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The indefatigable chromatic wrote this review of what sounds like another solid offering from the hard workers at O'Reilly & Associates. If you're in the market for dead-tree references to XML, it probably belongs on your list of candidates. XML in a Nutshell author Elliotte Rusty Harold & W. Scott Means pages 480 publisher O'Reilly & Associates rating 8.5 reviewer chromatic ISBN 0-596-00058-8 summary A solid and useful reference for XML developers.

The Scoop

While one of the original goals of XML was to create a specification simple enough that a computer science student could produce a working parser in a week, a few new developments have complicated things slightly. The sea of W3C-recommended acronyms includes namespaces, XPath, XSL, XPointers, schemas, and dozens of specific XML applications. Adopting the simple rules of well-formed data helps, but the quickly-growing stable of related technologies is enough to make the sturdiest information architect weep. The specifications aren't as easy to read as, say, the latest Terry Pratchett novel, either.

XML in a Nutshell covers just the most important concepts. Cleanly written, it walks through the XML aspects likely to be used in most projects. As it assumes existing familiarity with the subjects, it does not spend much time in tutorial mode. Instead, these are the guts of the subjects, arranged nicely in dissection jars.

The first section covers XML basics. This includes the ubiquitous grove of angle brackets, the semantic intent and implication, a good chapter on DTDs, as well as internationalization concerns. The short discussion of namespaces is the clearest explanation this author has yet encountered.

Part two delves further into the reasons for using XML, exploring documents that use the structure to explain semantic relationships. DocBook and XHTML appear, as extended examples. Further, it explores the assistive technologies of XSL, XPath, XLinks, and XPointers. Again, the discussions of XSL and XPath compare very favorably to longer works, intended as tutorials. A brief examination of CSS and XSL Formatting Objects rounds out the section.

Part three explores the use of XML as a data transport. In this section, programming languages come into play. There's a strong hint of Java in the air, though most of the discussion follows a language-neutral path. Both the DOM and SAX parsing models have a dedicated chapter. They're short, but the essential pieces are described simply and effectively.

The final section makes or breaks the book. Luckily, XML in a Nutshell won't have much chance to gather dust. The two-hundred page reference section includes the most useful information. There's an annotated copy of the XML 1.0 Reference, arranged logically. The XSL reference, in particular, is quite good. DOM and SAX programmers will also enjoy their respective chapters. Finally, it's nice to have a large set of printed character tables handy.

What's to Consider

The parsing examples don't go much beyond DOM or SAX, and there's more than a strong Java flavor. (Of course, the models are very similar in most modern languages.) As well, some of the class interfaces in the SAX reference are hard to read. This is probably due to the complexity of the information instead of any editorial decision. There's also little discussion of actual XML applications. Instead, the book covers the principles behind perhaps 90% of XML usage. Again, this is not a complaint, just a clarification of the intended audience.

The Summary

The value of XML in a Nutshell should be readily apparent to XML developers. The material is well-organized and concise. It's a quintessential Nutshell book, upholding a tradition of utility and quality. Readers who've already been exposed to the presented material will likely keep this book close at hand.

Table of Contents

1. XML Concepts
2. 1. Introducing XML
   2. XML Fundamentals
   3. Document Type Definitions
   4. Namespaces
   5. Internationalization
3. Narrative-Centric Documents
4. 1. XML as a Document Format
   2. XML on the Web
   3. XSL Transformations
   4. XPath
   5. XLinks
   6. XPointers
   7. Cascading Stylesheets (CSS)
   8. XSL Formatting Objects (XSL-FO)
5. Data-Centric Documents
6. 1. XML as a Data Format
   2. Programming Models
   3. Document Object Model (DOM)
   4. SAX
7. Reference
8. 1. XML 1.0 Reference
   2. XPath Reference
   3. XSLT Reference
   4. DOM Reference
   5. SAX Reference
   6. Character Sets

You can purchase this book at Fatbrain.

O'Reilly has put up an interesting interview with Randal Schwartz and Tom Phoenix, the guys behind the llama book (Learning Perl). In addition to all the perl stuff, Randal gives his take on Smalltalk, Ruby, and Python. And (not surprisingly) they plug the newest edition of the book.

Simone writes: "2001 has been a bad year not just for dot-coms but also for people interested in preserving the public's right to fair use of copyright materials. From the shutdown of Napster and the DeCSS case to the prosecution of Dmitry Sklyarov, federal prosecutors and U.S. courts have acted in support of copyright interests and against the public's ability to use technology to secure fair-use rights. OpenP2P.com editor Richard Koman talks about these turns of events with Lawrence Lessig." Not particularly coincidentally, Lessig has a new book coming out on this very topic.

Jay writes: "This article is really helpful if you're new to Linux, or even if you're not-so-new. It helps Windows users transition to Linux, but those converting from other operating systems will find useful information here as well." Personally, I'd think that learning a new OS would be worth the cost of a book (which I note is out of print - does that mean a new edition is on the way?), but if you're too cheap to buy a book, well, here's a pretty decent guide to getting started with GNU/Linux.

Rosco P. Coltrane writes: "I don't know if this is old news, but I've just noticed that the "Linux Device Drivers, 2nd Edition" book by Alessandro Rubini & Jonathan Corbet has been published under the GNU Free Documentation License v1.1 by O'Reilly." Making the entire book available is a nice gesture by O'Reilly. And anything that helps get more device drivers written is a plus in my book... We reviewed the first edition, but obviously there have been one or two tiny changes since then.

Rosco P. Coltrane writes: "I don't know if this is old news, but I've just noticed that the "Linux Device Drivers, 2nd Edition" book by Alessandro Rubini & Jonathan Corbet has been published under the GNU Free Documentation License v1.1 by O'Reilly." Making the entire book available is a nice gesture by O'Reilly. And anything that helps get more device drivers written is a plus in my book... We reviewed the first edition, but obviously there have been one or two tiny changes since then.

bruce writes: "O'Reilly has just put up a page with conference reports from USENIX. The BSD BoF session sounds like it was pretty interesting, lots of info there." Yes, "*BSD is Dying" posts are up 75%, thank you very much.

There's a news article up at O'Reilly that hypes their upcoming Open Source Convention and also sets up a forum to submit questions to potentially be asked to Mundie when he gives a keynote at the convention. Should be an interesting, perhaps vitriol-filled morning there.

There's a news article up at O'Reilly that hypes their upcoming Open Source Convention and also sets up a forum to submit questions to potentially be asked to Mundie when he gives a keynote at the convention. Should be an interesting, perhaps vitriol-filled morning there.

Chris Coleman writes: "IPv6 is great in theory, but it won't do you much good if you can't get connected. Hubert Feyrer explains the basics of getting connected to IPv6 for BSD and Linux."

More updates and links below on HavenCo, robots that kick balls, and what can already be said to be one of the millenium's most anticipated movies thus far. Oh, and some nice auditory/textual backup to the recent story about RMS vs. Goliath.

Not asking, not telling. jeffthompson writes: "The Havenco web site says it is now fully operational and open for business." A lot of people seemed convinced that Havenco wouldn't even be around by this time, but sticking around is the best revenge. I'd like to go aboard one day, promise I'll wear a blindfold and not look at anything ...

