Compaq AA-PWCBD-TE Translation of Control Characters, Sample Dectpu Procedures Line-Mode Editor

Sample DECTPU Procedures

A.1 Line-Mode Editor

Example A–1 (Cont.) Line-Mode Editing

!Top of buffer command

["T"]:

POSITION (BEGINNING_OF (CURRENT_BUFFER)); MESSAGE (CURRENT_LINE);

!Next line command ["N"]:

MOVE_HORIZONTAL (-CURRENT_OFFSET); MOVE_VERTICAL (1);

MESSAGE (CURRENT_LINE); !Insert text command

["I"]:

SPLIT_LINE;

COPY_TEXT (SUBSTR (cmd, 2, 999));

MESSAGE (CURRENT_LINE); !List from here to end of file command

["L"]:

m1 := MARK (NONE);

LOOP

MESSAGE (CURRENT_LINE); MOVE_VERTICAL (1);

EXITIF MARK (NONE) = END_OF (CURRENT_BUFFER);

ENDLOOP; POSITION (m1);

!QUIT

["Q"]:

QUIT;

[INRANGE,OUTRANGE]:

MESSAGE ("Unrecognized command - enter I,L,N,Q or T");

ENDCASE;

ENDLOOP;

A.2 Translation of Control Characters

Example A–2 shows how to display control characters in a meaningful way. This is accomplished by translating the buffer to a different visual format and mapping this new form to a window. On the VT400, VT300, and VT200 series of terminals, control characters are shown as reverse question marks; on the VT100 series of terminals, they are shown as rectangles.

Example A–2 Procedure to Display Control Characters

!This procedure performs the substitution of meaningful characters

!for the escape or control characters.

!

PROCEDURE translate_controls (char_range)

LOCAL replace_text;

!

!If the translation array is not yet set up, then do it now. The elements

!that we do not initialize will contain the value TPUK_UNSPECIFIED. They are

!characters that TPU will display meaningfully.

!

IF translate_array = TPU$K_UNSPECIFIED THEN

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A–2Sample DECTPU Procedures