Compare

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This utility allows you to compare two records. It has a re-synch feature to look 20 lines ahead on either record to try and get things back into line. You can also input the line numbers to re-start from yourself if needed.

To get the code out quickly, I decided it would prompt for the files and items to compare, rather than parsing the command line. This makes it extremely portable, as does using TRUE = (1=1) rather than @TRUE.

It doesn't display characters below ASCII 32 or between 128 and 250 so that it should run on most terminals without creating problems.

     PROGRAM COMPARE
* TCL - KRJ - Comparison program; should run and display on anything

     PROMPT ''
     BELL = CHAR(7)
     TRUE = (1=1)
     FALSE = NOT(TRUE)

     OFFSET = 20
     ASK = TRUE
     SHOW = TRUE

     LL = 1
     BAD = ''
     FOR XX = 0 TO 31
        BAD := CHAR(XX)
     NEXT XX
     FOR XX = 128 TO 250
        BAD := CHAR(XX)
     NEXT XX
     GOOD = STR('~',LEN(BAD))

     CRT 'Comparison Program'
     CRT

     LOOP
        CRT 'Enter 1st file :':
        INPUT F1
        IF F1 EQ '' THEN CRT; STOP
        GOTIT = FALSE
        OPEN F1 TO FH1 THEN GOTIT = TRUE ELSE
           CRT BELL:' Cannot open the file ':F1
        END
     UNTIL GOTIT DO
     REPEAT

     LOOP
        CRT 'Enter 1st item :':
        INPUT I1
        IF I1 EQ '' THEN CRT; STOP
        GOTIT = FALSE
        READ R1 FROM FH1, I1 THEN GOTIT = TRUE ELSE
           CRT BELL:'  Cannot read item ':I1
        END
     UNTIL GOTIT DO
     REPEAT

     LOOP
        CRT 'Enter 2nd file : OR "." for ':F1:':':
        INPUT F2
        IF F2 = '.' THEN F2 = F1
        IF F2 EQ '' THEN CRT; STOP
        GOTIT = FALSE
        OPEN F2 TO FH2 THEN GOTIT = TRUE ELSE
           CRT BELL:' Cannot open the file ':F2
        END
     UNTIL GOTIT DO
     REPEAT

     LOOP
        CRT 'Enter 2nd item : OR "." for ':I1:':':
        INPUT I2
        IF I2 = '.' THEN I2 = I1
        IF I2 EQ '' THEN CRT; STOP
        GOTIT = FALSE
        READ R2 FROM FH2, I2 THEN GOTIT = TRUE ELSE
           CRT BELL:'  Cannot read item ':I2
        END
     UNTIL GOTIT DO
     REPEAT

     IF R1 EQ R2 THEN CRT 'SAME' ELSE
        CRT 'DIFFERENT'
        GOSUB COMPARE.LINES
     END
     STOP


COMPARE.LINES:
     WIDTH = SYSTEM(2)
     DEPTH = SYSTEM(3)
     HALF = INT(WIDTH/2)
     LHS = 'L#':HALF
     SPC = SPACE(HALF)
     LHL = HALF - 3
     FUL = WIDTH - 3

