gistfile1.php

<?php

// Print all Exception classes in PHP

foreach (get_declared_classes() as $class)
{
    if(is_subclass_of($class, "Exception"))
    {
        echo $class . "\n";
        echo "\tparent: " . get_parent_class($class) . "\n";
    }
}

gistfile2.txt

Typical result on PHP 5.2

ErrorException
	parent: Exception
ReflectionException
	parent: Exception
LogicException
	parent: Exception
BadFunctionCallException
	parent: LogicException
BadMethodCallException
	parent: BadFunctionCallException
DomainException
	parent: LogicException
InvalidArgumentException
	parent: LogicException
LengthException
	parent: LogicException
OutOfRangeException
	parent: LogicException
RuntimeException
	parent: Exception
OutOfBoundsException
	parent: RuntimeException
OverflowException
	parent: RuntimeException
RangeException
	parent: RuntimeException
UnderflowException
	parent: RuntimeException
UnexpectedValueException
	parent: RuntimeException