Filters

Summary

Filters and contexts allow generic stream types to be modified without requiring direct code changes, or INI settings that would affect an entire request. Using the techniques covered in this chapter, you'll be able to make your own wrapper implementations more useful and alter the data produced by other wrappers as well.

As you move on, we'll be leaving the workings of the PHPAPI behind and returning to the mechanics of the PHP build system to produce more complicated extensions that link into other applications, but find easier ways to generate them using collections of tools to handle the tedious work.