Customer Reviews

Learning Perl

5 star:		(37)
4 star:		(23)
3 star:		(10)
2 star:		(2)
1 star:		(1)

 

 

I learned Perl 4 from the first edition of this book years ago. I recently read the third edition to get up to speed with Perl 5 and found this book covers nearly every aspect of Perl I've used over the years. Perl is a complex language, and any introductory book on Perl needs to restrict itself to a subset of the language to prevent the reader from becoming overwhelmed. The authors did an excellent job of presenting a subset that is large enough to cover most everyday Perl tasks, yet small enough to remain accessible to the Perl novice. The exercises at the end of each chapter solidify most of the core concepts and syntax of each chapter.

There were some shortcomings to the book, however. The book is oriented heavily towards Unix systems, and programmers working on Windows systems will have a hard time getting started and completing some of the exercises. The authors should have provided instructions for downloading ActiveState Perl, a free professional Windows port of Perl, and provided more assistance on the Unix-oriented exercises.

Additionally, some basic language features were not covered, such as the peculiarities of do blocks and using chr and ord to convert between characters and their numeric codes. Most importantly, the book does not cover two-dimensional arrays. They are mentioned only in two paragraphs in Appendix B, which refer the reader to four different perldoc sections. This topic is complicated and important enough to warrant its own chapter.

In summary, this book is an excellent introduction to Perl for programmers who are experienced in other languages already. It's not so good for beginning programmers because basic programming concepts are not explained. The major shortcoming is that readers, especially those using Windows, will be frustrated at not being able to easily do what they want to do and will too often need to wade through the documentation.

If you have previous procedural programming experience (C for example) and/or have a STRONG desire to learn Perl (but don't have Perl experience), this book is for you.

If you do read the foreword, keep in mind that it's soley for your amusement. Beyond the foreword, the book takes a more serious approach to learning the basics of Perl but is still a far cry from the books that give you the feeling your mouth is full of sawdust.

After reading through this book, expect to be comfortable with

variables & literals (incl. strings)
arrays & hashes (associative arrays)
control structures (if/else, for, while, etc.) & functions(procedures)
simple I/O
basic regular expressions
file handling
and more...

At the end you get a nice introductory treatment of CGI programming using Perl...an incentive to buy the Camel to learn
more advanced Perl incantations. =)

The book is very professionally written-I didn't find many of those bugs/typos that so many books are infested with.

Thanks Randal & Editors!

The back cover of the 3rd edition says (roughly), "Ask a perl expert today what book they used when they were learning perl, and they'll tell you it was the llama." Well, yeah; probably when they were learning perl it was literally the only introductory book on the subject. So that's not really an endorsement of quality.

The llama is actually a decent companion on your perl voyage. Particularly if you already think of yourself as a programmer are at least acquainted with the unix way of thinking, it will show you much of what you want to know about perl. And if you're new to perl you'll want to have this book (there still aren't any better options for the newcomer). However,

1. The nonstop Flintstones references are hard to stomach. (Yes, that's a trivial complaint. But it drives me nuts.)

2. There aren't enough exercises. This is a nontrivial complaint. For example, the chapter on control structures has only ONE exercise (!), which you can solve by ignoring most of the material in the section. The chapter which introduces SPLIT and JOIN has no exercises that use them (there aren't any exercises anywhere in the book that use split and join, as far as I can tell.) It's a persistent problem; since most folks learn by doing, they'll be required to exercise some imagination in creating and testing their own exercises. An introductory text should be much stronger in this area.

3. The 3rd edition rewrite moved some fundamental (and easy) stuff into a late-in-the-book "Advanced Perl Techniques" chapter. A few examples off the top of my head are the transliteration operator, slices, and sorting subroutines, which are meat and potatoes perl. They were better integrated into the body of the text in the 2nd edition.

4. The authors actually warn you away from trying things out in some cases! I'm thinking, for instance, of the offhand "CSV files are too hard, don't try splitting them" and "Don't try to work with HTML, it's too hard" comments. That is not in the spirit of perl at all. A few exercises that show what the difficulties are and give a few tricks for handling them would be better. And you'll be in a much better position to used and appreciate a prewritten module if you understand the difficulties it's supposed to be taking care of.

The biggest improvement in the 3rd edition is the reorganization of the regular expression material (into three chapters). They still need more exercises, but the presentation is good. On the whole, though, I liked the organization in the old editions better and probably recommend using one of them if you can find it.