GNU, Linux, GNU/Linux, Freedom and the American Way. bkuhn writes: "Now, both the electronic audio and transcript of RMS' NYU talk are available."

The audio is in Ogg format, and the transcription is in blessed plaintext. Thanks!

Sign #37 of the coming apocalypse: Speaking of Mundie, software Freedom (and free-ness), Simone Paddock of O'Reilly writes with news that might raise a few eyebrows:

"Microsoft Senior Vice President Craig Mundie set off a compelling debate recently when he discussed Microsoft's Shared Source Philosophy, which blends the sharing of source code with the preservation of intellectual property rights.

Tim O'Reilly invited him to attend the upcoming O'Reilly Open Source Convention (July 23-27, 2001 in San Diego). Mundie not only agreed to attend, he agreed to speak.

Mundie will discuss ways in which shared source differs from open source, and how the Shared Source Philosophy supports a strong software business case for commercial software use."

Michael Tiemann (CTO of Red Hat) will speak after Mundie, and a panel of IP law and software experts (including Tim O'Reilly) will discuss the issues raised. Sounds worth being in San Diego for. If you're interested, there's more information online.

In the Tolkein, not the endocrinological or Snow White sense. SomeoneYouDontKnow writes: "This is a follow-up on the recently-released LOTR trailer. It's now available for download. Two versions are available to suit your bandwidth and patience. Unfortunately, it's still only available in Real format, but I guess we can't have everything."

Semi-alive and kicking. IEEE Spectrum Associate Editor Stephen Cass writes:

IEEE Spectrum , the house magazine of the IEEE is launching an online forum devoted to the noble sport of robosoccer . Robosoccer is different from things like Battle Bots or Robot Wars in that the robots play in teams and the whole thing is completely autonomous once started. There are a number of competitions, the biggest of which is the annual Robocup tournament, which will be held in Seattle this year. Robosoccer is a great reasearch tool for exploring A.I., automous agent behaviour, computer vision, simulation and mechanical and electrical design. It attracts participants ranging from high school students to academic researchers.

Our website (which incidentally runs slashcode) will also be a clearing house for us to award sponsorship money for teams building robosoccer robots as well as a place to exchange information.

Hard to get enough of Robots playing soccer, and prize money means you can buy more marshmallows to roast at your victory bonfire.

More updates and links below on HavenCo, robots that kick balls, and what can already be said to be one of the millenium's most anticipated movies thus far. Oh, and some nice auditory/textual backup to the recent story about RMS vs. Goliath.

Not asking, not telling. jeffthompson writes: "The Havenco web site says it is now fully operational and open for business." A lot of people seemed convinced that Havenco wouldn't even be around by this time, but sticking around is the best revenge. I'd like to go aboard one day, promise I'll wear a blindfold and not look at anything ...

GNU, Linux, GNU/Linux, Freedom and the American Way. bkuhn writes: "Now, both the electronic audio and transcript of RMS' NYU talk are available."

The audio is in Ogg format, and the transcription is in blessed plaintext. Thanks!

Sign #37 of the coming apocalypse: Speaking of Mundie, software Freedom (and free-ness), Simone Paddock of O'Reilly writes with news that might raise a few eyebrows:

"Microsoft Senior Vice President Craig Mundie set off a compelling debate recently when he discussed Microsoft's Shared Source Philosophy, which blends the sharing of source code with the preservation of intellectual property rights.

Tim O'Reilly invited him to attend the upcoming O'Reilly Open Source Convention (July 23-27, 2001 in San Diego). Mundie not only agreed to attend, he agreed to speak.

Mundie will discuss ways in which shared source differs from open source, and how the Shared Source Philosophy supports a strong software business case for commercial software use."

Michael Tiemann (CTO of Red Hat) will speak after Mundie, and a panel of IP law and software experts (including Tim O'Reilly) will discuss the issues raised. Sounds worth being in San Diego for. If you're interested, there's more information online.

In the Tolkein, not the endocrinological or Snow White sense. SomeoneYouDontKnow writes: "This is a follow-up on the recently-released LOTR trailer. It's now available for download. Two versions are available to suit your bandwidth and patience. Unfortunately, it's still only available in Real format, but I guess we can't have everything."

Semi-alive and kicking. IEEE Spectrum Associate Editor Stephen Cass writes:

IEEE Spectrum , the house magazine of the IEEE is launching an online forum devoted to the noble sport of robosoccer . Robosoccer is different from things like Battle Bots or Robot Wars in that the robots play in teams and the whole thing is completely autonomous once started. There are a number of competitions, the biggest of which is the annual Robocup tournament, which will be held in Seattle this year. Robosoccer is a great reasearch tool for exploring A.I., automous agent behaviour, computer vision, simulation and mechanical and electrical design. It attracts participants ranging from high school students to academic researchers.

Our website (which incidentally runs slashcode) will also be a clearing house for us to award sponsorship money for teams building robosoccer robots as well as a place to exchange information.

Hard to get enough of Robots playing soccer, and prize money means you can buy more marshmallows to roast at your victory bonfire.

richard writes: "Clay Shirky has an interesting article on Hailstorm on OpenP2P.com. He looks especially at how MS mixes decentralization with strong control of third party development and user data. Think of it as an authentication-centric, rather than hardware-centric system." A very nice analysis, neatly mapping out Microsoft's plans and how they intend to control the system. Well worth the read.

Janon writes: "There's a rather interesting interview with Antony Fountain, a Motif developer and reference manual author at O'Reilly. He makes some rather well-founded (or at least it seems so to me) claims that Motif has some rather important advantages over the likes of GTK+ and Qt, such as an open and superior component model." It's a great illustration of the split between open and closed development, too -- fans of the Bazaar may see only waste in Fountains assertion that "Millions of lines of Motif get written and not one word about it leaves the company doors."

Janon writes: "There's a rather interesting interview with Antony Fountain, a Motif developer and reference manual author at O'Reilly. He makes some rather well-founded (or at least it seems so to me) claims that Motif has some rather important advantages over the likes of GTK+ and Qt, such as an open and superior component model." It's a great illustration of the split between open and closed development, too -- fans of the Bazaar may see only waste in Fountains assertion that "Millions of lines of Motif get written and not one word about it leaves the company doors."

tadghin pointed out this Newsweek article on bioinformatics, and also notes: "At O'Reilly, we just published our first bioinformatics book last week, Learning Bioinformatics Computer Skills, by Cynthia Gibas and Per Jambeck, and it immediately rocketed to the top of the Amazon Computer bestseller list. This definitely appears to be a new area for the computer industry that's just starting to hit people's radar big time. I've also made the point to VCs looking at distributed computation startups that what I see on sites like slashdot is a lot of movement by hackers towards new and interesting problems. And science looks a lot more interesting than some of the business computing that's been front and center the past couple of years. And the Biological Open Source Computing Conference I spoke at last year was definitely popping with ideas and excitement. Unfortunately, this year's conference is in Copenhagen, right before the O'Reilly open source convention, but I definitely urge slashdotters to check out this area. Demand for perl expertise is especially high."

