AT THE CORE OF THE ZEND ENGINE ARE TWO FUNDAMENTAL SETS of APIs. The first is instruction processing, which includes script tokenization, compilation, and execution, as well as generating and handling function calls and object instantiation and destruction. The second set of APIs revolves around the manipulation of variables, or as you've come to know them, zvals. In this appendix you'll look at the functions and macros exported by the Zend Engine that simplify these operations and make them nearly consistent across all versions of PHP.
The PHP Life Cycle
Variables from the Inside Out
Memory Management
Setting Up a Build Environment
Your First Extension
Returning Values
Accepting Parameters
Working with Arrays and HashTables
The Resource Data Type
PHP4 Objects
PHP5 Objects
Startup, Shutdown, and a Few Points in Between
INI Settings
Accessing Streams
Implementing Streams
Diverting the Stream
Configuration and Linking
Extension Generators
Setting Up a Host Environment
Advanced Embedding
Appendix A. A Zend API Reference
Appendix B. PHPAPI
Appendix C. Extending and Embedding Cookbook
Appendix D. Additional Resources