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1. SOLID STATE DRIVES vs ROTATIONAL MEDIA o 2 l More TFLOPS Fewer WATTS Microway delivers the fastest and greenest floating point throughput in history Enhanced GPU Computing with Tesla Fermi 480 Core NVIDIA Tesla Fermi GPUs deliver 1 2 TFLOP single precision amp 600 GFLOP double precision performance p New Tesla C2050 adds 3GB ECC protected memory New Tesla C2070 adds 6GB ECC protected memory Tesla Pre Configured Clusters with 52070 4 GPU servers p WhisperStation PSC with up to 4 Fermi GPUs OctoPuter with up to 8 Fermi GPUs and 144GB memory New Processors 12 Core AMD Opterons with quad channel DDR3 memory 8 Core Intel Xeons with quad channel DDR3 memory gt ms ad i Superior bandwidth with faster wider CPU memory busses Increased efficiency for memory bound floating point algorithms Configure your next Cluster today ww w microway com quickquote 508 746 7341 a 10 TFLOPS STOR QDR InfiniBand Switches and HCAs 4 45 TFLOPS 36 Port 40 Gb s Low Cost Fabrics Compact Scalable Modular Architecture Ideal for Building Expandable Clusters and Fabrics MPI Link Checker and InfiniScope Network Diagnostics FasTree 864 GB sec Achieve the Optimal Fabric Design for your Specific MPI Application with ProSim Fabric Simulator Now you can observe the real time communication coherenc
2. 5 marks of Intel Corporation or its subsidiaries in the United States and other countries VMware is a registered 77 7 trademark or trademark of VMware Inc in the United States and or other jurisdictions ss s i 4 fe 888 297 740 For terms and conditions please see www aberdeeninc com abpoly abterms htm 1034 72 ae ae gt www aberdeeninc com 1j034 d Current_Issue tar gz SHAWN POWERS The Mad Scientist Starter Kit here s something about the Cool Projects issue that always makes me think of science fiction In my youth used to tape electric motors to popsicle sticks to form makeshift propellers on fanciful airplanes Of course also used to make shocking devices from the ignition coils of old abandoned cars so it s not as if were terribly innocent in my tomfoolery This month although we don t have any stun guns to fend off bully attacks we do have some extremely fun and interesting projects bound to inspire those creative juices of youth Anton Borisov starts off the issue with an interview with Alberto Broggi Alberto is designing a car that will drive from Italy to China That may sound insignificant but it s important to realize I m being literal The car itse f will be driving from Italy to China The best my car does on its own is veer left of center if start to fall asleep Alberto is hoping to create computer systems to stop needless accidents
3. config Recall that using means that any variables set in the secondary file affect the current shell not a subshell The Source command does the same thing as the command Here s our script to experiment with this feature bin bash config our config file 26 august 2010 www linuxjournal com sigusr1 echo SIGUSR1 re reading config file config trap sigusrl USRI catch USR1 signal echo Daemon started Assigned PID is config read it first time while usr bin true do echo Target number number sleep 5 done trap USR1 reset to be elegant exit 8 We ll start with the configuration file containing number 5 then after 10 15 seconds change it to number 1 Until we send the actual USR1 signal however the script just plugs along without a clue that it has changed test2 sh Daemon started Assigned PID is 25843 Target number 5 Target number 5 Target number 5 Meanwhile in another window l ve already edited the file so type in this command kill USR1 25843 And here s what happens in the main script window SIGUSR1 re reading config file Target number 1 Target number 1 Cool eh hope this exploration of signal handling in shell scripts is useful actually learned quite a bit about advanced handling as researched the code here I m still a bit stymied about how to reset the output stream after catching a SIGTSTP but bet that some sh
4. 19 http 192 168 1 1 Management asp Figure 1 Firmware Upgrade Utility Now that you have installed your firmware on the router it s an appropriate time to focus your attention on the USB disk that will serve as the router s data store Connect the disk to your build workstation You re going to create two partitions on the disk one 64MB swap partition and one filesystem partition spanning the rest of the disk You can do this with the following parted commands parted dev sdX parted mklabel msdos parted mkpart primary 0 64 parted mkpart primary ext3 64 0 www linuxjournal com august 2010 57 ES parted quit mkswap dev sdX1 mkfs ext3 dev sdX2 Remember to replace the X in dev sdX with the correct letter for the newly connected drive on your system Finally create a direc tory skeleton as follows assuming mnt is an unused mountpoint mount dev sdX2 mnt mkdir p mnt Storage Music mnt home mnt mt daapd Now copy your music library to mnt Storage Music One final step remains before you turn your attention to your clients The final step on the router is the post install configura tion Connect the newly initialized disk the hub and the printer to your router and restart the router with the router connected to your build workstation but not yet connected to a public network Ensure that your workstation is configured to obtain an IP address using DHCP Once the router has finished st
5. KATHERINE DRUCKMAN COLUMNS FORGE REUVEN LERNER CouchDB Views Retrieve your CouchDB data using views and map reduce functions Last month s column was an initial look at CouchDB a non relational open source database server now sponsored by the Apache Software Foundation CouchDB uses many Web related standards data is stored in JSON format communication takes place using JSON and RESTful resources and functions are written in JavaScript CouchDB is not as speedy as some of the other non relational NoSQL databases such as MongoDB and Cassandra However CouchDB is designed to be dependable and easily replicated across multiple servers a far cry from relational databases for which replication remains slightly annoying at best Last month explained how once you have created a CouchDB database you can use the curl utility to insert update and remove documents Each document is CouchDB however offers a completely different query system based on JavaScript functions and the map reduce paradigm nothing more than a JSON object which means it s basically a hash a Python dictionary which then may contain arbitrarily nested levels of arrays hashes and scalar values that is strings and numbers So can create a database with an HTTP PUT request curl X PUT http localhost 5984 atf Then can add some documents to that database with HTTP POST requests curl X POST http
6. Simply point your Web browser at the server on which CouchDB is running on port 5984 and go to your database of choice Then select temporary view from the pull down menu in the top right hand corner Your screen now should consist of two parts on the left side you have a simple JavaScript function under the header map function doc emit null doc If you ever have used map in a language such as Ruby Python JavaScript or Lisp this function already might make sense to you your function is invoked repeatedly for a list of documents If it produces a key value pair that pair is added to the output from the function running across all documents For instance the example function which is anony mous takes a document as an argument and returns a null key and the document itself as the value If you click Run under the code you get a set of results three null keys on the left side and the original documents with their mandatory id field on the right You can of course modify the function such that it outputs only information about girls To do that write function doc if doc sex f emit null doc Notice how by using a simple if statement you can eliminate unwanted rows Now what if you re interested in getting all the documents but sorted CouchDB orders the results by their keys which means the key you use is useful not only for identifying the resulting documents but
7. Open source provides a unique opportu nity to help us bridge this gap In an article titled Computer Science Education in the 21st Century David A Patterson former president of ACM and Pardee Professor of Computer Science at UC Berkeley explained that open source provided unique opportunities for injecting realism and relevance into the classroom One of Patterson s laments is that students can easily go through their undergraduate education without real exposure to computing 68 august 2010 www linuxjournal com Students rarely read other people s code and sharing of code is often the same as cheating The largest codebase students might see is a few thousand lines of their code written over a period of 6 12 months with at most a half dozen other students This code will not evolve or be maintained In all likelihood it will be discarded as soon as the class ends Open source allows educators to change this dynamic opening a window into the chaotic and complex yet realistic world of software development A place where code is designed and written by many and the context metadata discussion and collaboration required is available to all It s a unique resource for educators to present an invaluable opportu nity to students to learn real skills Oregon State University has been busy developing curriculum centered on open source and it is aware of how to navigate its sometimes discouraging waters Dr Carlos Jensen
8. Text Play It All Target Play All v Font 35 DejaVu Sans v NENNEN EIL Button colors 2 3 Load Save lt Back Next gt Cancel Figure 5 Kdenlive s DVD Wizard Coffee Amici 17 December 2009 Student Show Students of Dave Phillips Live at the Coffee Amici in Findiay OH December 17 2009 Coffee Amici 17 December 2009 Student Show The Robinsons What Chid ts Tris Alexandra Farmer 1 Know Know laraich Avenue Beth Shaheen Almost Lover Night Christina Amoki Hark The Herald Angels Sing Best Days Of Your Life Paige Trafton ja Qn My Ming Sittin On The Dock Of The Bay Oh Holy Night One Sweet Love Contact emait dave tinux sound org 418 425 3946 Figure 6 A CD Insert Produced by cdlabelgen set the background to a color an image or a video file selected an image of the coffeeshop at night and added a text overlay of menu items Each item is linked to a particular target that is one of the chapters defined during the Wizard s configuration The whole process was uncomplicated enough to bring me quickly to the final stage of creating the DVD image clicked on the Create ISO Image and again let Kdenlive do the rest while finished that coffee brewed earlier The ISO image creation dialog includes an option to start a disc burning program when the image is ready selected the K3B option and followed that programs instructions until
9. interface typically passes a data structure for complex configu rations while a sysfs interface might use a space separated list of ASCII encoded values Demand Peripherals uses the ASCII encoded numbers approach because the overhead of decoding and parsing a line of text is not too onerous given the relative infrequency of driver configuration Also being able to cat a sysfs type file to see the driver configuration is kind of handy The third use case bidirectional transfer is really the most common use case You probably are already familiar with serial ports the most common example of bidirectional Although none are included in the examples above the FPGA based robot controller needs bidirectional I O for peripherals that transparently pass data from one end to the other These include both FPGA defined serial ports and SPI ports You may prefer as we did to be able to do block reads and writes until both sides of the interface are open REQUIREMENTS FOR USER SPACE DRIVERS Our number one requirement for this project was to spend as little programmer time as possible on it This meant minimiz ing the number of lines of code to be written and avoiding modifying someone else s poorly or completely undocumented code This requirement also implied that we not try to hide our interfaces in an application library Because a library is part of the higher level control application you still would need a daemon still need some comm
10. 5 Year Warranty Industry s Longest Small Scale to Mass Production Manufacturing Fulfillment Shipping and RMA Repairs Polywell Computers Inc 1461 San Mateo Ave South San Francisco CA 94080 650 583 7222 Fax 650 583 1974 NVIDIA GeForce and combinations thereof ore trademarks of NVIDIA Corporation Other names are for informational purposes only and may be trademarks of their respective owners First Class Customer Service Polywell Mini PCs EE The World s Small Greenest Fanless PC bas ITX 10A NVIDIA ION ITX 30G with NVDIA ION Graphics Barebone system S 1 99 VESA Wallmount option ITX 50 Series ITX 40A with Slim Optical Bay Full Height Riser or Low Profile Add on Slot up to 8 x 2 5 or 4 x3 5 Hard Drives Over 250 Mini ITX Models Available NVIDAI GeForce 8200 8100 with AMD Athlon Phenom Processor NVIDIA GeForce 9300 9100M 7050 with Intel Core 2 Duo Processor PCI PCle MiniPCle Slot for TV Tuner or Industrial Add on Custom Design Chassis for Small to Mid Size OEM Project W 23 Years of Customer Satisfaction Polywell Computers Inc NVIDIA ION nForce GeForce and combinations thereof are trademarks of NVIDIA Corporation Other 5 Year Warranty Industry s Longest 1461 San Mateo Ave South San Francisco 94080 650 583 7222 650 583 1974 888 765 9686 linuxsales polywell com polywell com us Lx ITX 1000C with 4LAN and W
11. AppLogic Cloud includes 5 one on one training sessions with our cloud certified experts to get you to speed Cloud is no longer just a buzzword but is here to stay Don t get left behind Find out what the excitement is all about risk free with CariNet the Cloud Computing Specialists No Contract No Risk carinet www cari net LJ SAS70 Certified www linuxjournal com august 2010 43 eiesveresverey rl we me Keyboard driven twin pane file management in glorious screen it s lovely As these blank options show Sunflower is at a rather early stage in life stated above you ll need Python GTK 2 0 PyGTK Once you re ready to go run Sunflower by entering Sunflower py Usage Inside the Sunflower window things feel like a cross between Norton Commander hereby referred to as NC along with its subsequent clones and newer file managers such as Nautilus Konqueror and so on Now must say that this definitely is early alpha stuff and as Such a great deal of features that most people take for granted are still missing which is evident when you click on Tools only to be greeted with nothing This current sparseness extends to the Options list where every tab also is empty at least it was at the time of this writing As a result of this recommend clicking on Settings Show command bar so basic fun
12. had suc cessfully burned the number of discs needed Some discs were specially prepared media for use in my laptop s Lightscribe drive Templates for making detailed CD DVD labels are available for various Linux graphics programs and the Lightscribe technology will burn the label graphics directly to the surface of the special discs giving them a professional appearance Simplicity and ease were my prime directives throughout this The fade ins and fade outs are drag and drop effects with user definable lengths and auto sync between the audio and video fades a handy default action project so when wanted to make inserts for the disc jewel cases availed myself of the services of Avinash 5 cdlabelgen an on line insert creation utility selected a background added titles songlists and credits and saved the output as a PDF file to be printed as needed Figure 6 Notes for Fellow Novices I m definitely an amateur in the video domain but I m having a lot of fun learning about it I ve benefited from the advice and sugges tions from many people far more knowledgeable so in keeping with the spirit of sharing helpful information l ve assembled the following notes in the hope that they might benefit other newcomers First take the time to learn about your hardware You need to know exactly what to expect from it during and after the shoot Buy an extra battery and keep it charged Buy a good stand and extra
13. is targeted at specific organizations by attackers who first go to great lengths to learn what data and systems to have their malware seek out based on known or highly probable vulnerabilities on those systems In other words nowadays malicious hackers often deploy worms as avatars of themselves Such targeted malware is extremely difficult to detect remediate against or trace back Often it s placed directly on target networks or systems by co opted insiders Therefore firewalls frequently have little useful role in blocking the activity of targeted malware It doesn t matter how thick your fortress walls are if your mailroom guys have been bribed to ignore the fact that the large package addressed to your king is ticking But ask you does the fact that bad guys may simply mail your king a bomb mean that you can safely replace those expensive castle walls the tuckpointing bill for which in any given year is probably astronomical with cardboard I for one don t think you can Just because attackers are developing ever more sophisticated tools doesn t mean they ll forget how to use the old ones Remember the LAND attack from the late 1990s It involved sending spoofed TCP packets bearing the same source IP address as the target to which you re sending them causing a massive reply to myself sort of loop which impairs system performance potentially cripplingly LAND was made obsolete by system patches and firewa
14. just tell the cpan program yes Also the first time you run cpan you might have to go through the initial setup program If so just accept the defaults and you should be fine Here are the different cpan commands you need to run in order to install the various modules sudo cpan Bundle CPAN sudo cpan ExtUtils MakeMaker sudo cpan Inline MakeMaker sudo cpan Device USB sudo cpan Device USB PCSensor HidTEMPer ott uU Ut Next downloaded a Perl script from www cs unc edu hays dev bash temper temper mon pl and made it executable When run the script will print the temperature from the thermometer In my case modified it so it output in Fahrenheit instead of Celsius usr bin perl use 5 010 use strict use warnings use Carp use Device USB use Device USB PCSensor HidTEMPer Device use Device USB PCSensor HidTEMPer NTC use Device USB PCSensor HidTEMPer use lib use Device USB PCSensor HidTEMPer my pcsensor Device USB PCSensor HidTEMPer gt new my Gdevices pcsensor list devices foreach my device devices say device internal fahrenheit stored the script in usr local sbin temper mon pl and ran it a few times to make sure it output the correct temperature Then connected the thermometer to a USB extension cord that was long enough to reach inside the fridge My Custom Fridge Script The fin
15. limit and trying to give the vehicles a lot of intelligence to be able to drive by themselves completely Anton Do you mean that with this trip you re trying to get as much road statistics as possible Alberto Not only that The vehicle instead of only helping the driver in some dangerous situations will fully manage itself it will have full control of gas steer ing and brakes for the whole trip In other words it will not only be active for a given set of situations but also for the whole 13 000km We also will record all the data so we can play back the whole trip many times once we return to Parma In the end we plan to test other driving assistance systems in a huge number of completely different situations such as mountain flat hilly traffic no traffic rain dust off road and so on Anton What organizations helped you design the car and supportive technologies Alberto It s just us thanks to a grant received from the ERC European Research Council Anton So you ve got an ordinary Fiat car you created supportive software and here it goes Alberto No we have electric vehicles manufactured by Piaggio an Italian motor company The vehicles we will use on the China trip are electrical and will have a solar panel to power the electronic pilot Originally we wanted to recharge the driving batteries with the solar panel but current technology is not mature enough Therefore we are powering only the
16. sensors the PCs and the actuators namely the whole automatic pilot The vehicle we are using right now but not the vehicle that will travel to China is called BRAIVE www braive vislab it and it includes a superset of the technology that we will have on our China vehicles is a traditional petrol based car Anton Elaborate on the vehicle s architecture espe cially the software part of it Alberto The architecture is simple seven cameras five laser scanners GPS IMU Inertial Measurement Unit A half dozen cameras and sensors and here s an automated Linux vehicle all connected to three Linux PCs The PCs get the data Computers and Display Q process it and send commands to actuators that drive the steering wheel gas and brakes amp All the software was developed i by us during the last 15 years We have been using this soft i Stich Cameras and LaserScanner ware for other challenges like the DARPA Grand Challenge Pea Urban Challenge E Anton The DARPA Challenge is performed in dry and sunny places Did you try to run tests some where in more severe condi tions like in rain or snow Alberto We did tests in 2006 at the US Yuma base in Arizona where we automated a PLS vehicle and in 2001 in Antarctica we automated a snowcat that followed tracks left by preceding vehicles also works under light rain Heavy rain is
17. so of course that s where they are stored Once a program is entered and saved you need to compile it Under the Sketch tab select Verify Compile to produce the machine code After a short period a message noting the program size will appear in the status window at the bottom of the main editor window Errors will show up highlighted in red Most of my errors are usually typos or forgetting a variable declaration As in C don t leave out any semicolons Make sure the Arduino module is connected to the Linux notebook by the USB cable and click the little upload button with the right facing arrow on the toolbar Some messages may appear in the status window at the bottom of the editor screen Again errors again will show up in red If you happen to be using an older version of the Arduino such as the NG you ll have to push the onboard reset button right before pressing the upload button to get the upload to start There is a short upload window before the Arduino bootloader starts that is used to upload the program via the USB connection Late model Arduinos run a reset without the need for a manual button push In the middle of the Arduino module the two onboard RX TX LEDs will show that the machine code has been transferred from the notebook to the board The Arduino IDE and related programs are updated frequently and I m happy to report that version 0018 is much faster at compilation and uploading than version 0012 The speed incr
18. tural domain Think about autonomous tractors that move on the field automati cally and work 24 7 And we have been working and are currently working with Caterpillar for a number of years now and they are interested in putting our technologies on their mining vehicles Besides through all these years we ve done a couple auxiliary projects in aviation project PEGASE road construction project TOPCON and many others vislab it Projects Anton What stops them from using your technology right now Alberto The environmental condi tions are the most difficult challenge We are now working to adapt our algorithms to have them working on very rough ter rain when the vehicle jumps on terrain bumps Now we are able to reconstruct the world in 3 D with two cameras in real time 10Hz and warn the driver about the presence of obstacles Anton Tell us about your team Alberto All the people on my team are engineers almost all are PhDs and all of us have an electrical CS background Anton You ve got an alumni proce dure What qualifications do you expect from a student joining your team to help further develop this prototype Alberto Well regarding this proto type we already are almost done we leave in less than three months But for further projects and we have plenty of them the ideal candidate should be well motivated and should be able to speak fluently ANTON BORISOV UPFRONT We all ag
19. was looking at a very neat device but I didn t have the foggiest idea of how to get started There is a wiki and several mail ing lists and recently found a nice blog post showing 36 august 2010 www linuxjournal com how someone ported gnugo over to the device see Resources After spending some time researching was forced to admit that it was too early for me to jump in The device has potential but the project as a whole just is not far enough along for me to partici pate Maybe I should run some kind of contest and give it away to a deserving hacker instead of letting it sit on my desk mocking me That Other Smartphone have been following Android for some time It seemed like an interesting platform but in order to take advantage of it would have to switch carriers which for a variety of reasons was not on my to do list Then Google released the Nexus One for AT amp T and I was excited have grown increasingly frustrated with my iPhone and thought this would be a great oppor tunity to try Android on great hardware So far it has been great There have been problems but don t end up as frustrated because most of the problems have encountered are bugs which means they can be fixed On the iPhone several of my problems were related to running Linux instead of Windows or Mac OS X which is not a bug in my book have a cou ple Android books sitting on my bookshelf to read which realize now are pro
20. was unable to get select to work on both sides of a FUSE interface I like FUSE it can solve a lot of user space driver problems but it seems unfair to me to ask FUSE a filesystem to double as a character driver After all who would expect ext3 or other kernel filesystems to have built in character drivers The last requirement was that writers block until a reader is present Both named pipes and pseudo ttys allow the writer to write 4KB before blocking It was important to us that the driver not fill a buffer with stale data that a higher level robotic application must discard to get to the current data A SIMPLE APPROACH TO USER SPACE DRIVERS In the end we didn t find any existing Linux facilities that satisfied all of our requirements and use cases However we were able to find or create two relatively simple device drivers that could Figure 3 illustrates the basic idea The idea is to have two very thin drivers that sit between the higher level applications and the user space driver These are real drivers and appear as such to the higher level soft ware The data exchanged between the application and the user space driver passes as transparently as possible through the kernel Even flow control passes transparently between the application and the user space driver The first use case that of multicasting sensor data is solved by the fanout driver described in detail at www linuxtoys org Demand Peripherals uses fanout devic
21. www codeweavers com Please send information about releases of Linux related products to newproducts linuxjournal com or New Products c o Linux Journal PO Box 980985 Houston TX 77098 Submissions are edited for length and content www linuxjournal com august 2010 41 NEW PROJECTS Fresh from the Labs Tiny Ear Trainer Color Based Interval Training 29a ch tinyeartrainer An ongoing fascination of mine has been with Synaesthesia the crossing of senses often leading to new and unique perceptions in the mind of the Synaesthete This is particularly com mon among musicians myself included where individuals will see sound as color possibly along with shapes num bers textures and so on It seems that Jonas Wagner has the concept of linked sound and color quite firmly embedded in his own thoughts when it comes to his program Tiny Ear Trainer an ear training program designed to teach you musical intervals with color association To quote the Web site Tiny Ear Trainer is a tiny piece of software that helps you recognize musical intervals Tiny Ear Trainer is free open source software written for the GNU Linux operating system According to the Web site its features include Associates colors to intervals Features learning mode which plays intervals together with color and name Plays harmonic or melodic intervals Uses fluidsynth soundfonts for playback Uses Python GTK
22. 1 mknod dev fanout2 c FANOUTMAJOR 2 mknod dev fanout3 c FANOUTMAJOR 3 mknod dev fanout4 c FANOUTMAJOR 4 chmod 666 dev fanout modprobe proxy PROXYMAJOR grep proxy proc devices awk print 1 mknod dev proxy PROXYMAJOR 9 mknod 1 PROXYMAJOR 1 mknod 2 PROXYMAJOR 2 mknod dev proxy3 c PROXYMAJOR 3 mknod dev proxy4 c PROXYMAJOR 4 chmod 666 dev proxy The robot s bootup scripts are slightly different because we wanted the device node names to reflect the device it serves For example the dual quadrature decoder might create fanout device nodes with the following mknod dev dp quad0 FANOUTMAJOR 0 mknod dev dp quad1 c FANOUTMAJOR 1 The source tarball contains some simple demonstration pro grams in the demo directory The program pxtest2 c shows how to use the proxy device to configure a user visible string and pxtest2 works by accepting a short string and echoing it back on request As mentioned above drivers often have to limit or otherwise modify a configuration value set by the user The pxtest2 program demonstrates this kind of processing by adding one to each non newline character in the input You can run pxtest2 with the following commands gcc o pxtest2 pxtest2 c pxtest2 dev proxy amp echo 111 222 gt dev proxy cat dev proxy output of the cat command should be 222bbb333 SUMMARY AND NEXT STEPS Our ad hoc approach to buildi
23. 100 option limit 150 option leasetime 24h 3 GW DNS etc config network config interface loopback option ifname 10 option proto static option ipaddr 127 0 0 1 option netmask 255 0 0 0 config interface lan option ifname ethO ethl 58 august 2010 www linuxjournal com option dhcp option 3 192 168 1 1 6 192 168 1 1 config dhcp wan option interface wan option ignore config dnsmasq option leasefile option resolvfile tmp dhcp leases tmp resolv conf auto Next remove the default fstab using rm etc config fstab because all mounts and swap space will be set up dynamically by the hotplug system Configure the disk s two shared directories using etc exports mnt sda2 Storage fsid 0 rw insecure no_subtree_check sync mnt sda2 home insecure no_subtree_check sync Configure Kerberos by creating etc krb5 conf libdefaults default realm EXAMPLE COM dns lookup realm false dns lookup false ticket lifetime 24h forwardable yes realms EXAMPLE COM localhost 88 admin server localhost 749 default domain local domain realm local EXAMPLE COM local EXAMPLE COM OpenLDAP s configuration file is etc openldap slapd conf include etc openldap schema core schema include etc openldap schema cosine schema include etc openldap schema inetorgperson schema include etc openldap schema nis schema include etc openldap schema autofs sch
24. B and the Internet The firewall blocks all inbound traffic from the Internet to either zone but allows hosts in Zone B to initiate transactions with hosts in Zone A In this case the firewall is highly effective in making it unfeasible for Internet based attackers to exploit the trust relationship between Zones A and B even if the firewall filters only on source IP address ALLOWED Y Figure 1 Filtering Only by Source IP Address But I m not really advocating address only filtering The fact is there are still plenty of important network services that use ports and protocols besides TCP 80 443 and HTTP HTTPS Domain Name Services still use TCP and UDP 53 Microsoft Remote Desktop Protocol Terminal Services still uses TCP port 3389 Oracle still uses TCP port 1521 and so on Modern firewalls still make plenty of meaningful decisions about what traffic to allow based on service type Another argument against the useful ness of firewalls is the fact that malware viruses trojans worms has evolved from being mainly a nuisance to becom ing a sophisticated means of infiltrating even well secured networks Ten years ago the most likely impact of a virus or worm outbreak in one s organization was a disruption of service Malware tended to strain system and network resources but by its indiscriminate nature it wasn t very useful for stealing data or breaching sensitive systems Nowadays however malware often
25. E is tiny Installation i386 based Debian and Ubuntu users are in luck as a deb file is Plsy a Preferences 6 about Tiny Ear Trainer takes the unique approach of teaching musical intervals through color association start Audio MIDI ALSA Readable Clients Output Ports fluldsynth system Connect X Disconnect v JACK Audio Connection Kit default Started Stop X Quit 38 C Messages Status Setup 3 Connections JACK Audio Connection Kit UE 3 Disconnect All lt gt Writable Clients Input Ports Refresh Making Tiny Ear Trainer work with JACK can be tricky for a first timer but all you need to do is connect fluidsynth with system and you re away available at the Web site For those using other systems the obligatory source tarball has been provided but thankfully the library requirements are fairly modest and don t require anything particularly obscure for installation The documentation says you need the following Python 2 6 2 5 might work too and will require simplejson PyGTK gt 2 10 Wi fluidsynth A soundfont fluid soundfont gm Once you have the needed libraries download the latest tarball extract it and open either a terminal or a file manager inside the new folder For those with a modern file manager like Nautlius or Dolphin you can insta
