Perl for Web Site Management

Checking links, batch editing HTML files, tracking users, and writing CGI scripts--these are the often tedious daily tasks that can be done much more easily with Perl, the scripting language that runs on almost all computing platforms. If you're more interested in streamlining your web activities than in learning a new programming language, Perl for Web Site Management is for you: it's not so much about learning Perl as it is about using Perl to do common web chores more efficiently.

The secret is that, although becoming a Perl expert may be hard, most Perl scripts are relatively simple. Using Perl and other open source tools, you'll learn how to:

• Incorporate a simple search engine
  
• Write a simple CGI gateway
  
• Convert multiple text files into HTML
  
• Monitor log files
  
• Track users as they navigate your site
  

Even if you don't have any programming background, this book will get you quickly past Perl's seemingly forbidding barrier of chops and chomps, execs and elsifs. You'll be able to put an end to using clunky tools, editing files tediously by hand, or relying on programmers and system administrators to do "the hard stuff" for you. Sure, you might learn a little bit about programming as well, and perhaps something about the role of open source tools on the Web. But the purpose of Perl for Web Site Management isn't to educate you--it's to empower you. Whether you're a developer, a designer, or simply a dabbler on the Web, this book is the plain-English, hands-on introduction to Perl you've been waiting for.

Table of Contents

Preface 

1. Getting Your Tools in Order

      Open Source Versus Proprietary Software 

      Evaluating a Hosting Provider 

      Web Hosting Alternatives 

      Getting Started with SSH/Telnet 

      Meet the Unix Shell 

      Network Troubleshooting 

      A Suitable Text Editor 

2. Getting Started with Perl

      Finding Perl on Your System 

      Creating the "Hello, world!" Script 

      The Dot Slash Thing 

      Unix File Permissions 

      Running (and Debugging) the Script 

      Perl Documentation 

      Perl Variables 

      A Bit More About Quoting 

      "Hello, world!" as a CGI Script 

3. Running a Form-to-Email Gateway

      Checking for CGI.pm 

      Creating the HTML Form 

      The <FORM> Tag's ACTION Attribute 

      The mail_form.cgi Script 

      Warnings via Perl's -w Switch 

      The Configuration Section 

      Invoking CGI.pm 

      foreach Loops 

      if Statements 

      Filehandles and Piped Output 

      die Statements 

      Outputting the Message 

      Testing the Script 

4. Power Editing with Perl

      Being Careful 

      Renaming Files 

      Modifying HREF Attributes 

      Writing the Modified Files Back to Disk 

5. Parsing Text Files

      The "Dirty Data" Problem 

      Required Features 

      Obtaining the Data 

      Parsing the Data 

      Outputting Sample Data 

      Making the Script Smarter 

      Parsing the Category File 

      Testing the Script Again 

6. Generating HTML

      The Modified make_exhibit.plx Script 

      Changes to &parse_exhibitor 

      Adding Categories to the Company Listings 

      Creating Directories 

      Generating the HTML Pages 

      Generating the Top-level Page 

7. Regular Expressions Demystified

      Delimiters 

      Trailing Modifiers 

      The Search Pattern 

      Taking It for a Spin 

      Thinking Like a Computer 

8. Parsing Web Access Logs

      Log File Structure 

      Converting IP Addresses 

      The Log-Analysis Script 

      Different Log File Formats 

      Storing the Data 

      The "Visit" Data Structure 

9. Date Arithmetic

      Date/Time Conversions 

      Using the Time::Local Module 

      Caching Date Conversions 

      Scoping via Anonymous Blocks 

      Using a BEGIN Block 

10. Generating a Web Access Report

      The &new_visit and &add_to_visit Subroutines 

      Generating the Report 

      Showing the Details of Each Visit 

      Reporting the Most Popular Pages 

      Fancier Sorting 

      Mailing the Report 

      Using cron 

11. Link Checking

      Maintaining Links 

      Finding Files with File::Find 

      Looking for Links 

      Extracting 

      Putting It All Together 

      Using CPAN 

      Checking Remote Links 

      A Proper Link Checker 

12. Running a CGI Guestbook

      The Guestbook Script 

      Taint Mode 

      Guestbook Preliminaries 

      Untainting with Backreferences 

      File Locking 

      Guestbook File Permissions 

13. Running a CGI Search Tool

      Downloading and Compiling SWISH-E 

      Indexing with SWISH-E 

      Running SWISH-E from the Command Line 

      Running SWISH-E via a CGI Script 

14. Using HTML Templates

      Using Templates 

      Reading Fillings Back In 

      Rewriting an Entire Site 

15. Generating Links

      The Docbase Concept 

      The CyberFair Site's Architecture 

      The Script's Data Structure 

      Using Data::Dumper 

      Creating Anonymous Hashes and Arrays 

      Automatically Generating Links 

      Inserting the Links 

16. Writing Perl Modules

      A Simple Module Template 

      Installing the Module 

      The Cyberfair::Page Module 

17. Adding Pages via CGI Script

      Why Add Pages with a CGI Script? 

      A Script for Creating HTML Documents 

      Controlling a Multistage CGI Script 

      Using Parameterized Links 

      Building a Form 

      Posting Pages from the CGI Script 

      Running External Commands with system and Backticks 

      Race Conditions 

      File Locking 

      Adding Link Checking 

18. Monitoring Search Engine Positioning

      Installing WWW::Search 

      A Single-Search Results Tool 

      A Multisearch Results Tool 

      The map Function 

19. Keeping Track of Users

      Stateless Transactions 

      Identifying Individual Users 

      Basic Authentication 

      Automating User Registration 

      Storing Data on the Server 

      The Register Script 

      The Verification Script 

20. Storing Data in DBM Files

      Data Storage Options 

      The tie Function 

      A DBM Example Script 

      Blocking Versus Nonblocking Behavior 

      Storing Multilevel Data in DBM Files 

      An MLDBM-Using Registration Script 

      An MLDBM-Using Verification Script 

21. Where to Go Next

      Unix System Administration 

      Programming 

      Apache Server Administration and mod_perl 

      Relational Databases 

      Advocacy 

Index