Perl by Example [Paperback]

Ellie Quigley (Author)

Book Description

ISBN-10: 0136556892 | ISBN-13: 978-0136556893 | Publication Date: October 1997 | Edition: 2nd

Through proven sample programs, professional Perl trainer Ellie Quigley takes you from your first program to highly sophisticated Perl scripting. She shows how Perl can be a convenient substitute for utilities like grep, awk, sed, tr, shells and C, and how it can serve the specific needs of system administrators. Perl by Example even shows you how to script complex networking and interprocess communications tasks.

Editorial Reviews

From the Publisher

This tutorial/reference is the ideal guide for UNIX professionals who want to (or must) learn Perl as quickly as possible. Perl (Practical Extraction and Report Language) -- a public domain interpreted language used for manipulating text, files, and processes -- combines the best features of many of the UNIX utilities, including grep, awk, sed, tr, shells, and the C programming language. Due to its unique features, Perl has gained popularity recently, and is quickly becoming the preferred programming language of systems administrators. --This text refers to an out of print or unavailable edition of this title.

From the Inside Flap

About the Author


Ellie Quigley is president of Learning Enterprises, LE, a small training/consulting company specializing in teaching UNIX related subjects and writing customized classes for on-site training. The original version of Perl by Example was designed as a Perl Programming class for the University of California, Extension, Santa Cruz, complete with training guide and exercises. Due to the success of the class, this book evolved. She has also authored UNIX Shells by Example, published by Prentice Hall last year. Any comments or questions can be forwarded to Ellie Quigley at Learning Enterprises by e-mail: shellieq@netcom.


Acknowledgments


I would like to send a special appreciation to Mark Houser, a system administration instructor for Remedy Corporation. Mark, with an MS in computer science, enjoys "extending his systems beyond the ordinary" with tools like Perl. He has always been there to answer questions, and he donated his taintperl database application in Appendix B. Mark's email address is [e-mail].
I also owe a great deal to Deac Lancaster, a true scholar, co-worker, and good friend. While working for Sun Education, Deac spent many an evening after a long teaching day to guide me patiently through the workings of sockets, message queues, and semaphores. He loaned me his demo C programs, and together we re-wrote them in Perl for this book. Deac is now teaching at Remedy Corporation. Thanks, Deac! John Nouveaux, from Nouveaux Consulting, Santa Rosa, California, has also contributed a number of his Perl programs for the Appendix B in this book. John, an expert network programmer and system administrator, is a consultant and a dynamic teacher, specializing in connectivity issues using tcp/ip and the Internet.
Thanks also to Steve Hanson for his system administration work and to George Williams for compiling the CD-ROM and setting up the Web server.
Richard Evans, from Sun Microsystems, volunteered his time to test the examples in this book and offered helpful suggestions on how to improve them. Thank you, Richard.
Of course, appreciation to my editors, Mark Taub and Patti Guerrieri, for teaching me about the book business and patiently awaiting overdue chapters and correction pages. And to Roberta Harvey, from RAH Consulting, for her technical review and valuable criticism.
Thanks to Perl pioneers Larry Wall and Randal L. Schwartz, authors of the following books: Learning Perl by Randal L. Schwartz and Perl Programming by Larry Wall and Randal L. Schwartz.
And last, but not least, a huge thanks to all of my students out there who helped me learn Perl and kept it fun.


Preface


A picture is worth a thousand words, and so is a good example. Perl by Example is organized to teach you Perl from scratch with examples of complete succinct programs. Each line of a script sample is numbered, and important lines are highlighted. The output of the program is then displayed with numbers corresponding to the script numbers. Following the output is a separate explanation for each of the numbered lines. The examples are small and to the point for the topic at hand. Since the backbone of this book was used as a student guide to Perl, the topics are modularized. Each module builds on the previous one with a minimum of forward referencing and a logical progression from one topic to the next.
Perl by Example is not just a beginner's guide, but a complete guide to Perl. It covers many aspects of what Perl can do, from regular expression handling, to formatting reports, to interprocess communication. It will teach you about Perl and, in the process, a lot about UNIX. Although some UNIX knowledge will greatly accelerate your learning path, it is not assumed that you are a guru. Anyone reading, writing, or just maintaining Perl programs can greatly profit from this text. Topics such as networking, system calls, IPC, and CGI are designed to save the time it takes to figure out how the functions work, what libraries are needed, and the correct syntax, etc. Now, in this second edition, Perl5 objects and references have been added, and since Perl is the standard for writing CGI scripts for the Internet, there is a chapter to get you started writing your own dynamic Web pages.
Perl has a rich variety of functions for handling strings, arrays, the system interface, networking, and more. In order to understand how these functions work, background information concerning the how's, why's, and what for's is provided before demonstrating sample programs that function. This eliminates constantly wading through manual pages and other UNIX books to understand what is going on, what the arguments mean, and what the function actually does.
The Appendices contain a complete list of functions and definitions, command line switches, debugging options, special variables, Perl translators and sample scripts, including a fully functional, annotated Perl program using taintperl and interfacing with a database application.
I have been teaching now for the past 30 years and am committed to understanding how people learn. Having taught Perl now for over a year, I find that many new Perlers get frustrated when trying to teach themselves how to program in Perl. I, too, experienced frustration when first tackling Perl. So I wrote a book to help myself learn and to help my students, and now to help you. In my book you will not only learn Perl, you will also save yourself a great deal of time.