26. Proset Vaive Station ET YTD Preset Value YTO Proset Yoor z Location Station Elevation fot Ln Sesion Latte decal degens N is postion 3s tation Longitude decimal degrees E is positive W is negative 7 9 Timing Archive interval minutes 539 Sensor Polling Interval vecondal 30 8 Push interval seconds D Miscellaneous Do RX Check Vantage Pro only D Figure 3 Station Configuration Weatherforyou File Export SSH or FTP and Process Monitoring For now let s not enable any additional services until you have confirmed your station interface Station Confirmation Now let s proceed to the station interface verification Open a shell on the system that is running wview so you can follow updates to the system log At the prompt enter the following sudo tail f var log syslog rabie te generation HTML XML Vraphicttete hianigend Enable Alarms wvsiarmd Enable CWOP Submission wvowopd Enable HTTP Wunseeground Weatherforyou Submission wehttpd Export to remote host rre Enable process monitoring Logging Station Intertace wviewd logging Fue generation mtmigena verbose logging Alarma wvalarmd verbose logging FTP wviewntps verbose logging wvemsaha verbose fogging wvcwopd verbose logging H
27. an assistant profes sor at Oregon State University and driving force behind this project explains Students do not want to re invent the wheel and can be intimidated by the quantity and quality of easily available software Many of us learned how to program by writ ing small programs designed to meet some need other software couldn t Some of us attained glory by writing something our fellow students also found useful and would circulate Today chances are there is already an app to meet most needs and stu dents often see joining large open Source communities as their only choice to make a difference in computing It can be a daunting and intimidating prospect for someone learning how to code and therefore open source must be introduced in the right context The OSWALD To be true to this open source model the OSWALD development team decided to take this model and apply it to both hardware and software For students to learn through open source it s important that this extend all the way down to the hardware platforms they use which is still surprisingly difficult to do The OSWALD is a handheld ultra mobile PC designed to be accessible and affordable to students while incorporating many new technologies seen in the mobile device market The OSWALD is an open platform meant to open up the creative space for student projects With its rela tively novel form factor students are given the opportunity to explore
28. and hopefully now HP openly supports the Linux community See www webos internals org wiki Main_Page for more Michael Kyle Rankin replies We are both well aware of the webOS platform but we decided to limit our scope to Android Maemo and iPhone devices the latter mostly so could troll Bill We had to draw the line somewhere so mobile OSes like webOS Symbian and Windows Mobile were left out Plus at the time we wrote the column the future of webOS looked pretty grim but hopefully we ll see new interesting things on the platform now that HP has breathed new life into it Bill Childers replies Although webOS is on my radar I have a Pre sitting on my desk neglected and unused here Kyle and tend to write about what we know best Point Counterpoint is all about immediate off the cuff responses The column wasn t meant to be a shootout of mobile platforms but rather it was aimed at arguing about what works for each of us in daily life Thanks for mentioning webOS though Tech Tip On the Linux Journal 101 Tech Tips DVD you talk about using rsync with copying large amounts of files There is also a command line option for the cp tool that does the same thing It is u or update for example cp u media cd srv copyofcd just thought pass this along thought it might be helpful Michael F Trombley Jr Thanks for dropping us a line wanted to point out that cp u is not a good or reliable s
29. and server local router hostname You should replace these three items with your own names This project has seven steps preparing the build workstation downloading the OpenWrt build environment configuring and building a firmware image installing a firmware image onto the WRT160NL configuring the external USB disk performing a post installation configuration of the WRT160NL and configuring a network client In addition this article describes how to rescue misconfigured WRT160NL using the console cable If you find your router will not boot at any time while following these steps skip ahead to that final section The first step to building a firmware image using OpenWrt is preparing your build workstation OpenWrt requires that gcc g binutils patch bzip2 flex bison make gettext pkg config unzip the glibc headers the libz headers the ncurses headers and the perl XML parser are installed on the build workstation All major distributions provide packages for these items although the package names may be slightly different from the upstream titles Once you have installed all of the requisite packages on your build workstation download OpenWrt using the command svn co r 20526 svn svn openwrt org openwrt trunk Before downloading OpenWrt you may want to check if a newer version is available and substitute its revision number in the r option This creates a directory named trunk in the current working direc
30. bidirectional transfer use case The two defining features of proxy are that one side cannot write until the other side is open for reading and that a write of zero bytes is passed through the driver and seen as a read of zero bytes at the other end The usefulness of the sec ond feature is best shown by an example Consider the case of a user reading the current value of a configuration parameter cat dev dp bstep rate dev dp bstep rate is a proxy device and the user space driver daemon on the other side of it would see that a write is possible when cat opens the device The daemon writes the visit us at www siliconmechanics com or call us toll free at 866 352 1173 Dominic and Maddison are logistics and shipping Experts for Silicon Mechanics That s especially important recently They have geared up to deliver the newest Silicon Mechanics rackmount servers and storage products with next generation Intel CPU technology the Intel Xeon Processor 5600 Series They are both excited to be shipping products that take advantage of the increased performance and decreased energy consumption made possible by features like 6 core CPUs with up to 12 threads and 12 MB of cache and Intel Turbo Boost Technology No we can t put the Experts themselves into the boxes we deliver but you can be sure that every one of our products contains our Experts commitment to quality and service and that includes packagi
31. digital converters in the Arduino The Dallas sensor is a cool piece of technology because a whole bunch of these sensors will work on a simple three wire bus Each sensor has a unique 64 bit device number The Arduino code pings the Dallas sensors and receives a coded data stream from each one containing the device number and temperature reading The Dallas sensor and one wire libraries need to be added to the Libraries directory Miles Burton built some awesome libraries and code download them from his Web site see Resources Code particulars are a little beyond the scope of this article In a nutshell the Arduino reads the photocell and temperature sensor values and converts them into a data stream one line of data per program loop that is fed out over the USB port Again we don t change any output pins in this particular project Make sure the USB serial port is configured to accept the data from the microcontroller Open a terminal and use the stty command to set the baud rate for the port If you have the wrong baud rate you ll get funny characters that you can t read or import into kst rreilly gt stty F dev ttyUSBO 9600 clocal Plug the USB cable in to the port wait a couple seconds and the Arduino will start sending data to your notebook Use the cat com mand in a terminal to record the data to the testdata txt input file rreilly cat dev ttyUSBO testdata txt Stop the data stream with Ctrl C Once you have the
32. ear to intervals Now let s take a look at the Preferences screen Two default soundfonts usually are provided for you under usr share sounds sf2 but if you don t like these soundfonts don t have any or want to change the instrument a guitar springs to mind you can change the soundfont with the Soundfont option at the top The next option Learning Mode is equally important Learning Mode plays the sound with the color at the same time instead of a black screen so you can learn it now and test yourself later From here onward the options start getting musical You can choose whether notes are played together which intervals to play from a long list as well as the all important key in which they ll be played with the default being the obvious C recommend starting off with Learning Mode with only several intervals selected testing yourself on these and then gradually adding more to the list ANEW PROJECTS I m not sure if Synaesthesia is what file manager for Linux It supports Jonas really had in mind or if he just plugins It is possible to run this happened to strike upon the same theme application on other systems Mac but this is the first time l ve come across OS Windows but you will have to what Synaesthetes always have seen in their install necessary libraries Python minds being used practically Of course it all 2 04 and PyGTK could backfire as some other Synaesthete shouts No no a ma
33. in sync spent a lot of time searching and didn t find what was looking for so started to sketch up some ideas of how to solve the problem That s when realized something very important about writing a column there always is a deadline looming ended up shelving the idea of starting a brand new project and focused on writing about something actually could finish in time to talk about In that case it was a BeagleBoard As was working on a project last week stumbled into Homesick It was designed to solve this exact problem It introduced the idea of castles which are different repositories of dot files stored in git reposi tories You then can choose to pull down a variety of different castles on each machine and choose which ones you actually want to use In order to use it you need to have Ruby RubyGems and git installed Once those are installed simply install the homesick gem sudo gem install homesick A castle can be pulled in by referencing a local folder a remote git repository or by using the short form if the repository is on GitHub The example provided here is from Homesick s author s GitHub site homesick clone technicalpickles pickled vim This pulls down the vim files from technicalpickles It does not replace your existing vim dot files yet In my case l d like to build my own vim castle you do not have to keep the files in a git repository although it doesn t hurt cd Deskt
34. indeed a problem as is heavy fog Or snow Anton How many prototypes had been developed before this roadrunner Alberto Well a good number BRAIVE TerraMax T2 Oshkosh PLS Mini Hummer just have a look at our prototypes page vislab it Prototypes Anton How did you come to use Linux Alberto have been using Linux since it was created Linux is more stable than Windows and for these critical applica tions it delivers the performance we need Anton What flavor of Linux exactly do you use and how do you process data 18 august 2010 www linuxjournal com Disparity Cameras and LaserScanner Control and X By Wire 8 1 Scanner Camera Three Linux PCs process data and generate a 3 D representation of the surrounding environment recognize video objects is this an HPC cluster or an ordinary PC Alberto We started with Fedora 11 and we customized it to remove all features services and software packages typical of a desktop distribution keeping only the minimum We use Fluxbox as a window manager and gcc 4 4 3 kdevelop 3 9 99 gdb 7 0 1 as a development environment We use normal PCs on a local LAN Core 2 Duo T7100 at 1 8GHz 2MB Cache L2 FSB 800MHz 1GB DDR2 Anton What components were pro grammed by your team and what has been done by the Open Source community Alberto The real substance of our work is visual recognition and data processing so my team has been busy wi
35. instance though there is no shortage of companies that can assemble and test these devices the devices are built by undergraduates This means there will be positive and negative outcomes There will be quality issues and the devices take longer to assemble but there is a relatively large number of fresh man and sophomores working with the devices and in the process learning and gaining the confidence to work with computer hardware Ben Goska an undergraduate in Electrical Engineering and Computer Science and chief hardware developer elaborates We only make 300 OSWALDs in a build run Talking to devel opers is tricky because most manufacturers are used to numbers in the thousands We are building these by hand The hardware is also not as optimized as one would expect with commercial support but there is intentionally a fair bit of redundancy As Dr Jensen explains I m a user interface researcher What want to do is use this device to help students understand the trade offs between different inter face techniques When you pick a phone or a mobile device typically you will have an interaction method chosen for you For the iPhone everything is touch There is no way of doing anything other INDEPTH The OSWALD at Oregon State University Jefferson Street Corvallis Oregon Photographer Victor Kuechler than by touching the screen This is a very intuitive slick interface but there are instances where i
36. item Press the Esc key to return to a previous menu screen Within the configuration menu provided by the make menuconf ig command first select Target System and choose the Atheros 71 7240 913 option Set the Target Profile to Linksys WRT160NL In the Target Images submenu ensure that only squashfs is activated Activate Advanced configuration options for developers and press Enter while this option is highlighted Select Toolchain options and press Enter again Deactivate Build install c compiler and libstdc because none of the packages for this example build require a C environment Return to the main menu using the Esc key Select Base System and then block mount and block hotplug Return to the main menu and select Network Activate Filesystem nfs kernel server Time Synchronization ntpd Printing p910nd howl mdnsresponder and openldap server Return to the main menu and select Kernel Modules Activate Filesystems kmod fs ext3 and USB Support kmod usb printer and kmod usb storage Return to the main menu select Extra Packages and activate krb5 server Return to the main menu select Sound and activate mt daapd Finally Esc out of the configuration tool ensuring that you save your configuration when prompted Now that your OpenWrt build is configured execute the command make V 99 to build the firmware image This process takes a long time to complete because OpenWrt is compiling the buil
37. ll find its new Illumination Software Creator 1 0 a visual software application builder extremely intuitive A user even non programmer can easily experiment with software building blocks in a completely visual and understandable way and create software that can be run on Linux Mac OS X and Windows com puters The application converts visual concepts into source code No virtual machine is involved In addition software built with Illumination Software Creator can be run as a rich Internet Web page or an Internet tablet applica tion for Nokia Internet Tablets The languages utilized are Python and GTK for desktop and mobile applications and JavaScript for Web applications www radicalbreeze com Robert Love s Linux Kernel Development 3rd Ed Addison Wesley Our old friend Robert Love whose popular Kernel Korner column long graced these pages has updated his classic book Linux Kernel Development to a new 3rd edition Published by Addison Wesley this work details Li nux Ke rnel the design and implementation of the Linux kernel presenting the content in a manner that is beneficial for those writing and developing kernel code as well as for programmers seeking to better understand the Development operating system and become more efficient and productive in their coding The book details the kernel s major subsystems and features including its design implementation and interfaces It covers the Linux kernel wit
38. localhost 5984 atf d first name Atara middle name Margalit sex f last name Lerner Friedman birthday 2000 dec 16 curl X POST http localhost 5984 atf d first name Shikma middle name Bruria sex f last name Lerner Friedman birthday 2002 dec 17 curl X POST http localhost 5984 atf Amotz middle name David last name Lerner Friedman birthday 2005 oct 31 d first name Then can check to see that there are three docu 20 august 2010 www linuxjournal com ments by using an HTTP GET request on the database bash 3 2 curl X GET http localhost 5984 atf db name rmltest doc count 3 doc del count 0 update seq 3 purge seq 0 compact running false disk size 12377 instance start time 1273430793169153 disk format version 4 As you can see the doc count attribute shows that there are indeed three documents in this database Now if you have only three documents querying them doesn t make much sense But if you have 300 or even 300 000 documents you certainly are not going to want to iterate over them just to determine which is the best match and or most appropriate If you were using a relational database server you would use SQL to retrieve the rows that match a par ticular set of criteria Even MongoDB which covered earlier this year offers a query language that is
39. more often Do you like tinkering with Arduino boards If so Rob Reilly s article on kst might tickle your fancy Rob shows how to make data plots with kst and a Linux machine Or perhaps you want to roll your own firmware If you have a compatible router there are quite a few you can turn your off the shelf router into a full fledged server with OpenWrt Mike Petullo shows how Finally we have OSWALD Don t confuse the cute name for WALL E rather the OSWALD unit is an open computing device developed at Oregon State University It was designed to get computer science students excited about developing With its unique open nature students are able to bend OSWALD to their whims and come up with creative new programming in an era when students often feel all the cool innovations already have been invented Hopefully OSWALD will change that If all this talk of gadgets robots and death rays isn t really your cup of tea that s okay We have our full lineup of columns focusing on the things that keep us excited about Linux month after month Reuven M Lerner continues telling us about using CouchDB Mick Bauer discusses transparent firewalls Dave Taylor shows how to use signals in shell scripts Dirk Elmendorf has a few pages on smaller projects you ll want to check out And of course Bill and Kyle are at it again Whether you prefer rotating magnetic media or the newer solid state devices it s always fun to see them battle out the
40. tapes On the set set up your shoot carefully and take extra care for camera position and lighting Record your audio and video at the highest quality your camera allows Record your audio at a strong level but avoid clipping Normalize audio only as a last resort Bear in mind that normalization raises the level of the noise floor along with all other sound in the normalized track Be generous when transferring your video from camera to computer Approximately 13GB of storage space is required for 60 minutes of DV formatted video but massive storage is cheap these days Restrict your edits to simple functions Avoid fancy transitions and don t get distracted by effects Yes effects are great fun but unless they truly add something to the final product they are best left for another project Know your target destination disc stream file and format your rendering options accordingly Two passes are better than one but life is short Do what you can with the time you have then move on The Wrap felt that had done my homework that had made my choices as wisely as possible Nevertheless was a newbie at video pro duction and expected surprises As my work progressed was surprised indeed but only at how easily the entire process flowed along My hardware behaved as expected Linux provided the necessary low level support and the applications software worked without troubles throughout the process Kdenlive was a specia
41. the embedded program Arduino microcontrollers are known as open hardware In the spirit of the open source software tradition the board designs schematics and code are freely available to download modify and enhance The Arduino home page has active forums for information exchange and there is a comprehensive set of reference documents Figure 2 Arduino Board Naturally the boards and raw components cost money A number of Arduino clones are available offering board configurations for a variety of specialized applications Prices for solder it yourself boards start at around 20 Complete ready to run boards with built in USB interfaces cost about 30 You ll also need a breadboard a few resistors some jumper wires a wall wart or battery and some sensors suppliers are listed in the Resources for this article Inputs are either analog or digital An analog device might be a potentiometer or photocell while a digital device might be a magnetic reed switch or a push button Outputs control things You could turn on a light with a digital 64 august 2010 www linuxjournal com output operating through a relay or transistor In this article we won t control anything with output pins Instead the Arduino will communicate sensor data to a Linux notebook over the USB line Modern microcontroller modules like the Arduino take advantage of what s called in circuit programming The processor chip uses Flash memory for program stor
42. the point What I m really trying to illustrate is that no attack is truly obsolete for as long as it s still feasible and as long as systems are vulnerable to it In theory if your organization rigorously hardened every single computer connected to the network if you took down your firewalls you might not get infected or attacked right away But guarantee you would sooner rather than later and not strictly by com pletely cutting edge attack techniques So to summarize even if you think all your fire wall does is block traffic from unexpected sources it still provides meaningful protection Modern net work traffic does not in fact consist solely of HTTP and HTTPS it still plays out over a surprisingly wide range of different ports and protocols And the rise Standard routing firewall Each interface s IP address must be routable on the network to which it s connected Interface 10 20 30 254 Interface B 44 55 66 254 Network 10 20 30 0 24 Network By 44 55 66 0 24 Figure 2 A Standard Routing Firewall Transparent bridging firewall Each interface is associated with a virtual switch having a single shared IP address It doesn t matter how thick your fortress walls are if your mailroom guys have been bribed to ignore the fact that the large package addressed to your king is ticking Firewall s switch IP 44 55 66 254 Individual ports do NOT have their S
43. when it gets too warm the fridge is powered on These devices range from around 70 to more than 100 depending on whether they are analog or digital and almost bought one until realized could do the same thing with an old Linux laptop a couple pieces of hardware and a few scripts If you are into home automation at all you are familiar with the X10 suite of home automation 32 august 2010 www linuxjournal com 40 C 120 C Figure 1 TEMPer USB Thermometer photo from the Amazon product page gadgets Essentially you can connect lamps and appliances to different X10 gadgets and then power them on with a remote control There s even a remote control that connects to a serial port so you can control everything from a computer Linux has a program called bottlerocket that works great with X10 serial port controllers and had used one to control my DSL modem for many years but that s something for another column The TEMPer USB Thermometer So had a laptop and could control the fridge power but still needed a thermometer that worked under Linux and was relatively cheap discovered a great little USB powered thermometer made by a company named It s small cheap less than 15 shipped supports temperatures between 40 and 120 C and with a little effort it works under Linux It turns out many Linux administrators are using these devices to monitor temperatures in their data c
44. without actually unarchiving the video file Here s how unrar inul path to movie_folder movie name r 0 vlc MALICK KHADY DIA Send a tech tip to techtips linuxjournal com and if we publish it in the magazine we ll send you a free T shirt POINT COUNTERPOINT Solid State Drives vs Rotational Media SSDs are the future but are they ready for prime time today BILL You know just got a new 2 5 drive for my laptop KYLE Yeah What d you get BILL Picked up a 7200RPM 500GB disk for 100 half a terabyte man KYLE That s a lot of storage but really 7200RPM That hasn t been a fast rotation speed for about a decade Why not get a solid state drive BILL SSDs are too expensive for my taste and they don t hold nearly enough data like carrying my movies music and docs around with me despite the fact that love cloud storage KYLE suppose they are a little pricey but you get a huge performance boost with that price Plus it s not too expensive to get a 100Gb drive which should be enough for most of the things you d need on a laptop Oh and nice try throwing the cloud in there to distract me The fact is many people are using their laptops as their primary machines these days and for heavy use 7200RPM laptop drives just don t cut it That s especially true if you want to play around with any kind of virtual ization Have you ever tried running two VMs at the same time on a 7200R
45. 010 www linuxjournal com own IP addresses Zone 44 55 66 1 44 55 66 99 24 Figure 3 A Transparent Bridging Firewall One ramification of the firewall as router approach is that normally if you have a big bunch of existing systems you want to divide into two security zones one trusted and the other non trusted you ll probably need to re IP address the hosts in one or both zones or re mask the subnet they re on which may not be possible and insert a firewall configured as a gateway between those zones In other words inserting a routing firewall into an existing network usually means reconfiguring both the network and the systems connected to it But what if you wanted to insert a firewall between two parts of the same network without re addressing anything Is it possible to configure firewall to act more like a bridge than a router Indeed it is And best of all the firewall s rules will What Is Bridging Exactly This month s column assumes you know something about networking IP firewalls whether standard routing or transparent bridging are at least an intermediate level topic and you really can t expect to configure either kind unless you have a working understanding of how TCP IP protocols work But even if you do you might be a bit rusty on the difference between bridging and routing Here s a quick simplified primer Routers operate at Layer 3 the IP la
46. 1394 ohci1394 ieee 1394 all of which are autoloaded when the machines go through their hardware discovery during the boot process The process of finding the right video editor consisted of trying out the available NLEs for Linux to determine which one offered the most amenable work flow During the process wrote a series of profiles on Linux NLEs that you can read at LinuxJournal com worked on a simple project in each editor and found that more than one program could serve my purpose finally decided that Kdenlive Figure 2 provided the tools needed in a layout that was easy for me to understand and operate For the project described in this article used Kdenlive 0 7 6 but since then I ve been building the program from the latest SVN codebase By the time you read article this minitutorial Kdenlive should be available in a shiny new version 0 7 7 The Transfer Kdenlive records real time video over a FireWire connection or from a Video4Linux V4L compliant Webcam The program also utilizes the RecordMyDesktop software for capturing on screen actions such as mouse movements window placement program controls and so forth used Kdenlive s Record Monitor panel Figure 3 to transfer the videotape recording to my computer The panel provides full transport control of my camcorder and quickly searched for and found the sections wanted to transfer to disc clicked on the Record control when wanted to transfer t
47. 2 R 5 s a t Core U ND FOU COLUMNS EE ay DAVE TAYLOR b Dealing with Signals Y By handling signals in your bash scripts you can provide features that are otherwise difficult such as telling your script to reread its configu ration file after it s already been started This month thought it would be interesting to take a bit of a detour from my usual multi month program ming projects and instead focus on a specific topic that is of great importance to people writing longer scripts signal management Signals are numeric messages sent to running applications from the operating system other applica tions or the user and they generally invoke a specific response like shut down gracefully stop running so can put you in the background or die Most likely you ve used the kill command to send signals to different programs but if you ve ever pressed Ctrl C or Ctrl Z to stop a running app you ve also sent signals to a running application A signal is managed in a cascading manner It s sent to the application or script then if the application Most likely you ve used the kill command to send signals to different programs but if you ve ever pressed Ctrl C or Ctrl Z to stop a running app you ve also sent signals to a running application doesn t have a specific handler signal management or response function it s pushed back to the shell or operating system Some signals
48. 20 aa Intel the Intel logo Intel Xeon and Xeon Inside are trademarks or registered trademarks of Intel Corporation or its subsidiaries in the United States and other countries INDEPTH The OSWALD Project Open source and education a match made in computer heaven VICTOR KUECHLER AND CARLOS JENSEN Computer Science CS education for some time now has been accused of being outdated and failing to capture the hearts and minds of the next generation of leaders and innovators Rekindling the pioneer spirit and excitement of the hacking culture of the 1970s and 1980s requires flexible and accessible open hardware and software in an environment that promotes experimentation and collaboration Although the software community has a long history of building and sharing such platforms open and flexible hardware platforms have been few and far between Oregon State University developed the Oregon State Wireless Active Learning Device OSWALD to help close this loop The OSWALD is an open Linux based ultra mobile personal computer incorporat ing many of today s new technologies and gives students and enthusiasts full access to both its hardware and software Based on discussions with the OSWALD develop ment team this article provides a brief overview of the platform and explores the lessons learned in re inventing computer science through open source Open Source and the State of Computer Science E
49. 2010 www linuxjournal com 68 THE OSWALD PROJECT Create DVD Menu Create basic menu Button Background Text Play It All Target Play All v Font 350 DejaVu Sans v Button 2 A 3 72 KDENLIVE 2 lt Back Next gt Cancel USPS LINUX JOURNAL ISSN 1075 3583 USPS 12854 is published monthly by Belltown Media Inc 2211 Norfolk Ste 514 Houston TX 77098 USA Periodicals postage paid at Houston Texas and at additional mailing offices Cover price is 5 99 US Subscription rate is 29 50 in the United States 39 50 in Canada and Mexico 69 50 elsewhere POSTMASTER Please send address changes to Linux Journal PO Box 16476 North Hollywood CA 91615 Subscriptions start with the next issue Canada Post Publications Mail Agreement 41549519 Canada Returns to be sent to Bleuchip International P O Box 25542 London ON N6C 6B2 If You Use Linux You Should Be Reading KVM Clutter FPGAs Android Coreboot RSpec SRANDOM for Low Level Syste m Po rammin Ka Bare Metal Hacks with F GA Ke Since 1994 The Original Magazine of theLinux Communily Peace Mo Mare Real Ti m Kernel Interact with the iRobot Create Convert amp mm Film to DVD Developan Autonomous Underwater Vehicle a LinuX n d Rocket In depth information providing a full 360 degr
