Compaq AA-PWCBD-TE Using Command Files, Sys$Exampleseve$Core.Tpu, $ EDIT/TPU/COMMAND = filespec

DEC Text Processing Utility Program Development

5.6 Using DECTPU Startup Files

In EVE, the code that implements the initialization sequence calls

TPU$LOCAL_INIT before executing your command or initialization files. EVE defines this procedure but leaves it empty. The user can use this procedure in a command file to contain DECTPU statements that implement private initializations.

You can see the code that implements TPU$LOCAL_INIT in EVE in

SYS$EXAMPLES:EVE$CORE.TPU.

A section file that implements a layered application should assign values to the following special variables in the procedure TPU$INIT_PROCEDURE:

•TPU$X_MESSAGE_BUFFER or MESSAGE_BUFFER

•TPU$X_SHOW_BUFFER or SHOW_BUFFER

•TPU$X_SHOW_WINDOW or INFO_WINDOW

If you write a section file that extends the EVE section file, EVE provides six variables (three pairs of synonyms) to be used by layered applications. Although DECTPU automatically declares the variables, the application must assign a value to one of the synonyms in each pair. If you choose to write your own application, your application must contain these structures and procedures.

Table 5–2 shows the names and uses of these variables.

Table 5–2 Special DECTPU Variables That Require a Value from a Layered Application

	Synonym Provided
	for Backward	Data Type
Recommended Name	Compatibility	Structure	How DECTPU Uses the Variable
TPU$X_MESSAGE_	MESSAGE_BUFFER	Buffer	DECTPU writes messages in this buffer. If the
BUFFER			MESSAGE_BUFFER is associated with a window
			that is mapped to the screen, DECTPU updates the
			window. If the application does not assign a buffer
			to this variable, DECTPU writes messages to the
			screen.
TPU$X_SHOW_	SHOW_BUFFER	Buffer	DECTPU writes information stored by the SHOW
BUFFER			built-in in this buffer.
TPU$X_SHOW_	INFO_WINDOW	Window	DECTPU displays information stored by the SHOW
WINDOW			built-in in this window.

If you want to use the SHOW built-in procedure in your application, you must create these special variables that DECTPU uses for SHOW.

5.6.6 Using Command Files

A command file is a DECTPU source file that can contain procedures, key definitions, and other DECTPU executable statements. You can have any number of command files in your directory. You might want to write one command file that customizes your editor for programming in Pascal, another command file that customizes your editor for text editing, and so on. If you have several command files, give them names that remind you of their contents. If you have one command file that you use most of the time, name it TPU$COMMAND.TPU.

The command to invoke DECTPU with a command file is:

$ EDIT/TPU/COMMAND [[= filespec]]

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