NOTE

Use of file update logic. This program updates data on lots in a housing tract. Item-IDs in the file LOT are TRACT.NAME*LOT.NUMBER.

*** Initialization

   PROMPT '='

   CLEAR

   DIM DESC(30), TYPE(30)

   OPEN 'DICT', 'LOT' TO DICTLOT ELSE

      PRINT "CAN'T OPEN DICT LOT"

      STOP

   END

   OPEN ",’LOT’ TO LOTFILE ELSE

      PRINT "CAN’T OPEN LOT FILE."

   STOP

END

*** Get descriptions, conversions

200   FOR I = 1 TO 30

   READ DICT ITEM FROM DLOT,I ELSE

      PRINT "DICTIONARY ITEM '":I:"' NOT

            FOUND"

   END ELSE

      D = EXTRACT(DICT.ITEM,3,0,0) ;

          *S/NAME-- Description      

      IF D # '' THEN DESC(I) = D:STR('.',15-LEN(D))

      IF C[1,2] = 'MD' THEN

         TYPE(I) = 'NUM'

      END ELSE

         IF C[1,1] = '0' THEN TYPE(I) = 'DATE"

      END

   END

NEXT I

*** Get the tract name

300   PRINT

   PRINT "TRACT NAME.....":

   INPUT TRACT

   IF TRACT = 'STOP' OR TRACT = 'END' THEN STOP

   IF TRACT = '' THEN GOTO 300

   READ INFO FROM TRACT ELSE

      PRINT "TRACT '":TRACT:"'LOT ON FILE"

      GOTO 300

   END

Get a valid lot number

400   PRINT

   PRINT "LOT NUMBER.....":

   INPUT NUMBER

   IF NUMBER = '' THEN GOTO 400

   IF NUMBER = 'END' OR NUMBER = 'STOP' THEN

      GOTO 300

   IF NUM(NUMBER) = 0 THEN

      PRINT "MUST BE A NUMBER"

      GOTO 400

   END

   NUMBER = TRACT:'*':NUMBER

   READ ITEM FROM LOTFILE,NUMBER ELSE

      ITEM = ''

      PRINT "NEW LOT"

   END

*

   NOT.SOLD = 0

   FOR I = 1 TO 30

      GOSUB 1000      ;  * updates the i’th attribute

      IF I = 10 THEN

         IF EXTRACT(ITEM,10,0,0) = '' THEN

            NOT.SOLD = 1

            I = 19

         END

      END

*

      IF I = 21 THEN

         IF NOT.SOLD THEN GOTO 500

      END

   NEXT I

*** Verify data & store

500   PRINT

   PRINT"         OK      ":

   INPUT OK

   IF OK = '' THEN

      WRITE ITEM ON NUMBER

      GOTO 400

   END

   IF OK = 'L' THEN

      PRINT

      FOR L = 1 TO 30

         ATT = EXTRACT(ITEM,I,0,0)

         IF ATT # ''THEN

            PRINT DESC(L):

         IF TYPE(L) = 'DATE' AND NUM(DATE) THEN

            ATT =  OCONV(ATT,'DO')

         END

         IF TYPE(L) = 'NUM' AND NUM(ATT) THEN

            ATT = 0.01 * ATT

         END

         PRINT ATT 'R#15’

      END

   NEXT L

   GOTO 500

END

GOTO 400

*** Updates the i’th attribute of "ITEM"

1000   * IF DESC(I) = '' THEN RETURN ;*not needed or not

       found

   PRINT DESC(I):

   CURRENT = EXTRACT(ITEM,I,0,0)

   IF TYPE(I) = 'NUM' THEN ;*Need a number (amount)

1100   * PRINT CURRENT*.01  'R##############':

      INPUT RESPONSE

      IF RESPONSE = '' THEN RETURN ;* Just looking

      IF NUM(RESPONSE)  = 0 THEN

         PRINT "MUST BE A NUMBER"

         GOTO 1100

      END

      IF RESPONSE = ’\’ THEN

         ITEM = REPLACE(ITEM,I,0,0,'')

      RETURN  ;* Delete this attribute

   END

   ITEM = REPLACE(ITEM,I,0,0,RESPONSE*100)

   RETURN

END

*

   IF TYPE(I) = 'DATE' THEN ;*Need a date

1200   * PRINT OCONV(CURRENT,'DO') 'R#14’:

      INPUT RESPONSE

      IF RESPONSE = '' THEN RETURN ;* Just looking

      IF RESPONSE = 'T' THEN

         ITEM = REPLACE(ITEM,I,0,0,") ;’*delete this

            attribute

         RETURN

      END

      IF RESPONSE = ’T’ THEN

         DATE = DATE()

      END ELSE

         DATE = ICONV(RESPNSE,’D’)

         IF DATE = " THEN

            PRINT "USE DATE FORMAT

            ’MONTH/DAY/YEAR’"

            GOTO 1200

         END

      END

      ITEM = REPLACE(ITEM,I,0,0,DATE)

      RETURN

    END

*** no necessary formats

   PRINT CURRENT 'R#15':

   INPUT RESPONSE

   IF RESPONSE = '' THEN RETURN

   IF RESPONSE = ’\’ THEN RESPONSE = ''

   ITEM = REPLACE(ITEM,I,0,0,RESPONSE)

   RETURN

END