tadghin pointed out this Newsweek article on bioinformatics, and also notes: "At O'Reilly, we just published our first bioinformatics book last week, Learning Bioinformatics Computer Skills, by Cynthia Gibas and Per Jambeck, and it immediately rocketed to the top of the Amazon Computer bestseller list. This definitely appears to be a new area for the computer industry that's just starting to hit people's radar big time. I've also made the point to VCs looking at distributed computation startups that what I see on sites like slashdot is a lot of movement by hackers towards new and interesting problems. And science looks a lot more interesting than some of the business computing that's been front and center the past couple of years. And the Biological Open Source Computing Conference I spoke at last year was definitely popping with ideas and excitement. Unfortunately, this year's conference is in Copenhagen, right before the O'Reilly open source convention, but I definitely urge slashdotters to check out this area. Demand for perl expertise is especially high."

tadghin pointed out this Newsweek article on bioinformatics, and also notes: "At O'Reilly, we just published our first bioinformatics book last week, Learning Bioinformatics Computer Skills, by Cynthia Gibas and Per Jambeck, and it immediately rocketed to the top of the Amazon Computer bestseller list. This definitely appears to be a new area for the computer industry that's just starting to hit people's radar big time. I've also made the point to VCs looking at distributed computation startups that what I see on sites like slashdot is a lot of movement by hackers towards new and interesting problems. And science looks a lot more interesting than some of the business computing that's been front and center the past couple of years. And the Biological Open Source Computing Conference I spoke at last year was definitely popping with ideas and excitement. Unfortunately, this year's conference is in Copenhagen, right before the O'Reilly open source convention, but I definitely urge slashdotters to check out this area. Demand for perl expertise is especially high."

Betsy Waliszewski sent in this interview with Mark Lutz, author of Programming Python. He discusses the evolution of Python during its brief history, XML support and .NET, and takes a brief look at the future of Python.

Betsy Waliszewski sent in this interview with Mark Lutz, author of Programming Python. He discusses the evolution of Python during its brief history, XML support and .NET, and takes a brief look at the future of Python.

swagr writes "Some new and interesting information on the Ruby website.
1: O'Reilly is apparently publishing a translation of "Ruby Pocket Reference" (although this news doesn't seem to be on O'Reilly's site
2: There is a Ruby Conference happening in October.
3: They need some help with a Ruby mascot (1337 gimpists: go nuts)."

Ellen writes "Apache's Jakarta-Tomcat server is an open source, Java-based Web application container that was created to run Servlet and JavaServer Page (JSP) web applications. In O'Reilly Network's "Using Tomcat" series, author James Goodwill previously has explained how to install and configure Tomcat. His latest article provides in-depth information about how to deploy it. Read "Deploying Web Appliactions to Tomcat"

Thanks to Simone for pointing out this article by Andy Duncan regarding Oracle and its relationship to Open Source. The article starts out with background, and the metaphor to the Italian Renaissance is a bit odd, but I do think that this is a path Oracle is looking to walk down - what do you all think?

Lisa wrote to us about an interview with Brian McConnell, the author of a new SETI book, who talks about how the search has touched many different scientific disciplines, and has spawned improvements in astronomy, computing, and wireless communications.

Lisa wrote to us about an interview with Brian McConnell, the author of a new SETI book, who talks about how the search has touched many different scientific disciplines, and has spawned improvements in astronomy, computing, and wireless communications.

Updates and revisions for you on various and sundry stories you've seen here recently, from Parrot to Linux on handhelds to the recent judgement against MP3.com and more. Read on below to find them.

At least the jurors don't get to set the value of Pi. openbear writes: "According to a story at c|net the jurors meant for MP3.com to pay $3 million and not $300,000 in the court decision made last week. This may sound bad for MP3.com, but considering that TVT was originally going for $8.5 million I suppose that $3 million still looks like a good ruling. Espically since they have $42.9 million set aside for damage awards in pending suits."

(Here are some other articles about MP3.com as well.)

Parroting the (ORA, ActiveState, etc.) company line: rjoseph writes: "Perl.com's managing editor Simon Cozens has written a quick article on O'Reilly.com that explains the April Fools joke of the faked colaboration between Perl and Python to produce Parrot. He explains how the most interesting aspect about the whole affair is the fact that, to pull it off succesfully, the Perl and Python communities had to work together more than they had in a long time!"

Humor may suffer from analysis, but this is a cool explanation of what it took to pull off what turned out to be probably the most convincing Fool of the year, at least for those in the very small Venn diagram with the background and motivation to care about open-source programming languages and their creators;) Of course, now no one will believe it when the two do actually merge. (For a while I thought that the talk of "Python 3000" was a joke, too.)

Small steps on tiny machines n7lyg writes: "IEEE Computer has an article this month about a prototype PDA developed at Compaq's Western Research Labs: Itsy: Stretching the Bounds of Mobile Computing. Itsy has been through two implementations and has several unique features, including using MEMS accelerometers to implement a gesture interface (Rock'n'Scroll). This is all just research, but it does show promise for Linux-based PDA's. Itsy runs the X Window System and Qt Palmtop. The WRL website for Itsy is here."

This is really cool background material; now the earlier Itsy work has led to Linux on the iPAQ, I wish Compaq would actually sell a PDA with the size and shape of the Itsy itself. And tiny accelerometers for gesture-control would be welcome on my visor as well, and surely for small video game systems.

Big Blue, Big Blue, your transmission is fading, please say again, over. An Onymous Coward writes: "This sucks. At LWCE there was a big display at the KDE booth using ViaVoice to control KDE apps through Qt. Now it looks like the project is dead in the water, according to this article at Newsforge -- maybe lack of interest from IBM?"

What with the billion dollars that IBM has pledged to spend on Linux-related projects, and the fact that ViaVoice has shipped for a while with the high-end boxed version of Mandrake, hopefully this is just an oversight. ViaVoice is a cool technology -- but if things don't work out between Qt and IBM, perhaps KDE (and GNOME, and others, level playing field here!) can work on integration with Sphinx. An Apache-style license should be all-around friendly, right?

Updates and revisions for you on various and sundry stories you've seen here recently, from Parrot to Linux on handhelds to the recent judgement against MP3.com and more. Read on below to find them.

At least the jurors don't get to set the value of Pi. openbear writes: "According to a story at c|net the jurors meant for MP3.com to pay $3 million and not $300,000 in the court decision made last week. This may sound bad for MP3.com, but considering that TVT was originally going for $8.5 million I suppose that $3 million still looks like a good ruling. Espically since they have $42.9 million set aside for damage awards in pending suits."

(Here are some other articles about MP3.com as well.)

Parroting the (ORA, ActiveState, etc.) company line: rjoseph writes: "Perl.com's managing editor Simon Cozens has written a quick article on O'Reilly.com that explains the April Fools joke of the faked colaboration between Perl and Python to produce Parrot. He explains how the most interesting aspect about the whole affair is the fact that, to pull it off succesfully, the Perl and Python communities had to work together more than they had in a long time!"

Humor may suffer from analysis, but this is a cool explanation of what it took to pull off what turned out to be probably the most convincing Fool of the year, at least for those in the very small Venn diagram with the background and motivation to care about open-source programming languages and their creators;) Of course, now no one will believe it when the two do actually merge. (For a while I thought that the talk of "Python 3000" was a joke, too.)

