NOTES:
        REM------------------------------------------------
        REM   VIEWFILE.BAS 1.03
        REM File viewing utility
        REM         by
        REM   Charles Stross
        REM      ¤ 1987
        REM   PUBLIC DOMAIN
        REM------------------------------------------------
        REM Modification history:
        REM
        REM 1.00 -- basic file viewer       -- 05/10/87
        REM 1.01 -- with jump to EOF        -- 12/10/87
        REM 1.02 -- with temp file on M:
        REM         and fast random access  -- 12/10/87
        REM 1.03 -- parse COMMAND$ for
        REM         optional tabify         -- 13/10/87


INITIALIZE:

        REM-----INITIALIZE ALL VALUES----------------------
        REM-----NEEDED LATER IN PROG-----------------------

        TAB.SPC% = 0
        T.LINE$ = " "
        VIEWFILE$ = ""
        NUM.STREAMS% = 2
        ROUNDS% = 0
        OFFSET% = 1
        ESC$ = CHR$(27)
        CR$ = CHR$(13)
        ERA.LINE$ = ESC$+"M"
        UP$ = ESC$+"A"
        SCREEN.WIDTH% = 90

FUNCTIONS:

REM-----INITIALIZE FUNCTIONS-------------------------------

DEF PROCESS.LINE$(RAWTEXT$,TAB.SPC%)

        REM-----Expand embedded tabs-----------------------
        REM-----and return a processed line----------------

                COUNT% = 1
                TEMP$ = ""
                CH$ = " "
                WHILE  (COUNT% <= LEN(RAWTEXT$) )
                        CH$ = MID$(RAWTEXT$,COUNT%,1)
                        COUNT% = COUNT% + 1
                        IF ASC(CH$)<>9 THEN TEMP$ = TEMP$ + CH$ \
                                ELSE TEMP$ = TEMP$ + STRING$(TAB.SPC%," ")
                WEND
                TEMP2$ = TEMP$
                IF (LEN(TEMP2$) > (SCREEN.WIDTH%-2)) THEN \
                        TEMP2$ = LEFT$(TEMP2$,(SCREEN.WIDTH%-2))
                PROCESS.LINE$ = TEMP2$
                RETURN
FEND


START:

        REM-----PRINT COPYRIGHT ETCETERA-------------------
        PRINT
        PRINT "VIEWFILE V 1.02 (¤ Charles Stross, 1987)"
        PRINT

GET.FILE:

        INTERIM$ = COMMAND$
        IF (INTERIM$ = "") THEN\
                PRINT:\
                INPUT "Please enter file to view ";INTERIM$:  \
                INTERIM$ = UCASE$(INTERIM$):                  \
                VIEWFILE$ = INTERIM$                          \
                ELSE VIEWFILE$ = INTERIM$

PARSE.INTERIM:

        REM-----READ COMMAND TAIL AND CHECK FOR [/] -------
        REM-----IF PRESENT, PARSE CONTENTS FOR COMMANDS ---
        REM-----IF CORRUPT, CET A NEW INTERIM$-------------

        TAIL.START%=MATCH("[",INTERIM$,1)

        IF TAIL.START%>0 THEN                                 \
                TAIL.END% = MATCH("]",INTERIM$,1):            \
                VIEWFILE$ = LEFT$(INTERIM$, (TAIL.START%-1)): \
        ELSE GOTO FIRST.CHECK:                                \

        IF ((TAIL.END%=0) AND (TAIL.START%>1)) THEN           \
                PRINT "Error -- ']' missing":                 \
                GOTO GET.FILE:

        IF TAIL.START%=(TAIL.END%-1) THEN                     \
                PRINT "No parameters specified":              \
                GOTO FIRST.CHECK:

        REM-----TAIL.START% = start of command string ([) -
        REM-----TAIL.END% = end of command string (]) -----

        TAIL$ = MID$(INTERIM$,(TAIL.START%+1),(TAIL.END%-(TAIL.START%+1)))
        ARG1$ = UCASE$(LEFT$(TAIL$,1))

        IF (ARG1$ = "T" AND ((TAIL.END%-TAIL.START%)>2) ) THEN              \
                ARG1.VAL$ = MID$(TAIL$,2,1):                                \
                ARG1.VAL% = ASC(ARG1.VAL$):                                 \
        ELSE PRINT "Recoverable Error; command tail parameter is unknown" : \
                GOTO FIRST.CHECK:

        IF (ARG1.VAL%<48) OR (ARG1.VAL%>57) THEN                            \
                PRINT "Recoverable Error; no tab size specified ":          \
                GOTO FIRST.CHECK:                                           \
        ELSE TAB.SPC% = VAL(ARG1.VAL$)