50. 2010 www linuxjournal com latitude and longitude www topozone com viewmaps asp Click the Services tab and enable the HTTP service Click HTTP Services and configure the Weather Underground settings Click Save Changes Look in the system log for something similar to WUNDERGROUND configured to submit V station KTXCOLLI1 data to wunderground com Confirm your data at the Wunderground server http www wunderground com weatherstation WXDailyHistory asp ID XXXXXXX where is your Wunderground Station ID This should start displaying your weather data graphically and as a packet list Data Archive and External Applications A number of simple open source weather station applications are avail able that do little more than extract the data from the weather station and archive it for later post processing or retrieval by another server for multisite analysis Researchers wanting to gather weather data for their own purposes is one example of such an implementation It is often incorrectly asserted that wview is more application than is needed for simple archival purposes In fact wview allows for much configuration as to how much it does for you Designed as a series of loosely coupled UNIX processes wview easily can be configured as an archive only server It also is easy to add CWOP and or Wunderground Weatherforyou to the archive server all without any fancy HTML or other file generation If you don t want to ge
51. 7 Bob Smith Mike Petullo Rob Reilly COVER IMAGE the Biclops by Bob Smith shows how easy it is to build robots when you have Linux on a Chumby and the peripherals on an FPGA card 2 august 2010 www linuxjournal com We Speak Your Language if Sordered_online amp amp Scoupon_code linux journal 1 server discount Sserver price 11 107 off for coupon code linuxjournal T V V NV Vo VV OM Choose the dedicated and managed hosting provider that understands you 1 677 999 2701 www codero com CONTENTS COLUMNS 20 24 28 32 36 77 80 Reuven Lerner s At the Forge CouchDB Views Dave Taylor s Work the Shell Dealing with Signals Mick Bauer s Paranoid Penguin Building a Transparent Firewall with Linux Part Kyle 5 Hack Dirk Elmendorf s Economy Size Geek Cool Project Potpourri Kyle Rankin and Bill Childers Point Counterpoint Solid State Drives vs Rotational Media Doc Searls EOF Waving Goodbye to Facebook INDEPTH 68 72 The OSWALD Project Re inventing Computer Science through open source Victor Kuechler and Carlos Jensen Video Production 101 Making a Movie with Kdenlive Lights Camera Action Dave Phillips IN EVERY ISSUE Current Issue tar gz Letters UPFRONT New Products New Projects Advertisers Index Tech Tips Marketplace 4 august
52. 800W Redundant Power Sur swap SATA D Intel 82576 Dual port Gigabit Ethernet Controller growing busine 50 34 tn ELE 1 HIGH CAPACI Mart 3 5 hot Swap drives md 36x 24 front 12 rear Hard Drive Bay Et Expander supports SAS Redundant 1 1 1400W Gold Level power supply with PMBus functio Redundant Hot pluggable cooling system Power Supplies Hot swap drives ESS TO BE MORE PRODUCTIVE The ServersDirect Systems powered by Intel Xeon Processor provides the au uality 4 Y POW amp amp HIGH GH STORA GO STRAIGHT TO THE SOURCE 1 877 727 7887 www ServersDirect com lt Support up to 192GB DDR3 1333 1066 800MHz ECC Reg DIMM Intel 82576 Dual Port Gigabit Ethernet Controller 80 PLUS SDR S2318 T06 2U INTEL amp XEON amp PROCESSORS 5500 SERIES SERVER W 8X 3 5 HOT SWAP SAS SATA BAYS Supermicro 2U Rackmount Server w 650W HE Power Supply Sup rver Board w Intel 5520 Chipset ip to Dual Intel 5500 series Xeon Quad Dual Core with QPI up to 6 4 G t up to 192GB DDR3 1333 106 800MHz ECC 6x 3 5 Hot swap SAS SATA Drive Bay Gigabit Ethernet Controller SDR S4314 T08 TOWER 4U INTEL XEON PROCESSORS 5500 SERIES SERVER W 8X 3 5 HOT SWAP SATA BAYS SUPPORT UP TO 4 DOUBLE WIDTH GPU 4U Rackmountable Tower with 1400W Gold Level Redundant Power Supply tional Rackmount Ki
53. CUDA and OpenCL to work for YOU Every Microway system is backed pre and post sale techs who speak HPC Whether it s graphics or GPGPU FORTRAN or MPI hardware problems or Linux kernel issues you can talk to Microway s experts to design and support solutions for power hungry applications 1U Node with 2 Fermi GPUS Microway s Latest Servers for Dense Clustering gt 10 nodes with 48 CPU cores 512 GB and QDR InfiniBand gt 10 nodes with 24 CPU cores 2 Tesla GPUs and QDR InfiniBand 2U Twin with 4 Hot Swap MBs each with 2 Processors 256 GB gt 10 2070 servers with 4 Tesla Fermi GPUs The Fastest CPUs and GPUs Ever 12 Core AMD Opterons with quad channel DDR3 memory gt 8 Core Intel Xeons with quad channel DDR3 memory 448 Core NVIDIA Tesla Fermi GPUs with 6 GB GDDR5 memory Configure your next WhisperStation or Cluster today www microway com quickquote or call 508 746 7341 2U Twin Node with 4 Hot Swap Each with 2 CPUs 256 GSA Schedule Microway a Contract Number GS 35F 0431N Technology you can count on
54. Can it be done To start working out a solution create a function test sh that not only handles the specified signal but also test script started My PID is 25309 disables itself after a single invocation signal QUIT received signal INT received script ending sigtstp echo SIGTSTP received gt dev tty Perfect To send the signals execute the following trap TSTP commands from a different terminal window echo SIGTSTP standard handling restored kill HUP 25309 kill QUIT 25309 Invoke trap signal somewhere else in the script Q Small Portable Devices with Ubuntu Linux 4 ubuntu Provider Small Form Factor Intel Atom Platform No fans no moving parts Just quiet reliable operation Incredibly tiny 0 6 L takes up minimal desktop space Low Profile Intel Atom Industrial System Small footprint platform featuring solid state storage System is less than 1 5 thick yet rugged and sturdy Value only an Industry Leader can provide Selecting a complete dedicated platform from Logic Supply is simple Pre configured systems perfect for both business amp desktop use Linux development services for greater system customization and a wealth of online resources all within a few clicks SUPPLY Learn More gt 17191704 2010 Logic Supply Inc All products and company names listed are trademarks or trade names of their respective companies COLUMNS and yo
55. Instruments Vaisala WXT510 520 Oregon Scientific WMR9X8 and La Crosse WS 23XX Next you need a platform to host the wview application Desktop computers of any vintage work well but it often is desirable to host wview on a low power unattended system The now discontinued Linksys NSLU2 has been a popular choice The new SheevaPlug quickly is gaining popularity as a wview host also Industrious people even have used a Western Digital Worldbook NAS as their wview host Because wview is modular and designed for embedded applications it can be hosted on low horsepower systems Next you need to install a Linux distribution of your choice The Debian and derivatives wview packages provide the most idiot proof installation path but source installs also are straight forward for any Linux distribution Finally you need an interface cable This may be a simple 9 pin serial cable or perhaps a USB serial adapter if your host has no serial ports A re you fascinated with weather Do you often find yourself 52 august 2010 www linuxjournal com Figure 1 Dave Vantage Pro2 Weather Station Configuration To configure wview open your favorite browser and point it to the wview management Web site typically http lyour wview server wviewmgmt login php An HTTP server is required on the wview host this will be installed automatically if you use the APT packages Use the default administration password wview you can change this lat
56. JECT CLASS automountMap ENTRY OBJECT CLASS automount MAP ATTRIBUTE automountMapName ENTRY ATTRIBUTE automountKey VALUE ATTRIBUTE automountInformation Other distributions may configure the automounter differently 60 august 2010 www linuxjournal com If the automounter is configured to use the appropriate schema it will learn of the NFS provided home share from the LDAP entry you created earlier and mount users home directories on demand Refer to your client system s documentation for instructions covering how to connect to the network printer Your OpenWrt firmware will share an attached USB printer using the HP Jetdirect protocol This protocol is supported by Linux Mac OS X Windows and many other operating systems Your OpenWrt device s music share is accessible by iTunes Rhythmbox and any other media player that supports the DAAP protocol Compatible players usually will display the share as an option alongside their local music library list What if you install a defective firmware and the router is left in a state that will not boot This is where your console cable comes in Figure 2 shows a completed console cable next to an unmodified DKU 5 There are three points on the WRT160NL to which you can connect a console cable first are two identical sets of leads within the WAN and LAN 4 RJ45 sockets opposite the Ethernet leads The second is a five post connector on the WRT160NL s motherboard In
57. P database First create a file named example com ldif with the following contents a database defining a user account and automount configuration in LDIF format dn dc example dc com objectClass organization objectClass dcObject o Example Organization dc example dn ou people dc example dc com objectClass organizationalUnit ou people dn ou group dc example dc com objectClass organizationalUnit ou group dn cn ldapusers ou group dc example dc com objectClass posixGroup objectClass top cn ldapusers userPassword WFhYWA gidNumber 1002 dn uid someuser ou people dc example dc com uid someuser cn Some User objectClass account objectClass posixAccount objectClass top userPassword WFhYWA loginShell bin bash uidNumber 1100 gidNumber 1002 homeDirectory home someuser gecos Some User www linuxjournal com august 2010 59 Ss dn automountMapName auto master dc example dc com objectClass top objectClass automountMap automountMapName auto master dn automountKey home automountMapName auto master dc example dc com objectClass top objectClass automount automountKey home automountInformation auto home dn automountMapName auto home dc example dc com objectClass top objectClass automountMap automountMapName auto home dn automountKey automountMapName auto home dc example dc com objectClass top objectClass automount automountKey automo
58. P protocols as part of their networking classes The Future of the OSWALD A university designing a UMPC like the OSWALD relies on the benevolence and support of both hardware and software partners To stay on the upside of technolog ical change the OSWALD developers need to work with the Linux community to make sure their changes and needs are met Tim Harder a graduate student in Electrical and Computer Engineering and lead software developer for the OSWALD puts it like this In open source you have a lot of updates because a lot of people are working on different things Currently we use OpenEmbedded to create the BitBake files needed to create our custom Linux distribution but an important fix to help us move forward is to find a development environment with rich contributions We want to have flexibility as well as the high configurability that some thing like Gentoo provides Gentoo packages more software for us and we can take advantage of that Moving to a bigger development community such as Gentoo will minimize risks in the future On the hardware side fortune smiles with positive support from a number of chip companies who have provided their chips free of charge at a reduced rate or subsi dized the build process These include Texas Instruments Tektronix Intel Corporation and the National Science Foundation Their sup port for this device comes from OSU s belief that the OSWALD will help trai
59. PM laptop drive I have and it s painful BILL For heavy use 7200RPM drives don t cut it What crack are you on man My machines are plenty fast for what need I just priced a 128GB SSD and it s 475 That s nearly 4x the cost for 1 4 the storage A 256GB SSD is 679 Crazy prices man can buy a whole laptop for 679 KYLE The prices are a bit high right now but they keep coming down Sure you can buy a whole laptop for 679 or for 1k you could buy a laptop with twice the performance With the multicore and other high specs in machines these days the disk is definitely the bottleneck If you solve that problem you can take advantage of the rest of the machine BILL Not to mention there s the whole not fully baked yet issue with the technology Do you remem ber Intel s boo boo when it had some firmware glitch that killed performance and ate your data Rotating media isn t perfect but its issues are known I love the KYLE RANKIN smell of baked data in the morning just like when tried XFS at your insistence KYLE That s true rotational media has never had a firmware problem nor issues that resulted in data loss They certainly don t have any problems in portable devices like laptops if they get any kind of shock The fact is it s common now for laptops to have at least two cores if not more Parallel computing is not just the future it s how we use our computers today and you need storage that doesn t c
60. Resources Arduino Home Page www arduino cc Arduino IDE Download Page www arduino cc en Main Software The Arduino IDE on Ubuntu Tutorial www codetorment com 2009 11 02 tutorial getting started with arduino ide on linux ubuntu 9 10 Miles Burton Dallas Temperature Sensor Libraries www milesburton com index php Dallas Temperature Control Library Sparkfun www sparkfun com commerce product info php products id 666 Adafruit www adafruit com index php main_page index amp cPath 17 Maker Shed www makershed com ProductDetails asp ProductCode MSGSA Linux FreeBSD OpenSolaris etc an t afford to take chances with your usiness data or productivity rely on a Genstor server powered by the Intel Xeon processor roven ERFORMANCE 4 and 6 Core Xeon Processors ee Up to 12 cores in a 1U 5500 5600 series Low 350W power for dual processing CPUs with TDP lt 100w Up to 48GB DDR3 memory Up to 12 cores in a 2U 5500 5600 series Dual redundant high efficiency power Up to 96GB DDR3 memory Server Power Capping via Intel Intelligent Power Node Manager Up to 20 DP nodes 2 56TB memory in 7U Infiniband QDR DDR support 93 power efficiency Up to 60x 2 5 HDDs in 7U Genstor Systems Ihe inte 780 Montague Express 604 Xeon San Jose CA 95131 inside www genstor com E mail sales genstor com Powerful Phone 877 25 SERVER Intelligent 408 383 01
61. SEEMS UNFAIR TO ME TO ASK FUSE A FILESYSTEM TO DOUBLE AS A CHARACTER DRIVER driver configuration parameter one socket for reading the current value and another socket for setting the value There are a couple good ways to add bidirectional data streams to your user space drivers The proxy driver provides this immediately and was our choice for the robotics project The other approach is to use UNIX sockets Sockets work well with select and their permissions map into a filesystem but they don t work easily with echo cat and command line pipes Also if you use UNIX sockets for bidirectional transfers you really shouldn t call them device drivers when you describe your system INSTALLING THE FANOUT AND PROXY DRIVERS The fanout and proxy modules are fairly straightforward to build and install Be sure the kernel header files for your kernel are available Both drivers are in the tarball at www linuxtoys org usd usd tar gz Download the driver tarball then untar build and install the drivers tar xzf proxy tar gz cd proxy make sudo make install How and where you install your modules and create device nodes is a matter of personal preference You can for example add the following to your rc local startup script or put the equivalent commands in a udev rules file modprobe fanout fanout proc devices awk print 1 mknod dev fanout c FANOUTMAJOR 0 mknod dev fanout1 FANOUTMAJOR
62. T APPEN Www oscon com Last week at the O Reilly Open Source Convention was truly epic The Community Leadership Summit OSCON 2009 epitomized everything l ve ever wanted to do in community as a Microsoft employee Sarah Ford Microsoft REGISTER NOW AND SAVE 15 use discount code os10ljr COLUMNS economy size seek 4 DIRK ELMENDORF Cool Project Potpourri A look at Caffeine Homesick and Mockingbird admit that when signed on to do this column was really excited to see Cool Projects on the editorial calendar It was months away and figured by the time the issue rolled around would have something big to share with you Things did not quite work out that way Because every article write involves failure in one way or another I m going to start off telling you a little about the projects that sat on my bench Tiny and Shiny A very very tiny handheld computer showed up on my doorstep It was the completely copyleft Ben NanoNote The manufacturers are not really sure what to do with it so they have made it as open as possible to give people a chance to figure it out originally got it because I thought it might make a neat portable Linux device for my son hoped to get basic video replay on it if nothing else to give him something to play with instead of my phone Figure 1 Ben NanoNote In some ways had flashbacks to playing with the BeagleBoard because quickly realized
63. TTP wvhttpd vervone logging Email Alerts Enable email notification for wview alerts From Emst T To Emal address Enable test emaii Figure 4 Services Configuration This displays new system log messages as they are generated Here you will monitor wview startup and status messages Open another shell and execute the following sudo etc init d wview stop sudo etc init d wview start You will see a flurry of activity in the system log from the wview processes as they start up It is a good idea to familiarize yourself with these wview log messages as a wealth of detail is included that can be very helpful Return to the System Status page and observe the status of the station interface and the file generation If both are not status green and Running further investigation in the system log file will be required to find any configuration or station interface issues Default Web Site If all is well you now can view the default wview weather site This is typically found at http your_server_url Aweather index html Figure 5 Current conditions are given in the table on the left and by the dials in the center and on the right These values are updated every time station data is polled default is 30 seconds The weather site pages are regenerated every 60 seconds configurable Observing changes in the current conditions is an easy way to confirm proper station interface operatio
64. a spot and don t have your Linux notebook close at hand Download the latest Arduino software from the Web site Various Java packages gcc avr and avr libc need to be installed along with the Arduino integrated development environment See Resources for a good tutorial on getting everything working in a 64 bit Ubuntu environment Open a terminal and move to the directory where you installed the Arduino IDE On the command line start the IDE rreilly gt arduino The main Arduino code editor screen will appear From the File Edit Sketch Tools Hel ONE_WTRE_BUS 10 w re ONE WIRE BUS Figure 3 Arduino IDE and Editor Window Listing 1 Source Code for This Project CHECK OUT OUR BUYER S GUIDE ON LINE Go to www linuxjournal com buyersguide where you can learn more about our advertisers or link directly to their Web sites include lt OneWire h gt include lt DallasTemperature h gt Data wire is plugged into digital port 10 on the Arduino Thank you as always for supporting our advertisers by buying define ONE WIRE BUS 10 their products Setup oneWire instance to communicate with OneWire temp device OneWire oneWire ONE WIRE BUS Advertiser Advertiser 181 INTERNET INC 1 45 Pass oneWire reference to Dallas Temperature www oneandone com www ullabot corn DallasTemperature sensors amp oneWire ABERDEEN LLC 7 Microway C2 C4 Photocell
65. accelerometer Five way rocker switch up down left right and center E Six general purpose buttons B Microphone Connectors and IO 3 5mm stereo headphone port HDMI not fully complaint just as small DVI port Secure Digital card slot SDIO and SDHC compatible Two full speed USB host ports USB type Power 1300mAh Polymer Li ion battery 7 hour battery life Charging via USB or power adapter For more information go to beaversource oregonstate edu projects cspfl OSWALD User s Guide 9 thus besrmowirvrs Tekrrontxe ted The OSWALD and the OSWALD User s Guide Photographer Victor Kuechler vehicles The OSWALD is more robust than a laptop it has a solid state drive which makes it durable Dr Jensen explains We re envisioning as we go forward people will be taking some of these devices taking them apart and refashioning them into whatever they need them to be whether it s a mini Web server file server media server or whether it s embedded other things It has enough process ing power to do that and it has very low energy requirements which make it ideal for embedding in many different applications It s a general purpose computing solution for your home market Why Linux On the software side the choice of operating system was much clearer Linux is a real operating system it s not a toy Students take it seriously and see the lon
66. ackctl1 Now click Start inside the GUI and if you re lucky it will start straightaway But wasn t lucky This was the first time used JACK with this distro and it came up with an error that didn t understand until looked further into it You may encounter this too JACK usually is set up by default to run in real time generally coupled with a real time kernel Real time kernels crash constantly on my hardware so that wasn t an option for me In this case my only real choice was to disable real time in the Settings tab in the Setup option Now that JACK is running start Tiny Ear Trainer and in the JACK Audio Connection Kit click Connect on the bot tom left and open the Audio tab In the left pane under Readable Clients Output Ports is the client fluidsynth and in the right pane under Writeable Clients Input Ports is the client system Click on fluidsynth on the left and system on the right and then click the Connect button on the bottom left and you should be good to go Back over to Tiny Ear Trainer the pro gram will be sitting idly with a blank screen presumably so you can connect to JACK in the meantime until you click the Play but ton When you do several notes will play in a randomly chosen interval for instance a minor third and when the notes are over it will tell you what was played along with a colored background This builds your association between sound and color as well as trains your
67. age and is accessed via the USB connection Flash is a type of Electrically Erasable PRogrammable Read Only Memory EEPROM which means it can be erased and rewritten multiple times using the proper electrical signals These days the term EEPROM normally is used only to refer to the more traditional type of EEPROM which is still used in smaller sizes due to some of its other advantages In circuit programming is great because it minimizes equipment costs and prototyping turnaround time The flagship Arduino module is known as the Duemilanove It is a 2 7 x 2 1 circuit board that has 14 digital I O input output pins and 6 analog input pins It also has a built in USB port uses an Atmel Atmega 328 processor and screams along at 16MHz Modules are powered by batteries or from a wall wart with a recommended range of 7 12 volts DC Setting Up the Arduino Arduinos are programmed in a language called Processing The Arduino integrated development environment IDE manages compilation of the Processing source code into machine code that is then uploaded to the Arduino board Veteran programmers quickly will note Processing s remarkable similarity in format and syntax to the C language The Arduino IDE runs on 32 bit or 64 bit Linux notebooks and Netbooks Obviously Netbooks are cool because they are tremendously portable Windows versions of the IDE are available So you ll always have the capability to program an Arduino even if you get in
68. aig Oda Jeffrey D Parent Charnell Pugsley Thomas Quinlan Mike Roberts Kristin Shoemaker Chris D Stark Patrick Swartz James Walker Advertising E MAIL ads linuxjournal com URL www linuxjournal com advertising PHONE 1 713 344 1956 ext 2 Subscriptions E MAIL subs linuxjournal com URL www linuxjournal com subscribe PHONE 1 818 487 2089 FAX 1 818 487 4550 TOLL FREE 1 888 66 LINUX MAIL PO Box 16476 North Hollywood CA 91615 9911 USA Please allow 4 6 weeks for processing address changes and orders PRINTED IN USA LINUX is a registered trademark of Linus Torvalds PRINTED WITH SOY INK SERVERS AND STORAGE We hear you Deliver simultaneous file and block level storage without tw volume limitations and throw in enterprise class data protection v features Aberdeen gets it The AberSAN Z Series brings enterprise level benefits with a sub 9 000 starting price PROTECTION Real time block level mirroring Unlimited snapshots SCALABILITY Unlimited array size with storage pooling Expand capacity to beyond a Petabyte DEDUPLICATION VIRTUALIZATION No partion limitations Thin provisioning Active Active storage fail over VMware Certified management Inline bidirectional replication Intel Xeon processors 5600 series Standard 5 year warranty Intel Intel Logo Intel Inside Intel Inside Logo Pentium Xeon and Xeon Inside are trademarks or registered trade
69. ake effect at the next htmlgend HTML generation daemon generation cycle Changing the config files images conf html templates conf and if supported forecast conf does not require restarting wview but it does require an HUP signal to be sent to htmlgend to cause these files to be reread Do this as follows this also will toggle log verbosity sudo kill s HUP cat prefix var wview htmlgend pid wview supports template macro file inclusion in template files The meta tag is lt include filename xxx gt Any template macro file that is to be included in one or more template files should be listed before any templates including it in the prefix etc wview html templates conf configuration file There is no restriction on the levels of inclusion just be sure you specify macro templates early in the html templates conf file The wview default Web site templates utilize several header macro files HTML template files in prefix etc wview html can be customized to your language and design preferences The configuration file html templates conf specifies the template files to be used for genera tion You may add or remove from this list as needed Weather image captions can be edited in the prefix etc wview images conf file for your language preferences The configuration parameter on the File Generation Page Enable Metric Units For Generation allows for configuration of metric units If set to yes it causes wview to out put al
70. al step in the process was to write a script that would pull the temperature and control the power to my fridge based on whether it was within the proper maximum and minimum temperature ranges had set decided to separate the max and min by two degrees so that the compressor wouldn t kick on too much also wanted to write the results to a log so could monitor how well the fridge maintained the temperature Plus thought it would be cool to ssh in to my laptop from anywhere in the world and check on the temperature When first set this up the weather was cool in the evenings so discovered that my fridge would dive down way below the minimum My solution was to buy a 15 electric heating pad from the drug store connect it to another X10 outlet and put it in the bottom of the fridge figured the heat would be gentle enough to maintain the temperature at night without the risks that a proper space heater would have set up the script so that it would turn on the heater only if the temperature dipped down one degree below the minimum saved www linuxjournal com august 2010 33 COLUMNS s HACK AND 5 amazing how much we take the hard work of package maintainers for granted my script in usr local sbin temper pl usr bin perl use 5 010 use strict use warnings use Carp Figure 2 A West Coast Style Red Ale in My Linux Powered Fridge use Device USB use Device USB PCSensor HidTEMPe
71. also for ordering them You could for example sort the results by first name function doc emit doc first_name doc In my case this means first get the record for my son Amotz followed by Atara followed by Shikma Sorting by last name in this particular case doesn t help very much because they all have identical last names But keys can be any data type which means you even can use an array to arrange items by last and then first name function doc emit doc last name doc first name doc You also can sort them by birthday function doc emit doc birthday doc However this will not necessarily have the effect you want The birthday field is a text string which means the sorting will be done as a string rather than as a date In the case of my children s birthdays the sorting happens to work out fine but this is a happy accident not inherent to CouchDB If you want to create a permanent view there are a few ways to do so You can use the Futon Web based interface and any temporary view can be turned into a permanent one by clicking on save as from the tempo rary view s screen But another way and one that s a bit more flexible if you re writing complex code is to use curl to PUT a new design document on the server This document contains JSON like all other documents in CouchDB but it has a number of fields that are treated specially by CouchDB Here is my file which I called simplevie
72. and Linus Torvalds asked him to fix the ugliness first Now Phillip is stuck with this thorny batch of ugliness that touches a number of different architectures which aren t directly related to the SquashFS Project but which he can t avoid working on if he wants his SquashFS patches to make it into the kernel Tim Bird recently asked about the status of SquashFS and that s basically what Phillip told him in reply The patches will have to wait until Phillip finds the time to delve into those messy include files The Linux Plumber s Conference will be held in Cambridge Massachusetts this year November 3 5 The overarching theme will be projects that span multiple interfaces and thus will involve groups of developers who might not normally work directly with one another The format will be a set of brainstorming tracks where folks will try to figure out the best way to deal with these various cross project issues Check out wiki linuxplumbersconf org 2010 topics for the current list of tracks being considered The SCST generic SCSI target subsystem has migrated from using ProcFS for configuration to using SysFS The new interface is documented in README files in the source tree Vladislav Bolkhovitin announced the change recently adding that the old ProcFS interface was now officially obsolete which means that developers maintaining drivers dev handlers and management utilities should start updating their code with th
73. and customization are possible In this article show how to link all the parts together to produce a real time plot of live data and explain how to install and test kst also cover Arduino programming environment installation so you can get the board programmed and stream data right into a Linux notebook Installing and Testing kst kst can read text based data from a file and has basic data analysis capabilities As part of the KDE suite of applications it is available on virtually all modern Linux distributions The easiest way to put kst on your machine is with your distribution s package manager used Synaptic under Xubuntu for the installation on my ASUS 64 bit Core Duo X83 VM notebook Once installed kst appears under the Applications and Accessories pull down tabs on the desktop taskbar Below is a small segment of some temperature and light level data that captured The data snapshot will be used to test kst Later this same format will be used to stream real time data from the Arduino into our Linux machine Copy the data into a text file named testdata txt 74 64 444 74 64 448 74 64 452 74 64 450 74 64 447 74 64 439 74 64 435 Then start kst The main kst window will show the task bar across the top and the kst QuickStart window in the middle Click on the Data Wizard button at the bottom of the Kst QuickStart pop up pane Figure 1 shows the kst toolbar data source and configure data source windows The pop u
74. and push the boundaries of computing again as well as explore contemporary interaction techniques through hardware such as a touchscreen and accelerometer The device was carefully designed to balance power and performance with cost equivalent to a college textbook We could have encouraged the use of Netbooks running open source software The price point and capabilities of these machines make them a tempting alterna tive to full laptops The form factor was important to us for this reason The device is an auxiliary computing device rather than a desktop or laptop replacement Students treat their primary computing devices with care this is where they store their media and do their work The primary computing platform therefore is not a place where we would expect to see a lot of exper imentation The relatively little software customized for this form factor is a benefit to the OSWALD A student might create or port an interesting piece of software and share it with another student who will appreciate it With this in mind students will have a long list of desired features to bring to the platform and are motivated to create better software The biggest challenges to building an open platform such as the OSWALD are the costs associ ated with manufacturing it espe cially on a small scale Because this is a university project the devices basically are manufactured for students own consumption at this point For
