src/PEAR/PackageFile/v2.php
function getTask($task)
    {
        $this->getTasksNs();
        // transform all '-' to '/' and 'tasks:' to '' so tasks:replace becomes replace
        $task = str_replace(array($this->_tasksNs . ':', '-'), array('', ' '), $task);
        $taskfile = str_replace(' ', '/', ucwords($task));
        $task = str_replace(array(' ', '/'), '_', ucwords($task));
        if (class_exists("PEAR_Task_$task")) {
            return "PEAR_Task_$task";
        }
        $fp = @fopen("PEAR/Task/$taskfile.php", 'r', true);
        if ($fp) {
            fclose($fp);
            require_once "PEAR/Task/$taskfile.php";
            return "PEAR_Task_$task";
        }
        return false;
    }
function getTask($task)
    {
        $this->getTasksNs();
        // transform all '-' to '/' and 'tasks:' to '' so tasks:replace becomes replace
        $task = str_replace(array($this->_tasksNs . ':', '-'), array('', ' '), $task);
        $taskfile = str_replace(' ', '/', ucwords($task));
        $task = str_replace(array(' ', '/'), '_', ucwords($task));
        if (class_exists("PEAR_Task_$task")) {
            return "PEAR_Task_$task";
        }
        $fp = @fopen("PEAR/Task/$taskfile.php", 'r', true);
        if ($fp) {
            fclose($fp);
            require_once "PEAR/Task/$taskfile.php";
            return "PEAR_Task_$task";
        }
        return false;
    }
Determine whether a task name is a valid task.  Custom tasks may be defined
using subdirectories by putting a "-" in the name, as in <tasks:mycustom-task>

Note that this method will auto-load the task class file and test for the existence
of the name with "-" replaced by "_" as in PEAR/Task/mycustom/task.php makes class
PEAR_Task_mycustom_task
@param string
@return boolean