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Product Details

• Paperback: 552 pages
• Publisher: Prentice Hall Ptr; 2nd edition (October 1997)
• Language: English
• ISBN-10: 0136556892
• ISBN-13: 978-0136556893
• Product Dimensions: 9.3 x 6.9 x 1.6 inches
• Shipping Weight: 2.4 pounds
• Average Customer Review: 3.8 out of 5 stars  See all reviews (45 customer reviews)
• Amazon Best Sellers Rank: #2,144,648 in Books (See Top 100 in Books)

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Most Helpful Customer Reviews

34 of 38 people found the following review helpful:

2.0 out of 5 stars Perl by trivial and repetitive examples, April 1, 2003

By 

David M. Ng (Palo Alto, CA USA) - See all my reviews
(REAL NAME)   

This review is from: Perl by Example (3rd Edition) (Paperback)

This book was the required and only text for an introductory Perl class that I took. The students generally panned the book. While we appreciated having an extensive source of examples (the book is over 800 pages long), the examples often seemed trivial and repetitive.

Let's look at what the book is not. This book is not an introductory programming book-it does not cover basic principles of programming. This book is not a Perl tutorial-it does not introduce Perl concepts and features in a systematic and integrated way. For example, consider the various array functions. All you get in the book is a series of separate sections on each function. There is no discussion that push and pop might somehow be related. This book is not a Perl reference-it does not provide complete and easy-to-access information. For example, it only rarely covers exception conditions. Consider the pop function-the book never indicates what happens if you apply the pop function to an empty array.

So what is this book? It is an extensive source of trivial and repetitive examples. This book might be a good supplementary text for people who learn best through numerous repetitive examples. Also, the systematic three-part layout of each example is helpful (the format of the Perl language element, an example script with output, and an explanation).

If you want a book of Perl examples, you might consider the "Perl Cookbook" by Christiansen and Torkington.

16 of 17 people found the following review helpful:

5.0 out of 5 stars I have 24 Perl books and this is one of my two favorites, August 10, 1999

By A Customer

This review is from: Perl by Example (Paperback)

I've been a programmer for over 23 years (started very young) and I've programmed in Perl for about two years. Out of the 24 Perl books I own (including most of the O'Reilly books), this is one of my two favorites. The examples are excellent and there is a brief description of almost everything. I have used Perl on both UNIX and Windows NT, but am using mostly Windows NT now and this book has helped greatly just by explaining things better than Learning Perl and Programming Perl (O'Reilly). My other favorite which lists many libraries/packages is Perl Cookbook (O'Reilly).

6 of 6 people found the following review helpful:

3.0 out of 5 stars Excellent Explanations, Sparse Coverage, June 25, 2003

By 

Joaquin Menchaca (San José, CA USA) - See all my reviews
(REAL NAME)   

This review is from: Perl by Example (3rd Edition) (Paperback)

I picked up this book as a tutorial/reference for my Perl class. Overall I found this books explanations to be very clear and comprehensible for even the novice. There are many good illustrative examples. It covers some very important features like sort, map, grep and also split. The regular expression coverage is really well done. In addition to coverage these foundation concepts, the book also delves into some more advanced features of Perl such as file i/o and database (DBI).

Despite, the this excellent work, I have found the book does have some shortcomings that I think should be taken into account. There are several foundation concepts that are not adequately covered. For example, substr() only has a little reference blurb, but one cannot comprehend what substr is doing without seeing adequate examples. The vanilla reference from PerlDoc.com is a bit more adequate. I also found the file i/o cumbersome to sift through. I had to hunt for information I needed.

The book's attempt to be platform neutral, or rather multi-platform embracing, is great. I thought adding Mac and Win coverage for file i/o was more than appropriate and very useful. However, when covering advanced features, I wish Quigley could have sprinkled some resourceful platform specific coverage, such as Administration, Registry, and OLE Automation (VBA-like functionality) on Windows, or OSA (Open Scripting Architecture) or AppleScript-like functionality, on the Macintosh.

Overall, I think the book is excellent, but definately not the only book needed for foundation concepts of Perl. In my narrow scope of getting a good reference book for my Perl course, I would have chosen another book.