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ARexx on the Amiga

ARexx is supported on all Amiga hardware configurations. Beginning with the release of Amiga Workbench Version 2.0, ARexx has been integrated into the Amiga operating system. Specifically, ARexx uses two important features of the Amiga operating system: multitasking and interprocess communication.

Multitasking is the ability to run more than one program at a time. For example, you can simultaneously edit a file, format a disk, and adjust your screen's colors.

Interprocess communication (IPC) is the ability to allow the exchange of information between applications. Interprocess communication is accomplished through the use of message ports, an address contained in an application that can receive and send messages, attached to each program. Each message port has a name and sending a message to an application requires the use of the port's name in an ARexx script.

The sequence of events in sending and receiving a message is:

  1. On initialization an application opens its message port.
  2. The application waits to receive a message.
  3. The Amiga operating system notifies the application that a message has arrived at its port.
  4. The application acts on that message.
  5. The application notifies the message's sender (ARexx) that the message has been received and processed.

This transfer of messages is not limited to one application and ARexx. Several application can send messages back and forth using ARexx as the central transfer location. However, all the applications must be ARexx-compatible.

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