Archive | March 19, 2007

MonadLUG notes, 8-Mar-2007: tac and “Pitch Your Distro”

The second Thursday of the month is the usual meeting of the Monadnock Area Linux User Group, MonadLUG, at the SAU #1 offices on Hancock Road in Peterborough. This month, Ray Côté ran a discussion on “Pitch Your Distro” and Bill Sconce took on the “Man Page of the Month” on the command tac.

You won’t think you could make much of a presentation on tac, but that would be underestimating Bill Sconce 😉 Here’s the short form: tac is cat backwards. Longer form: tac lets concatenates files, but reverses the line ordering of the result, so you get last line first. There are only a couple switches, -s to specify a separator other than newline and -r to use a regex separator. Using this simple tool, Bill was able to present a wicked example that reversed not only line order by character order, and lead to a discussion about the use of regular expressions, piping, precedence, quoting and backticks. A good time was had by all.

The main discussion was a let’s-go-around-the-room discussion of what distros are in use and why and for what. With nine people present (and one of them a non-combatant), how many distros would you expect? We heard about: Debian, Slackware, OpenBSD, OS X, Fedora, RedHat, CentOS, SuSE, Mandrake, Ubuntu, Xubuntu, more RedHat, Knoppix, Gentoo, Libranet and some Knoppix war stories. Many aspects of the different distros were discussed: cost, support, lifespan, the difficulties of sound cards, and more.

Many thanks to Ray for running the meeting, Bill for tac and bringing a projector, and all for participating.

Next month’s meeting (April 12th) will have Seth Cohn presenting Drupal. Hope to see you there!

CentraLUG notes from Andy Bair’s Digital Forensic File Carving presentation

Our thanks to Andy Bair for making the trip north from Massachusetts to present to the Central New Hampshire Linux User Group on March 5th, 2007, the first Monday of the month, at the New Hampshire Technical Institute’s Library. Andy announced that his work at MITRE was done and that he would be starting a job at Korelogic in the immediate future.

Andy worked with several friends at KoreLogic to take on the Digital Forensic Research Workshop (DFRWS) 2006 File Carving Challenge. They were supplied with a 50 megabyte “chunk” from a hard drive with the assignment to find as many files in that chunk as possible. The DFRWS’ motivation was to move the state of the art forward, and all participants were required to supply the source code of the applications they developed. Andy and his team won the challenge, beating out a number of other teams, notably Simson Garfinkel, who came in second. Andy demonstrated the procedures they worked out, talked about the algorithms they used, and showed the graphing of the results that made boundary detection and anomaly detection more easy to pick out. Andy and his team extended the UNIX magic technique to detect patterns in files, extending magic to XMagic which included regular expressions and more sophisticated rules to match files to the patterns. It was a very interesting presentation, presented well. Andy’s presentation, the source code and original data can be found at this link [Updated link – tr, 15-Feb-2010].

Thanks to Andy for the presentation, to Bill Sconce for supplying the projector, and to the New Hampshire Technical Institute for providing the facilities.

Upcoming presentations include:

  1. Bill Stearns demonstrating Logical Volume Management April 2nd,
  2. Seth Cohn presenting Drupal on May 7th, and
  3. Ben Scott presenting OpenWRT on June 4th.

We plan to meet at the usual location, but keep an eye out for a more detailed announcement as the date gets closer.

Blog, the first five years…

… ended yesterday, and today I start the sixth year of blogging. The first year was blogging on the Perl-based TWiki software, 2003 through 2006 on Radio Userland. This year, I’m using WordPress, on a self-hosting Linux-Apache-MySQL-PHP platform. Wonder what I’ll be running in another five years? It’s been a blast, and I hope it continues to be. Primarily, my blog is my voice online: notes of places I’ve found and want to share (or publicly bookmark so I can find them again), news to pass on, or events on which I comment. Thanks for reading.

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