     XXCNT = DCOUNT(R1,CHAR(254))
     YYCNT = DCOUNT(R2,CHAR(254))
     MINM = XXCNT
     MAXM = XXCNT
     IF YYCNT LT MINM THEN MINM = YYCNT
     IF YYCNT GT MAXM THEN MAXM = YYCNT
     XSIDE = TRUE
     XX = 0; YY = 0
LOOPHERE:
     XX += 1; YY += 1
     IF XX GT MAXM AND YY GT MAXM THEN
        IF NOT(SHOW) THEN CRT 'Same until end of items'
STOPIT:
        CRT
        STOP
     END
     IF XX GT MAXM THEN
        START = YY
        FINISH = YYCNT
        DISP = R2
        PG = 'i ':SPC
        GOSUB DISPZZ
        GO STOPIT
     END
     IF YY GT MAXM THEN
        START = XX
        FINISH = XXCNT
        DISP = R1
        PG = 'd '
        GOSUB DISPZZ
        GO STOPIT
     END
     LINEX = R1<XX>
     LINEY = R2<YY>
*    TESTX = TRIM(LINEX,' ','L')
*    TESTY = TRIM(LINEY,' ','L')
     TESTX = TRIM(LINEX)
     TESTY = TRIM(LINEY)
     IF TESTY EQ TESTX THEN
        LCT = XX 'R#4':' '
        LINE = '  ':(LCT:TESTX)[1,FUL]
        CONVERT BAD TO GOOD IN LINE
        GOSUB DISP.LINE
        GO LOOPHERE
     END
* they're different - now resolve it
     ASK = TRUE
     SHOW = TRUE
* first go up to OFFSET from YY - if we hit YYCNT then back up
     YYLIM = YY + OFFSET
     IF YYLIM GT YYCNT THEN YYLIM = YYCNT
     FOR BB = YY TO YYLIM
*       TESTIT = TRIM(R2<BB>,' ','L')
        TESTIT = TRIM(R2<BB>)
        IF TESTIT EQ TESTX THEN
           START = YY
           FINISH = BB-1
           DISP = R2
           PG = 'i ':SPC
           GOSUB DISPZZ
           XX = XX-1
           YY = BB-1
           GO LOOPHERE
        END
     NEXT BB
* then go up to OFFSET from XX
     XXLIM = XX + OFFSET
     IF XXLIM GT XXCNT THEN XXLIM = XXCNT
     FOR BB = XX TO XXLIM
*       TESTIT = TRIM(R1<BB>,' ','L')
        TESTIT = TRIM(R1<BB>)
        IF TESTIT EQ TESTY THEN
           START = XX
           FINISH = BB-1
           DISP = R1
           PG = 'd '
           GOSUB DISPZZ
           YY = YY-1
           XX = BB-1
           GO LOOPHERE
        END
     NEXT BB
     LCT = XX 'R#4':' '
     LINE = 'c ':(LCT:TESTX)[1,LHL]
     LINE = LINE LHS
     LCT = YY 'R#4':' '
     LINE = LINE:'  ':(LCT:TESTY)[1,LHL]
     CONVERT BAD TO GOOD IN LINE
     GOSUB DISP.LINE
     GO LOOPHERE


DISPZZ:
     FOR ZZ = START TO FINISH
        LINE = DISP<ZZ>
        LINE = TRIM(LINE,' ','L')
        LCT = XX 'R#4':' '
        LINE = PG:(LCT:LINE)[1,LHL]
        CONVERT BAD TO GOOD IN LINE
        GOSUB DISP.LINE
     NEXT ZZ
     RETURN


DISP.LINE:
     IF SHOW THEN CRT LINE
     LL += 1
     IF ASK AND LL GE DEPTH THEN
        CRT XX,YY,'Enter <New line> to continue...':
        LOOP
           HELP = FALSE
           INPUT NL:
           NL = OCONV(NL,'MCU')
           BEGIN CASE
              CASE NL[1,1] EQ 'Q'
                 GO STOPIT
              CASE NL[1,1] EQ 'N'
                 ASK = FALSE
              CASE NL[1,1] EQ 'S'
                 ASK = FALSE
                 SHOW = FALSE
              CASE NL[1,1] EQ 'T'
                 XX = 0; YY = 0
              CASE NL MATCHES '1[[N0N]]'
                 XX = NL; YY = NL
              CASE NL MATCHES "1[[N0N]]','1[[N0N]]"
                 XX = FIELD(NL,',',1)
                 YY = FIELD(NL,',',2)
              CASE NL MATCHES "'-'1[[N0N]]"
                 NL = NL[2,LEN(NL)]
                 XX = XX - NL
                 IF XX LT 0 THEN XX = 0
                 YY = YY - NL
                 IF YY LT 0 THEN YY = 0
              CASE NL = ''
              CASE 1
                 HELP = TRUE
           END CASE
           CRT
        WHILE HELP DO
           GOSUB SHOW.HELP
        REPEAT
        LL = 1
     END
     RETURN

SHOW.HELP:
     CRT
     CRT 'Note that only the first character of a command is required'
     CRT
     CRT '  Q - Quit'
     CRT '  N - No prompt: display until there is a mismatch'
     CRT '  S - Scan until there is a mismatch'
     CRT '  T - Top (start again)'
     CRT
     CRT 'line number commands'
     CRT
     CRT '  n - Start at line number "n".'
     CRT ' -n - Go up "n" lines'
     CRT 'n,m - Start again with line "n" from ':F1:' item ':I1
     CRT '      and line "m" from ':F2:' item ':I2
     CRT
     RETURN