75. ariety of pin configurations so be sure you have the right connectors on both ends of the cable For example my camcorder wants a 4 pin connector and the ports on my machines require a 6 pin adapter also bought a carrying case for the cameras and a good tripod with bubble levels and a variety of gizmos to position the camera in just about any direction l ve been especially happy with the tripod and advise anyone interested in amateur video recording to invest in a decent stand for your camera Yes you can solve a lot of problems in your edit stage but you ll save time and energy if your basic material is centered correctly from a stable position drew the line for my expense account at lighting The camera provides autocorrection for lighting and focus and my project didn t need a dedicated light system was ready to consider my software requirements The Software Side had two primary concerns on the software side needed to ensure that the kernel versions included the IEEE 1394 modules and that would find a video editor user friendly enough for a total newbie The modules issue was non problematic My main box runs 64 Studio 2 1 a by now old Debian based system running on a 2 6 21 kernel compiled for 64 bit hardware and real time operation while my secondary 32 bit machine runs a more modern Ubuntu Jaunty system with a 2 6 29 kernel optimized for real time performance Both systems provide the required modules raw
76. arp Linux Journal reader will have an answer Dave Taylor has been hacking shell scripts for a really long time 30 years He s the author of the popular Wicked Cool Shell Scripts and can he found on Twitter as GDaveTaylor and more generally at www DaveTaylor nline com SEPTEMBER 11 13 2010 COLUMBUS CONVENTION CENTER OHIOLINUX ORG OHIO FREE LINUX oma THE FEST 7 AdvocsBHilX amp ouwwo PARANOID PENGUIN Building a Transparent Firewall with Linux Part Yes you still need a firewall How about a transparent one When I started writing this column in autumn of 2000 had the day job of firewall engineer enjoyed that type of work but was enough of a big picture kind of guy to be aware that every year firewalls were becoming less important in the overall scheme of things In fact was convinced that within a decade or so firewalls would be nearly if not completely obsolete But was wrong Firewalls aren t dying They re evolving and even though traditional firewall technolo gies probably achieve less than they did ten years ago the threats we d face if we did without them still justify the effort and expense of keeping them around So I think the time is ripe for me to return to my roots so to speak This month kick off a series of articles l ve been meaning to tackle for some time how to build a transparent firewall using Linux To begin I set the stage by explaining why firewa
77. arting connect to it using telnet 192 168 1 1 Change the root password using passwd Once this is complete the router will no longer accept telnet connections Instead you will connect using secure shell ssh root 192 168 1 1 Now that you ve logged in to the router let s pause and address an issue you may be wondering about the next firmware upgrade Once the OpenWrt firmware has been installed you can no longer use the Linksys firmware upgrade tool that you used previously You will perform future firmware installations using an OpenWrt provided command line tool First use the scp command to copy a firmware image to the router s tmp directory Then log in to the router and execute mtd r write path to image firmware Continuing work at the router s command prompt now let s create nine configuration files The first file configures the router s hostname and timezone etc config system config system option hostname server local option timezone UTC The next three files configure the router s network parameters First you ll configure the router s Ethernet devices The following configuration will cause all five Ethernet interfaces to be bridged to perform switching on one network 192 168 1 0 The configu ration sets the router s IP ad from the default 192 168 1 dress to 192 168 1 2 this is a change 1 This configuration assumes that routing between the 192 168 1 0 and upstream networks and Internet DNS resolut
78. as let s hear them Maybe we can coax some Facebook occupants including ourselves in many cases to come enjoy the Great Outdoors W Doc Searls is Senior Editor of Linux Journal He is also a fellow with the Berkman Center for Internet and Society at Harvard University and the Center for Information Technology and Society at UC Santa Barbara IXsystems is proud to introduce the latest offering in our ix Gemini line the Gemini Cleverly disguised as any other 2U server the Gemini secretly houses 4 highly efficient extremely powerful RAID 5 capable servers Each node supports the latest Intel Xeon 5600 or 5500 series processors up to 192GB of DDR3 memory three 3 5 hot swappable hard drives This system architecture achieves breakthrough x86 server performance per watt 375 GFLOPS kW to further satisfy the ever increasing demands for efficiency density and low TCO of today s high performance computing HPC clusters data centers For more information and pricing please visit our website at http www iXsystems com gemini2 A ES Four hot pluggable systems nodes ina 2U form factor Each node supports the following Dual 64 Bit Socket 1366 Six Core Quad Core Dual Core Intel Xeon Processor 5600 5500 Series 3x3 5 SAS SATA Hot swappable Drive Bays Intel 5520 Chipset with QuickPath Interconnect QPI Up to 192GB DDR3 1333 1066 800 SDRAM ECC Registered Memo
79. bably out of date as got them long before got the phone had hoped to walk through the process of getting an application up and running Instead have settled into the role of end user rather than power programmer which has been great for my phone experience even if it does not help my writing What s Cool Now that I ve cleared my guilt backlog the good news is that have found some cool projects out there they re just being done by other people and get to use them In all three cases these are tools have picked up recently and use them to get stuff done Caffeine Caffeine was one of those wonderful discoveries because it brought to light a problem did not even know had and it originally was demonstrated on a Mac Let s say you re watching a video After a while you get so engrossed in the clip that you don t move your mouse or touch your keyboard because you actu ally are watching it with your full attention Then your screensaver kicks in as a bonus you have a password on it Or say you re giving a presentation and you stay on a slide a while so you can answer a bunch of ques tions and the screen blacks out to save power In the past there were two ways to handle this You could just remember to flick your mouse every so often which is annoying and error prone or you turn off the screensaver which means you have to remember to turn it back on later GFA AN I mI Figu
80. by putting tireless computers behind the wheel One part terrifying and one part awesome it s a project I m excited to read about If the thought of computer controlled vehicles stresses you out you might want to speak with Kyle Rankin This month he shows off his Linux powered refrigerator which he happens to use to brew beer l ve never had Kyle s beer but knowing Kyle the recipe is probably open sourced He most likely would give us all the gruesome details if we asked Although Kyle may be using Linux to take over his fridge the mad scientist in me thinks he might be setting his scope too small Perhaps taking over the world with killer robots is more your line of thinking If so read Bob Smith s article on controlling robotic peripherals with Linux It seems clear to me that criminal masterminds would want to use Linux for their killer robot army and with article your world takeover will be a bit easier Perhaps world domination and computer driven cars are little more than you re up for this month That s fine we need to save something for next year s Cool Projects issue Check out Mark Teel s article on wview a Linux based program for communicating with weather station devices Although wview won t necessarily enable you to control the weather it might help a bit with predicting it Maybe if the 8 august 2010 www linuxjournal com local weatherman used Linux he d be correct about the weather here in Michigan
81. can t be managed within individual apps like SIGKILL which is caught by the operating system and immediately kills the running application including the shell SIGKILL your login shell and you just logged out To start this journey let s find out what signals your version of Linux can handle Do this by typing kill 1 that s a lowercase L not the digit 1 kill 1 1 SIGHUP 2 SIGINT 3 SIGQUIT 4 SIGILL 5 SIGTRAP 6 SIGABRT 7 SIGEMT 8 SIGFPE 9 SIGKILL 10 SIGBUS 11 SIGSEGV 12 SIGSYS 13 SIGPIPE 14 SIGALRM 15 SIGTERM 16 SIGURG 17 SIGSTOP 18 SIGTSTP 19 SIGCONT 20 SIGCHLD 21 SIGTTIN 22 SIGTTOU 23 SIGIO 24 SIGXCPU 25 SIGXFSZ 26 SIGVTALRM 27 SIGPROF 28 SIGWINCH 29 SIGINFO 30 SIGUSR1 31 SIGUSR2 we 24 august 2010 www linuxjournal com Most of these are uninteresting The cool ones are SIGHUP which is sent on a hangup or the user logging out SIGINT which is a simple interrupt Ctrl C usually SIGKILL the terminate with extreme prejudice of signals SIGTSTP which is Ctrl Z SIGCONT which is what the application gets from the shell commands fg and bg subsequent to a SIGTSTP SIGWINCH which is for window system events like a window resize and SIGUSR1 and SIGUSR2 which are intended for interprocess communication Let s write some code to see what happens shall we Signals are caught with the trap built in and the general format of these signal mapping commands is exemplif
82. ctions such as copying moving edit ing and others at least will be provided for you at the bottom of the screen Nevertheless don t let what I ve just said put you off because Sunflower has one supreme strength it s delightfully keyboard driven It takes me back to the days of lazily browsing around inside the NC with only the arrow and Enter keys without all of the comparatively headache inducing GUI elements that were about to come competing for your attention and getting in the way As the keyboard is so essential to Sunflower Here s a guide for your reference Ctrl T duplicate tab W close tab E Q 3 Tab next tab E Q 3 E Q Shift Tab previous tab S Z open terminal tab Ctrl R reload list Backspace go to parent directory F4 open text editor Alt Letter quick search Menu open file directory menu Ctrl Menu open with menu F7 create directory F8 Delete delete selection F11 full screen Ctrl F7 create empty file 44 august 2010 www linuxjournal com One of the first things you should try is pressing F11 which makes Sunflower go full screen giving you that old NC feel but with modern GUI elements You can open files and folders by double clicking but recommend skipping the mouse entirely and just using the keyboard with the well known combo of the arrow keys for navigating up and down and Enter for op
83. d and dropped my clips along the timeline in the www linuxjournal com august 2010 73 4 multitrack display wasn t concerned with their accurate place ment yet because had three main jobs to do first as an editor E Trim excess footage Add audio and video fades to the start and end of each clip Create title clips to introduce each performance clip Kdenlive s Scissor tool made quick work of the excess footage The fade ins and fade outs are drag and drop effects with user definable lengths and auto sync between the audio and video fades a handy default action The material had no need for color correction or other repair so proceeded to create my title clips The name and length of the title clip can be redefined at will and a titling editor is provided for adding text images and back ground colors to the clip The editor has a number of amenities including some handy positioning tools and animation effects However intended to use the title clips only for introducing each performer s footage so kept things simple again with a yellow text against a basic black background After editing my title clips could then drag and drop them as needed Thanks to Kdenlive s Snap function they aligned themselves instantly when placed them near their respective footage yet another friendly default action added fades to those clips too and was effectively done in the edit room Configuring the Outpu
84. d environment itself followed by a Linux kernel and all of the firmware s programs More than likely this will take several hours The result of the build process is a firmware image stored at bin ar7 1xx openwrt ar71xx wrt160nl squashfs bin You may install the OpenWrt firmware onto your router using Linksys firmware upgrade tool assuming you have not already replaced Linksys default firmware The Linksys firmware provides a Web based configuration Figure 1 The Linksys firmware has a default IP address of 192 168 1 1 a default user name of admin and a default password of admin After configuring your build workstation by adding it to the 192 168 1 0 network point your browser to 192 168 1 1 Click Administration and then Firmware Upgrade Finally click Choose File and select the firmware image you just built namely openwrt ar7 1xx wrt160nl squashfs bin Follow the directions on the screen to replace Linksys firmware with the OpenWrt firmware Restart the router once the upgrade process is complete Basic setup File Edit View Go Bookmarks Tabs Help 19 http 292 168 1 1 i Go LINKSGYS by Cisco Wireless Security Storage Language Select your language Internet Connection Type DHCP Optional Settings required by some Internet Service Providers Host Name Domain Name pm uo Sire 3500 Network Setup Router iP o Address 292 164 Subnet Mask
85. d shorthand for talking about idealized user types in a way that s instantly accessible in the same way that Soccer Moms are an idealized voter demographic Apologies for the offense and welcome to the power user club The Magazine and the Digital Edition subscribed about a year ago but having read the issues received decided to not 10 august 2010 www linuxjournal com renew because almost all the articles were well above my capability of understanding My wife and are merely ordinary computer users who having become annoyed with Microsoft Windows and its myriad problems decided to try Ubuntu Linux two years ago Both she and have Ubuntu installed on our respective computers 9 10 soon to be upgraded to 10 04 and we ve never looked back As said the overwhelming majority of your articles are of no interest to me but then came the May 2010 issue with two extremely interesting and useful articles useful to me and l m sure others Full Speed Ahead with Handbrake by Anthony Dean and Comparing Five Music Players by Bruce Byfield These are the type of articles would like to see more of in the magazine After reading Mr Dean s article immediately installed Handbrake and following his detailed instructions was able to use it to convert some of my videos And one of these days when can overcome inertia l d like to comment on Mr Byfield s article So decided right then and there to
86. data coming in from the USB port start kst to view it Remember you set up the kst template file earlier Select your template file from the menu when kst starts The two graphs should appear and the plot will change as data streams in Scaling is automatic by default and will work for many situations Figure 5 That s pretty much the rundown on plotting real time data Temp F Se oe 5000 10000 15000 20000 25000 1 Second Interval Light Level 5000 10000 15000 20000 25000 1 Second Interval Figure 5 A Couple Live Data Plots with kst with an Arduino microcontroller and a Linux notebook Explore the kst program for more display options Wrap Up This article looks at real time data plotting with an Arduino microcon troller and the kst viewer program on a Linux machine Use this system as the basis of a more advanced setup with multiple inputs and sen sors The system also might expand to include wireless or battery oper ation didn t talk about sending data to the Arduino from the Linux notebook so perhaps that will be a topic for a follow up article m Rob Reilly is a technology consultant writer and portable computing expert Early adopter tech trends seminars and media projects are his stock in trade Links to many of his published articles appear on his Web site at home earthlink net rohreilly Contact Roh at robreilly earthlink net
87. ded to control my refrigerator with Linux If loving Linux ever became a crime and were hauled into court think the prosecution s argument would go something like this Your honor need to submit only two pieces of evidence to make my case First present Exhibit A a stack of Linux Journal magazines of which the defendant is a columnist And your second piece of evidence Your honor the defendant s refrigerator is powered by Linux The audience gasps Order I ve heard enough Guilty can t help it mean why wouldn t you power your fridge with Linux if you had the chance In my can t help it mean why wouldn t you power your fridge with Linux if you had the chance case we recently purchased a new fridge for our house which meant our spare fridge was headed for the garage where would use it for beer fermentation Fridges are well insulated and it seemed ideal for the task at hand but the problem ran into was that the built in thermostat for the fridge would go up to only around 45 50 F at its warmest To ferment ales needed to maintain temperatures between 60 72 When most people convert fridges to ferment beer they purchase a purpose built device from their local brew shop Essentially you plug your fridge in to the device plug the device in to the wall and then set the analog thermostat on the device to your desired tem perature A temperature probe goes into your fridge and
88. ducation One of the most frustrating challenges CS educators face today is convincing the next generation of students that room still exists for innovation and making a differ ence in computing With the advancement of computing and its proliferation into most aspects of our lives many prospec tive students feel computing is a solved problem that the days of innovation and chances to make a significant contribution have passed We are victims of our own success The rapid spread of cheap hardware and polished applications had removed one of the most compelling rea sons many have had for studying computer science the need to scratch our own itch As a consequence CS enrollment has dropped for more than a decade doesn t help that the CS curriculum The OSWALD in Memorial Union Square at Oregon State University Holding the OSWALD is Patrick Fancher a New Media Communications student at OSU Photographer Victor Kuechler has in many ways failed to keep up with changes Here refer to the core curriculum not the electives or advanced courses where we often see a much richer and up to date set of topics Little has changed in the core curriculum during the last 15 years short of programming language choices In all fairness the body of CS has been growing tremendously and the fundamentals are still fundamental but academia has failed to make sure this core stays relevant and visible to current and future students
89. e expecta tion that the ProcFS interface will be going away at some point The way this typically would work is that all active maintainers would migrate their code and then someone would try to remove the SCST ProcFS interface Next some one would come out of the woodwork to say there s this or that driver that breaks and then there would be another waiting period The process would repeat until it became clear that any remaining code using the ProcFS interface is either completely unmaintained or has no users at all Then the ProcFS interface will be removed and possibly the projects still depending on it might be removed from the kernel as well ZACK BROWN HTML5 New Technology for Old Dogs Everyone myself included is excited about HTML5 and how it will allow us to have richer content without propri etary plugins Those who hate Adobe are excited about breaking away from Flash s dominance in the Internet scene but there s also a group of folks excited to have any option on the Internet mul timedia scene PowerPC users Open source alternatives to Flash certainly exist but unfortunately they don t work well on the majority of sites requiring Flash Because Adobe has never released a PPC version of Flash for Linux users those of us hoping to repurpose old Apple computers are left without any answer when users ask about p 14 august 2010 www linuxjournal com Flash and Flash is everywhere W
90. e for me is that my laptop is more than just a portable computer it s my main computer for anything resource hungry these days use a pocket computer for everything else So performance matters especially when have multiple processes accessing different parts of the disk at once SSDs are the future and although they are a bit pricey now the price keeps coming down and will continue to come down BILL Hey it s all about price performance ratio SSDs appear to have about an 8x premium and that s not something I m willing to pay when a 7200RPM disk gets the job done for me and allows me to carry all the data could possibly want and more SSDs are the future yes grant you that But we live in the present and I m totally fine with letting early adopters like you find the data eating bugs and drive the cost down to the point where it does make sense for me to buy Today my money s still on good old rotating media m Kyle Rankin is a Systems Architect in the San Francisco Bay Area and the author of a number of books including The Official Ubuntu Server Book Knoppix Hacks and Ubuntu Hacks He is currently the president of the North Bay Linux Users Group Bill Childers is an IT Manager in Silicon Valley where he lives with his wife and two children He enjoys Linux far too much and he probably should get more sun from time to time In his spare time he does work with the Gilroy Garlic Festival but he does not smell li
91. e functionality will make their way into the interface and the beautiful design ethic behind Sunflower will really shine m John Knight is a 26 year old drumming and climbing obsessed maniac from the world s most isolated city Perth Western Australia He can usually be found either buried in an Audacity screen or thrashing a kick drum beyond recognition Brewing something fresh innovative or mind bending Send e mail to newprojects linuxjournal com A Simple Approach to CHARACTER DRIVERS USER SPACE The BaseBoard4 from Demand Peripherals can contain different combinations of 25 different character devices all multiplexed on to a single USB serial link Its drivers described here show how writing drivers in user space can get a complex device up and running quickly BOB SMITH 46 august 2010 www linuxjournal com emand Peripherals Inc makes an FPGA based robot controller that gives a robot or other industrial control systems the high I O pin count and precise timing that a Linux laptop or single board computer alone cannot offer The com pany has built more than 25 different FPGA defined peripherals for the controller and it wanted to offer Linux device drivers for all of them Doing 25 drivers in the kernel although possible would have required time and effort far beyond what the company could afford The process of building kernel device drivers would have been even more comp
92. e on line communities Reuven lives with his wife and three children in Modi in Israel Resources The home page for CouchDB is at the Apache Project couchdb apache org There you not only can download the software but also read documentation from tutorials to an active wiki The CouchDB Web site also has links to drivers for the various languages you re likely to use when working with CouchDB If you re interested in the JSON format used by CouchDB you can learn more about it at the main Web site json org Finally two good books on CouchDB were released in the past few months Beginning CouchDB by Joe Lennon published by Apress is aimed more at begin ners but it has a solid introduction to CouchDB Futon and how you might use the system CouchDB The Definitive Guide by J Chris Anderson Jan Lehnardt and Noah Slater published by O Reilly is a bit more advanced and meaty but it might not be appropriate for beginning users of non relational databases For a list of interesting map reduce functions for CouchDB along with explanations of how they work see this page on the CouchDB Wiki wiki apache org couchdb View Snippets 7 Vu TUER HB PEU PUPILLAM Hah arn 1 7 e E Ji i HR B t 25 k E 7 I E E CH P e 1 3
93. e possibility is Google s Wave It s a 80 august 2010 www linuxjournal com way to meet collaborate share files and do other literally social stuff 5 also an open source project that still needs a lot of shaking down And although Google hosts the first incarnation it s still there for anybody else to run with it fork it or whatever Here s how Joel David Palmer summed up the possibilities in a blog post by Steven Hodson At the extreme in personal control we could each configure our own computer as a little wave server and have primary control of our social networking server logs Less extreme than this any community or associa tion that s used to serving e mail could as easily and securely serve waves to their group Widespread adoption of waves would automatically reclaim a lot of user privacy and personal responsi bility for on line communications of every kind The contents cannot be mined by outside interests without committing criminal acts waves are as private as e mail Waves give you and your connections complete control over your social net working experience and real oppor tunities for creative collaboration A wave can be e mail telephone IM videophone collaboration platform art form performance venue Transitioning to waves appears to be a good strategy toward a collabora tive social Web that is peer to peer rather than server client Sounds good to me If you ve got any better ide
94. eafpad A simple GTK based text editor tarot freeshell org leafpad ePDFView A lightweight PDF viewer trac emma soft com epdfview EH GPicView A lightweight GTK based image viewer with low memory usage http Ixde sourceforge net gpicview PCManFM A lightweight tabbed file manager used for basic graphical file manipulations pcmanfm sourceforge net Xournal An application for note taking and sketching using the OSWALD s touchscreen xournal sourceforge net m MPlayer A media player for Linux that plays most movies and music www mplayerhq hu design7 news html HARDWARE SPECIFICATIONS AND FEATURES Size and Weight B Height 80mm 3 2 Width 150mm 5 9 BW Depth 25mm 10 Weight 210g 7 407 Core System Texas Instruments OMAP3530 applications processor 500MHz ARM Cortex A8 Core NEON SIMD Coprocessor 430MHz TMS320C64x DSP Core SGX530 2D 3D graphics processor OpenGL ES 2 0 compatible 70 august 2010 www linuxjournal com 128MB DDR SDRAM 266 256MB NAND Flash memory Display 3 5 resistive touchscreen LCD QVGA resolution 320x240 24 bit color DVl out at HD resolution 1024 768 Audio Texas Instruments TLV320AIC33 stereo audio codec 24 bit resolution 96kHz sampling rate 3 D bass treble EQ de emphasis effects Speaker Wireless W IEEE 802 15 4 ZigBee wireless Buttons and Sensors Touchpad Three axis
95. ease goes hand in hand with the in circuit programming capability These steps minimize the program compile upload cycle and increases available prototyping time After the machine code is uploaded the Arduino will perform a reset and two seconds later the bootloader will run the program and begin reading inputs and writing outputs You ll see the power LED light up and if data is being sent over the USB or optional serial line the RX TX LEDs will flash as data is moved back and forth The toolbar button in the very middle of the editor will open a new screen to view data coming in from the Arduino It s called the serial monitor and is used to watch data transferred from the Arduino to the notebook Note that the USB port on the Arduino is a USB to serial converter an FTDI chip so the Arduino shows up as a serial port on your computer Enough about Arduino programs Let s link things together and make a real time plot Putting kst and Arduino Together Figure 4 shows the circuit required to read the photocell and hook up the Dallas D 18B20 one wire temperature sensor The 66 august 2010 www linuxjournal com Dallas DS18B20 Temp Sensor 10 Digital Inputs Arduino Board Analog Inputs 0 Photocell 10K Ohm Figure 4 The Circuit Required to Read the Photocell and Hook Up the Dallas DS18B20 One Wire Temperature Sensor photocell produces changes in the voltage that is processed by one of the built in analog to
96. ee look at featured topics relating to Linux Tools tips and tricks you will use today as well as relevant information for the future Advice and inspiration for getting the most out of your Linux system Instructional how tos will save you time and money SUBSCRIBE NOW AT WWW LINUXJOURNAL COM SUBSCRIBE ilu n USo only Newsstand E per is is 5 99 USD Canada Mexico is 39 50 USD P e I dines pri e is 69 50 Free gift valued at 5 99 ps Spal aid in er nds Fir stis e will a pf ew or manage your subscriptio lh uxjournal com subscribe JOURNAL Since 1994 The Original Magazine of the Linux Community DIGITAL EDITION NOW AVAILABLE Read it first Get the latest issue before it hits the newsstand Keyword searchable Find a topic or name in seconds Paperless archives Download to your computer for convenient offline reading Same great magazine Read each issue in high quality PDF Try a Sample Issue www linuxjournal com DLISSUE RITTER N 2 V NN me JOURNAL Executive Editor Senior Editor Associate Editor Associate Editor Art Director Products Editor News Editor Editor Emeritus Technical Editor Senior Columnist Security Editor Hack Editor Virtual Editor Jill Franklin jillelinuxjournal com Doc Searls doc linuxjournal com Shawn Powers shawn linuxjournal com Mitch Frazier mitch linuxjournal com Garrick Antikajian garrick linuxjournal com James Gra
97. el in which there are really only two types of network transactions Web sessions and database transactions Well before then people started figuring out ways to do practically everything that can be done over networks from browsing a filesystem to running a remote desktop session over HTTP using a Web browser But does this really mean that firewalls are obso lete Definitely not not even in contexts where Web servers are involved Let s suppose it were true that a network traffic between two security zones happened over TCP port 443 By restricting traffic by source IP address and destination IP address you still could make decisions about which hosts could initiate any transactions to any other given host If one filters traffic strictly based on source and destination IP addresses and in practical terms not by TCP UDP port ser vice type you may think that you haven t achieved much All an attacker has to do in order to attack a protected system is gain access to some other system that the firewall allows to initiate transactions with your actual target But what if none of those secondary systems that the firewall considers trusted is externally reachable If that s the case your crude firewall rules may in fact have effectively mitigated the risk of remote compromise for that system This scenario is illustrated in Figure 1 which shows a firewall that sits in between two different networks Zone A and Zone
98. ema allow bind v2 pidfile argsfile var run openldap slapd pid var run openldap slapd args database ldif directory etc openldap ldif suffix dc example dc com rootdn cn Manager dc example dc com rootpw lt PASSWORD gt Configure the media server mt daapd by writing to etc mt daapd conf web_root usr share mt daapd admin root port 3689 admin_pw lt PASSWORD gt db_dir mnt sda2 mt daapd mp3_dir mnt sda2 Storage Music servername server local runas nobody playlist etc mt daapd playlist extensions mp3 m4a m4p Finally use etc config p910nd to configure printer sharing config p910nd option device dev 1p0 option port 0 option bidirectional 1 option enabled 1 Because OpenWRT sometimes starts services before the kernel initializes the USB subsystem you need to make one last modification Edit etc rc d S5Omt daapd and add sleep 5 as the first line the start function This ensures that mt daapd does not start until the kernel is aware of the USB disk containing your media files Reboot the router to ensure all configuration changes take effect The next step is to initialize the router s Kerberos database Log back in to the router using ssh root 192 168 1 2 Initialize the account database using the command kadmin local which provides an interactive interface kadmin local gt add_principal someuser gt exit Returning to the build workstation let s initialize the LDA
99. en logfile n shelf Even though my laptop is old it has plenty of horsepower to spare so eventually will graph all of the B4 Fridge power BS Heater power temperature data and serve it out over Apache If Bill were here I m sure he d tell me to tweet the temperature turn on heater if I m 1F below the low temp if temperature lt temp_min 1 Kyle Rankin is a Systems Architect in the San Francisco Bay Area and the author of system br port dev ttyS0 85 a number of books including The Official Ubuntu Server Book Knoppix Hacks and print LOG time t temperature tHON n Ubuntu Hacks He is currently the president of the North Bay Linux Users Group elsif temperature lt temp min system br port dev ttySO B4 OFF Resources system br port dev ttySO0 B5 OFF print LOG time t temperature tOFF n Guide to TEMPer Support under Linux https wwwx cs unc edu hays archives 2010 03 elsif temperature gt temp_max entry_25 php system br port dev ttySO B4 ON print LOG time t temperature tCON n One of Many Places to Buy the Thermometer On line www amazon com TEMPer USB Thermometer w Alerts else dp B002VA813U print LOG time t temperature t n TEMPer Thermometer CPAN Module search cpan org dist Device USB PCSensor HidTEMPer close LOG 34 august 2010 www linuxjournal com O REILLY OSCON Open Source Convention portland Oregon WAKE I
