LJ Archive CD

Letters

May 2011 Cover

My manga reading/drawing daughter saw the cover of the May 2011 issue of LJ and asked me why there was manga on it. I told her, “Linux is just cool like that!” Then, she asked if there was an article about manga in the magazine. I told her about past issues covering Blender, GIMP and so on, which prompted a discussion about the great open-source software she uses every day.

Thanks for the great cover!


Eric Miller

That's awesome! It's great when things like cover art can make Linux relevant for people who otherwise might not care.—Ed.

Utility I Wrote (Open Source, of Course)

I'm a longtime reader and fan of LJ, and I thought you might be interested in a tool I wrote for system admins and developers named chip. It's basically a logfile multiplexer and monitor: https://github.com/katzgrau/chip.

I remember you wrote about swatch (www.linuxjournal.com/article/4776), and chip basically does what swatch does, but additionally, it can do it on multiple remote files. That becomes super handy when you want to monitor multiple production logs on hosts behind a load balancer. You don't have to set up handlers like swatch, and you also can just use chip to see of all of your logs like a pimped version of tail.

I've used it here at Yahoo pretty frequently during the past month for deployments and bug investigations.

Here's a blog post, if you're interested: codefury.net/2011/04/video-chip-a-log-file-monitor-multiplexer.


Kenny Katzgrau

Thanks Kenny. Sharing tools is one of the things that makes the Open Source community so great. I appreciate you sharing with us!—Ed.

Receiving Digital TV Signals, No Longer Analog Signals

Regarding the new digital TV world: I am receiving three stations via digital signal on my digital-to-analog-converter TV, with my outdoor antenna. Two other stations, in the same area, hardly come in at all. The first group transmits at 1MW power; the other group transmits at only 0.25MW power. My signal strength meter seems consistent with these numbers (above). My question is, why is hardly anything written on the transmit power of the sending stations? Why do some “stations” get to transmit at 1MW, while others can transmit only at one-fourth of this? All the complaints about digital TV signals abound, but nobody ever seems to mention the power used by the sending stations to send their signals. I believe this has to be the main reason for fair-to-bad TV receptions of digital signals, not all the malarkey you read—for example, airplanes, leaves, slight temperature changes and so on. I get better reception in cold, cloudy, rainy weather than on “nice days”! And, I live more than 60 miles from the transmitters of these five stations. Who decides who gets what MWs?


R. E. Mackey

I didn't know the answer to this, so I called a friend of mine who manages local low-power television stations. His understanding of the situation is that the FCC dictates to broadcasters the power at which they can transmit based on several technical factors. Those factors include things like terrain, desired broadcast coverage, distance from other broadcasts running on close frequencies and so on. In fact, the FCC sometimes will dictate that the signal can't be broadcasted omnidirectional. I'm close to the Canadian border, and some stations are not allowed to broadcast toward Canada.

Before researching, my guess was that broadcast power was based on fees paid to the FCC. As it turns out, that's not the case. The fees do vary widely based on location, however, and usually frequencies are auctioned off to the highest bidder.

Finally, you might want to check out www.antennaweb.org. It offers some great tools to help you get the best possible reception.—Ed.

777 Permissions

While reading the article titled “Numeric Relativity” by Joey Bernard on page 14 of the May 2011 issue, I was a little disappointed to notice that the instructions for installing the Einstein Toolkit contain a chmod 777. Being a systems administrator, this made my eye twitch a bit. The world write bit should be used only under rare circumstances. In fact, I would argue that it should be used only for common storage locations, such as /tmp, and even then, it should be accompanied by the sticky bit (that is, 1777). In most cases, 700 or 755 permissions are most appropriate.


Elliott Forney

Sky Survey Using Linux

There's an incredible survey of the entire night sky, using a laptop powered by Fedora Linux, and I thought Linux Journal readers may be interested: skysurvey.org.


Jim Gagnon

How cool! Thanks for the link.—Shawn, the space nut.

Linux to the Rescue!

Situation: 1998-vintage Compaq small-form-factor desktop (Pentium-II 400MHz) running Fedora Core 5 as a home firewall/DHCP/DNS server. After a power failure, it refuses even to POST. The lights come on, but nobody's home. I'd buy a used Dell SFF system to replace it, but I'm looking at several hours of work to install and configure with Fedora 14. There goes my evening plans, sigh.

Brilliant idea: move the old hard disk to the new system and see what happens, but I'm quite skeptical based on my experiences with Windows and changing out hardware.

Result: it boots! It works! Nary a hiccup. I'm back in business in 15 minutes. I got my evening back, thanks to Linux.


Jim Garrison

I feel obliged to recommend a system upgrade, as FC5 reached end of life back in 2007. I also feel obliged to note how awesome it is that a system running FC5 still is running well! And, you gotta love Linux. It makes most hardware, “just work”.—Ed.

It Starts with the Kids

A few years ago, I read a book called The Culture Code by Clotaire Rapaille. One concept that he explained intrigued me. He described how in the 1970s, Japan's consumption of coffee was 0%. If you were to go to a restaurant and ask for coffee, it was not on the menu. How do you impose a new beverage into a nation that does not have coffee in its vocabulary? You start by making candies infused with coffee flavor. Who eats these candies? Children. This is exactly what was done. They whet a generation's appetite with caffeine, and in around the year 2000, coffee accounted for billions and billions of Japan's GDP. What is my point? Next paragraph.

Last month, I was honored with the opportunity to expose home-schooling parents to a presentation on “Free Software to Augment your Child's Learning”. In this presentation, I attempted to cover various open-source projects as well as operating systems that are freely available to everyone. If we start to infuse the idea of Linux and open source in the conscience of the generation coming after us, maybe, just maybe, Linux would be synonymously in the minds of people when they say “PC”, instead of the other OSes available. I've started with the home-schooling community in Ontario, Canada. What “Baby Penguins” are you going to target?


Dean Anderson

You're totally preaching to the choir here, as I've been pushing Linux in education for more than a decade. (I am the Technology Director for a school district in Michigan.) I didn't know about Japan and coffee, but it's a great story and encouraging for those of us in the trenches. I do hope the next generation “gets it” when it comes to the advantages Linux and open source can provide. Great job!—Ed.

Dropbox

I received the June 2011 issue of LJ today, and as usual, I proceeded to read it cover to cover on the day it arrived. I immediately noticed your article on Dropbox, as it is an integral part of my daily toolkit.

For my part, I find one of the key uses of Dropbox is to turn regular desktop applications into Web-synchronized applications. As many LJ readers do, I work across different laptops and desktops, but I would like to keep some key apps immediately available, with the same data, no matter where I am working, such as time-tracking and my to-do list. There are many Web-based solutions for this, but I found a couple client applications I prefer to use for their feature sets.

For time-tracking, I use Klok 2 (www.getklok.com), and for task lists, I use Task Coach (www.taskcoach.org). By moving the data files for these applications into Dropbox, I immediately have my time-tracking and to-do lists synchronized across all my working environments. Thanks Dropbox for the synchronizing feature, and thanks to the Linux Journal team for a great publication.


Randy Earl

I use Dropbox in a similar way as well! I find it works great to sync Pidgin preferences, so I don't need to enter all my account information on each computer I use. I also keep my desktop background photos (all space photos from NASA) in sync, so they are available on every computer. Syncing is awesome technology, and I really look forward to open-source tools maturing to the point that they rival Dropbox's abilities.—Ed.

LJ Archive CD