Small steps on tiny machines n7lyg writes: "IEEE Computer has an article this month about a prototype PDA developed at Compaq's Western Research Labs: Itsy: Stretching the Bounds of Mobile Computing. Itsy has been through two implementations and has several unique features, including using MEMS accelerometers to implement a gesture interface (Rock'n'Scroll). This is all just research, but it does show promise for Linux-based PDA's. Itsy runs the X Window System and Qt Palmtop. The WRL website for Itsy is here."

This is really cool background material; now the earlier Itsy work has led to Linux on the iPAQ, I wish Compaq would actually sell a PDA with the size and shape of the Itsy itself. And tiny accelerometers for gesture-control would be welcome on my visor as well, and surely for small video game systems.

Big Blue, Big Blue, your transmission is fading, please say again, over. An Onymous Coward writes: "This sucks. At LWCE there was a big display at the KDE booth using ViaVoice to control KDE apps through Qt. Now it looks like the project is dead in the water, according to this article at Newsforge -- maybe lack of interest from IBM?"

What with the billion dollars that IBM has pledged to spend on Linux-related projects, and the fact that ViaVoice has shipped for a while with the high-end boxed version of Mandrake, hopefully this is just an oversight. ViaVoice is a cool technology -- but if things don't work out between Qt and IBM, perhaps KDE (and GNOME, and others, level playing field here!) can work on integration with Sphinx. An Apache-style license should be all-around friendly, right?

richard writes: "Clay Shirky has responded to Jon Katz's article, Does P2P Suck?, (and a WSJ article published the same day) in an article titled "Backlash!" on OpenP2P.com. Shirky says: "P2P means many things to many people. PC users don't have to be second-class citizens. PCs can be woven directly into the Internet. Content can be provided from the edges of the network just as surely as from the center. Millions of small computers can be more reliable than one giant server. Millions of small CPUs can do the work of a supercomputer. ... These are sloppy ideas, ideas that don't describe a technology or a business model, but they are also big ideas, and they are also good ideas.""

So, now that OS X has been out a few days and people have had a chance to put it though its paces, let's take a look at it. Upside.com wonders if the new OS was released half-baked. Ars Technica puts it through its paces with a very thorough review. O'Reilly plans to release tech books covering OS X, so if your bookshelf isn't full yet, you can add a few more. Certain major software projects are already being tried on OS X - look out Adobe. And finally, we know it's not April 1, but we thought the picture of OS X on a Visor was cute. Any other good links to reviews? Post them below.

chipmunk writes "My prayers have been answered! Larry and Guido have joined forces to produce Parrot, what will surely become the best language ever written. The power of Perl and the sanity of Python. The Py3K and Perl 6 development are merging, with Jeremy Hylton and Dan Sugalski as joint development leads. Read more in the press release on use Perl;, and see a joint interview on perl.com!"

It's about time. It's like the right brain and left brain are working together, at long last. O'Reilly has already inked a deal to publish Programming Parrot, and Yet Another Society is set to merge with the recently launched Python Software Foundation. Both Guido and Larry will be working for ActiveState.

chipmunk writes "My prayers have been answered! Larry and Guido have joined forces to produce Parrot, what will surely become the best language ever written. The power of Perl and the sanity of Python. The Py3K and Perl 6 development are merging, with Jeremy Hylton and Dan Sugalski as joint development leads. Read more in the press release on use Perl;, and see a joint interview on perl.com!"

It's about time. It's like the right brain and left brain are working together, at long last. O'Reilly has already inked a deal to publish Programming Parrot, and Yet Another Society is set to merge with the recently launched Python Software Foundation. Both Guido and Larry will be working for ActiveState.

High school is bizarre enough, but a private high school is an environment uniquely removed from reality. S. and G., two sophomores at such a school in one of the United States' hot technology corridors, put up a couple of private websites with their unflattering thoughts about the school experience. Last week those sites got them suspended for two days. Worse -- because he wasn't familiar with the distinction between perl's scalar and list context, S. now has a police record. Update: 03/14 10:49 PM by J : We had some database trouble in the last couple hours, but all the comments seem to be back... whew.

These two 15-year-old friends are well-spoken; self-described geeks, they choose their words deliberately, with a minimum of "um." I'm using their initials instead of names because they don't want more trouble than they're already in. Their school has rules against disparaging its reputation, and they have learned their lesson from last week -- so you won't learn from me who they are, or which school it is they go to.

Let's get the code out of the way here, as a public service to students everywhere thinking about putting up a website of their own. Every perl expression has a context: scalar or list. (And for the rabid purists among you, who will flame me if I don't mention these, the other possible contexts are boolean, void, and interpolative.)

Many operators behave differently depending on context: in this case, the backtick. The statement:

my($f) = `fortune`;

...puts the backtick operator in list context, so it returns a list, where each element is one line from the program's output.

S. wants to be a developer when he graduates; he certainly has the most important thing down, which is to always be exploring and learning new things. In the process of converting his website from PHP to perl for no especially good reason, he wrote the above line.

If he had written the code correctly:

my $f = `fortune`;

...the backtick operator would have been in scalar context, assigned its complete result to $f for printing, and you wouldn't be reading this sad story.

Last week, the administrators at his school just happened to take a look at his webpage when fortune pulled up this quote:

I put the shotgun in an Adidas bag and padded it out with four pairs of tennis socks, not my style at all, but that was what I was aiming for: If they think you're crude, go technical; if they think you're technical, go crude. I'm a very technical boy. So I decided to get as crude as possible. These days, though, you have to be pretty technical before you can even aspire to crudeness.
- Johnny Mnemonic, by William Gibson

Because only the first line about the shotgun was stored in $f and shown on the webpage, it wasn't immediately obvious that this was a quote.

Visions of kids with shotguns in Adidas bags must have gone through someone's head. The school went into a sort of a crisis mode. Later they would mention that this wouldn't have been an issue if there hadn't been school shootings elsewhere in the country just a week prior.

The sophomores were called down to the office separately for questioning, one at a time, each of them without being told the other had been there. Each of them separately explained that fortune is a unix program that returns random quotations, and each of them told me that the administrators scoffed. "You're saying all these big companies that use unix, like Sun, have this fortune program?"

I assume the staff knew better and was just trying to find holes in the kids' stories, because apparently they had reloaded the page dozens of times and, of course, had gotten a new quote each time. After being released, G. got in touch with their Advanced Placement Computer Science teacher, who is, it sounds like, one of the few authority figures working for the Light Side of the Force. Her explanation of fortune was, finally, believed.

But the police had been called anyway, just to be on the safe side.

The suspension portion of the kids' punishment, carried out last Thursday and Friday, was actually over a separate website, one whose domain name contained the school's name and the Fword. This is a word, by the way, which G. obviously typed in to register the domain but which he was too polite to use over the phone. By the time we hung up, he had me embarrassed for saying it.

The site was very private, all things considered. He and S. had only told a few friends. And they'd done their homework, going over the referer logs to see who knew about it, and making sure the search engines didn't index it. They even banned the school's proxy by IP. As G.'s father later said, "it was the analogue of students in middle school passing a note back and forth. It was never meant to be in the public eye."

But it was disparaging of the school and it was, after all, a publicly available website. That's against the rules. The two shared joint responsibility, so they were both suspended.

Personally, I think a school's job is to teach not just the three R's, but also participation as a citizen in our Republic. That may be more important. For a school to teach freedom as a dry document while crushing student dissent is a waste.