100. ends up performing addition or multiplication returning the result of executing the function on all documents One example of a reduce function that found cal culates the standard deviation from mapped results so you can find out how similar the documents are along at least one dimension 22 august 2010 www linuxjournal com Learning to use map reduce in CouchDB can take some time However this paradigm has proven itself for a decade or so For example as the back bone for Google s search system map reduce has demonstrated excellent performance and flexibility Granted Google is using something or some things that are not CouchDB but with a similar interface and paradigm Conclusion If you like the idea of using JavaScript MVCC easy replication and JSON documents CouchDB might be a good choice It apparently is not as fast as some of its non SQL competition such as MongoDB and Cassandra However CouchDB s built in and sophis ticated Web interface RESTful communication and the flexibility of map reduce are all good reasons to use it CouchDB is so easy to set up and use why not try it out Even if you end up not using it CouchDB is a great way to learn about map reduce and to try to create some small functions using it m Reuven M Lerner is a longtime Web developer architect and trainer He is a PhD candidate in learning sciences at Northwestern University researching the design and analysis of collaborativ
101. ening or executing something Pressing Tab changes between the left and right panes but unlike NC and its clones each pane can have another tab added onto it bringing this style of design ethic firmly into the 21st century Something that seems to be missing in the Midnight Commander that took for granted in NC is the ability to jump between the starting letters of filenames with two keystrokes this saved untold amounts of time Thankfully this is featured early on and works well Just press and hold Alt fol lowed by whichever letter you re searching for and you quickly can navigate inside huge lists of filenames with ease Sunflower may be a very early alpha but it already feels pretty solid in parts and looks very promising My apologies go out to developer MeanEYE for my constant Norton Commander refer ences but this old design ethic features here so prominently and it s refreshing not only to see and feel it again but also to have it re interpreted in a way that fits 21st century computing habits so well Sunflower seems bent on keeping only what is necessary And for those who keep stripping away often to the extent where features and functionality are laughable Sunflower retains what is genuinely useful over the last decade of computing minus the bulk Although this early Sunflower currently is far from what most people will be expecting from a file manager as time goes by expected elements especially more mous
102. enters Apparently the older versions of this thermome ter showed up as a USB to serial interface however the newer models including the one bought show up as a USB Human Interface Device when you plug it in Apr 16 14 44 33 muriel kernel 11601 992205 usb 1 1 low speed USB device using uhci_hcd and address 2 Apr 16 14 44 33 muriel kernel 11602 182910 usb 1 1 configuration 1 chosen from 1 choice Apr 16 14 44 33 muriel kernel 11602 188481 usb 1 1 wNew USB device found idVendor 1130 idProduct 660c Apr 16 14 44 33 muriel kernel 11602 188529 usb 1 1 wNew USB device strings Mfr 0 Product 2 SerialNumber 0 Apr 16 14 44 33 muriel kernel 11602 188563 usb 1 1 wProduct PCsensor Temper Apr 16 14 44 35 muriel kernel 11604 090148 usbcore registered new interface driver hiddev Apr 16 14 44 35 muriel kernel 11604 119323 input wPCsensor Temper as class input input7 Apr 16 14 44 35 muriel kernel 11604 140885 input hidraw0 USB HID v1 10 Keyboard PCsensor Temper usb 0000 00 07 2 1 Apr 16 14 44 35 muriel kernel 11604 170151 input wPCsensor Temper as class input input8 Apr 16 14 44 35 muriel kernel 11604 188677 input hidrawl USB HID v1 10 Device PCsensor Temper usb 0000 00 07 2 1 Apr 16 14 44 35 muriel kernel 11604 188931 usbcore registered new interface driver usbhid Apr 16 14 44 35 muriel kernel 11604 188980 usbhid v2 6 USB HID core driver At
103. er After logging in success fully the System Status page is displayed Figure 2 The System Status page displays the current state of all wview services as well as other status information Configuration is broken up into logical sections with context sensitive help available by mousing over the configuration items Click the Station tab to configure the station parameters Figure 3 The critical parameters here are the station type and the interface characteristics Select Save Changes when you are done Next click the Services tab Figure 4 This page provides the configuration of wview services log verbosity for the services and e mail alerts Services available are File Generation Alarms CWOP HTTP Weather Underground and System Status Sus Vas sua vave vave Si vave koce she hd tale poces recat T ore b fewoR lt orrect lt he sce qvem ltt eet cial ea e em Rurceg Norme operator Processes Figure 2 System Status Station Device tation Host ethernet oniy 10101010 Seaton Pon ethernet oy D 210 Stems Rain Sosson Stan 1 12 Rein Rate Storm Trigger Start aos Vile Hours Storm Trigger stop D R Presets Station Rain YTD
104. erals All with Linux Drivers are on the Demand Peripherals Web site All of the peripherals shown in Figure 2 can be configured and controlled using device nodes in the dev directory The following Bash commands for example might be part of the higher level control software for the system pictured Feed wheel quadrature counts to a motor control program cat dev dp quadO my motor amp Feed the same quadrature counts to a navigation program cat dev dp quadO my navi amp Set a stepper motor step rate to 1000 echo 1000 gt dev dp bstep1 rate Now step 300 steps echo 300 gt dev dp bstepl count Monitor distance reported by a Parallax Ping cat dev dp ping0 dist amp Set a servo pulse width to 1 5 ms 1500000 ns echo 1500000 dev servo servo4 USE CASES The above commands illustrate two of three important use cases for the user space drivers sensor broadcast and driver configuration The third use case is bidirectional transfer The first use case is sensor broadcast and in the example above it s actually multicast of sensor data Did you know that the dev input drivers implement a multicast mechanism Multiple readers get identical copies of the events that come from the input devices There is a simple experiment you can do to demonstrate this Press Ctrl Alt F2 to go to a different console log in and run the command sudo cat dev input mice od b Do the same for anothe
105. es for quadrature decoders To FPGA f dev fanout devittyUSBO dev proxy Figure 3 Two New Drivers Link Applications to Driver Demons dev fanout User Space User Space User Space a User Space Figure 4 A Simple Multicast Device IR receivers ultrasonic range sensors PlayStation controller inter faces event counters and all other continuously sampled sensors Figure 4 shows the basic data flow in a fanout device You can skip further down in this article to get and install fanout or you can continue reading and come back to try the examples Once you ve installed fanout and created the device nodes for it you can test it with a few simple commands cat dev fanout amp cat dev fanout amp cat dev fanout amp echo Hello World gt dev fanout The message appears three times as you d expect Fanout is like dev input in that it protects the writer not the reader If a reader does not keep up the reader gets the error allow ing the writer and other readers to continue unimpeded For data flowing in the opposite direction you need some thing like a fan in device that is something that protects the reader A named pipe works reasonably well for this The low speed nature of driver configuration the second use case makes possible several approaches The approach we took was to write a driver called proxy that solved both the configuration use case as well as the
106. esistive touch screen The dimensions of the PPC E4 are 4 8 by 3 0 about the same dimensions as that of popular touch cell phones The PPC E4 is small enough to fit in a 2U rack enclosure Price is 345 at quantity 1 For more info visit www emacinc com panel_pc ppc_e4 htm Since 1985 OVER PN E AL gt ine SINGLE BOARD ENT SOLUTIONS N Phone 618 529 4525 e Fax 618 457 0110 e www emacinc com www linuxjournal com august 2010 61 REAL TIME PLOTS ith ks and a Microcontroller Follow along as we build a real time data graphing system using kst an Arduino microcontroller and a Linux notebook Rob Reilly ots of programs take data from a file and create an X Y graph under Linux Desktop applications like xplot gnuplot or even PHPlot do a great job But what if you want to see how a physical process changes and use a real time plot on your Linux machine couldn t find this capability for a long time Then I discovered kst kst is a fast large data set real time viewing and plotting program and it s part of the KDE suite You need to have some way to get real time sensor data 62 august 2010 www linuxjournal com into the kst program I ve used Arduino microcontrollers to automate different things so it seemed only natural to combine one of these boards with kst to build an easy to use and very capable real time data gathering system Because it s open source based expansion
107. ferent page in the app and so on that realized how much need to look at some of the application frameworks for JavaScript The last time looked at them was several years ago when I played with ExtJS It provided a lot of whiz bang GUI elements but it proved to be too difficult to work with Maybe that has gotten better in the interim Conclusion l ve realized that for me cool has a lot more to do with usage than fashion Sure thought it was an impressive proof of concept that someone got Android onto the iPhone but I m much more impressed when discover something that changes how work every day These tools certainly have done that for Dirk Elmendorf is cofounder of Rackspace some time home hrewer longtime Linux advocate and even longer time programmer Resources Copyleft Ben NanoNote en qi hardware com wiki Main_Page My first port to the Ben NanoNote gnugo www mostlymaths net 2010 04 my first port to ben nanonote gnugo html Caffeine https launchpad net caffeine Homesick github com technicalpickles homesick Mockingbird gomockingbird com ExtJS www extjs com Linux on the iPhone linuxoniphone blogspot com 2010 04 ive been working on this quietly in html Washington DC August 11 13 2010 The USENIX Security Symposium brings together researchers practitioners system administrators system programmers and others interested in the latest advances in the secu
108. first thought could get the temperature from this thermometer through some proc or sys interface but unfortunately the thermometer is more proprietary than that The Linux community is resourceful though and a quick search turned up a number of guides on how to pull the temperature from Linux see Resources for the most helpful guide found Essentially you need to install a few custom Perl modules including a special one created just for this device that depends on Perl 5 10 so you need a relatively new distribution for this to work I used the latest stable Debian release Install Libraries and Perl Modules l ve always considered Debian as the distribution with the most packaged CPAN modules but even it didn t have many of the modules needed for the TEMPer thermometer so I had to install them from scratch I ll warn you in advance this process is a bit tedious and it reminded me of what it was like to install programs on Linux more than a decade ago It s amazing how much we take the hard work of package maintainers for granted At least the first dependencies had headers for libusb and a build environment to compile the Perl modules were available with packages sudo apt get install libusb dev build essentials Next needed to install a few Perl modules with the cpan program What you ll find is that many of these modules have their own set of dependencies so when you are prompted to install dependencies
109. form s architecture offers a number of disruptive innovations that are critical to managing dynamic and virtual ized environments that are common in IT environments today The new version 2 focuses on mid market service providers and enterprises enabling them to assure delivery of dynamic IT services through advanced event capture correlation and alerting A free and open source RiverMuse Core also is available RIVER x MUSE www rivermuse com CodeWeavers CrossOver Games 27055 20067 Games Our zany friends over at CrossOver were on the verge of mutiny since the grand poobah boss Jeremy White scheduled the release of CrossOver Games 9 0 just when ron Man 2 was hitting the theaters We re told that in order to ensure programmers continued work ing weekends without break White created a makeshift electric whip and paced around the office screaming full Steam ahead minions in a mediocre Russian accent The intimi dation apparently worked because the team pushed out both Linux and Mac versions of CrossOver Games which allows one to play Windows based games on these platforms Version 9 0 supports the new Steam UI StarCraft 2 beta and StarTrek Online as well as enables users to install games from a single screen and a single click on CodeWeavers compatibility center Furthermore users who figure out how to use CrossOver to install a Windows compatible game can upload the installation recipe to the company s database
110. g term benefits of learning Linux in depth Students also benefit from joining Linux s rich open community where newbies can find guidance and plenty of resources From a development stand point Linux supports many types of software and devices so it has simplified development On the downside little development has occurred on Linux for handheld devices but this also means students still can make meaningful contri butions with relatively modest effort Embracing Linux also differentiates the OSWALD from the many media player devices out here like as the iPod Touch Although many of these platforms offer a sleeker design and an attractive price point development for these devices is difficult as vendors either lock their platforms or apply stringent IP restrictions In this consideration the OSWALD has been designed with the flexibility needed to support a wide range of classes Two USB ports were critical in meet ing this design requirement This component extends the platform in any number of direc tions something that no current media player platform allows you to do With Linux as a foundation if someone has written a driver for it the OSWALD can support it This gives it great flexibility in terms of curriculum design In freshman courses students use the OSWALD to control small robots and sensors In graphics classes USB cameras enable simple image recognition and the built in networking allows students to design P2
111. h both a practical and theoretical eye which is intended to appeal to readers with a variety of interests and needs Updated content includes an all new chapter on kernel data structures details on inter rupt handlers and bottom halves extended coverage of virtual memory and memory allocation and more Developer s Library MO www informit com CloudLinux s LVE Wrappers Hosting service providers may want to read on about the new LVE Wrappers from 2 CloudLinux CloudLinux tools that let the server owner control the exact CPU usage for individual gt users and applications LVE Wrappers are based on CloudLinux s Lightweight Virtual gt Environment technology that allows administrators to control CPU usage a server at the tenant or application level It does so by isolating specific hardware resources in a lightweight container and prevents one tenant on a shared server from affecting others LVE Wrappers which start individual applications and daemons inside LVE environments allow for control of resources for each application which allows for greater flexibility and stability on the overall server infrastructure The software is available to all CloudLinux subscribers www cloudlinux com Tony Mullen and Claudio Andaur s Blender SERE Studio Projects Digital Movie Making Sybex Authors Tony Mullen and Claudio Andaur have set out to prove that the amazing open source 3 D animation software Blender is
112. hat you want MIKE PETULLO penWrt provides an environment for building custom Linux kernel based firmware for a variety of embedded devices Originally targeting the Linksys WRT54G series of routers OpenWrt now provides support for a wide range of devices including Openmoko mobile phones and routers from Linksys NETGEAR and D Link This article focuses on the Linksys WRT160NL router which chose because of its support for 802 11n wireless networking its USB connectivity and its reasonable price Within this device s 8MB of Flash and 32MB of RAM explain how to fit a Kerberos authentication server LDAP directory server NFS file server print server and iTunes compatible media server In addition to the Linksys WRT160NL router you ll need an external USB hard drive a USB printer a USB hub a build workstation and a custom built console cable To help build the console cable You ll also need a continuity tester often available as a function of a multimeter The first two items are available for a total of less than 200 Any USB printer should suffice as long as your network clients support it The build workstation should be running an up to date Linux distribution Finally the console cable is a modified Nokia DKU 5 connectivity cable this type of 56 august 2010 www linuxjournal com cable has a USB connection and embedded USB to serial adapter In this article use the example com domain someuser user account
113. he video and clicked it off until the video reached the next interesting point Record Monitor i9 x Figure 2 Kdenlive a Video Editor for Linux The Shoot The coffeehouse is a single room with good acoustics and lighting that poses no special problems for a video recording Coffee Amici also has an excellent in house sound system manned by co owner Craig Allen so knew the original sound source would be well balanced planned to perform with most of the students so needed to position the camcorder where could operate it remotely also needed to get a good shot of the performance area and a good audio level Fortunately had no problems with my setup and the shoot was trouble free Incidentally learned that the camera s battery will last just long enough to record a complete 60 minute miniDV tape The student shows routinely last at least that long and often longer Wherever possible plan to use the camcorder s power supply but now know how long can expect the battery to perform before need to switch it out for a recharge 00 35 27 29 efreespacen22 9 Auto add Figure 3 Kdenlive s Record Monitor Panel When was finished with each transfer Kdenlive asked if wanted to import the resulting DV file said yes and my transferred video appeared in the Kdenlive Clip list When my clip collection was complete my project was ready for the editing stage Into the Editing Room dragge
114. hings with words but sometimes words just don t cut it tried a lot of different software tools but none of them worked Some failed because they required too much artistic talent on my part always end up feeling like they re designed for designers which I m not In other cases hit a wall with adoption because work with peo ple who do not use Linux which means have to select from tools that are completely cross platform In the past resorted to scribbling things on paper so had some kind of diagram to discuss Paper was a great medium when everyone on my team sat in one room but now that work with a distributed team end up losing the imme diacy of the paper drawing It also became a pain to manage scanning and distributing paper documents That s when Mockingbird got dropped my lap meaning my brother sent me a link Mockingbird is a Web based wire framing tool Wire framing is where you just sketch the outline of a design so that you get the idea of what is happening It does not provide every last detail Mockingbird allows you to design a basic interface and then easily share the URL of your design with others or you can export it as a PNG or PDF The tool ends up being awesome for me as it provides a bunch of template items that make it easy to grab the interface pieces need If need to change something simply drag it around and make quick changes on the fly Because it is Web based my teammate
115. hoke with multiple processes accessing random sections of disk BILL CHILDERS BILL This from a guy who was running a single core laptop until just a few months ago with a 1 8 disk if recall KYLE Yeah in fact it was a 1 8 disk a 5400RPM one the fastest they made at the time until upgraded it to SSD The old rotation media in the laptop just didn t cut it BILL didn t say they haven t had issues But SSDs were touted as invulnerable and the greatest thing since sliced bread until that point KYLE m sure you still listen to music on vinyl so no wonder you prefer your storage to use the same technology At least if you bump your record player you risk only a scratch and not a head crash BILL Hey don t listen to vinyl Are you not paying attention to our own column listen to music on my iPhone man And not all SSDs are super performance oriented have a Netbook with an SSD in it and the thing is the biggest POS I have ever used KYLE agree not all SSDs are equal You have to do a bit of research just like with video cards or any hardware purchase where performance matters Oh and thanks for the lessons on data integrity must be remembering some other friend of mine who trashed his rotational laptop drive by putting his magnetic palm pilot case too close to it BILL Yes killed my disk Like you ve never smoked a piece of gear It s funny how recently you got on the performance ba
116. iFi Option POLYWELL E First Class Customer Service names are for informational purposes only and may be trademarks of heir respective owners www linuxjournal com august 2010 79 EOF Waving Goodbye to Facebook We need an alternative Google Wave is one possibility DOC SEARLS In a blog post last April titled Building the Social Web Together Mark Zuckerberg of Facebook wrote The power of the open graph is that it helps to create a smarter personalized Web that gets better with every action taken The open graph of which he speaks is your social graph your collection of contacts on Facebook augmented by personalized experiences with the likes of Microsoft Docs Yelp and Pandora which are Facebook s three pre selected partners Responding in his own Newsweek blog Barrett Sheridan called Zuckerberg s plans a Play to Take Over the Entire Internet In TechCrunch MG Siegler s headline read 1 Think Facebook Just Seized Control Of The Internet Whether or not Facebook is that ambitious it won t succeed at anything other than enlarging itself The limits to that are those of any private architecture It can get big but not bigger than the planet What Facebook has built is the Great Indoors A lot of people like going there just like a lot of people like going to shopping malls But Facebook is a building not geology The Web is geology It is a wide open public space
117. ic controller but they are actually fairly generic What Linux problems can you solve using fanout and Bob Smith bob demandperipherals com is a consultant specializing in embedded Linux www linuxjournal com august 2010 51 USING e WVIEW If knowing what the weather is gets your blood pumping and your heart racing you need to get wview and hook it up to your other great passion which is of course Linux MARK TEEL checking local weather conditions Is the weather your favorite part of the news broadcast If so you may be a weather geek and wview may be the application for you wview is an open source weather application that retrieves sensor readings from a weather station The sensor data is stored in SQLite3 databases Aggregate data such as minimums maximums and averages are computed and stored in the database back end Optional uses of the stored data include weather Web site generation generic file generation for external applications data submission to third party organizations including Citizen Weather Observer Program CWOP and Weather Underground and store forward to remote data collection centers A user friendly HTML interface is provided for configuring your weather station as well as for optional features To set up your weather station and publish your data with wview you need a weather station Supported stations include Davis Vantage Pro Pro2 Figure 1 or Vantage Vue Texas Weather
118. ied with trap echo Ctrl C Ignored INT How do we play with that as a shell script 5 an easy way bin bash trap echo Ctrl C ignored INT while usr bin true do Sleep 30 done exit 0 Did you catch the infinite loop there It s barely using any resources because most of its time is spent in sleep but if you don t do something to end it this script will run forever or until the Mayans are proven right two years from now one of the two Let s look at a more flexible way to manage signals by creating shell script functions sigquit echo signal QUIT received sigint echo signal INT received script ending exit 0 trap sigquit QUIT kill INT 25309 trap sigint INT trap HUP ignore the specified signals Armed with this useful script let s have a look at how to handle a more complex signal like Ctrl Z within echo test script started My PID is a shell script while usr bin true do sleep 30 Stop Don t Stop done I m going to create a scenario here rather than just going through the intellectual exercise In a complex Run this then from another terminal window and script you realize that you have certain passages where shoot some signals at it you need to ignore the TSTP signal SIGTSTP or Ctrl Z Now let s get that script started and watch what or signal number 18 and other spots where it s fine to happens when we send a few different signals stop and restart
119. ill HTML5 be the knight in shining armor for folks running Linux on G4 and G5 computers Will the Internet s transition to HTML5 take longer than what the old PowerPC beasties have left in them to run We ll see pretty soon I sure know I d love to see our old Apple computers go back into service SHAWN POWERS Ubuntu One Selling Free Love it or hate it cloud computing is here to stay Handfuls of cloud services are being offered to computer users now and like I ve mentioned before Canonical is doing the same As it matures Ubuntu One is beginning to roll more and more services into its feature set including m File syncing like Dropbox or Mobile Me for Macs E Preference syncing Mobile Me does bit of this Contact syncing Mobile Me and Google do this I m sure as more developers take advantage of the open source client for Ubuntu One we ll see more and more applications take advantage of syncing backup and off line functionality Unfortunately although Canonical does offer free storage in the cloud for all users that doesn t mean all the features will be included in the free install Contact syncing for example uses Funambol s technology to sync with mobile devices That means Canonical has to pay for contact syncing and must pass that fee to the end users Certainly paying for a service isn t a bad thing The unfortunate part is that Google does provide the vast majority of its services incl
120. input pin number int potPin 0 Declaration for photocell value int val 0 Arduino init functions void setup void Start serial port Serial begin 9600 Start up the library sensors begin Celsius to Fahrenheit conversion function float c2f float val float aux val 9 5 return aux 32 www aberdeeninc com WWW microway corn ASA COMPUTERS INC 63 www asacomputers com O REILLY OSCON 35 en oreilly com oscon2009 43 www cari net Linux Fest 27 www ohiolinux org 3 www codero com PoLYweLL COMPUTERS INC 79 www polywell com 61 www emadcinc com SERVERBEACH 13 www serverbeach com GENSTOR SYSTEMS INC 67 www genstor com Servers 9 www serversdirect com Gutsy GEEKS 75 www gutsygeeks com SHARE ORG 78 www share org IXsvsrEMS www ixsystems com SILICON 49 55 wwwsiliconmechanics com Main Arduino program loop void loop void LINUX FOUNDATION 23 TECHNOLOGIC SysTEMS 29 www linuxfoundation org www embeddedx86 com Read photocell for light value val analogRead potPin Logic 0 25 USENIX Security SYMPOSIUM 39 www logicsupply com www usenix org events usenix07 Send command to get temperature from Dallas device sensors requestTemperatures Convert returned C temp to F print val
121. inuxjournal com content kdenlive meets studio dave The first and only radio show broadcast in the USA dedicated exclusively to spreading the word about the LINUX OPERATING SYSTEM and FOSS 4 i COMPUTER SHOW gutsygeeks com www linuxjournal com august 2010 75 TECH TIPS gt Making ps aux grep Work Right When using ps aux grep to look for processes get annoyed when find the grep process in my search For example ps aux grep firefox user sso f sr vtib Tiretfox 3 5 0 firefox user grep color auto firefox To avoid this issue use a character class regular expression that is only one character long Simply put enclose one of the letters in my search term in brackets like this ps aux grep firef o x user usr lib firefox 3 5 8 firefox This prevents the grep process itself from matching the search term because the search term is firefox but the grep com mand contains firef o x ROSS LARSON P Extract Audio from the pacpl Perl Audio Converter Command Line Tool The pacpl command line tool allows you to extract the audio from any type of video format The command usage is like so Linux News and Headlines Linux Journal topical RSS feeds available http www linuxjournal com rss feeds 76 august 2010 www linuxjournal com pacpl to OUTPUT FORMAT INPUT FILE For example to extract the audio from an mov video and store it in an mp3 file d
122. ion Because manual measurement of quality is expensive and time consuming automation is useful for exposing flaws that cause applications to perform erratically www castsoftware com Bricsys Bricscad The team of Linux based CAD programs just added a new star player to its roster namely Bricscad V10 from Bricsys NV a high end DWG based CAD platform that previously was only for Windows Bricsys calls Bricscad 4 sricscao V10 the most application friendly CAD platform in the industry thanks in part to DCL and LISP APIs that allow existing applications and customizations written for Windows based Bricscad and or AutoCAD to run without modification Besides essential CAD functions for users in GIS AEC mechanical CAD and civil engineering additional core product benefits include a recognizable interface comprehensive support and reasonable price points Initially Bricscad will support Red Hat and Ubuntu Linux www bricsys com RiverMuse Pro The developers at RiverMuse have given their IT operations management platform RiverMuse Pro its vitamins for a stronger more robust offering Now in version 2 0 RiverMuse Pro combines the power of a robust Manager of Managers MoM functionality centralizing event collection from other management systems as well as from the infrastructure with real time event correlation and analysis ECA capabilities to detect and alert on business impacting incidents RiverMuse says that the plat
123. ion will be performed by another device for example a DSL device with an IP address of 192 168 1 1 epp cl C g Custom Firmware with OpenWrt SSS o option type bridge option proto static option ipaddr 192 168 1 2 option netmask 255 255 255 0 option dns 192 168 1 1 option gateway 192 168 1 1 The WRT160NL has a total of five Ethernet ports but the configuration option above shows two option ifname 1 This is correct The WRT160NL 5 four LAN ports perform switching functions and are collectively referred to by the Linux kernel as ethO The kernel refers to the single WAN port as eth1 This configuration bridges all five Ethernet ports together to perform switching functions on one subnet It also configures the switch to act as a host assigned the IP address 192 168 1 2 After applying this configuration all five Ethernet ports are equivalent switch ports Next configure the router s wireless interface etc config wireless config wifi device radio0 option type mac80211 option channel 5 option macaddr lt MAC ADDRESS gt option hwmode 11ng list ht capab 40 list ht_capab SHORT GI 40 list ht_capab DSSS_CCK 40 config wifi iface option device radio0 option network lan option mode ap option ssid lt SSID gt option encryption psk2 option key lt WPA2 KEY gt Configure the DHCP service by writing etc config dhcp config dhcp lan option interface lan option start
