needs the opposite treatment if scripted to avoid potential disaster. The problem is the “globbed” for statement, which will fail if the total length of matching filenames causes the expanded command line to exceed the shell's command-line buffer. Although that buffer is very large, it is finite (of the order of 10,000 bytes usually), and I've fixed more than one production script that had failed due to this defect.

The solution is to replace the first line of the loop:

for file in *; do
 data_source $file | ...

with one that uses the find utility to avoid shell expansion, as in the replacement loop below:

find . -maxdepth 1 -type f -print | while read file; do
 data_source $file | ...

I hope this helps someone avoid that otherwise inevitable call in the middle of the night.

Ross Johnson

Live CDs

In the Linux world, many things have been changing during the past few years. The boom that had started with Knoppix, a live CD that was easy to use and made it possible to learn about Linux and use it without being an expert, changed everything. Now there are hundreds of distributions, many of which can be used as live CDs. But, it became difficult to have a clear overview of all of them. Many are good, and some are specialized, such as GoboLinux (KDE, de/engl/mag/port). In GoboLinux, you don't need a package database, because the filesystem is the database; each program resides in its own directory. There's also OpenGEU (Enlightenment, Italian/English), openmamba (KDE, Italian/English, good for beginners), Puppy (JWM, manual, English, small, quick, easy to use, good on old and new hardware), SAM (Xfce, multilingual), SliTaz (JWM, English/French, extra small) and so on.

It's fascinating what can be offered by mini-distributions—they're fast, easy to install and extremely quick. DSL is well known in the Linux world, but there are more, such as Puppy, Feather, Slax and, last but not least, SliTaz, the smallest distribution I know of at the moment that includes programs like an Internet browser.

I think it would be a great idea to publish the strength of live CDs and show the developments, especially with the very small distributions that do a great job, and demonstrate that there are not only alternatives to Windows but also alternatives to the big ones like Sabayon, Mandriva, Ubuntu and SUSE.


Unfortunately, as Linux users, one of our biggest strengths is also one of our biggest weaknesses. As you've outlined, “Linux” for the end user doesn't come close to describing the desktop experience. We do try to cover a wide variety of distributions, but there are so many options, it's hard to cover everything equally. Be sure to check out our Web site as well (www.linuxjournal.com). It's another way to spread the attention around a bit.—Ed.

Photo of the Month

Have a photo you'd like to share with LJ readers? Send your submission to publisher@linuxjournal.com. If we run yours in the magazine, we'll send you a free T-shirt.

This was just a few of all the plush penguinistas at the Penguin exhibit shop at SeaWorld in San Diego. At least there is not a Window or Apple amongst them! Submitted by Curtis Vaughan.



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Climate change

petersk's picture

The fact remains that Linux Magazine probably shouldn't be a forum for the discussion... Especially since it's so controversal and politically charged:

The original article shouldn't have included the subject in the first place.

My Carbon Footprint is also just fine

indymaynard's picture

(Portions of this are copied from an already sent e-mail to a friend)

We read what other people put out and accepted it without question. Hence, the belief that people are causing the hole in the ozone. While we may have made a contribution to its depletion at one point in time, the chemicals that were purported to cause this were banned more than a decade ago. How would we explain a growing "hole"?


The fact is not only is it cyclical, but natural. Even if you read the Wikipedia link, it tells you this.


I include these links to the places where I have done some of my research, so trust me that it's not from a lack of research that I reach my conclusions. I research all of the time.

I've sent you this link before. It is a petition against the Kyoto agreement. Signed by over 31,000 scientists. They state that there is no real evidence to the global warming theory.


What kind of sense does that make?

And some other stories to read about the "melting" ice caps. By the way, that's also cyclical.





So you can see that I certainly have done my research on the matter. But there is plenty more out there to read.

(End previous research)

You cite one reference for your "proof". If that's all it takes, I may have run overboard. But the truth is that you have to dig deeper than what is predominantly pushed in popular media.

It's especially tough for someone who doesn't subscribe to a political party to survive in the GNU/Linux world. Everyone hates conservatives in the FOSS community. That's where I become an outcast, but I think that in the fight to become a major contender in the OS/Software community, we must realize that the fight is not about our political beliefs, but our intentions to push the importance of free software to the users of all operating systems so that we can open the minds of those people who are stuck with what is the "majority vote", or should I say, "the majority push."

On a side note, I tell everyone that I know to use Linux. I hope I don't have to explain that one any more. I believe in freedom. I also believe in usability. I believe that Linux encompasses all of that except for games and some drivers, though it has the potential to cover both of those aspects. I know several people who were impressed despite these facts.

What does the environment have to do with GNU/Linux? It doesn't matter in the long term of the GNU/Linux OS/software contributions and capabilities. VM environments feature ease of use and minimizing hardware requirements more than environmental concern placation.

Last side note; I recycle and turn off electronics and water when I'm not using them. I don't believe in waste, which is also why I eat all of my dinner. :) I love the earth and all it has to offer. I also believe that human progression is going to be more important than what we think the earth is going to suffer because of us. After all, the earth has survived for an estimated 4 billion years before us, and it is still here.