It's legal, of course. The First Amendment doesn't apply to private schools. They can make whatever rules they want. Rules like theirs are great for raising robots. But anyone who's going to make a difference in this world is going to have to be comfortable with laughing at authority.

Unfortunately, the message the administration is sending gets heard. When I asked G. what he thought about being suspended for venting about his school, he told me he just didn't want to fight it. He said he might have felt differently a year ago, but now, "I don't know if it's from brainwashing or just not wanting to get expelled, but ... I just want it to be over." I can't blame him.

And S. said he understood the school's point of view. "People who were thinking about attending [his school] might see the site and think that they might not want to attend. ... I guess they do have reason for concern, because what if it shows up on a search engine."

S.'s family moved from Russia to the United States when he was four. His father painted for me an interesting picture of the interrogation by the police officers who were called to the school. Keep in mind that S. had already been told by his school that he fit the profile of a potential killer.

The police questioned them for a couple of hours. The "killer" profile was brought up again. Questions were raised about S.'s psychological state, whether he had made threats before, and whether the family had guns in the house.

His father repeated to me twice, as if he couldn't quite believe the whole thing had actually happened, that the police gave him a case number and are keeping the report on file. "I grew up in an environment," he told me, "where they are labeling people and where there is a witch hunt." He brought up McCarthyism. Eleven years in the States had led him to believe that this kind of thing doesn't happen here, or at least not anymore. I wish he were right.

The moral of the story is to be careful when passing notes to your friends. And believe the Camel when it says -- third edition, page 69 -- "You will be miserable until you learn the difference between scalar and list context."

Sommelier writes " Interesting article on the O'Reilly Python site about Walt Disney Feature Animation adopting Python to accomplish a lot of their work. "

Sommelier writes " Interesting article on the O'Reilly Python site about Walt Disney Feature Animation adopting Python to accomplish a lot of their work. "

An unnamed reader writes: "Looks like O'Reilly and Associates have killed off their software development division because it wasn't a strategic fit with their other efforts. Tim O'Reilly writes 'We will continue to sell and support our primary software products, WebSite and WebBoard, as we look for new homes for them.' While these were both Windows-only products, they are fairly well respected in the industry, and it's a shame to see something like this shut down to be aligned with their 'strategy,' despite Tim's own admission that the projects were profitable."

Tim O'Reilly writes "Dave Farber is not only a great technologist (one of the founding fathers of the Internet) but also one of the people most concerned with technology and society (co-founder of the Electronic Frontier Foundation, for example). This brief report on Dave's year as Chief Technologist of the FCC gives a few impressions of the policy makers in Washington D.C. Well worth a read, and immensely credible to those of us who know Dave." (Read More.)

"One highlight:

Washington is a town with very, very few technical people advising the top levels of decision-makers. In an era where technology has such an impact on our economy, that is dangerous. Most of the senior people are lawyers and economists with little knowledge of science and technology. They get their information largely from the few technical people on their staffs and from hordes of lobbyists.

For those who don't know it, Dave's IP (Interesting People) email list is a previous generation of the same spirit that led to slashdot. The interesting people on the list send interesting tidbits to Dave, who forwards them on (or not) depending on whether he finds them interesting. Dave does no reformatting or cleanup of submissions, so the stuff is sometimes a bit hard to read, depending on how many times it's been forwarded, but the content is almost always worthwhile. And Dave's own pieces are almost always worth a read. They range from what's new and hot in Akihabra (Dave's a gadget guy) to what Dave had to eat on that same trip to Tokyo. There's a leaning towards stories that hit the intersection between technology and policy, but lots of other goodies come by here too.

For web archives going back to mid-1993, see http://www.interesting-people.org/."

Lisa Mann of O'Reilly sent us this story about anticryptography - sending messages which are easy to understand rather than the reverse. This is something which has applications in communicating both extraterrestrially and on Earth.

Lisa Mann of O'Reilly sent us this story about anticryptography - sending messages which are easy to understand rather than the reverse. This is something which has applications in communicating both extraterrestrially and on Earth.

richard koman writes: "In an interview with Bill Joy on openp2p.com, Bill reveals that he's working with Sen. Orrin Hatch to devise public policy on the Net and copyright infringement, and states his belief that wholesale copying of content is "too much of a nerd view of the world."" He's got an interesting perspective on Napster, despite being a shareholder of it.

Richard Koman writes: "Tim O'Reilly and I interviewed cyberspace lawyer Lawrence Lessig about the law and P2P for O'Reilly's OpenP2P site. He makes some great points about the legal and investment climate for P2P (the RIAA's goal is to "guarantee that no venture capitalist invests money in new modes of distribution unless Hollywood signs off") and the full-bore attack on fair use in the DeCSS case (the DMCA says "you cannot crack copyright protection schemes even if your purpose is to allow you to have fair use of the underlying material.")" I disagree a bit with Lessig's statement on the second page about why we don't have book licenses - I think it's because the legal system refused to enforce them, not because the book industry thought it was futile. But overall it's definitely a good read.

So, ever had a question you wanted to ask the various folks behind Slash and/or Slashdot? A healthy assortment of Slashdot coders and authors (like krow, cliff, roblimo, jellicle and timothy) will be on hand for a BOF session at the Linux World Expo on Wednesday, January 31, 2001, Room 1E11, 6:00 p.m.-7:30 p.m. So, if you happen to be around, feel free to join us and have your questions answered. And of course, the Slash and Slashdot folks will also be at random times in the OSDN booth on the show floor, so please stop by. Hope to see you there!Update: 01/15 12:55 PM by H : Rob and I won't be able to make itto the BOF -- outstanding plans -- but you can catch us on February 15th at the O'Reilly P2P conference in San Fransico. We speak at something like 11:30 AM or so, on a panel - but we'll be at LWCE as well.

Reader John Regehr contributed this review of O'Reilly's Understanding the Linux Kernel, which goes into greater depth than most people have ever seen of the kernel source itself. (I wonder what it costs to look at the Windows source.)

Understanding the Linux Kernel author Author: Bovet, Daniel P. / Cesati, Marco pages 684 publisher O'Reilly & Associates rating 8.5 reviewer John Regehr ISBN 0596000022 summary The guts of the kernel, labeled and explained.

Although isolated pieces of operating system internals are usually not difficult to understand, learning how a significant portion of a real OS works is a daunting task: there's a lot of code, some of it is complicated, and some of it operates under obscure assumptions that can be difficult to figure out by reading the sources. Two of the best existing books about OS internals have explained either a simplified but working OS (Tanenbaum's Minix book) or a real, but very small OS (Lions' book on Unix v6). Although these systems have the advantage of being easier to understand, there's an important reason why one might want to study Linux internals instead: Linux is currently relevant, it's likely to be around for a while, and any code you write can potentially be used by thousands of people the day after tomorrow. So, taking it as a given the a book about Linux internals is a good thing, how good is this one? Happily, it's very good - better than any previous such book that I've seen (Rubini's Linux Device Driver book is also excellent, but it has a limited scope).