124. ir opinions in the Point Counterpoint column As always we have new product announcements tech tips and all the other things you look forward to in Linux Journal In my part of the world summertime is well underway now so perhaps l Il avoid that hot sun by building a few projects at home Hopefully unlike in my youth won t do dumb things like fill my basement with chlorine gas But that s a story for another issue m Shawn Powers is the Associate Editor for Linux Journal He s also the Gadget Guy for LinuxJournal com and he has an interesting collection of vintage Garfield coffee mugs Don t let his silly hairdo fool you he s a pretty ordinary guy and be reached via e mail at shawn linuxjournal com Or swing by the linuxjournal IRC channel on Freenode net 52 LS gp MOREP PRODUCTS ER SERVICE GUARANTEED 80 PLUS 08 1343 04 10 INTEL XEON PROCESSORS 5500 SERIES SERVER W 4X 3 5 HOT SWAP SATA DRIVE BAYS upermicro 1U Rackmount Server with HE 560W Power Supply Supermicro Server Board w Intel 5520 Chipset Support up te al Intel 5 r 1 Dual Core with up to 6 iT s Support up to 96GB DDR3 1333 1066 800MHz E Reg DIMM 4x 3 5 Hot swap SATA Drive Bays Intel 82576 Dual Port Gigabit Ethernet Controller SDR S4309 T08 TOWER 4U INTEL XEON PROCESSORS 5500 SERIES SERVER W 8 X 3 5 HOT SWAP DRIVES TRAYS Supermicro Tower
125. ived and flopped in 2001 As with all heavy weather it threatened to change at least superficially the Web s geology The HailStorm architecture is designed for seamless extensibility and con sistency across services It provides common identity messaging naming navigation security role mapping data modeling metering and error handling across all HailStorm services And rather than risk com promising the user centric model by having advertisers pay for them the people receiving the value end users will be the primary source of revenue HailStorm will help move the Internet to end user subscriptions in which users pay for value received by putting the Net itself inside Microsoft s own building That didn t work Nor will anything Facebook does for roughly the same purposes Of course Microsoft wasn t talking about the real Internet It was talking about the com mercial activity happening on top of the Net Likewise Facebook isn t talking about the Web but rather the social networking that s been all the craze during the past few years and which seems to be happening mostly within and between commercial entities As Facebook seems determined not to learn from the failings of its elders how about moving past all the commercial interests here How about making our own social networks ones that are owned by nobody or close enough used by everybody and improved by anybody How would we do that On
126. jor third is light green Currently this program is still in the damn you but personally look forward heavy development phase and is to the inevitable color arguments with glee open for testing plan on releasing versions often during development Sunflower Twin Pane File Management Installation Installing Sunflower rcf group com actually went off without a hitch just Anyone chasing a lightweight file manager downloaded it and it worked The hardest is pretty spoiled for choice when it comes part was finding it on the Web site but that to Linux However lightweight usually shouldn t be hard for smart LJ readers Head brings along with it some nasty compro to the Download Section click on Sunflower mises perhaps an awkward interface and at the bottom is a download link where hideous grayness bad design or a total you can grab the latest tarball Download lack of aesthetics Not so with Sunflower and extract the tarball and open a terminal To quote the Web site where you extracted the contents As far as library requirements go Sunflower is an open source small didn t have to install anything but anyone and highly customizable twin panel with a minimalist system may have to As 1990s E nat elond Web 2 0 Social Media 2010s Well why not Streamline your business y y operations utilizing the always on redundant CLOUD and fully scalable cloud architecture CariNet s Starter Cloud running 3tera s
127. ke garlic SHARE August 1 5 2010 Hynes Convention Center Boston Massachusetts SHARE in Boston is the one conference that is e 500 technical sessions e 20 hands on labs e 40 products and services vendors e Professional networking Access to a community of IT professionals IBM developers and industry experts ss SHARE Technology Connections Results the answers you need at SHARE Visit boston share org 2010 Polywell Storage Servers More Choices Excellent Service Great Prices Quiet Storage NAS SAN iSCSI 8 1 999 sooo 12TB 2 599 Spare 30TB 6 599 Silent Eco Green PC The Best Terminal PC Intel AMD x86 Processor Energy efficient Quiet and Low Voltage Platform starts at 199 E mail Notification Tower or Rackmount E 2 C gt o 2 Z gt m LD 001 4U24A 1U945GCL2 4U 24Bay 48TB RAID 6 5 15 51 5 Storage Mix SAS SATA 4 Giga 10Gbit LAN 2U 12Bay 24TB RAID 6 5 15 51 5 Storage Mix SAS SATA 4 GigaLAN Mini 1U Server 499 Intel Dual Core Processor 2 x 5006 RAID Dual GigaLAN 4GB DDR2 RAM 888 765 9686 linuxsales polywell com www polywell com us Lx OLY POLYWELL 5U 48Bay 96TB Storage Server Polywell OEM Services Your Virtual Manufacturer 20 Years of Customer Satisfaction Prototype Development with Linux FreeBSD Support
128. l id 1f Slot System board or motherboard size 512MiB bank description DIMM DDR2 Synchronous 400 MHz 2 5 ns product PartNumO vendor Manufacturer9 physical id 0 serial SerNumO slot DIMMO 16 august 2010 www linuxjournal com size 512MiB width 64 bits clock 400MHz 2 5ns This utility is basically an all in one tool that spits out every thing on your system in one go But what if you want information only about specific subsystems in your machine An entire suite of utilities exists for this and they might be more useful when you need some specific piece of information or want to do some system querying in a script You may want to look at the CPU The Iscpu utility provides output similar to the following Architecture 1686 CPU op mode s 32 bit CPU CS 1 Thread s per core 1 Core s per socket 1 CPU socket s 1 Vendor ID GenuineIntel CPU family 6 Model 13 Stepping 8 CPU MHz 571 427 From this you can see the manufacturer whether it s 32 bit or 64 bit the exact version and model as well as the current CPU frequency If you want to know whether your video card is supported by X11 or whether you need to find a third party driver you can use lspci This utility gives a list of all the devices plugged in to your PCI bus The output looks something like this 00 02 0 VGA compatible controller Intel Corporation Mobile 915GM GMS 910GML Express Graphics Controller rev 04 00 02 1 Display c
129. l images buckets and charts as well as all values for HTML tags in metric units The file images conf can be edited to translate the English labels titles and units to any language By editing this file and the HTML template files any language can be supported by wview In fact you easily can switch back and forth between US and metric units by toggling this configuration parameter and restarting wview Advanced Features wview provides a number of features that allow advanced use of the weather data collected from your station Alarms may be defined such that if an upper or lower bound is exceeded a user defined script will be executed These scripts may send a notification e mail or trigger an external application It s also possible to connect to the wview server via TCP IP socket and receive an unsolicited periodic data feed of weather data By using the Virtual station type you can connect to another wview server remotely and receive the station data as if it were connected directly to the station hardware m Mark Teel is the Software Engineering Manager for a major supplier of display and control Systems for mass transit and commercial airline systems He is also an advocate of open source software development and has contributed to several projects including CodeAnalyzer a Java based source code analyzer radlib Rapid Application Development Library and wview Resources wview Home Page and On line User Ma
130. l pleasure had no problems with its interface and its tools and utilities were easy to learn and apply Since my first project l ve learned more about Kdenlive and continue to work with it as my primary video production software There s far more to the program than the few features presented in this article so if you re interested in affordable video production with Linux be sure to check out Kdenlive hope you ve enjoyed this little introduction to amateur video production with Linux I ve had a lot of fun making my own movies with my little setup and hope to improve its capabilities in the future It may be some time before can afford a better camcorder but in the meanwhile can look forward to new releases of Kdenlive to keep me busy m Dave Phillips has been using Linux for sound and music since 1995 He is one of the original founders of the Linux Audio Developers Users groups and has been the maintainer of linux sound org for more than ten years He is the author of The Book Of Linux Music amp Sound and has written many sound related articles for various Linux publications His other activities include playing in a blues band reading Latin literature playing with his shar pei Maximus and spending time with his beloved Ivy You can hear Dave s music at linux sound org ardour music html Resources Kdenlive www kdenlive org K3B k3b plainblack com cdlabelgen www aczoom com tools cdinsert Kdenlive Profile www l
131. lar network hardware like the Linksys WRT160NL provide a solid basis for developing innovative devices m Mike Petullo serves in the US Army and enjoys solving prohlems with innovative open source software He has been working with Linux since 1997 and welcomes your comments at mike flyn org Resources OpenLDAP Everywhere by Craig Swanson and Matt Lung December 2002 see the section titled Configure the Linux LDAP Client www linuxjournal com article 6266 Centralized Authentication with Kerberos 5 Part by Alf Wachsmann LJ January 2005 see the section titled Configuring the Clients www linuxjournal com article 7336 Serving Apples Integrating Mac OS X clients into a Fedora network by Mike Petullo Red Hat Magazine January 2008 demonstrates how to configure Mac OS X clients magazine redhat com 2008 01 17 serving apples integrating mac os x c lients into a fedora network Ultra Small Panel PC 4 e Fanless ARM9 200MHz CPU 3 Serial Ports amp SPI Open Frame Design 24 2058 2 0 Host Paris e Battery Backed Real Time Clock 64 MB Flash amp 64 MB RAM Merona A TTC ata 1 Windows JTAG for Debuging with Real Time Trace WQVGA 480 x 272 Resolution TFT LCD with Touch Screen Four 12 Bit A Ds Two 16 Bit amp 0 2 Bit Timer Counters 2 6 KERNEL The PPC E4 an ultra compact Panel PC with a 4 3 inch WQVGA 480 x 272 TFT color LCD and a r
132. le documentation But Linus Torvalds vetoed the whole plan saying that ambient light sensors essen tially were input devices and shouldn t be given their own subsystem So Jonathan s new ALS subsystem may not come to pass but presumably folks now are working on gathering those drivers together into a saner organization Constantine Shulyupin is soliciting input on how to update his map of the Linux kernel located at www makelinux net kernel map It s a high level view of the overall structure of the kernel complete with links into Ixr free electrons com where the various identifiers are defined and tracked Greg Kroah Hartman has been maintaining the staging tree but recently he started falling behind in considering patch submissions Joe Perches asked why and it turned out Greg had been giving presentations writing articles and moving houses with the result that there was now a 600 patch backlog Various folks discussed possible changes to Greg s standard process which included him just looking at patches as they came in and making decisions about them Joe volunteered to help out Greg was reluctant to change his work flow especially since the problem had been the result of a confluence of events but he did take Joe up on his offer and asked him to handle the incoming patch requests while Greg continued to plow through the backlog Phillip Lougher hit a snag with SquashFS He tried to update some very ugly code
133. licated because the FPGA card connects to the Linux host over a USB serial link The solution illustrated in Figure 1 is to have a d mon manage the USB serial port and demultiplex the various FPGA based peripherals out to their own device nodes The device nodes are little more than shims that let the high level application deal with separate device entries for each peripheral Device Nodes User Space Driver Daemon _ devidp bstep count Bipolar Stepper p bstepirate Motor Controller N USB Sorial PL r To FPGA Card devidp servoo idevidp servot Servo Controller idevidp quado Quadrature devidp quadt Figure 1 Example of a User Space Device Driver The customer selects the mix of peripherals to be loaded into the FPGA Figure 2 shows a BaseBoard4 with some cards that demonstrate what might be a fairly common peripheral mix The system pictured has eight peripherals including a four channel servo controller a dual H bridge controller a quad interface for the Parallax Ping range sensor a RAM based pattern generator driving the data and clock lines going to a 48 bit shift register that connects directly to the LCD a unipolar stepper motor controller a bipolar stepper motor controller a quad event or frequency counter connected to a single Parallax light to frequency sensor and a dual quadrature decoder Schematics for all of these demo cards Figure 2 Robot Periph
134. ll Tiny Ear Trainer simply by clicking on the file install sh where you ll be prompted to enter a root password For those with a minimalist system or those who prefer the manual method you can install it by entering the following command either as root or by using sudo python setup py install Once the installation has finished Tiny Ear Trainer should be in your system menu 42 august 2010 www linuxjournal com Tiny Ear Trainer Preferences gt Soundfont 2 Unison sf2 earning Mode Play individual notes Play notes together v Key Intervals gt perfect unison v minor second major second minor third major third Y perfect fourth tritone Y perfect fifth minor sixth major sixth minor seventh major seventh perfect octave Q cancel s Apply Tiny Ear Trainer gives you a number of useful options from which to choose including a learning mode all in one concise package or you can run it by entering tinyeartrainer Usage Before going any further must warn you that Tiny Ear Trainer uses JACK That s not a bad thing but it can be tricky getting it to work for the uninitiated experi enced JACK users will have no trouble at all and can skip the next few paragraphs First start JACK Most people will be using the JACK Audio Connection Kit which usually can be found in your menu as JACK Control or you can run it from a terminal with the command qj
135. ll appear across the x axis on each respective plot Plot customization is done with several pop up windows Click anywhere on the top temperature plot label to bring up the Edit Plot pop up window Select the Appearance tab to edit the labels kst assigns its own default labels In my case changed the x and y labels to reflect the data that the plot was showing namely the temperature light levels and time interval Modify the label fonts font sizes justification and other assorted options to your tastes Other tabs under this window control how data is plotted on the x and y axes and the range of numbers displayed Whenever you make a change on one of these tabs be sure to click the Apply button then the OK buttons to save the changes This sets up a template for future runs with that data file It doesn t matter if the file is static or grows over time kst will start plotting what s in the file the next time the template is selected Assign an appropriate name to the template file Now that you ve installed and tested kst with a static data file it S time to program the Arduino to sense the environment temperature and light level then stream the data out over the USB line to the notebook Arduino Open Hardware Primer A simplified description of a microcontroller is that it s a small footprint computer that can read and interpret input pin values make a few calculations or decisions and then control output pin signals based on
136. ll protec tions or so we thought But in 2005 a security researcher named Dejan Levaja discovered that Windows Server 2003 and Windows XP SP2 were vulnerable TS SOCKET Macrocontrollers Jump Start Your Embedded Design Series starts at 92 qty100 WO Wyypeppequie MAM Id 00Gv Sl vn 75 2 953 236 in 55 mm 2 165 in E E o TS SOCKET Macrocontrollers are CPU core modules that securely connect to a baseboard using the TS SOCKET dual connector standard with common pin out interface COTS baseboards are available or design your own baseboard for a custom solution with drastically reduced design time and complexity Start your embedded system around a TS SOCKET Macro controller to reduce your overall project risk and accelerate time to market TS 4200 Atmel ARM9 with super low power TS 4300 Cavium ARM11 with dual 600 MHz and FPU TS 4500 Cavium ARM9 at very low cost TS 4700 Marvell PXA168 with video and 1 2 GHz CPU TS 4800 Freescale iMX515 wi video and 800 MHz CPU Several COTS baseboard evaluation amp developme Design your solution with one of our engineers Never discontinued Engineers on Te Open Sour We use our stuff visit our TS 7800 powered website at www embeddedARM com 480 837 5200 COLUMNS PARANOID PENGUIN to the LAND attack The fact that LAND attacks are still trivially blockable by firewalls is actually beside
137. ll use plain old iptables to evaluate packets in the same way that routing firewalls do using IP TCP UDP header information Conclusion But that will have to wait until next time Hopefully you now understand the difference between a standard routing firewall and a trans parent bridging firewall In my next column sketch out an example usage scenario conceptually very similar to the network in Figure 3 describe a couple different approaches to selecting Linux fire wall hardware and begin showing how to configure a transparent firewall starting with bridge switch setup Until then be safe m Mick Bauer darth elmo wiremonkeys org is Network Security Architect for one of the US s largest banks He is the author of the O Reilly book Linux Server Security 2nd edition formerly called Building Secure Servers With Linux an occasional presenter at information security conferences and composer of the Network Engineering Polka Resources Linux Firewalls for Everyone by Mick Bauer LJ April 2007 www linuxjournal com article 9569 Internet News report on Dejan Levaja s latter day LAND attack against Windows Server 2003 and Windows XP SP2 www internetnews com security article php 3488171 Ethernet Bridge Wikipedia en wikipedia org wiki Ethernet_bridge www linuxjournal com august 2010 31 COLUMNS Sky KYLE RANKIN Temper Temper A 15 USB thermometer and some spare parts are all nee
138. lls are still relevant in the first place and the difference between routing and bridging transparent firewalls What Firewalls Do and Don t Do was tempted to begin with a primer on firewall architecture and design discussing the difference between the multihomed and sandwich topologies rule design methodology and so forth But my April 2007 article Linux Firewalls for Everyone does that just fine and you still can read it on line see Resources Instead I m going to talk about why firewalls are still useful An IP firewall as opposed to an application firewall or XML gateway inspects network traffic at the IP and TCP UDP layers possibly with some very limited amount of application intelligence for example being able to distinguish between FTP get and put commands HTTP post vs get and so forth In actual practice most packet filtering and stateful IP filtering firewalls evaluate traffic primarily based on source and destination IP addresses and source and destination UDP or TCP ports When I started out in network engineering just fil tering traffic based on these few criteria seemed plenty powerful enough for most practical firewall applications especially if the firewall was smart enough to track network traffic by session rather than by individual 28 august 2010 www linuxjournal com packet In olden times it wasn t enough to program your IP filtering firewall to allow outbound DNS querie
139. matches this against the entries in its local MAC table which is simply a list of the MAC addresses of all devices currently attached to active ports and delivers the frame to the corresponding local port For more complete discussions of how routers and bridges switches work Wikipedia is a good place to start look and behave in much the same way as if it were a standard routing firewall All the trickery is in the firewall s network configuration Figure 3 shows a transparent bridging firewall In this example the firewall has been configured to treat both of its network interfaces as switch ports Neither interface has an IP address bound to it Instead the virtual switch that they comprise has a shared IP address of 44 55 66 254 Although the firewall might be reach able by this IP address actually there are good reasons for it not to be none of the hosts in Zone A need to use that IP as a gateway in order to reach the hosts in Zone B or vice versa Just as with any other switch the firewall will propagate packets automatically without needing to be explicitly routed through However the firewall will propagate packets only after first matching them against its firewall rule set and determining whether it even should propagate them If you want to evaluate packets based on Ethernet header attributes you can do so using ebtables However in this series of articles on building your very own transparent Linux firewall we
140. mmand You will get a list that looks like this agpgart 31788 2 drm intel_agp lp 7028 9 video 17375 1 1915 output 1871 1 video You can see that the agpgart module has a size of 31788 bytes and is used by the drm and intel_agp modules Now hopefully you can configure and optimize your hardware so that you get the most out of it If you find other utilities not covered here would love to hear about them JOEY BERNARD Android Too Much of a Good Thing Android is everywhere Really It runs phones tablets and recently even saw it running on an iPhone Just a few years ago that would have thrilled me to no end Truthfully it still does but I m more skeptical now See two years ago Linux was everywhere on Netbooks thought it was a big break Linux finally hit the mainstream But vendor customization and dumbing down made Linux look like an inconsistent kludge rather than a free and powerful choice So far Android looks fairly consis tent across hardware So far many apps work regard less of the Android version your device CINDROID Es Hopefully vendors will see the mistakes made with Netbooks and keep their branding to a minimum There are many ways phone vendors and wireless carriers could mess up our world domination efforts Again Dear Vendors please don t try to sell more phones by adding proprietary software on top of Android If you add software contribute it back to the com
141. munity If you want to sell more phones make better phones than your competition Please SHAWN POWERS UPFRONT NON LINUX FOSS Just because your phone is running Linux and let s hope it is hat doesn t mean you can t talk to it with your Windows computer Droid Explorer is an open source program that allows you to manage your Android device in the same way hat Windows Explorer allows you to manage your local files Droid Explorer supports multiple devices allows you to copy iles to and from your device easily assists in applying system updates provides a shell window allows you to reboot into recovery mode provides a package manager to install uninstall Android Packages APK and it even lets you take a screenshot of your Android device And that s just for starters Droid Explorer is written in C for the NET platform The current version is 0 8 4 3 Beta and it lives at de codeplex com If you re a Mono programmer looking for a new project the developer is looking for someone to pitch in and help convert the UI to run on Mono 1 Device Found Ryan s Phone Path lala ap Sook ack data sop com googe androd appe france apk org shakey apk FTPServre apk ieptem npo Gmal pe gouge anrod apps maps ak Jeystem aco T8kk ac system apo qusiksenace Ata app com gonge andad apk data app foam inan hacky a
142. n Historical data for the last 24 hours are presented as graphs Graphs of the last 24 hours the last 7 days the last 28 days and the last 365 days are available on other site pages Citizen Weather Observer Program CWOP CWOP is a system by which individuals with weather stations and the proper software can submit their weather data to an APRS based data storage system so that others including NOAA www linuxjournal com august 2010 53 FEATURE Using wview Collinsville Texas Weather Mw wn 05 02 10 10 34 10 30 Surmet 20 12 Voce Wang E Fut 0660 1 caya 4 52 Figure 5 Default Web Site National Oceanic and Atmospheric Administration can use the data however they see fit There are some really neat station display Web sites including some Java apps to look up station data position maps and so on See www findu com cgi bin wxpage cgi call CW4097 for an example weather station CWOP participation requires registering for an APRS callsign Once you have configured wview for CWOP properly and confirmed your data on line you must contact the maintainers via e mail to confirm your registration Then your data will be available for anyone to see and possibly be used in NOAA forecast models and so on When CWOP support is enabled and configured properly wview transmits a new WX packet to the APRS server every ten minutes based on the last digit of
143. n better engi neers and programmers but also because these partners believe in a substantial future demand for people trained in UMPC and embedded platform development Currently the OSWALD s biggest challenge is broadening the program Manufacturing hardware for a small commu nity is expensive and risky and the long term costs may outweigh the benefits Therefore scaling up demand to other universities and even enthusiasts is the key to this device s success Right now the OSWALD is available to students and a handful of friends OSU like many universities is not set up for large scale manufacturing or distribution It will have to think up ways as an Open Source community to support these types of educational efforts in the future Acknowledgements Thanks to Ben Goska Tim Harder Techtronix Texas Instruments Intel and the National Science Foundation m Victor Kuechler is an undergraduate student studying English literature and writing at Oregon State University He works as technical writer for the department of Electrical Engineering and Computer Science Dr Carlos Jensen is an assistant professor in the school of Electrical Engineering and Computer Science at Oregon State University where he leads the Human computer interaction research group His research focuses on usable privacy and security open source systems and open source development www linuxjournal com august 2010 71 Video Pr
144. n t just for hobbying anymore Their new book Blender Studio Projects Digital Movie Making now out from Sybex shows readers how to do on Blender what one typically has done with high end and high priced apps Maya and 3ds Max Sybex bills the book as a real world roll up your sleeves guide that plunges straight into step by step instructions designed to help you build skills and create solid assets for film video and games The companion DVD includes starter intermediate and final files as well as movie files to help you every step of the way www sybex com 40 august 2010 www linuxjournal com NEW PRODUCTS P CAST Software s Analysis and Measurement Software for SAP Siebel and PeopleSoft Managing ERP apps can require the patience of Job which is why CAST Software released its new Analysis and Measurement Software for SAP Siebel and PeopleSoft The product s mission is to bring consistent and objective measurement of these platforms and eliminate costly customization errors in critical business applications CAST s own studies of ERP installations showed a large percentage of issues that normally go undetected in functional testing and result in serious performance stability and maintainability problems For instance 80 of database interactions in ERP installs are handled improperly leading to significant business disruption Environments like SAP Siebel and PeopleSoft says CAST require a deceptively high level of customizat
145. ndwagon too remember you telling me that a single 1 2GHz core was fast enough and I m www linuxjournal com august 2010 77 POINT COUNTERPOINT willing to pay the penalty for a slow 1 8 disk for the portability KYLE Yeah was willing to pay the penalty for portability Now my main portable computer is 00 so can stand to have a slightly larger laptop that can handle a larger drive Recently I ve tried using it for virtual machines and the 7200RPM drive it has is a pain just chokes when you have too much going on I m wishing had invested an SSD when first spec d it out but figured give the 7200RPM drive a chance first BILL Regarding g forces and rotating media the new accelerometer based tech has helped disks survive crazy things and the smaller lighter head shave helped too Anytime you have IO contention you ll have performance issues Faster disks move that out But really it s not like two VMs are unusable l have two going on my laptop routinely Matter of fact one of them is how access e mail don t ask have some totally bizarre corporate antics to put up with KYLE glad they ve made the tech equivalent of a seat belt and airbag to save your rotating media but l d rather it not be a problem in the first place mean even the iPod figured out SSDs were the way to go years ago l d figure if it s good enough for Apple it d be good enough for you The bottom lin
146. nerate a Web site you don t have to have one After installation and typical configuration disable all wview Processes under the Services tab in wviewmgmt The station interface process always is enabled and thus is not configurable Start wview as normal Only the wviewd station daemon will be running collecting data from the station and archiving records and HILOW values in the archive databases Because wview stores archive data in SQLite3 databases it is a simple matter to implement scripts or applications that access the data via SQL Many wview users create their own custom Perl PHP Java WordPress applications for their weather data Weather Site Customization The default generation model for wview is to generate a weather Web site based on a series of HTML file templates and images For any template file named example ext x and listed in html templates conf wview will generate a file named example ext Thus myscript phpx listed in html templates conf and found in prefi var wview html will have all wview tags replaced and the resulting file will be named myscript php For any template file named example htmx and listed in html templates conf wview will generate a file named example htm The resulting files are stored at the location specified on the wviewmgnmt File Generation page Generation Target Path Changing HTML templates in prefix etc wview html does not require you to restart wview The changes you make will t
147. ng and shipping When you partner with Silicon Mechanics you get more than increased performance and improved energy efficiency you get Experts like Maddison and Dominic For more information about products featuring the Intel Xeon Processor 5600 Series visit www siliconmechanics com 5600 Xeon inside Powerful Intelligent IL IC Or FEATURE A Simple Approach to Character Drivers in User Space dev proxy User Space User Space Figure 5 A Device to Pass Data between Two Applications current value and then does a write of zero bytes both of which are read seen by cat It is the write of zero bytes that tells cat it is done and can exit One drawback to the proxy driver is that it required the customer to build and install a kernel module Although Dynamic Kernel Module Support can help a lot of customers are intimidated by this even if it s not that difficult see Exploring Dynamic Kernel Module Support DKMS LJ September 2003 www linuxjournal com article 6896 FUSE is a good approach for customers who do not want to deal with building modules and who don t need select support Another approach for driver configuration is to use a regular ilesystem file and the inotify facility to alert the user space driver that a new configuration is being requested You get wo nice features by keeping the configuration files on a volume with persistent storage The first is
148. ng device drivers in user space has some nice features It does not add a lot of kernel code and does not require any user space libraries It supports select everywhere you might want it and it has good flow control for streamed data Fanout and proxy have some shortcomings too The data stream from a fanout device is byte aligned which makes it inappropriate for an application that needs to send blocks of binary data Fanout could not for example be used to simulate a new dev input device Demand Peripherals gets around this problem by sending lines of ASCII text that are terminated by a newline If you need multibyte transfers you could add an ioctl to fanout that sets the byte count for atomic reads from the data source If you like the simplicity of dev proxy but really need ioctl support you can add it to the proxy driver by allocating two minor numbers for each proxy device Use the even numbered minor numbers for the data interface and the odd numbered minor numbers for the ioctl interface Your configuration might look like this mknod dev proxy_data PROXYMAJOR 0 mknod dev proxy ctrl PROXYMAJOR 1 Your additions to the proxy driver would have to serialize the data passed to and from the ioctl request and your user space driver daamon would have to open both devices to handle the ioctl requests separately from the data stream requests We used fanout and proxy to add device drivers for an FPGA based robot