I hate to slam a book that is considered such an essential book in the community. But I feel compelled.

First, the good points: It has great reference sections. Very, very important for such a book. It is also reasonably comprehensive. Sure, you'll probably also want Perl Cookbook to really know what you are doing, but it's too much to ask for Learning Perl to contain such practical uses. It crams so much more in than most programming books.

As for the bad, I could rant for a long time, but I will try to be brief. First, the book's organization leaves much to be desired. While the macro-organization is perhaps reasonable enough, a trial lawyer would have a field day with the objection, "Facts assumed not in evidence." There are numerous code snippets in this book that are only understandable at even the most basic level by flipping ahead 100 pages, then cross-referencing to the appendix and then flipping back to a different chapter. A novice programmer shouldn't have to deal with terms like "grep" or the like until the definition of "grep" is actually given since, after all, the last time I checked, "grep" was not a standard phrase in the English language that is understandable to all.

The book is written for people with a broad background in programming. For example, the reference section, which is supposed to describe the functions in depth describes how the command "printf" works as follows: "This is similar to the C library's printf(3) and fprintf(3) functions." While there was some other gobbledygook in his listing, none of the gobbledygook explained how the function worked. Last time I checked, the book was titled Programming Perl, not Programming C, Volume II. Why its only description for how the function actually works is a reference to another language is typical of the breezy arrogance of the authors. This was more egregious than most other examples, but in general, the authors were telling their story to insiders who needed a refresher course, not people who wanted to hear the story from the beginning.

In retrospect, after reading other books about programming, most horrifying to me is the utter lack of disregard for good programming standards at the most basic level. The authors seem to glorify the "Obfuscated Perl" approach, which is to write the language in as tightly wound and obfuscated a way as possible. This is simply bad programming, even it does take a very smart person to understand what's going on.

Ideally, good code should be readable like a novel, if you have a basic understanding of the language. In a good novel, you don't flip back and forth between pages trying to remember who or what something was. Variables and subroutines should have clear, unambiguous names. Variables should be clearly spelled out, as opposed to the way the authors (and most Perl programmers) seem to think is best, which is to refer to such constructs as $_[1], requiring one to flip pages to where the subroutine was called to understand what information is being passed to the the subroutine.

Rather than taking the attitude -- almost universally held in the Perl community -- that There Is More Than One Way To Do It, the authors should have emphasized, You Might Want To Think About The Option That Will Make It Easier For You And Others To Understand Your Code When You Look At It 3 Months From Now. Journalists don't score points for writing obscure text. Yes, they can write things any way they like, but they have professional standards - codified in the AP Style Guide, among other places - that say that certain ways of doing things are better for readers. Programmers should adopt a similar way of thinking - both about the readibility and workability of code -and this book does everything to undermine this notion.

Luckily I am familiar with how to code, and so this book turned out to be a fabulous resource. To be fair, the authors state that you should really have done some sort of programming before or this book will not be as much value to you. But with that pre-requisite covered 'Learning Perl' is a fun and information dense learning tool. Not to say that you can't do it if you have never coded before, but it will be more of a struggle.

Coming in at under 275 pages, the book doesn't waste time in getting down to what you need to know. I am a self-learner, and I was constantly amazed at the end of each chapter at how much we had covered. Given such information rich text, you might imagine it to be a little dry. Not so. The book exhibits a quirky, geeky sense of humor. And be warned; it uses footnotes extensively. While that may not be your bag, I found the footnotes made the book more like an internet browsing experience. You use the footnote like a link to more detailed and in-depth information.

I would give the book 5 stars but for one small beef. The authors assume that you are a UNIX programmer. There are numerous references to UNIX arcana, which you are supposed to just know. Phrases like 'If you want to make a Perl program [..] like the utilities cat, sed, awk, [..] and many others..' mean nothing to me. Furthermore there is little (a couple of paragraphs) to explain how to get Perl up and running on a Windows box. Now, I can easily overlook the little Microsoft digs, but I think more of an effort could have been made to reach out to the 'other side'.

So now, I am building my own Perl library. And I love the functionality it gives me. Once I figured out how to call programs from other web platforms I was one happy camper. All in all the time spent with this book was well worth it. Mainly the book provided a quick and comprehensive introduction to a powerful and flexible language. Thankfully the authors took a difficult subject and made it easier with their light in tone / heavy on the info style. Check it out.