Understanding the Linux Kernel is good for several reasons. First, the authors have included quite a bit of explanatory material that isn't specifically about Linux - it's the kind of thing one would find in a good undergraduate OS textbook. This helps the reader link explanations of pieces of code to the abstract OS functions that they implement. Second, the authors have chosen a good level of abstraction: core kernel algorithms are explained in text, supplemented with short code sequences (simplified to remove optimizations) for important routines. Flowcharts are used to explain components with complex control flow, and tables and other diagrams are used when appropriate. Finally, the book is well arranged and well written, and there's an auxiliary index at the end that maps symbols mentioned in the book to source code files.

There are a few things I don't like about this book. Most importantly, there is no discussion of the network stack. As the authors say, this is a subject for another book, but by leaving out one of the most interesting and relevant parts of the kernel they are limiting their audience. A second drawback of this book (and of any Linux kernel book) is that since it seems to take about as long to write a good book as it does to write a major version of the Linux kernel, as I write this review it's about to become obsolete - it describes Linux version 2.2. However, at the end of each chapter there's a short note about things that are done differently in version 2.4. This will help preserve the relevance of the book after 2.4 comes out and, maybe more importantly, it gives the reader a sense of what parts of the kernel are under active development and what parts have become mature and stable.

Although Linux is very much in the Unix tradition, many details have changed. For example, early Unix kernels used simple algorithms (such as linear searches) and fixed table sizes. Modern Linux kernels, on the other hand, avoid arbitrary limits on the numbers of many kinds of internal OS objects, do not use linear searches when the number of objects to be searched is potentially large, and use amortized algorithms in many places. In all parts of the kernel, any special knowledge about the way that OS services will be used is exploited in order to improve average-case performance. For example, the slab memory allocator makes use of the fact that kernels often allocate many objects of the same size in order to reduce memory fragmentation and to avoid creating hot spots in the data cache. These algorithmic optimizations are much more pervasive (and much more effective) than micro-optimizations such as tuning register allocation or packing flags into the bits of a memory word - they're what make Linux useful in large-scale server environments where high throughput is critical. However, they also make the kernel code quite a bit more difficult to understand.

Given this complexity, it seems reasonable to ask who needs to read this book and how well does it suit their needs. Three groups of people come to mind. First, potential kernel hackers will find this book to be a good overview of different parts of the kernel. Of course, for people like this a book is no substitute for lots of code reading, but it's a good start. Another potential audience is the group of people who need to understand the kernel in order to extract high performance from it; for example, authors of databases or network servers. This group's needs are well served by this book: the authors often point out why certain heuristics were chosen - this may help people whose applications have run afoul of a resource allocation policy that was designed to serve a different class of applications. Finally, computer science students interested in the internals of a real OS would do well to read this book. It would make a good supplement to a standard OS textbook in an introductory class on operating systems. However, Linux appears to be far too large to understand in its entirety in a single semester: classes that attempt to do this should use a teaching OS like Minix. To benefit from this book, readers should have knowledge equivalent to a couple of semesters of computer science: a basic understanding of programming, of the services an OS provides to user-level programs, and of the hardware mechanisms used by an OS.

This is a good book. The authors have cracked open a large collection of code that's currently very relevant. If they are in for the long haul and release revised books in a timely way, then this will likely become and remain the definitive explanation of Linux internals.

The web site for the book is here.

You can purchase this book at Fatbrain.

If you seek updates this evening, you're in luck. Below, we have some additional information for you on: the state of the dot-com-economy; more information (and a link to a very neat site) about your private bar-coding adventures; more about the bad things that can result from farming out your spam prevention; and the threads being plucked ungently from the fabric of the Matrix sequels. Enjoy.

Wait -- I thought we were already on the new, new, old, new, old new economy. davecb writes: "To compliment Jon's essay on the Myth of the Tech Slump, have a look at last month's cover article in The Atlantic, where computer technology is quietly changing the old-economy companies of the rust belt into something rather different: the new old economy.

The author asks (and answers) 'The great question about the surge in American productivity since 1996 is, Will it last, or is it simply a brief, blessed pop that will disappear forever when the next recession comes? That is essentially another way of asking whether the New Economy and the New Old Economy are real, or are just the Old Economy on adrenaline.'

He and I suspect it's the very opposite of a slump."

Mommy, where is my new baby brother's barcode? raincrow writes: "One of the only good things that came out of the CueCat fiasco (for me, anyway, besides the free barcode scanner and accompanying shiny coaster), was the discover of ReaderWare, which has made the management of my personal library so much better. The ReaderWare newsletter, in turn, has a lot of good tips on bar code scanners, and turned me on to Qode (http://www.qode.com/), which is a shopping system that uses a personal barcode scanner to let you set up your own shopping lists and other goodies (ReaderWare folks just like it because it can store barcodes untethered from the PC and therefore keeps you from having to lug all your books to the computer). What's interesting is that Qode.com makes a really big deal about being *anonymous*. Quoting from the site 'Note that we said anonymity, not privacy. Qode has been working to solve the problems of consumer privacy by designing a system that does not require any personal or identifying information. Qode matches promotions specifically to the products entered into the system by its anonymous users. It is impossible to connect this information to any individual. We then deliver the promotion to your private, custom web site ? not your e-mail.' Any experiences out there? I'm still looking for the holes, but that's a niftly little gadget for $50.00."

Lose mail free with Not-so-Hotmail! Just when you thought the confluence of spam (note to Hormel -- the bad kind, not your tasty meat product, which is uppercased) and email had exerted all the evil it could, the opposite proves true. Read this account on ZDnet about what happens when your mail doesn't get sent on hotmail due to hyperactive, automatic spam-prevention bots. (The "your" of course referring to people with Hotmail accounts.)

Don't they make video cards or something? Johnathon Walls writes "It seems that the sequels to The Matrix are in even more trouble as Carrie Moss ends up on crutches for six weeks due to a knee injury. This is added trouble to the previous holdups reported by Slashdot. Jet Li has also pulled out (though I'm uncertain how new this bit is)."

curtS writes "Cnet has a piece about industry reaction to Amazon's now offering used books. A copy of the Authors Guild letter to Jeff Bezos is here." I've got a discussion piece from tytso as well below - what do you think about it?

tytso writes:

In my opinion there are plenty of subjects for which Bezos deserves to be berated, including overly agressive accounting tactics, and their one-click patent. But selling used books?

The Authors Guild's argument is that authors don't get any compensation if someone purchases a used book; only the seller and Amazon.com make out on the transaction. So when amazon.com makes it easier for consumers to buy and sell used books which could also be purchased new --- at a more expensive price, of course --- it hurts the authors. The Authors Guild and the Association of American Publishers would prefer that Amazon.com only allow their users to sell used books if they are out-of-print books.

Well, excuuuuuuuse me! I can understand that authors need to eat, and send their kids off to college, and all those good things. But if a book wasn't good enough for me to want to keep it, why shouldn't I be able to sell it? Using the same logic, the Authors Guild should logically be against public libraries. After all, people who use libraries can (oh horrors!) read a new book without having to pay for it!

This really goes to show the fundamental tension between content providers and consumers. If you take the Authors Guild position to its extreme, you'd think that they would much prefer that bookreaders purchase books from bookstores, and if they didn't like it, that they throw it into a landfill rather than resell it or give it away, or lend it to a friend. After all, all of these activities compete with new book sales. Fortunately for us, the doctrine that the owner of a book is allowed to do all of these things is fairly strongly encoded into law --- which is why all the President of the Authors Guild can do to write a whiny letter to Bezos asking him to please don't do this.