149. nto something even more useful typically a single value For example you can define the reduce function as follows function keys values rereduce return 1 From within Futon this returns a list of three documents the keys of which are the birthdays and the values of which is the number 1 This isn t very interesting to be honest because you could have accomplished the same thing from within the request But if you invoke the same query from curl you get something else entirely rows key null value 1 1 Why the difference And why is there only a single row now The answer is that reduce is designed to well reduce things That means instead of returning a result for each row it returns a single result from all rows The reduce function actually can be invoked in two ways The usual way in which the keys and values represent document keys and values In such cases the rereduce parameter is set to false For rereducing the rereduce parameter is set to true the keys are null and the values repre sent values from a previous partial run of the reduce function As the CouchDB Wiki states this means the reduce function must be both commutative that is the order in which arguments are processed doesn t matter and associative that is the order in which operations are executed doesn t matter This often but not always means the reduce function
150. nual www wviewweather com wview Google User Group groups google com group wview Citizen Weather Observer Program CWOP www wxqa com The Weather Underground Wunderground www wunderground com Ryan is the newest addition to the staff of Experts dedicated to technical support for Silicon Mechanics He came aboard knowing that the standards we set are for all around Powerful Intelligent excellence That s why he s pictured here with our newest storage server the Storform iServ R518 v2 This storage server distinguished by front and rear drive deployment exemplifies the same commitment to quality value and service that Ryan does With 36 hot swap SAS SATA drive bays 24 in the front 12 in the rear the R518 v2 offers innovative engineering and superior density With 2 Intel Xeon Processors 5600 Series the R518 v2 offers state of the art multi core power and intelligent energy efficiency Try the Silicon Mechanics online configurator for comprehensive configurability and very competitive prices When you partner with Silicon Mechanics you get more than front to back quality value and service you get an Expert like Ryan ntel the Intel logo Xeon and Building Custom Firmware with OpenWrt Using an inexpensive wireless router you can build a file server a print server and even a media server Plus you can put all of those together and build the network device that does w
151. o the following pacpl to mp3 2010 01 Five Minutes SpringRoo mov Perl Audio Converter 4 0 5 Converting 2010 01 Five Minutes SpringRoo mov gt mp3 done Total files converted 1 failed 0 The output is stored in the 2010 01 Five Minutes SpringRoo mp3 file in the same directory MAHENDRAN NATARAJAN gt Convert PDF Documents to JPEG Images If you want to convert a PDF document to a JPEG image first use pdftoppm to convert it to a PPM Portable Pixel Map file and then use ppmtojpeg to convert it to a JPEG file First convert the PDF pdftoppm input pdf output This generates one PPM image per PDF page in files named output N ppm where N is the page number If you want only part of the document specify the first page to convert with f N and the last page to convert with 1 N Finally to convert all the PPM files to JPEG images you can do something like this for file in ppm gt do gt ppmtojpeg file gt file ppm jpg gt rm file gt done MALICK KHADY DIA gt Play Videos Packed a RAR File without Extracting Them Most DivX Xvid movies you download from Torrent sites are packed in multiple RAR archives It takes some time and space to extract each of them If you don t want to wait or use the space you can use VLC and unrar to play the files without extracting them You won t be able to rewind and fast forward within the file but you ll be able to play and stop the movie
152. ocessor in thousands 275 Transistor count of an Intel Pentium microprocessor in thousands 3 100 Transistor count of an Intel Pentium 4 microprocessor in thousands 42 000 Transistor count of an AMD K8 Athlon 64 microprocessor in thousands 105 900 Transistor count of an Intel Core i7 microprocessor in thousands 731 000 Transistor count of an Eight Core Xeon Nehalem EX microprocessor in thousands 2 300 000 Transistor count of an RV820 ATI AMD GPU in thousands 2 154 000 10 Transistor count of a GF100 NVIDIA GPU in thousands 3 000 000 11 Hard drive cost per gigabyte in 1990 53 000 12 Hard drive cost per gigabyte in 1995 850 13 Hard drive cost per gigabyte in 2000 20 14 Hard drive cost per gigabyte in 2005 1 15 Hard drive cost per gigabyte in 2010 10 16 RAM cost per gigabyte in 1990 119 706 17 RAM cost per gigabyte in 1995 33 024 18 RAM cost per gigabyte in 2000 1 598 19 RAM cost per gigabyte in 2005 189 20 RAM cost per gigabyte in 2010 21 Sources 1 10 en wikipedia org wiki Transistor_count 11 14 ns1758 ca winch winchest html 15 20 www newegg com 16 19 www jcmit com memoryprice htm www linuxjournal com august 2010 15 UPFRONT What Hardware Do I Have Often you may not necessarily know what kind of hardware you have you may have a no name box from a smaller company or a used machine This month present the tools you can
153. oduction 101 Making a Movie with Kdenlive With an inexpensive camera and a Linux system you can be producer director editor and even the grip of your next blockbuster DAVE PHILLIPS By profession I m a music teacher Four times a year my students perform a show at a local coffeehouse called Coffee Amici The room hosts regularly scheduled performers open mic nights and various community events My students love to play there It s a great opportunity for them to show their stuff for an attentive crowd and eventually they asked about the possibility of doing video recordings of the shows looked into the affordability of the requisite gear the extent of Linux support for recommended hardware and the availability of software that would help me produce a simple DVD from my recordings was happy to discover that the project was well within my price range and that my software choices included more than one adequate solution This article describes how recorded a student show with an inexpensive camcorder and how produced a movie from that footage with Kdenlive a non linear editor NLE for Linux Kdenlive is a powerful program but my project was simple and the methods describe here should be usable in other Linux NLEs Learning about the Hardware First needed a video camera My research and my budget led me to the Samsung SC D382 miniDV camcorder Figure 1 For about 100 got a camera with a remote con
154. on IPC mechanism and still need to document the internal and the external interfaces The other problem with a library approach is that it is usually not just one library you may need to write a library or bind ing for every programming language you want to support Using a real character device instead of a library means your customers can program in any language they want not just the ones for which you ve written a binding The second requirement was that the driver security model be based on file permissions This implied that all of the device 48 august 2010 www linuxjournal com data and configuration interfaces should be visible in the filesystem That is you should to be able to do a chmod 644 on something like dev dp bstep1 rate Using named pipes and FUSE Filesystem in USErspace could have fulfilled this requirement Doing this using pseudo terminals would have been tricky Another requirement is that select works both in the higher level control application and in the user space driver itself This requirement comes about because select is so much faster than threads in most applications Embedded systems such as robotic or other industrial control systems often run on the cheapest lowest cost hardware possible and in the case of robots often on battery power These constraints lead embedded Linux programmers to prefer select based systems FUSE often is suggested as a way to implement character drivers but
155. on which private and public structures can be built in boundless varieties Linux is probably the most widely used build ing material below and within those struc tures Calculating its value is pointless because as Eric S Raymond made clear long ago Linux has use value more than sale value As useful stuff its leverage is boundless and therefore incalculable It also will last as long as it remains useful The same cannot be said of Facebook whose value is quite calculable and which will thrive only as long as its revenue model and its investors patience holds out Both of those will be shortened by the dissatisfaction of users which Facebook has been risking increasingly over the years To see how this has been going it helps to check with Facebook s Eroding Privacy Policy A Timeline by the EFF It shows how during the five years of its existence Facebook s priva Cy policy has ratcheted down from respectful to exploitative And why not Facebook s cus tomers are advertisers not users As a user your influence on Facebook rounds to zero The company is far more interested in making you into better bait for advertisers and visitors who click on ads A side benefit is a smarter personalized Web that is not the Web at all but rather an indoor commercial habitat with some nice conveniences We ve seen this movie before many times The most important and dramatic example is Microsoft s HailStorm which arr
156. ontroller Intel Corporation Mobile 915GM GMS 910GML Express Graphics Controller rev 04 This information shows that the video controller in my EeePC is an Intel controller So if you wanted you now could search Google with this information to learn about your video card and how best to configure it If you want to see what USB devices are on your system use lsusb On my EeePC have an SD card installed and it shows up as this Bus 001 Device 002 ID 0951 1606 Kingston Technology If you re interested in the disk subsystem you can find out what your system has with the blkid utility This utility prints out all the available filesystems with the following output format dev sdal UUID XXXXXXXX XXXX XXXX XXXX XXXXXXXXXXXX TYPE ext2 dev sda2 UUID XXXXXXXX XXXX XXXX XXXX XXXXXXXXXXXX dev sda3 UUID XXXXXXXX XXXX XXXX XXXX XXXXXXXXXXXX TYPE ext2 dev sdb1 UUID XXXXXXXX XXXX XXXX XXXX XXXXXXXXXXXX TYPE ext2 With this utility you can learn what devices are available and what filesystems are being used on them The associated UUIDs also are available if you want to use them in the entries in etc fstab Now that you know what kind of hardware you have on your system the last thing to check is to see whether your kernel actually is using the available hardware On most modern distribu tions the kernel is compiled to use modules You can check to see which modules are loaded by using the Ismod co
157. op mkdir p delmendo vim home cd delmendo vim cp R vimrc viminfo vim home homesick clone Desktop delmendo vim Now you can ask which castles are installed In my case it shows technicalpickles and delmendo vim It should list technicalpickles pickled vim a bug that should be fixed by the time this goes to print To activate it execute the command homesick symlink technicalpickles pickled vim Or homesick clone delmendo vim This starts the process of linking in the files It also warns you of conflicts and allows you to look at differ ences before you make the swap The system does not handle synchronizing the files across different machines but you easily can handle that either by putting them in a network accessible git repository or host the files remotely and mount them There are a bunch of ways to do both but GitHub and Ubuntu One come to mind The first commit on the project was March 3 2010 so it s still early hope the features continue to evolve because it saves me from having to cobble it together Mockingbird To be honest have absolutely no artistic talent This is generally not a problem because I partner with a great designer who happens to be my brother so he doesn t take it personally when yell at him I m in the process of launching a Web application As you probably can tell www linuxjournal com august 2010 37 COLUMNS from my writing I m very comfortable describing t
158. order to use the latter interface you have to open the WRT160NL s case which voids the device s warranty Figure 2 Console Cable Figure 3 provides a picture of a Nokia DKU 5 cable connector The other side of the cable has a USB connector Cut the cable in half so that most of its length is on the USB connector side Now expose the six leads on the Nokia connector side Use a continuity tester to identify which four of the six leads correspond to the functional pins noted in Figure 3 Note the insulator color of the lead connected to each pin Now focus your attention to the other half of the cable the one with the USB connector Expose the four leads matching the colors noted earlier Connect each of these leads to the four of five binding posts labeled in Figure 4 ensuring that the lead and post functions match You may connect them using a PCB connector hook to pico hook jumpers or a more primitive technique Connect the USB connector of the console cable to your build workstation Install a serial terminal emulator such as minicom on your build workstation and run the program Configure the emulator to use eight data bits no parity bit and one stop bit Select 115200 baud Boot the router and observe the emulator console You should see the router print 3 3 Transmit Ground Figure 3 DKU 5 Connector wm ANS LEN LUE LS R cem 09224 UE 7 3 3 Volt Transmi
159. p Data Source pane will appear Enter the data filename testdata txt Press the Configure button The Configure Data Source pane appears Enter the custom delimiter character to separate the values in the data set used the vertical bar as a delimiter between the temperature and light level values M ae manoa Fo 1 1 Range pots los itip v wOos ivgdHooooBUWImMGSE pat om Date warn oo select a date sours to trom This will typically be your Nie containing data ponts er Data vource of type ASCH Configure Figure 1 kst Toolbar Data Source and Configure Data Source Window Once the delimiter character is set click the Apply then the OK buttons to save the settings and close the window Click Next on the Data Source pane to bring up the Select Data pop up window In the Data Source pane hold down the Ctrl key and select numbers 1 and 2 in the left hand pane These correspond to the temperature left and light level right values in the data file Once selected click the right pointing arrow to copy the data streams to the right hand pane Using two data streams will give two separate graphs one for temperature and one for light levels referenced by a common line number Temperature and light levels Want your business to be productive The ASA servers powered by the Intel Xeon Processor provide the quali
160. pk dsta scp com getkyouup android latisuncher apk data spp edu mt locale ack EE Locale SMS Plugin com twefemylnumm wengu app icem nolomcurmm incole seeing ma nic FA Leg Colector cem erioge mama gene data app andreid ing collector 1 0 0 apk Managing Your Droid s Packages MITCH FRAZIER Readers Choice Awards 2010 Vote for your Linux and open source favorites in this year s Readers Choice Awards at www linuxjournal com rc10 Polls will be open through August 20 2010 Winners will be announced in the December 2010 issue of Linux Journal Choice JOURNAL www linuxjournal com august 2010 17 UPFRONT AUTONOMOUS CARS RUNNING LINUX This summer two electric cars will be traveling from Milan Italy to Shanghai China on an ancient silk route vislab it Projects view 32 VisLab 27s_new_ adventure_on_the_Silk_road The driving will be completely autonomous controlled by Linux recognition and processing soft ware The cars are being developed at the Artificial Vision and Intelligent Systems Lab of Parma University by Alberto Broggi and his team Read on for an interview with Alberto about the project Anton You recently announced the Milan Shanghai initiative Could you explain the main purpose behind it Alberto We design driver assistance systems to help drivers and reduce acci dents increasing road safety With this trip we are pushing our technology to the
161. pplies Up to 14 hot plug proc based blades One Management modules come Supermicre sure chassis with two ssor blades standard with each One hot plug management module and IPMI 2 s providing remote KVM 0 functionalities Support one hot plug Gigabit Ethernet switeh Through Module Powerful Intelligent letters MongoDB OpenVPN Nmap Pogoplug MINIX Tech Tips MongoDB s High Powered Features JUURNAL DISTRIBUTIONS LINUX NON X86 COMPUTERS Philosophy of Distributions Commons Interests Regarding Doc Searls EOF in the June 2010 issue you didn t do anything wrong with your ice pictures They are yours to distribute as you like All the critics of how you handled things are just jealous My understanding of the Creative Commons license is just like the GPL the license means others can use your copyrighted work without explicit permission as long as they abide by the license If they want to use it in another way they must get your permission just as they would if you hadn t placed it under Creative Commons or GPL etc NBC requested a special license and you gave them one So what If you had never placed your work under a Creative Commons license NBC never would have found it and it never would have been used Bonus to you The license requirements under Creative Commons GPL and similar licenses apply only to use without pe
162. r Device The way the logic of the script works it allows the use Device USB PCSensor HidTEMPer NTC temperature to drop or rise naturally while the com use Device USB PCSensor HidTEMPer TEMPer pressor or heater is on respectively It changes the use lib power state of my X10 devices with the br command use Device USB PCSensor HidTEMPer only when the temperature is outside the preset ranges set this script to run every minute with cron my pcsensor Device USB PCSensor HidTEMPer new and because I log all of the power states it s easy to my Gdevices pcsensor list devices watch the temperature float between extremes did a my temp min 71 bit of tuning at the beginning with the various ranges my temp max 73 and with the current script the temperature floats my logfile var log temper log between 1 F below the minimum temperature and my time localtime 1 F above the maximum temperature which is good my temperature enough for me If wanted more accuracy always could set min and max to be closer to each other foreach my device Gdevices Since the system has been in place l ve been able to temperature device internal fahrenheit maintain the temperature successfully for the first batch of beer I put in the fridge If you look closely at Figure 2 you can see the little thermometer on the right hand open LOG gt gt logfile or die Can t op
163. r console for example Ctrl Alt F3 Now move the mouse a little and switch between the F2 and F3 consoles They both display the same thing don t they What a shame that Linux does not www linuxjournal com august 2010 47 FEATURE A Simple Approach to Character Drivers in User Space FOR ROBOTICS THE ABILITY TO FAN A SENSOR READING OUT TO SEVERAL PROCESSES IS PARTICULARLY IMPORTANT have some generic way to do multicast like that of the dev input subsystem For robotics the ability to fan a sensor reading out to several processes is particularly important For example a quadrature encoder attached to a wheel needs to be seen by both the motor controller software and by the navigation software The motor controller might need to know if the wheel is turning to know whether the motor is stalled and the navigation software might count the wheel revolutions to compute the robot s current location The second use case is peripheral or driver configuration DC motor controllers need to know the frequency of the PWM pulses Stepper motors need to know the step rate and the SPI Serial Peripheral Interface ports need to be told the clock frequency and the mode of operation Either an ioctl call or a sysfs style interface can be used for driver configuration Configuration interfaces can be a little tricky in that the information is often not a simple stream of bytes it may encompass several different pieces of information An ioctl
164. r to our attention It s always our goal to bring content that covers our entire readership but sometimes we need to be reminded when we are leaving a group feeling a bit left out As far as the digital issue goes it s been an ongoing discussion and struggle for more than a year now I m confident someday we ll have a perfect eBook version of Linux Journal available but right now the PDF offers fewer sacrifices in layout quality and maintains the look of the print magazine We realize it s not ideal but so far it is the best option we have haven t seen Full Circle Magazine so I ll have to check it out Ed LJ Infects Another have been buying Linux magazines but most of them are so expensive Then I found a copy of Linux Journal without DVD really who needs it Digital sub scription ooh yeah You just infected another Linux user in the country of cheese The Netherlands Chihwah Li I m thrilled you found a copy of Linux Journal For folks in other countries the digital edition can be a great way to get a timely and affordable subscription I m glad it works for you Welcome to the family Ed Left Out In the June 2010 Point Counterpoint Mobile Phones it was obvious neither party knew of the Palm webOS mobile platform This is by far the most Linux hacker friendly mobile OS out there For example OpenOffice org and Xorg were just ported to the Palm Pre bit ly aUIWOv Palm
165. re 2 Caffeine Enter Caffeine This handy app puts a small coffee cup in your notification bar When you want your com puter to stay awake just click the coffee cup If you re okay with normal behavior click on the cup again This is nice because it is easy to access and it gives you a visual cue to remind you what you have done There even are options to tell it to kick in for a certain amount of time If clicking is too much trouble you also can tell it to kick in automatically when certain applications are running Flash videos OpenOffice org Presentation or Skype for example On Ubuntu you can add in the PPA Personal Package Archive Then installation is easy sudo add apt repository ppa caffeine developers ppa sudo apt get update sudo apt get install caffeine It ends up being very handy As mentioned versions of Caffeine exist for other platforms so end up recommending it whenever see people give presenta tions and their screens go dark Now it s a standard part of my installation for my workstations Homesick Homesick proves that sometimes it pays to wait and spend time on Google When started writing this column had an idea to write about my struggle to keep my home directory synced across a lot of different workstations figured it was a common problem but couldn t find an elegant solution originally hoped to drag in cloud storage so didn t have to access my home computer directly to stay
166. ree that your theory is crazy but is it crazy enough Niels Bohr If you think education is expensive try ignorance Derek Bok Pain is inevitable Suffering is optional M Kathleen Casey Bad is never good until worse happens Danish Proverb Dream as if you ll live forever Live as if you ll die today James Dean Difficulty attracts the man of character because it is in embracing it that he realizes himself Charles de Gaulle Technology is like fish The longer it stays on the shelf the less desirable it becomes Andrew Heller IBM The last good thing written in C was the Pachelbel Canon Jerry Olson Watch me not care Dilbert EACH WEEK OR SO we re choosing a Linux distribution to highlight on LinuxJournal com You ll see the Distro Spotlight on every page of our Web site We hope you ll visit often and add a comment to cheer on your favorite and also share your thoughts tips and pitfalls In the process we hope to present some lesser known gems although we ll still celebrate crowd favorites Be sure to check out the current pick and maybe you ll find your new favorite distribution If you re up to a fun challenge try each distribution with us Who doesn t love a reason to re install Linux While you re at LinuxJournal com feel free to leave a note to tell me how things at the site are working for you You can find me at www linuxjournal com august 2010 19
167. renew my subscription and added the digital edition as well received my first digital edition today and have to state that am disappointed The disappointment comes from the way it s formatted Like most digital magazines one must scroll up and down the pages If adjust the file so each page fits completely on one screen the print is too small to read My computer has a 15 screen had hoped that Linux Journal would have its digital edition formatted in the manner of Full Circle Magazine Have you seen that magazine That is the way a digital magazine should be formatted Each page fits completely on the computer screen and the print is easily read Reading columns is quite easy in this format no scrolling up and down and up and down is necessary And to read further you merely click on next page button So in conclusion I d like to say that I sincerely hope you will publish more such basic articles as those two mentioned above more of these would make the magazine truly useful to com puter unsophisticates such as myself Of course your current types of articles should continue to be published for those who can appreciate them And I d like to suggest that you consider reformatting the magazine s digital edition in the manner of Full Circle Magazine Thank you for reading this and for considering my suggestions Lawrence H Bulk Thank you for bringing the tech level matte
168. rity of computer systems and networks rogram includes Co Located Workshops Keynote Address by EVT WOTE 10 2010 Electronic Voting Roger G Johnston Vulnerability Assessment Team Technology Werkshop Workshnopron Argonne National Laboratory Trustworthy Elections Refereed paper presentations showcasing new CSET 10 3rd Workshop on Cyber Security research in a variety of subject areas including Experimentation and Test cryptography Internet security dissecting bugs and August 9 21 more gt 24 WOOT 110 4th USENIX Workshop on Offensive Technologies Understanding Scam Victims Seven Principles for st 9 2 Systems Security by Frank Stajano Senior Lecturer at e NETE D E the University of Cambridge UK and Paul Wilson The CollSec 10 2010 Wor kshop 9n Collaborative Real Hustle Methods for and Privacy End to End Arguments The Internet and Beyond l by David P Reed MIT Media Laboratory HealthSec 10 1st USENIX Workshop on Plus a Poster Session BoFs and more Health Security and Privacy HotSec 10 5th USENIX Workshop Ho Topics in Security P http www usenix org facebook sec10 Auqus 1C http twitter com USENIXSecurity MetriCon 5 0 Fifth Workshop on Security Metrics Register by July 19 2010 and save www usenix org sec10 lj d New PRODUCTS Radical Breeze s Illumination Software Creator Were you a LEGO lover as a kid If so Radical Breeze thinks you
169. rmission If you get permission from the copyright owner to use the object under different terms you are free to do so NBC probably should have asked for something in writing just to protect themselves and verify the alternative license and perhaps they did but other wise don t see how they were bound by the terms of the Creative Commons license you published the photos under Alan Shea Which Is It Just curious as to which Distro logo is the one between Ubuntu and Debian on the front cover of the June 2010 issue www linuxjournal com forums june issue 194 David Novell Ed Grandparents Are Power Users Too am a subscriber to your magazine and do not appreciate Dan Sawyer s comment grandparents incapable see Philosophy and Fancy in the June 2010 issue have installed many dual boot distributions and program a little when I need to in shell awk and some C And with great assistance from my children installed LFS from source I ve also worked on recompiling the kernel but don t like to do it GrandparentNancy Dan Sawyer replies The hypothetical grandparent who is unfamiliar with afraid of technology is a longstanding hypo thetical user in the geek world just as is the teenager who knows everything about computers Neither of these hypothetical people are meant to imply that all teenagers are geek gods or that all grandparents are technophobic It s just a long establishe
170. ry 1 x16 PCI E Low Profile Matrox G200eW 8 DDR2 Memory Video Integrated Remote Management IPMI 2 0 IP KVM with dedicated LAN All four nodes share a Redundant 1200W High efficiency Power Supply Gold Level 92 power efficiency 800 820 BSDi http www iXsystems com Enterprise Servers for Open Source Intel the Intel logo and Xeon Inside are trademarks or registered trademarks of Intel Corporation in the U S and other countries Cool Fast Reliable GPGPU computing for your office and data center Designed from the ground up for ultimate customer satisfaction Microway s WhisperStation integrates the latest CPUs with NVIDIA Tesla GPUs Tesla s massively multi threaded Fermi architecture and FORTRAN language environments and OpenCL provide the best performance for your application Up to Four Tesla Fermi GPUs WhisperStation with 448 cores and 6 GDDR5 each delivering 1 TFLOP single and 515 GFLOP double precision performance Up to 24 cores with the newest Intel and AMD Processors 128 GB memory 80 PLUS certified power supply and eight hard drive gt Nvidia GeForce GTX 480 for state of the art graphics gt Ultra quiet fans strategically placed baffles and internal sound proofing x E Microway Advantage Custom Integrations and HPC Expertise Since 1982 Put our years of expertise with Linux Windows
171. s on UDP port 53 you also had to put in a corresponding rule to allow DNS replies originating from UDP port 53 State tracking or stateful firewalls automatically correlate packets to already allowed sessions Because in those days of yore different network applications all used different TCP and UDP ports TCP port 23 for telnet TCP and UDP ports 53 for DNS TCP ports 20 and 21 for FTP and so forth filtering by port number equated to filtering by application type This didn t mean firewalls could detect or prevent evil that might occur over an allowed source destination address port combination We had no illusions that the firewall could stop for example Apache buffer overflow attacks against a public Web server reachable from the entire world on TCP port 80 The firewall could and can however prevent attempts to connect to that Web server via Secure Shell on TCP port 22 except perhaps from some internal authorized access point The problem is that every year we re less able to rely on the assumption that the things we should be worried most about will happen on ports that the fire wall can block altogether This is because so much of what people use networks for happens on only two TCP ports TCP 80 HTTP and TCP 443 HTTPS Even ten years ago developers were racing to migrate from client server application architectures in which every network application used its own commu nication protocol to the Web services mod
172. s can use it on their OS of choice Figure 3 Mockingbird The first time used it was hooked but was a little nervous It seemed so interactive dreaded to find out what custom plugin was required to make it all work quickly learned it was built using Objective J was really worried this was some new form of Java but it turns out to be JavaScript Mockingbird is built using a framework called Cappuccino This LGPL d framework is built in 38 august 2010 www linuxjournal com JavaScript but modeled after GNUstep and Apple s Cocoa framework hence the name Objective J inspired by the Objective C of those frameworks Cappuccino makes a distinction between itself and libraries like jQuery by saying that those are about making a dynamic Web site Cappuccino is useful only if you are building a full blown application The other toolkit it compares itself to is SproutCore Cappuccino is differ ent because it is written entirely in JavaScript and does not require knowledge of HTML or CSS A word of warning Mockingbird is not open source It currently is free during the beta At the time of this writing don t know when the beta will end or what the pricing will be like admit that have spent more time drawing with Mockingbird than looking at Cappuccino which is open source was so impressed with the way you can interact with the drawings like being able to select interface items copy go to a dif
