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Overview | Basic Concepts | GUI Components | Architecture | How To Write An App

Basic Rhino Concepts

This is an introduction to basic concepts which will be used throughout the rest of the Rhino documentation.

Task

A Task is defined as an atomic operation that changes the state of the system. For example, Tasks that deal with user accounts might include "Add a User Account," "Modify a User Account," and "Change a User Account Password."

Each Task can be presented to the user through one (or both) of two interfaces: a terse, single-page Form or a more verbose, multi-page Guide. If both interfaces are defined for a Task, each will display a control that allows the user to switch between the two at any point while performing the Task.

Tasks can be launched from the command line and from many places in an application or applet which uses a Task Manager, a GUI component which contains organized sets of Tasks. The execution of a Task invokes one or more privileged commands (described below) on the server.

Multiple Tasks may be combined into a MetaTask, which is a GUI component containing a sequence of steps leading to a high-level goal.

Item and Category

Item and Category are the mechanism by which the server tells the client about the state of the system.

An Item represents a physical or logical entity that is manipulated by system administration operations. Each Item has an associated type and a unique name within that type. For example, a user account named "foo" can be represented as an Item of type "user account" and unique name "foo".

A Category represents a dynamic collection of Items of a specific type. For example, the collection of user account Items can be represented as a Category.

Privileged Command

A privileged command (or "priv command" for short) is a command-line program which is run on the server to change the state of the system. Priv commands are not setuid, but they are run by the runpriv command, which is setuid. runpriv checks privileges, makes a log entry, and runs the priv command as the user who invoked the command.

Priv commands have been in use since IRIX 6.3.