And thus we see the danger of the positions espoused by the Software Publisher's Association, and UCITA. Not only do they wish to take away our rights about what we can and can't do with software --- including rights which common sense would dictate are perfectly permissible in the case of the physical world, such as selling or loaning a book to a friend --- but their actions have emboldened folks such as the Authors Guild and the Association of American Publishers to try to take away rights which we always have had in the physical world. After all, if the software vendors can restrict what you can do their software, why shouldn't a book publisher be able to restrict what you can do with their books?

Fortunately, most book publishers don't have as much money to throw around as Disney, so they probably won't be able to purchase enough Senators to change copyright law to suit their purposes. But when thought patterns of the SPA have started infecting traditional book authors --- who really should know better --- it's obvious that we're living in dangerous times."

guido_sst writes "Richard Silverman, co-author of O'Reilly's SSH, The Secure Shell: The Definitive Guide , has written a response to Kurt Seifried's article entitled 'The End of SSL and SSH?' at at Security Portal written after the release of dsniff 2.3. You can read the original article at SecurityPortal, the original Slashdot coverage on Slashdot, and Silverman's response at O'Reilly.." We had link to the story as well.

guido_sst writes "Richard Silverman, co-author of O'Reilly's SSH, The Secure Shell: The Definitive Guide , has written a response to Kurt Seifried's article entitled 'The End of SSL and SSH?' at at Security Portal written after the release of dsniff 2.3. You can read the original article at SecurityPortal, the original Slashdot coverage on Slashdot, and Silverman's response at O'Reilly.." We had link to the story as well.

Chromatic, indefatigueable, has come up with another review. This time through the door he's gathered his reactions to Perl for System Administrators, one of the growing list of titles to help bridge the gap between SysAdmin and programmer.

Perl for System Administrators author David N. Blank-Edelman pages 430 publisher O'Reilly and Associates rating 9 reviewer chromatic ISBN 1-56592-609-9 summary A royal buffet of ideas to stimulate system administrators

The Scoop Despite being what some call 'the purest distillation of Unix thought,' Perl has earned a place on many Windows and Macintosh machines for its power and flexibility. Unix administrators have developed and honed small scripts for decades, but their brethren elsewhere have had no such luck until recently. Enter ActiveState, IndigoPerl, and MacPerl, to provide the tools, this book the knowledge. Floating subtle suggestions between pragmatic tips and tricks, David N. Blank-Edelman weaves nets, strong and sophisticated, for the perpetual battle against encroaching entropy. What's to Like? Anything that saves a beleagured sysadmin time is very good. Any one chapter read in isolation will yield at least one new idiom, if not many ideas on improving efficiency and accuracy. The central theme of the book ('make things better by using a database to store all of your information') is an excellent and timely idea. It's not essential to the presented examples, but has the potential to simplify your work dramatically. Besides maintaining a central repository for usernames, accounts, network information, and passwords, it allows automated configuration file building. Imagine never hand-editing DNS records again, or having to enter user data only once.

The sample code is clean and understandable, taking full advantage of many CPAN modules. When competing modules exist, Blank-Edelman demonstrates each, with an eye to advantages and disadvantages. This pragmatic analysis governs other discussions, especially concerning cross-platform and Pure Perl versus glue-code isses. Realizing that most networks combine many different clients (Unix flavors, the Windows cousins, and Apple machines), the author provides solutions to the same problem on all applicable platforms.

Though pushing the envelope on certain technologies (at the expense of others), the Appendices provide adequate introduction. The LDAP and SNMP sections stand out in particular. The author provides enough background, whether on Active Directory, TCP packet construction, or e-mail headers, to flesh out his examples. A table at the end of each chapter lists all modules covered, authors and versions, CPAN ids, and alternate download sites. In addition, the book provides many links to further information on techniques, RFCs, references, and vendors. If you're left wondering where to go to learn more, it will be your own fault.

What's to Consider? The book assumes a working knowledge of Perl. Anyone who's made it through 'Learning Perl' or 'Elements of Programming With Perl' should have no trouble -- complex idioms and module peculiarities receive sufficient explanation. Beware, though, that the sample code does not enable warnings or run under strict mode. (Production programs need error checking, which, the author explains, could easily double the size of his examples.)

Not all sections apply to all OSs. The Macintosh, for example, has no concept of multiple users (OS X not being covered). These differences could hinder the text, but are clearly marked and can be skipped with no ill effects. Besides, few networks are homogenous, and astute readers will learn more about the system in general from the similarities and differences.

Some common administrative tasks have been left out in favor of emerging or more complex technologies. There's nothing on managing printers or backups. A sysadmin of reasonable experience who makes it through the book will have gained a proper mental framework to tackle other tasks, though.

The Summary Perl for System Administrators is packed with useful tips, making the most of Perl's ecological niche. Whether you're a junior administrator venturing out into the wild world for the first time, or a seasoned BOFH, you'll find something to digest here. You might even get some free time out of it. Table of Contents

1. Introduction
2. Filesystems
3. User Accounts
4. User Activity
5. TCP/IP Name Services
6. Directory Services
7. SQL Database Administration
8. Electronic Mail
9. Log Files
10. Security and Network Monitoring

1. The Five-Minute RCS Tutorial
2. The Ten-Minute LDAP Tutorial
3. The Eight-Minute XML Tutorial
4. The Fifteen-Minute SQL Tutorial
5. The Twenty-Minute SNMP Tutorial

You can purchase this book at ThinkGeek.

Chromatic, indefatigueable, has come up with another review. This time through the door he's gathered his reactions to Perl for System Administrators, one of the growing list of titles to help bridge the gap between SysAdmin and programmer.

Perl for System Administrators author David N. Blank-Edelman pages 430 publisher O'Reilly and Associates rating 9 reviewer chromatic ISBN 1-56592-609-9 summary A royal buffet of ideas to stimulate system administrators

The Scoop Despite being what some call 'the purest distillation of Unix thought,' Perl has earned a place on many Windows and Macintosh machines for its power and flexibility. Unix administrators have developed and honed small scripts for decades, but their brethren elsewhere have had no such luck until recently. Enter ActiveState, IndigoPerl, and MacPerl, to provide the tools, this book the knowledge. Floating subtle suggestions between pragmatic tips and tricks, David N. Blank-Edelman weaves nets, strong and sophisticated, for the perpetual battle against encroaching entropy. What's to Like? Anything that saves a beleagured sysadmin time is very good. Any one chapter read in isolation will yield at least one new idiom, if not many ideas on improving efficiency and accuracy. The central theme of the book ('make things better by using a database to store all of your information') is an excellent and timely idea. It's not essential to the presented examples, but has the potential to simplify your work dramatically. Besides maintaining a central repository for usernames, accounts, network information, and passwords, it allows automated configuration file building. Imagine never hand-editing DNS records again, or having to enter user data only once.

The sample code is clean and understandable, taking full advantage of many CPAN modules. When competing modules exist, Blank-Edelman demonstrates each, with an eye to advantages and disadvantages. This pragmatic analysis governs other discussions, especially concerning cross-platform and Pure Perl versus glue-code isses. Realizing that most networks combine many different clients (Unix flavors, the Windows cousins, and Apple machines), the author provides solutions to the same problem on all applicable platforms.

