Compaq AA-PWCBD-TE 5.6.6 Using Command Files

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.

Table5–2 Special DECTPU Variables That Require a Valuefrom a Layered Application

Recommended Name

Synonym Provided

for Backward

Compatibility Data Type

Structure How DECTPU Uses the Variable

TPU$X_MESSAGE_

BUFFER MESSAGE_BUFFER Buffer DECTPU writes messages in this buffer. If the

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_

BUFFER SHOW_BUFFER Buffer DECTPU writes information stored by the SHOW

built-in in this buffer.

TPU$X_SHOW_

WINDOW INFO_WINDOW Window DECTPU displays information stored by the SHOW

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

Acommand 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]]

5–24 DEC Text Processing Utility Program Development