Before beginning this book, I knew what Perl is and what it's good for. However, looking at some Perl code, I was too intimidated to make a serious attempt at learning the language. I had a good foundation in programming concepts, as well as some experience writing simple C programs, so I decided to make the effort to learn Perl.

This book is very well-written, and even entertaining at times. I agree with other reviewers who suggest that this book is not for the programming neophyte, although a dedicated student will certainly be able to work through the book and come out knowing not only the foundation of Perl, but of programming as well. Those somewhat familiar with C will have no trouble at all, and will be particularly amused by the ease with which Perl handles things such as arrays and strings (read: in a much easier and more common-sense way than C does).

I highly recommend this book for anyone desiring to implement Perl in their daily computing lives.

Randal Schwartz's "Learning Perl" is an excellent book for those who want to learn the Perl language. "Learning Perl" covers the basics of programming in Perl through 17 chapters, each averaging 20 or so pages with practice exercises at the end of each chapter. While Schwartz claims a novice could learn from the book, I had to re-read several passages and chapters before I fully comprehended his ideas. Tinkering with some Perl code and writing some experimental programs with the book in hand is a must.

I would highly recommend this book to anyone who is serious about learning Perl and who has some experience in Unix and/or another programming language. I was a complete novice to both Unix and the basic concepts of programming when I bought the book. It took me the whole night to figure out how to execute a simple "Hello, world!" program on Mac OS X. After nailing down the basics of Unix through trial and error, however, I was able to execute more programs flawlessly. Assess your abilities and your commitment honestly before making the purchase. Good luck!

This book can be considered to be a part of a two part series - first you read this book, then you read "Programming Perl," after which time you start writing poetry in Perl. This book offers a good introduction to Perl with very little knowledge needed, but it does not bore someone experienced in shell scripting or general programming.

The sequence of events starts a bit slow, but picks up as experience grows. The exercises are exactly as they should be - they offer a good chance to get experience but don't feel as if they are coming out of the blue. They usually involve extending or changing the example programs given earlier in the chapter, and they are usually something that once you grasp the underlying concept will take very little time to implement.

The title is very appropriate. There is a lot to Perl that is not covered (at least in any depth) in this book. The much thicker Programming Perl book takes up that slack, but the existance of this book is inspiring - you can read this book to learn enough perl to use for most practical purposes - and then have a good foundation when jumping into the "big book" - I like that approach to learning programming languages and I like this book.

I've been through this book several times. I went through the 2nd edition on my own a couple of years ago when I learned perl. I have since (after a year of hiatus from perl) been through the 3rd edition in a classroom setting. The 3rd edition is much improved in terms of structure and pace. For example, explanation of regular expressions (one of the most powerful features of perl) is expanded into three chapters. On the down side, I would have liked to see a chapter or two covering references and OOP.
The authors are clearly expert coders and have an intimate knowledge of perl. The prose is clear and deliberate, over-simplifying when helpful, but being sure to point you to the details in footnotes. The book is also laced with wry humor that both makes the dryness of such a topic more palatable and serves as an introduction to the quirkiness of "perl culture" in general.
If you are a beginner in Perl, and have some programming experience in another language, this is the one to get. Not a great reference, but a great tutorial.

I gave the 2nd edition of this book 5 stars for its readability and concise coverage of the Perl basics. Unfortunately, the 3rd edition adds very little and takes away many of the best parts of the 2nd edition. The chapter on report formatting was completely removed in this edition. I guess we will have to call it Pel instead of Perl. (The "r" in the name stands for "reporting," but reporting is no longer covered at all in this book).

The second edition also had an excellent chapter on CGI programming with Perl. This was also sent to the dumpster. Another casualty was chapter one which previously contained a well crafted introduction to the language called a "stroll through Perl." It has been replaced by a boring and traditional introduction chapter.

So, what were the additions that warranted the creation of a new edition in the first place? The chapter on regular expressions was spilt into three chapters. A good idea, but the coverage is almost identical to that of the previous edition. A little more explanation is added in various chapters here and there, which is good. But, this edition also contains many more footnotes, which is bad! The authors seem obsessed with footnoting the most obscure and bizarre details in footnotes, and there are footnotes on almost every page. (Of course you don't have to read them, but like looking at a bad car accident, I just can't resist).

This is still a good tutorial on Perl, but the second edition is so much better I would recommend buying it instead of the third edition. Unfortunately, newer does not always mean better.