PHP_CompatInfo::parseString Introduction
PHP
PEAR Manual

PHP_FunctionCallTracer

Table of Contents
Introduction -- PHP_FunctionCallTracer creates function calls debug trace.
Basic Use -- Simple trace of function arguments and returned variables.

Creates a function calls debug trace. Functions arguments, returned parameters and watched variables are reported in the same section for each function call. The trace is available as an array, or can be displayed or written in a file. Traced variables can be processed by provided user functions for displaying purposes.

PHP_CompatInfo::parseString Introduction
PHP
PEAR Manual