FIRST.CHECK:

        REM-----MAKE SURE FILE IS PRESENT------------------
        IF END #1 THEN ABORT1:
        OPEN VIEWFILE$ AS 1
        CLOSE 1

SECOND.CHECK:

        REM-----LOCATE END OF FILE-------------------------
        REM-----( RETURN IT FOR E-END OPTION --------------
        REM-----( CALLED ONCE ONLY IN EACH RUN.) ----------
        REM-----AND CREATE TEMP FILE ON M: ----------------

        IF END # 1 THEN ABORT1:
        OPEN    VIEWFILE$               AS 1
        CREATE "M:VIEWTEMP.$$$" RECL 90 AS 2
        END.LINE% = 0
        DUMMY.FLAG$ = "Continue"
        PRINT "Thinking ";
        IF END #1 THEN SHUT:

        REM------Two options -- hinging on parsed command line

        WHILE (TAB.SPC%>0)
                READ #1 ; LINE JUNK$
                JUNK$ = PROCESS.LINE$(JUNK$,TAB.SPC%)
                JUNK$ = LEFT$(JUNK$,SCREEN.WIDTH%)
                PRINT USING "&"; #2 ; JUNK$
                END.LINE% = END.LINE% + 1
                PRINT ".";
        WEND

        REM-----Default -- TAB.SPC% = 0 if not specified

        WHILE (TAB.SPC%=0)
                READ #1 ; LINE JUNK$
                JUNK$ = LEFT$(JUNK$,SCREEN.WIDTH%)
                PRINT USING "&"; #2 ; JUNK$
                END.LINE% = END.LINE% + 1
                PRINT ".";
        WEND

SHUT:
        CLOSE 1, 2
        PRINT "Temp. file created"
        VIEWFILE$ = "M:VIEWTEMP.$$$"

PRINT.PAGE:

        REM-----PRINT A PAGE ; ANY PAGE--------------------
        REM     DEFAULT TO PAGE #1-------------------------
        REM
        IF END # 1 THEN ABORT2:
        OPEN VIEWFILE$ RECL 90 AS 1
        PRINT:
        FOR LINE.NUM% = OFFSET% TO (OFFSET%+27) STEP 1
                READ #1, LINE.NUM% ; LINE T.LINE$
                PRINT T.LINE$
        NEXT LINE.NUM%
        CLOSE 1
        ROUNDS% = ROUNDS% + 1

GET.CHOICE:

        REM-----GET FILE DIRECTIONS------------------------
        REM
        IF (ROUNDS% < 2)                    \
                 THEN PRINT :               \
                 PRINT "Enter command [F-orward | B-ack | S-tart | E-nd | Q-uit]";:\
                 INP.CHAR% = CONCHAR%:      \
                 ELSE PRINT:                \
                 PRINT  "Enter [F-orward | B-ack | S-tart | E-nd | Q-uit]";:\
                                INP.CHAR% = CONCHAR%
                 PRINT ERA.LINE$;UP$;UP$;CR$;

        CHAR$ = UCASE$(CHR$(INP.CHAR%))
        IF (CHAR$ = "Q") THEN GOTO SHUT.DOWN:
        IF (CHAR$ = "S") THEN OFFSET% = 1
        IF (CHAR$ = "F") THEN OFFSET% = OFFSET%+28
        IF (CHAR$ = "E") THEN OFFSET% = END.LINE%-28
        IF (CHAR$ = "B") AND (OFFSET% < 28) THEN OFFSET% = OFFSET%
        IF (CHAR$ = "B") AND (OFFSET% >= 28) THEN OFFSET% = OFFSET% - 28
        EXCEPT% = MATCH(CHAR$,"Q F B E S",1): \
        IF (EXCEPT%=0) THEN GOTO GET.CHOICE:\  Exception checking

GET.IT:

        REM-----NOW GET IT---------------------------------
        REM

        GOTO PRINT.PAGE:

ABORT1:

        PRINT CHR$(27);
        PRINT "Unable to open file "; VIEWFILE$
        PRINT "Please make sure that the file is present on the same"
        PRINT "disc drive ,or the AFN includes a drive letter: "
        PRINT "otherwise VIEWFILE will be unable to find it."
        GOTO TERMINUS:

ABORT2:
        PRINT "*** End of file ";VIEWFILE$
        CLOSE 1
        GOTO GET.CHOICE:

SHUT.DOWN:

        OPEN VIEWFILE$ AS 1
        DELETE 1

TERMINUS:

        PRINT:
        END
  GOTO GET.CHOICE:

SHUT.DOWN:

        OPEN VIEWFILE$ AS 1
        D