BACKWARDS FILE READING

 BBS: Inland Empire Archive
Date: 02-05-93 (03:52)             Number: 389
From: ROB MCKEE                    Refer#: NONE
  To: DAVID DUREL                   Recvd: NO  
Subj: BACKWARDS FILE READING         Conf: (2) Quik_Bas

Hello DAVID!
   You wrote in a message to ALL:

 DD> Does anyone out there have a simple routine to read an ASCII
 DD> file backwards? In other words, start from the end of the
 DD> file and read to the beginning, instead of the other way
 DD> around.

Something like this?  For RBBS no less! <G>

 ' Rbbs to English master list converter
 ' Kludge-O-matic by Rob McKee
 ' Written to run under Qbasic
 ' FreeWare SmearWear...
 ' Here's the guts..
 ' You can polish it if you like!

 DEFINT A-Z
 DIM a(1 TO 266) AS STRING * 80
 DIM ga$(1 TO 500)
 Year=88             ' First Year of FileList
 FileName$="125_27.Lst"   ' Output Name
 OPEN FileName$ FOR OUTPUT AS 2
 FOR t = 1 TO VAL(MID$(DATE$, 9, 2)) - Year
 F$(t) = MID$(STR$(t + (Year-1)), 2)
 NEXT
 F$(6) = "DIR"
 FOR t = 1 TO VAL(MID$(DATE$, 9, 2)) - Year + 1
     TheFile$ = "master." + F$(t)
     PRINT TheFile$:
     OPEN TheFile$ FOR INPUT AS 1
     Ptr = 0
     DO UNTIL EOF(1) ' read the file frontwards
         Ptr = Ptr + 1
         LINE INPUT #1, a(Ptr)
     LOOP
     FOR g = Ptr TO 2 STEP -1 ' Process it backwards
         IF MID$(a(g), 78, 3) = "  ." THEN
             b$ = LEFT$(a(g), 77)
             b$ = LTRIM$(RTRIM$(b$))
             a(g) = ""
             IF RIGHT$(b$, 1) = "-" THEN
                 b$ = LEFT$(b$, LEN(b$) - 1)
             ELSE
                 b$ = " " + b$
             END IF
             c$ = c$ + b$
             b$ = ""
         ELSE ' Unwrap the Line
             b$ = ""
             b$ = LEFT$(a(g), 77)
             b$ = RTRIM$(b$)
             IF RIGHT$(b$, 1) = "-" THEN b$ = LEFT$(b$,
LEN(b$) - 1)              Count = Count + 1
             ga$(Count) = c$
             c$ = "" ' cut down on Memory usage
             ' things get real tight here for string space
             c$ = MID$(a(g), 78, 3) + " " + b$
             a(g) = ""
             b$ = ""
         END IF
         IF INKEY$ <> "" THEN
            ' Pause routine
            DO: LOOP WHILE INKEY$ = ""
         END IF
     NEXT
     CLOSE 1
 NEXT
 FOR t = 1 TO Count - 1
     FOR g = Count TO t + 1 STEP -1
         IF ga$(g) < ga$(t) THEN SWAP ga$(g), ga$(t)
     NEXT
 NEXT
 FOR t = 1 TO Count - 1
     FOR g = Count TO t + 1 STEP -1
         IF ga$(g) < ga$(t) THEN SWAP ga$(g), ga$(t)
     NEXT
 NEXT
 CLS
 FOR t = 1 TO Count
     PRINT LEFT$(ga$(t), 40)
     PRINT #2, ga$(t)
 NEXT
 SYSTEM


  Catcha Later , I'll see you on the flip side - Rob


--- timEd/B6
 * Origin: Another Quik_Bas Point in Richmond, CA (1:125/1212.13)