Pascal: Speeding up Pascal text file reading (3 of 3)

PROCEDURE FILLBUFFER;
BEGIN
EMPTY := BLOCKREAD (INFILE,BUFFER,2) = 0;
IF NOT EMPTY THEN BEGIN
NOTNULLS := BUFSIZE + SCAN (- BUFSIZE, <> CHR(0),
BUFFER [1023]);
BUFINDEX := 0;
END;
END;

PROCEDURE OPENFILE (FNAME: STRING);
BEGIN
IF ((POS('.text',FNAME) = 0) AND
(POS('.TEXT',FNAME) = 0)) THEN
FNAME := CONCAT (FNAME,'.TEXT');
RESET (INFILE, FNAME);
FILLBUFFER; FILLBUFFER;
END;

PROCEDURE READFILE (VAR LINE: STRING);
VAR INDENT,
LINELEN: INTEGER;
BEGIN
IF BUFINDEX >= NOTNULLS THEN FILLBUFFER;
IF NOT EMPTY THEN BEGIN
LINELEN := SCAN (BUFSIZE, = CHR(13), BUFFER [BUFINDEX]);
IF BUFFER [BUFINDEX] = CHR (16) THEN BEGIN
INDENT := ORD (BUFFER [BUFINDEX + 1]) - 32;
(*$R-*)
LINE [0] := CHR (LINELEN + INDENT - 2);
(*$R+*)
IF INDENT > 0 THEN FILLCHAR (LINE [1], INDENT, ' ');
IF LINELEN > 2 THEN MOVELEFT (BUFFER [BUFINDEX + 2],
LINE [1 + INDENT], LINELEN - 2);
END ELSE BEGIN
(*$R-*)
LINE [0] := CHR (LINELEN);
(*$R+*)

IF LINELEN > 0 THEN MOVELEFT (BUFFER [BUFINDEX],
LINE [1], LINELEN);
END;
BUFINDEX := BUFINDEX + LINELEN + 1;
END;
END;

PROCEDURE GETOPTION;
BEGIN
REPEAT
WRITELN;
WRITE ('OPTIONS: Q)uickread, R)eadln, E)xit ');
CH := ' ';
READ (KEYBOARD, CH);
UNTIL CH IN ['Q', 'q', 'R', 'r', 'E', 'e'];
IF CH IN ['E', 'e'] THEN BEGIN
PAGE (OUTPUT);
RESET (INFILE, FILENAME);
CLOSE (INFILE, PURGE);
EXIT (PROGRAM);
END;
END;

PROCEDURE PRINTFILE;
BEGIN
PAGE (OUTPUT); WRITELN;
CASE CH OF
'Q', 'q': BEGIN
OPENFILE (FILENAME);
REPEAT
LINE := '';
READFILE (LINE);
WRITELN (LINE);
UNTIL EMPTY;
CLOSE (INFILE);
END;
'R', 'r': BEGIN
RESET (TEXTFILE, FILENAME);
REPEAT
READLN (TEXTFILE, LINE);
WRITELN (LINE);
UNTIL EOF (TEXTFILE);
CLOSE (TEXTFILE);
END;
END; (* CASE *)
END;

PROCEDURE INIT;
VAR TEMP: STRING;
BEGIN
PAGE (OUTPUT); WRITELN;
WRITE ('One momemt, please...');
REWRITE (TEXTFILE, FILENAME);
WRITE (TEXTFILE, 'This is a test file written to ');
WRITE (TEXTFILE, 'demonstrate the ');
WRITE ('.');
WRITELN (TEXTFILE, '"QUICKREAD" program.');
WRITE ('.');
WRITELN (TEXTFILE);
TEMP := 'I''m melting.';
REPEAT
WRITE (TEXTFILE, 'TEST STRING --> ');
WRITELN (TEXTFILE, TEMP);
DELETE (TEMP, LENGTH (TEMP), 1);
WRITE ('.');
UNTIL TEMP = '';
WRITELN (TEXTFILE, ' AHHHHHhhhhhh....');
WRITELN (TEXTFILE);
WRITE (TEXTFILE, 'Notice that using READLN takes much ');
WRITE (TEXTFILE, 'more time');
WRITELN (TEXTFILE, ' to read a long line');
WRITE ('.');
WRITELN (TEXTFILE, 'than it takes to read a short one.');
WRITE ('.');
CLOSE (TEXTFILE, LOCK);
WRITELN;
END;

BEGIN
INIT; (* Write a temporary file for *)
HELL_FREEZES_OVER := FALSE;
REPEAT
GETOPTIONS; (* Get users choice *)
PRINTFILE; (* Print the file *)
UNTIL HELL_FREEZES_OVER; (* Forever. *)
END.