Core components Introduction
Core components
PEAR Manual

PEAR base classes

Table of Contents
Introduction -- How to handle the PEAR base class (destructors, error handling)
Constants -- Predefined Constants
PEAR::PEAR() -- constructor (package developer related)
PEAR::_PEAR() -- Deconstructor (package developer related)
PEAR::getStaticProperty() -- handle static properties (package developer related)
PEAR::registerShutdownFunc() -- set a shutdown function for static classes (package developer related)
PEAR::isError() -- checks for a PEAR_Error object
PEAR::raiseError() -- Create a new PEAR_Error object and optionally specify error-handling instructions
PEAR::setErrorHandling() -- sets handling of errors generated through PEAR packages
PEAR::expectError() -- add an error code for non-disabling temporary error handling
PEAR::popExpect() -- removes the last error code for non-disabling temporary error handling
PEAR::loadExtension() -- OS independent PHP extension load
PEAR_Exception -- PEAR_Exception - PHP 5 and versions above
PEAR_ErrorStack
PEAR Error object -- PEAR_Error [deprecated]
System

The Core section provides information about the base classes in PEAR

PEAR

PEAR provides functions for handling errors and sets the behaviour in case of error. And, it gives package developers a set of functions to make their lives easier.

Core components Introduction
Core components
PEAR Manual