173. shirt Two week old William Eidsness finds comfort in his open source future Father of two week old finds comfort in anything that makes William sleep Submitted by Andrew Eidsness 12 august 2010 www linuxjournal com 9 ServerBeach DEDICATED SERVERS BY GEEKS FOR GEEKS WEIGEL 190959 PATIENT MRI EXAM S BEACH Turboclocked GEEK IMA CPU Cores 64 023Y MALE Clock Speed 6 66 GHz 1 800 7419939 Bandwidth 100 Gbps 23 59 59 Refresh Rate 240 Hz Storage 32 Latency 0 002 ms Packet Loss 0 00 Load Avg 0 01 Linux Journal Magazine Ex 15 0 Call 1 888 840 9091 serverbeach com Sign up for any dedicated server at ServerBeach and get 15 off Use the promo code LJ150FF when ordering Offer expires December 31st 2010 Terms and conditions 2010 ServerBeach a PEER 1 Company Not responsible for errors or omissions in typography or photography This is a limited time offer and is subject to change without notice Call for details diff u WHAT S NEW IN KERNEL DEVELOPMENT Jonathan Cameron had a bit of a dis appointment when he tried to introduce a new subsystem for ambient light sensors His reasoning was not poor There were several existing drivers for ambient light sensors and they were all scattered throughout different subsystems His creation of a new subsystem amounted to little more than gathering those drivers together and writing up a litt
174. t Supermicro Server Board Chipset ICH 10f Dual Intel 5500 1 jad Dua e with to 6 4 GT s Support up to 192GB DDR3 1333 1066 800MHz ECC Reg DIMM 8x3 5 wap Drives Trays Supports up to 6 SATA Drives Intel Dual 82574L Gigabit Ethernet 4x NVIDIA Tesla C1060 GPU Cards SERVERS DIRECT CAN HELP YOU CONFIGURE YOUR NEXT HIGH PERFORMANCE SERVER SYSTEM CALL US TODAY Our flexible on line products configurator allows you to source a custom solution or call and our product experts are standing by to help you to assemble systems that require a little extra Servers Direct your direct source for scalable cost effective solutions 1 877 727 7886 www ServersDirect com Intel Intel logo Intel Inside Intel Inisde logo Intel Centrino Intel Centrino logo Celeron Intel Xeon Intel SpeedStep Itanium Pentium and Pentium Xeon are trademarks of Intel Corporation or it s subsidiaries in the United States and other countries 80 PLUS 08 3308 08 3U INTEL XEON PROCESSORS 5500 SERIES SERVER W 8 X 3 5 HOT SWAP DRIVES TRAYS Supermicro Rackr int Server w 650W HE Power Supply Supermicro Server Board w Intel 5 rt up to Dual Intel 5500 series Xeon Pl up to 6 4 GT s D to 192GB DDR3 1333 1066 800MHz E D 825741 Gigabit Ethernet SDB S 7002 T00 9U INTEL XEON PROCESSORS 5500 SERIES SERVER W 50X HOT SWAP SATA II SAS BAYS 3BE 714D D28 Enc er SU
175. t Kdenlive s Render button opens a dialog for preparing your movie for its eventual output format Figure 4 selected the DVD f dvd vcodec mpeg2video acodec ac3 s 720x480 option from the b 6000k maxrate 9000k minrate 0 bufsize 1835008 Destination list mux_packet_s 2048 mux_rate 10080000 ab 192k ar 48000 g 18 me_range 63 trellis 1 named the output VOB file and profile dv_nisc_wide pass 2 defined the format as NTSC set the encoder for a 2 pass rendering to a widescreen display ticked the option to Render Project job Queue Scripts Destination DVD v Output file dIphilp kdenlive student show 072210 bj B Format NTSC v 1219 NTSC 4 3 VOB NTSC 4 3 VOB 2 pass NTSC 16 9 VOB NTSC 16 9 VOB 2 pass Scanning v Export audio Rescale Timecode overlay Open Dvd wizard after rendering Play after render Full project Selected zone Render to File v Close open the DVD Wizard after render ing and clicked the Render To File command Next made some coffee it seemed the appropriate thing to do while Kdenlive did the rest Figure 4 Kdenlive Render Dialog Making the Disc The DVD Wizard Figure 5 stepped me through the process of preparing an ISO image to burn to disc selected my files defined the disc chapters and made a basic menu The menu builder can 74 august 2010 www linuxjournal com Create DVD Menu Create basic menu Button Background
176. t Receive Ground Figure 4 Router s Console Interface diagnostic information through the console interface Pay close attention to the messages being printed through the console and press a key when the U Boot bootloader prompts you to Hit any key to stop autoboot You should see the U Boot command prompt ar7100 Enter the command upgrade code bin to instruct U Boot to initiate a tftp server Return to the build workstation command line enter the command tftp 192 168 1 1 and then tftp gt binary tftp gt put firmware filename Observe the data transfer being displayed over the console interface Return to the terminal emulator and enter go at the U Boot prompt The firmware you load using this technique may be an official firmware obtained from Linksys or an OpenWrt firmware that you built Conclusion This article demonstrates a technique for providing Kerberos LDAP network filesystem print and media services using a Linksys WRT160NL wireless router The result is a low cost network server for the home or small office OpenWrt has a wide range of pack ages available so there is potential for many other solutions to be developed around this capable platform For example Samba could allow tight integration with Windows clients Another option is Netatalk which provides native Mac OS X file sharing including integration with Apple s Time Machine backup software Linux open source applications and popu
177. t s just a dumb idea For a certain applica tion having a separate touch area makes more sense or a rocker Switch or a joystick We provide all of these because part of what want to do is have a device that lets students experiment with all aspects of computing including the interface That s the reason for its flexibility This is just one example of how for a very specific type of course or curriculum you can take advantage of that type of flexibility Even if we didn t have all three capabilities built in to the device could plug in a mouse or a joystick essentially anything through a USB port that would give me that flexibility and students can then learn their pros and cons At the university level a cheap and open embedded computing platform can be valuable in multiple ways At Oregon State University the Physics Department has taken OSWALDs and ripped them apart to control scientific instruments The robotics club uses the OSWALD board to control their Mars rover and aerial www linuxjournal com august 2010 69 4 OSWALD Specifications SOFTWARE LAYER RADIX A custom distribution of Linux created using OpenEmbedded Matchbox A lightweight themeable window manager designed for handhelds that provides the OSWALD s GUI framework and environment matchbox project org overview html JamVM A small and specification compliant Java virtual machine jamvm sourceforge net L
178. th this in house task for the past 15 years Environmental reconstruction is the most difficult task Once you have a 3 D representation of the surrounding environment controlling the vehicle is Driving conditions are recognized so the vehicle continues its way forward not very complex Our software is writ ten in ISO C using some minimal additional open source libraries like boost loki and wxWidgets Anton What general obstacles can your vehicle bypass now and what obstacles can t it bypass yet Alberto Any obstacle rising up from the road surface is detected We can t detect small obstacles For example curbs are not always detected but larger obstacles like pedestrians vehicles and small animals are detected Technically we can locate obstacles that are suffi ciently visible Indeed it takes time and therefore the system wouldn t be able to work at speeds such as 200mph we d need to increase our computer horsepower Our electric vehicles run at slow speeds the maxi mum speed so far is 70km h so we have no problems Other systems hard ware and software have been devel oped for other vehicles depending on their speed based on more penetrating sensors and faster processing Anton Where is such a technology unmanned driving already demanded and in what spheres can you envision it will be useful to deploy Alberto Definitely in the military field but there s a huge demand in the agricul
179. that you don t need to provide any other configuration storage the files hemselves are the persistent storage Another nice feature is hat the driver starts immediately with the correct configuration and does not need to be initialized from an external source Inotify works well with select and is ideal in many situations but be aware of a couple issues You may have a race condi tion if your driver modifies a configuration parameter before making it available Sound drivers often have this behavior you can set the sample rate to 45KHz but the driver probably will round it to closest standard value 44 1KHz If you do something like this with inotify you may have a window where a reader would get the wrong value for the configuration parameter Also be aware that you may need to rebuild the kernel to include inotify support You also can use UNIX sockets for driver configuration if you split configurations reads from configurations writes The problem is that when the user space driver daemon accepts a Socket open request the new socket is both readable and writable The daemon cannot tell if the user is trying to write a new configuration value or trying to read the existing one One way around this problem is to have two sockets for every release date february 2010 The 1994 2009 Archive CD back issues and more www LinuxJournalStore com I LIKE FUSE IT CAN SOLVE A LOT OF USER SPACE DRIVER PROBLEMS BUT IT
180. tory Enter this directory with cd trunk Inside you ll see the core OpenWrt build system Additional packages are provided by what OpenWrt calls feeds Pull in the feeds provided by the default configuration by executing scripts feeds update Finally complete the installation of the files required to build your optional packages with the command scripts feeds install krb5 server openldap server nfs kernel server p910nd mt daapd ntpd The third step is to configure your firmware and build an image containing it The OpenWrt build environment is similar to many BSD ports systems MacPorts or Gentoo Linux in that it allows users to define a list of packages that the system will download and compile Unlike these systems general use OpenWrt often must cross compile its packages For example although my build workstation has an Intel Core 2 Duo processor the WRT160NL router has an MIPS32 processor As a result before downloading and compiling general purpose packages from source OpenWrt downloads and builds a cross compiler and other build tools from source OpenWrt provides a configuration system that is very similar to the Linux kernel s and can be invoked with the command make menuconf ig You can navigate the menu based configuration tool using the arrow keys and select submenus by pressing Enter Activate an item with the Y key or in the case of a series of choices with Enter Conversely pressing N deactivates an
181. trol a DV interface IEEE 1394 aka FireWire and advanced settings that can be configured for a relatively good quality recording It s lightweight and found it easy to operate and control Obviously more money gets more camera but intended to keep expenses as low as possible without compromising the quality of the basic material By default the camcorder produces video in an NTSC 4 3 display format commonly associated with the square screen of a television in North America The default audio setting appears to be with a sample rate of 32kHz with a resolution of 12 bits The camera s advanced settings allow me to set the preferred display format to NTSC 16 9 also known as widescreen and to increase the audio bit resolution to 16 bits Alas the audio sample rate is fixed so CD quality sound is not possible with the Samsung a limitation overlooked when purchasing the unit Of my two studio machines only one has an integrated IEEE 1394 connection planned to use both boxes for video work so bought and installed an inexpensive PCI board that added three IEEE 1394 ports to my main machine If you plan 72 august 2010 www linuxjournal com Figure 1 Samsung SC D382 miniDV Camcorder to make a connection with a FireWire enabled camera check for a port on your motherboard and make sure you have an available slot for an extension board if you need one And by the way even the cables need attention FireWire cables have a v
182. ty and dependability to keep up with your growing business ASA 10 Series Intel Atom processors D510 and D410 based platform and are designed for embedded industrial PC IPC applications These quiet energy saving solutions make ideal network appliances print and email servers QPI Intel Xeon Processor 5500 Series in a high density 2U form factor are ideal for network infrastructure front end enterprise and minimal downtime cluster server systems maximum upto 4 nodes in 2U ASA 3U Series Server series excel under ISCSI NAS JBOD environments the 3U servers support high availability storage and mission critical business applications ASA 4U Series Optimized for enterprise level high capacity storage applications features 36x 24 front 12 rear 3 5 Hot swap HDD bays reliable and hassle free maintenance storage system ASA Blade Series Blade server with Highest computing density 20 DP nodes and 2 56TB mempry in 7U Fastest and Most Cost Effective Networking Solution Infiniband DDR QDR support intel gt Xeon inside ASA Computers Inc 645 National Ave Mountain View CA 94043 www asacomputers com Powerful Intelligent Intel the Intel logo Xeon and Xeon Inside are trademarks or registered trademarks of Intel Corporation in the U S and other countries FEATURE Real Time Plots with kst and a Microcontroller will appear on the y axis and the line numbers wi
183. u for your magazine It s been a treasure to read for many years Justin Ryan replies Thanks for bringing this to my attention noticed it much to my horror shortly after the issue went out but knew a sharp eyed reader would provide the opportunity to correct it Sadly like software articles sometimes suffer from bugs and some inevitably slip through Thankfully given enough eyeballs all bugs are shallow appreciate that you were on the eye ball At Your Service The date in question was intended to be August 16 1993 the date lan Murdock founded the Debian Project According to Debian s A Detailed History Debian 0 01 through Debian 0 90 were released between August and December of 1993 www debian org doc manuals project history ch detailed en html The June 1996 releases were the 1 0 series released after Murdock left the project and Bruce Perens took on the role of Debian Project Leader Thanks for your attention to detail and for providing the opportunity to highlight Debian s important place the Linux community as one of the oldest distributions still in active development after Slackware as the mother distro of many other well respected distributions and as a reliable innovative and rock solid distribution in itself 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
184. u ve reset that signal handler so if have the line trap sigtstp TSTP right before the section where I don t want the Ctrl Z to work it ll ignore that first Ctrl Z then reset the signal handler and work as expected the second time you press that key More useful is to ignore all Ctrl Z stop signals until you re ready to deal with them and that s quite easily done with the minimalist trap TSTP ignore Ctrl Z requests And then when you re ready to receive them again trap TSTP allow Ctrl Z requests Experimentation will show that there are some weird terminal buffering issues associated with SIGTSTP however so don t be surprised if you have a signal Experimentation will show that there are some weird terminal buffering issues associated with SIGTSTP however so don t be surprised if you have a signal handler that has output handler that has output In this particular instance it won t show up until the script quits Reading a Configuration File Let s look at a more practical example Say you have an admin script that is always supposed to be running as a daemon but occasionally you want to tweak its configuration file and have it reread its setup a lot faster than killing and restarting it Further let s use SIGUSR1 for this task as that is its intended use so we re using the kernel s signal handling subsystem in the manner it was intended Reading a configuration file might be something as simple as
185. ubstitute for rsync Using cp u causes cp to copy the file only if the destination is missing or is newer than the source Try the following cd tmp mkdir a b echo TEST gt a c echo test b c cp u a b cat b c t t t LETTERS You ll see that b c was not updated to match a c it still contains test and not TEST Because b c was created after a c cp doesn t update it Now try rsync a a b cat b c Here you ll see that b c equals a c rsync updates files if the contents of the source files are different from the contents of the destination files Furthermore if cp decides to update a file it copies the entire file from the source to the destination On the other hand rsync essentially breaks the file into chunks and copies only the chunks that have been modified It s not a big deal on small files or across your local network but with large files or across slow networks this can make a huge difference in how long the update takes Ed Thanks for the June 2010 Issue just wanted to let you know how much I enjoyed the June 2010 issue of LJ always read Mick Bauer s Paranoid Penguin column but also enjoyed Mike Diehl s Pogoplug review as well as Dirk Elmendorf s article on library programs I am a former Library Board President as well as a user of Alexandria Bruce Byfield s article on MINIX was interesting to read as was the article by Dan Sawyer I currently use Ub
186. uding syncing contacts on mobile devices for free Hopefully Canonical continues to keep the Ubuntu One API as open as possible and the community will come alongside them in order to provide features that otherwise would cost money don t mind paying for storage in the cloud but paying for features that are provided free elsewhere is a tough pill to swallow SHAWN POWERS LJ Store s Featured Product of the Month the Ultimate Linux Gift Pack The Ultimate Linux Gift Pack includes a one year 12 issues gift print subscrip tion to Linux Journal In addition to the one year subscription your recipient will receive a gift pack immediately Items in the package include A copy of the most recent issue of Linux Journal so the recipient can start reading before the subscription kicks in A Powered by Linux magnet A 2010 Linux Odyssey T shirt A pack of assorted stickers A Penguin Party bumpersticker EB An Want YOU button A Linux Journal Archive CD ROM featuring more than 180 back issues of the magazine A 2010 Tux the Penguin wall calendar Retail value is 120 Yours for only 59 95 79 95 outside the US Order yours today at www linuxjournalstore com UPFRONT August 2010 Transistor count of an Intel 8080 microprocessor in thousands 4 5 Transistor count of an Intel 80286 microprocessor in thousands 134 Transistor count of an Intel 80386 micropr
187. ue ATTENTION ADVERTISERS Serial print c2f sensors getTempCBy Index 9 November 2010 Issue 199 Deadlines Print delimit h i ial st SUL cat aa Sen Space Close August 23 Material Close August 31 Serial print Theme Hacking Print w line feed light level value Serial println val BONUS DISTRIBUTIONS USENIX OSDI Print contact Joseph Krack 1 713 344 1956 ext 118 delay 1000 joseph linuxjournal com On line contact Michael Beasley 1 713 344 1956 ext 119 michael linuxjournal com www linuxjournal com august 2010 65 FEATURE Real Time Plots with kst and a Microcontroller drop down File menu select New to get a blank code window Type in your program You also can copy code from another source such as Web examples or from the sample code bundled with the IDE in the Examples directory The examples offer standard routines to read various input sensors and control output pins The Arduino Web forums and reference pages contain all kinds of code snippets that you can use instead of having to write everything from scratch Just like open source in the Linux world Arduino users are encouraged to develop and share their code After entering the code in a new file select Save As under the File drop down tab Give your file a name that makes sense in my case simple_temp_f The file will be saved in the Sketchbook directory with a pde extension Arduino source code files are called sketches
188. untInformation server local mnt sda2 home amp Next load the file into the LDAP database on the router using ldapadd x D cn Manager dc example dc com W f example com ldif Finally return to the router and create someuser s home directory mkdir var sda2 home someuser and then do chown 1100 1002 Notice that the UID GID arguments to the chown command match those assigned to someuser in the LDIF file above Now you can connect the router to your real network To add additional users review the fifth block in the LDIF file above tailor it for each user and add them using 1dapadd Also create each user s home directory as before Your router now should be fully functional so it is time to configure the clients Several existing articles document how to configure a client to operate in LDAP and Kerberos environments see Resources You may configure your clients by editing configuration files or you can investigate your distribution s administrative tools One difficult point I ve encountered has to do with the LDAP schema used by the automounter Different UNIX flavors use dif ferent schemas My instructions use the schema employed by Mac OS X because it also is supported on Fedora order to instruct the Fedora automounter to use this schema write the following to etc sysconfig autofs MASTER MAP NAME auto master TIMEOUT 300 BROWSE MODE no USE MISC DEVICE yes Mac OS X 10 5 compatible schema MAP OB
189. untu 10 4 but also have used Fedora in the past and other members of my LUG use Mint and even Slackware We have experimented with SUSE Debian and MEPIS as well Michael J Hammel s article was a good reminder of why we do backups In short found lots of great reading in the issue and thought l d pass along my compliments to you Brian Clark Every once in a while a particular issue feels like it was written just for me It looks like the June 2010 issue did that for you Thank you for your kind words it s great to hear positive feedback Hopefully you ll keep getting Brian Clark Issues in the mail Ed Distro Chart Correction Regarding the Linux Distribution chart in the June 2010 issue l ve been using www linuxjournal com august 2010 11 LETTERS Linux to a greater or lesser degree since the mid 1990s I still have my Yggdrasil Plug and Play Linux CD somewhere and thought the chart very interesting especially the column on Best For because I m looking for a replacement for Ubuntu 9 04 right now However whoever researched the chart needs to learn a little more as you have the First Release date for Debian as 8 16 2003 According to DistroWatch its first release was 6 17 96 and still have an old Infomagic CD set with Debian 0 93R6 dated April 1996 as physical proof Tables are a great way to order information but only if it s accurate information Other than that thank yo
190. use to find out what you have installed First up is Ishw This utility LiSts HardWare Ishw If you run it as a regular user it actually warns you to run it as root So go ahead and run sudo 1shw You should see screens of information for your system The first section will be general information and should look something like this jbernard eeepc description Notebook product 700 vendor ASUSTeK Computer INC version 0129 serial EeePC 1234567890 width 32 bits Capabilities smbios 2 5 dmi 2 5 smp 1 4 smp configuration boot normal chassis notebook gt cpus 1 This is what get when run it on my little ASUS EeePC Right away you can find the manufacturer of this little beast ASUSTeK the BIOS version 0129 and the fact that it s a 32 bit machine with one CPU More information is broken down into the following categories core firmware motherboard and BIOS information cpu CPU information cache cache information memory memory information bank specific bank memory information pci PCI bus information display PCI display adapter multimedia PCI audio adapter pci other PCI devices network PCI network adapter usb USB devices ide IDE information disk individual disks volume volumes on this disk For an idea on how much information is available the main memory section shows this about my EeePC memory description System Memory physica
191. vaguely SQL like CouchDB however offers a completely differ ent query system based on JavaScript functions and the map reduce paradigm CouchDB s syntax takes some getting used to especially if you are relatively new at writing JavaScript functions However a few small functions can give you a great deal of power which is perhaps the secret behind CouchDB s success CouchDB Views I ve already explained that CouchDB refers to each stored data item as a document CouchDB defined a special kind of document known as a design docu ment which contains a view JavaScript code that is executed when you want to perform the query Design documents also may contain show functions which can sort or otherwise modify the way in which data is displayed but won t discuss show functions in this column If you are developing only a database or applications you might want to avoid the overhead of a permanent view by creating a temporary view instead Temporary views take less time to set up and are a bit more flexible but they execute much more slowly So let s begin by creating a temporary view and some basic JavaScript views For the data I m using the information entered above about my three children Feel free to substitute information about your own children if you prefer find it easiest to create tempo rary views using Futon the Web based administrative and maintenance tool that comes with CouchDB
192. w json id design example views show by birthday map function doc emit doc birthday doc Then uploaded the contents of this file using curl as follows curl X PUT http localhost 5984 atf design simpleview w d Gsimpleview json By using the d flag and the Q sign was able to tell curl to upload the JSON from a file rather than the command line uploaded it to a design document as you can see from the design at the beginning of its name with the view called simpleview Once uploaded then could run it from Futon by going to the menu item show by birthday or by again using curl curl X GET http localhost 5984 atf design simpleview view show by id The results of the query are the same no matter what Futon displays them in a nicer format but it obviously would be easier for a program to work with the JSON output via HTTP If you want to edit the view you can either re upload it via curl or use Futon to go to the view and edit the JavaScript function www linuxjournal com august 2010 21 COLUMNS Reduce So far the examples here have focused on writing map functions which take the list of documents and outputs a series of key value pairs But as you might imagine the map reduce paradigm has two parts the second of which is called reduce The idea is that you use map to filter and transform the data into a list and then use reduce to turn that list i
193. witch in use of targeted malware and attacks against Web applications aren t arguments against firewalls they re simply reasons that firewalls alone aren t sufficient to protect critical systems Can we agree then that firewalls are still an important tool in the network security toolkit hope so because I m about to spend several months show ing you how to build a particularly clever type of Linux firewall a transparent firewall Routing vs Bridging Firewalls Normally a firewall acts like a router It receives traffic from two or more network interfaces and makes deci sions about whether and how to route that traffic Any host that needs to send traffic through the firewall must either use the IP address of the firewall interface that faces it as its default gateway or a router between that host and the firewall must be configured to use the firewall as a route to whatever networks are on the other side of the firewall Figure 2 shows a routing firewall As you can see each firewall interface has its own IP address that is valid on the network to which that interface connects and that IP address serves as the route to the other side of the firewall In this example hosts in Network A have to know or send packets to some router that knows that 10 20 30 254 is the gateway to reach Network B Hosts in Network B have to know or speak to a router that knows that 44 55 66 254 is the gateway to reach Network A 30 august 2
194. y newproducts linuxjournal com Justin Ryan news linuxjournal com Don Marti dmarti linuxjournal com Michael Baxter mab cruzio com Reuven Lerner reuven lerner co il Mick Bauer mick visi com Kyle Rankin ljGgreenfly net Bill Childers bill childers linuxjournal com Contributing Editors David Bandel Ibrahim Haddad Robert Love Zack Brown Dave Phillips Marco Fioretti Ludovic Marcotte Paul Barry Paul McKenney Dave Taylor Dirk Elmendorf Proofreader Geri Gale Publisher General Manager Senior Print Media Sales Manager Digital Media Sales Manager Associate Publisher Webmistress Accountant Carlie Fairchild publisher linuxjournal com Rebecca Cassity rebecca linuxjournal com Joseph Krack joseph linuxjournal com Mi mi ichael Beasley ichael linuxjournal com Mark Irgang mark linuxjournal com Katherine Druckman webmistress linuxjournal com Candy Beauchamp acct linuxjournal com Linux Journal is published by and is a registered trade name of Belltown Media Inc PO Box 980985 Houston TX 77098 USA Editorial Advisory Panel Brad Abram Baillio e Nick Baronian Hari Boukis Steve Case Kalyana Krishna Chadalavada Brian Conner Caleb S Cullen Keir Davis Michael Eager Nick Faltys Dennis Franklin Frey Alicia Gibb Victor Gregorio Philip Jacob Jay Kruizenga David A Lane Steve Marquez Dave McAllister Carson McDonald Cr
195. y of your algorithms Use this information to evaluate whether your codes have the potential to suffer from congestion Feeding observed data into our IB fabric queuing theory simulator lets you examine latency and bi sectional bandwidth tradeoffs in fabric topologies Contract Number B s Technology you can count a NVIDIA CUDA FOR FREE php T 1 UNLIMITED s PHP5 6 beta Zend Framework Python Perl pr L e Google Sitemaps 1 amp 1 Dynamic Content Catalog 2 J Firewall Protection Webmail 2 0 Spam Filter N After the 1st year pay just 6 99 per month Easy RSS x 181 Blog C 1 Password Protected Directories MEMBER OF united internet CONTENTS FEATURES COOL PROJECTS 46 5 2 5 6 6 2 mid eig rmware with The OSWALD Project Open Source and Education p 68 A Simple Using wview Building Custom Real Time Transparent Firewall Primer 28 B e Drivers f Based Roboti Approach to Howto justify Firmware Plots with ud a NT Character Drivers buying your own with OpenWrt kst anda S uns in User Space weather station Add the functions Microcontroller ee Station with Drivers for the Mark Teel you want even a Graphing data from with kst and Arduino p BaseBoard4 media server Point Counterpoint Solid State E Drives vs Rotational Media p 7
196. yer They evaluate network packets based on their IP headers In contrast bridges oper ate at Layer 2 the Data Link most com monly Ethernet nowadays layer Bridges evaluate Ethernet headers A switch is simply a bridge with lots of ports To route is to make decisions on what to do with a packet based on its destina tion IP address specifically to determine the most efficient route series of for warding routers by which to deliver the packet to its destination These decisions can be complicated There may be many possible routes and because individual hops between gateways in a given route may become congested or other wise slow down the best route for a stream of packets may change during the course of a single network transaction For this reason routers use a combination of routing algorithms routing tables and forwarding tables to compute routes on the fly Note however that although firewalls act like routers they seldom have to make nearly so compli cated routing decisions as true routers typically do Typically a firewall uses a single gateway for all routes to internal networks and another for all other outside networks where both gateways are actual routers Bridging in contrast is much simpler A bridge or switch looks at each incoming Ethernet frame entering each bridge switch port and deter mines its destination Ethernet address also known as a MAC address It then
197. your callsign wwiew supports the APRS IS Rollover Automatic Packet Reporting System Internet Service functionality by enforcing the definition of three APRS IS server port pairs The goal is to avoid data loss to the CWOP system caused by connection errors Select three different servers from the list at www wxqa com activecwd html Click the Services tab and enable CWOP submission and CWOP verbose logging Click Save Changes Next click the CWOP tab and enter your callsign latitude and longitude see the mouse over help for format details the CWOP servers three should be entered and port numbers Go ahead and enable Log CWOP Packet you can disable it after submission is confirmed Click Save Changes Now restart wview sudo etc init d wview restart You can monitor CWOP packet submission in the system log and on the CWOP status pages Weather Underground The Weather Underground Wunderground is a privately held organi zation that provides many weather services some free and some not Among the free services is the ability to register your weather station and submit your data to them so you can access your data and some nice graphs from the Wunderground site Weatherforyou com also is a privately held outfit with similar capabilities to Wunderground Register for a Weather Underground Station ID unless you already have one at www wunderground com weatherstation usersignup asp Determine your accurate 54 august

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