Though pushing the envelope on certain technologies (at the expense of others), the Appendices provide adequate introduction. The LDAP and SNMP sections stand out in particular. The author provides enough background, whether on Active Directory, TCP packet construction, or e-mail headers, to flesh out his examples. A table at the end of each chapter lists all modules covered, authors and versions, CPAN ids, and alternate download sites. In addition, the book provides many links to further information on techniques, RFCs, references, and vendors. If you're left wondering where to go to learn more, it will be your own fault.

What's to Consider? The book assumes a working knowledge of Perl. Anyone who's made it through 'Learning Perl' or 'Elements of Programming With Perl' should have no trouble -- complex idioms and module peculiarities receive sufficient explanation. Beware, though, that the sample code does not enable warnings or run under strict mode. (Production programs need error checking, which, the author explains, could easily double the size of his examples.)

Not all sections apply to all OSs. The Macintosh, for example, has no concept of multiple users (OS X not being covered). These differences could hinder the text, but are clearly marked and can be skipped with no ill effects. Besides, few networks are homogenous, and astute readers will learn more about the system in general from the similarities and differences.

Some common administrative tasks have been left out in favor of emerging or more complex technologies. There's nothing on managing printers or backups. A sysadmin of reasonable experience who makes it through the book will have gained a proper mental framework to tackle other tasks, though.

The Summary Perl for System Administrators is packed with useful tips, making the most of Perl's ecological niche. Whether you're a junior administrator venturing out into the wild world for the first time, or a seasoned BOFH, you'll find something to digest here. You might even get some free time out of it. Table of Contents

1. Introduction
2. Filesystems
3. User Accounts
4. User Activity
5. TCP/IP Name Services
6. Directory Services
7. SQL Database Administration
8. Electronic Mail
9. Log Files
10. Security and Network Monitoring

1. The Five-Minute RCS Tutorial
2. The Ten-Minute LDAP Tutorial
3. The Eight-Minute XML Tutorial
4. The Fifteen-Minute SQL Tutorial
5. The Twenty-Minute SNMP Tutorial

You can purchase this book at ThinkGeek.

There's an interesting article currently running about the joys of mapping phone numbers to IP addresses, and what that means. Also talks about LDAP directory implementation and other potential fun interactions. (CT: Does anyone else think it's horribly stupid to map numbers onto names which map onto other numbers? Dumb da dumb dumb).

Chronic reviewer chromatic writes again, this time with a review of the newest iteration of what is probably the emblematic Perl book, the O'Reilly camel book. Read on to see how it stacks up to earlier versions of that work, and whether your Perl skills would benefit from reading through it.

Programming Perl (third edition) author Larry Wall, Tom Christiansen, & Jon Orwant pages 1067 publisher O'Reilly & Associates rating 9.5 reviewer chromatic ISBN 0-596-0027-8 summary The definitive guide to the Perl language, updated for 5.6.1.

The Scoop Longtime Perl fans know Programming Perl as the Camel, because of the cover animal. With the first edition in 1991, Perl programmers gained not only a charmingly appropriate mascot, but the ultimate language reference. True to form, this Camel's grown with the language. In the four years since the last release, it's increased in size by 67%.

Everything you liked about previous editions has returned, in one form or another. Additionally, this third edition covers the largest changes made for Perl 5.6 (actually 5.6.1, as the book's ahead of the current stable release by a bit) -- Unicode, threading, and more Perl guts.

While the previous editions were exceptionally well-written references, they were also aimed squarely at experienced programmers. This edition pushes back the starting blocks somewhat, providing a gentler introduction to the world of Perl. The wealth of new information is staggering, but as you'd expect from the luminous authors, even the core language reference is highly readable and entertaining.

What's to Like? Logically, the book is divided into five main sections. (Gone are the massive 80-page chapters of the second edition). The first section, one chapter, gives a good overview of Perl, as a language and a philosophy. It includes a quick introduction. The second section gives the language's gory details, covering just about everything you would need to know. It's arranged in terms of ascending complexity. The enhanced, extended, and improved regular expression chapter stands out as the best member of this group.

The third section discusses Perl as technology. Here's where Unicode comes in, as well as the internals of Perl (through the internal compilation process, using the debugger, or using XS to extend Perl with C code). Everything here is quite good. Expectably dry subjects like Unicode or threading are readable and even a little entertaining. If you're not convinced, you can skip around and still learn quite a bit.

The fourth section is devoted to Perl as culture, with discussions about portability, security, good practices, documentation, CPAN, and a bit of poetry. The security chapter is quite good, but left me wanting more information. Any chapter here is accessible if you've made it through the second section, so feel free to pick and choose what you need to know.

Rounding up the spare bits is the reference section. Not only will you find descriptions of the special variables, built-in functions, and standard library, but the organization and presentation of these descriptions has improved. Functions have little annotations listing which magic variables they set, possible exceptions they raise, and the like. That accounts for 150 pages of the overall goodness. Don't skip the glossary at the end, if you're confused or looking for amusement.

What's to Consider? While it's a temporary conundrum, it's a little odd to read about features that aren't quite implemented yet. This is most noticeable in the Unicode discussions and the chapter on threading. Occasionally, the authors will describe a feature and then admit that the specifics will likely change. (Have a look at the documentation.) Granted, the bulk of the language is mature and stable, and the definitive guide can't very well get by with ignoring major features, but it reads a little oddly.

The intended audience is still the serious Perl programmer. Dabblers and casual learners will find enlightenment and instruction. Realize, though, that while it's easier to start your journey here, absolute beginners would do well to explore a Learning Perl or Elements of Programming with Perl first. People who've programmed before (beyond dabbling with VB, or doing mouseovers in Web pages) should have little difficulty picking up the Perl language and mindset.

The only other possible improvement that comes to mind is expanding certain chapters. As noted before, there's more to say about security and efficiency. It would also be nice to have a chapter on common Perl idioms one might find in EFNet #Perl or at Perl Monks, or the latest Perl Mongers meeting. (Half of the fun is discovering and sharing new tricks and shortcuts.)

The Summary Part of being a good programmer is knowing where to turn for accurate and useful information. This is the place for all things Perl. If you use Perl regularly, put the new Camel on your shelf. Table of Contents

1. Overview
2. 1. An Overview of Perl
3. The Gory Details
4. 1. Bits and Pieces
   2. Unary and Binary Operators
   3. Statements and Declarations
   4. Pattern Matching
   5. Subroutines
   6. Formats
   7. References
   8. Data Structures
   9. Packages
   10. Modules
   11. Objects
   12. Overloading
   13. Tied Variables
5. Perl as Technology
6. 1. Unicode
   2. Interprocess Communication
   3. Threads
   4. Compiling
   5. The Command-Line Interface
   6. The Perl Debugger
   7. Internals and Externals
7. Perl as Culture
8. 1. CPAN
   2. Security
   3. Common Practices
   4. Portable Perl
   5. Plain Old Documentation
   6. Perl Culture
9. Reference Material
10. 1. Special Names
    2. Functions
    3. The Standard Perl Library
    4. Pragmatic Modules
    5. Standard Modules
    6. Diagnostic Messages
    
    Glossary
    Index

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