Webbots, Spiders, and Screen Scrapers

Table of Contents | Index
Dedication
ACKNOWLEDGMENTS
Introduction
FUNDAMENTAL CONCEPTS AND TECHNIQUES
WHAT'S IN IT FOR YOU?
Uncovering the Internet's True Potential
What's in It for Developers?
What's in It for Business Leaders?
Final Thoughts
IDEAS FOR WEBBOT PROJECTS
Inspiration from Browser Limitations
A Few Crazy Ideas to Get You Started
Final Thoughts
DOWNLOADING WEB PAGES
Think About Files, Not Web Pages
Downloading Files with PHP's Built-in Functions
Introducing PHP/CURL
Installing PHP/CURL
LIB_http
Final Thoughts
PARSING TECHNIQUES
Parsing Poorly Written HTML
Standard Parse Routines
Using LIB_parse
Useful PHP Functions
Final Thoughts
AUTOMATING FORM SUBMISSION
Reverse Engineering Form Interfaces
Form Handlers, Data Fields, Methods, and Event Triggers
Unpredictable Forms
Analyzing a Form
Final Thoughts
MANAGING LARGE AMOUNTS OF DATA
Organizing Data
Making Data Smaller
Thumbnailing Images
Final Thoughts
PROJECTS
PRICE-MONITORING WEBBOTS
The Target

Designing the Parsing Script
Initialization and Downloading the Target
Further Exploration
IMAGE-CAPTURING WEBBOTS
Example Image-Capturing Webbot
Creating the Image-Capturing Webbot
Further Exploration
Final Thoughts
LINK-VERIFICATION WEBBOTS
Creating the Link-Verification Webbot
Running the Webbot
Further Exploration
ANONYMOUS BROWSING WEBBOTS
Anonymity with Proxies
The Anonymizer Project
Final Thoughts
SEARCH-RANKING WEBBOTS
Description of a Search Result Page
What the Search-Ranking Webbot Does
Running the Search-Ranking Webbot
How the Search-Ranking Webbot Works
The Search-Ranking Webbot Script
Final Thoughts
Further Exploration
AGGREGATION WEBBOTS
Choosing Data Sources for Webbots
Example Aggregation Webbot
Adding Filtering to Your Aggregation Webbot
Further Exploration
FTP WEBBOTS
Example FTP Webbot
PHP and FTP
Further Exploration
NNTP NEWS WEBBOTS
NNTP Use and History
Webbots and Newsgroups
Further Exploration
WEBBOTS THAT READ EMAIL
The POP3 Protocol
Executing POP3 Commands with a Webbot
Further Exploration
WEBBOTS THAT SEND EMAIL
Email, Webbots, and Spam
Sending Mail with SMTP and PHP
Writing a Webbot That Sends Email Notifications
Further Exploration
CONVERTING A WEBSITE INTO A FUNCTION
Writing a Function Interface
Final Thoughts
ADVANCED TECHNICAL CONSIDERATIONS
SPIDERS

How Spiders Work
Example Spider
LIB_simple_spider
Experimenting with the Spider
Adding the Payload
Further Exploration
PROCUREMENT WEBBOTS AND SNIPERS
Procurement Webbot Theory
Sniper Theory
Testing Your Own Webbots and Snipers
Further Exploration
Final Thoughts
WEBBOTS AND CRYPTOGRAPHY
Designing Webbots That Use Encryption
A Quick Overview of Web Encryption
Local Certificates
Final Thoughts
AUTHENTICATION
What Is Authentication?
Example Scripts and Practice Pages
Basic Authentication
Session Authentication
Final Thoughts
ADVANCED COOKIE MANAGEMENT
How Cookies Work
PHP/CURL and Cookies
How Cookies Challenge Webbot Design
Further Exploration
SCHEDULING WEBBOTS AND SPIDERS
The Windows Task Scheduler
Complex Schedules
Non-Calendar-Based Triggers
Final Thoughts
LARGER CONSIDERATIONS
DESIGNING STEALTHY WEBBOTS AND SPIDERS
Why Design a Stealthy Webbot?
Stealth Means Simulating Human Patterns
Final Thoughts
WRITING FAULT-TOLERANT WEBBOTS
Types of Webbot Fault Tolerance
Error Handlers
DESIGNING WEBBOT-FRIENDLY WEBSITES
Optimizing Web Pages for Search Engine Spiders
Web Design Techniques That Hinder Search Engine Spiders
Designing Data-Only Interfaces
KILLING SPIDERS
Asking Nicely
Building Speed Bumps
Setting Traps
Final Thoughts
KEEPING WEBBOTS OUT OF TROUBLE

It's All About Respect
Copyright
Trespass to Chattels
Internet Law
Final Thoughts
PHP/CURL REFERENCE
Creating a Minimal PHP/CURL Session
Initiating PHP/CURL Sessions
Setting PHP/CURL Options
Executing the PHP/CURL Command
Closing PHP/CURL Sessions
STATUS CODES
HTTP Codes
NNTP Codes
SMS EMAIL ADDRESSES
Colophon
Index