You have already learned how to start a process with the SHELL or EXEC instructions. You also know the quick syntax for the two instructions, which opens a way to read data from the standard output channel of the process. Examples show the use of the quick syntax in the next chapter 21.3.1. In chapter 21.3.2, the use of the event handler

• PEventName_Read(),
• PEventName_Kill() and
• PEventName_Error(..)

are described and procedures are presented with which you pass input to a process.

Chapters 21.3.3 to 21.3.6 present projects in which the approaches from chapter 21.3.2 are implemented.

The use of the two instructions SHELL and EXEC forms the perfect basis for developing graphical user interfaces (GUI) for interactive console programmes under Gambas.

Figure 21.3.1: The MySQL client 'mysql' - started as a process.