Isam File Handler / Programming Interfaces / Visual Basic for DOS

FATS - Fast Access Tree System
	Table of Contents
		Programming Interfaces
			Visual Basic for DOS

The FATS Toolkit supports a calling interface that is 100% compatible with the program FABS-Plus Net of Computer Control Systems. All programming interfaces of this software were reproduced.

There is no need to change your source code. You just need to change obj-/dll files to use FATS in existing projects, for example in the MS-DOS environment you only have to replace the FABSP module with the FATS module.

The following VB DOS example demonstrates the use of the FABS PLUS compatible commands:

PRINT "Compatible Programming Interface (FABS PLUS)"
PRINT
PRINT "This Test Program was designed for Visual Basic (MS-DOS)"
PRINT
PRINT "To compile and link the test program, use ONE of the following methods:"
PRINT
PRINT "  1. METHOD: Linking FATS to the program"
PRINT
PRINT "     BC tst0_eng"
PRINT "     LINK tst0_eng fats.obj"
PRINT
PRINT "  2. METHOD: Calling the Workstation Engine"
PRINT
PRINT "     BC tst0_eng"
PRINT "     LINK tst0_eng fatsvbdr.lib   (FATS Standard Version FATS_WE.EXE)"
PRINT
PRINT "     or if you own the extended version of FATS:"
PRINT
PRINT "     LINK tst0_eng fatsxvbr.lib   (FATS Extended Version FATSXWE.EXE)"
PRINT
INPUT "Please press the [ENTER] key ...", X$
PRINT

REM  -------> open file with test data

OPEN "R", #1, "..\..\..\DEMODATA\CUSTOMER.ASC", 105
FIELD #1, 5 AS F1$, 25 AS F2$, 25 AS F3$, 25 AS F4$, 5 AS F5$, 20 AS F6$

REM  -------> create data file

PRINT "Creating Data File ..."

OPEN "R", #2, "CUSTOMER.DAT", 128
FIELD #2, 1 AS DELETEDMARK$,_
          5 AS CUSTID$,_
         25 AS NAME$,_
         25 AS JOB$,_
         25 AS STREET$,_
          5 AS ZIP$,_
         20 AS CITY$

REM  -------> create index file

PRINT "Creating Index File ..."

CALL FBSVBDOS("C\CUSTOMER.KEY\25\4\A\1", ERRORCODE%, RECNO%, ADRKEY%)
IF ERRORCODE% <> 0 GOTO ENDE

REM  -------> insert records

PRINT
PRINT "290 records will be inserted into the data file."
PRINT "For each record 4 keys will be stored in the index file"
PRINT
INPUT "Please press the [ENTER] key ...", X$

FOR X=1 TO 290
  GET #1,X
  LSET DELETEDMARK$=" "
  LSET CUSTID$=F1$
  LSET NAME$=F2$
  LSET JOB$=F3$
  LSET STREET$=F4$
  LSET ZIP$=F5$
  LSET CITY$=F6$
  CMND$="I\1\"+RTRIM$(CUSTID$)+"\"+RTRIM$(NAME$)+"\"+RTRIM$(JOB$)+"\"+RTRIM$(ZIP$+CITY$)
  CALL FBSVBDOS(CMND$, ERRORCODE%, RECNO%, ADRKEY%)
  IF ERRORCODE% <> 0 GOTO ENDE
  PRINT NAME$;" --> RecNo ";RECNO%
  PUT #2,RECNO%
NEXT X

CLOSE #1

REM  -------> print all customers, sorted in ascending order by NAME

PRINT
PRINT "This list shows some fields from the Customer Table,"
PRINT "sorted in ascending alphabetical order on the Customer's"
PRINT "surname and forename."
PRINT
INPUT "Please press the [ENTER] key ...", X$

CMND$="F\2\1"
LOOP1:
  CALL FBSVBDOS(CMND$, ERRORCODE%, RECNO%, ADRKEY%)
  IF ERRORCODE% <> 0 GOTO LABEL1
  CALL FABSGETKEY(FABSKEY$, ADRKEY%, 25)
  GET #2,RECNO%
  PRINT NAME$;" ";JOB$;" --> RecNo ";RECNO%
  CMND$="A\2\"+STR$(RECNO%)+"\1\"+FABSKEY$
  GOTO LOOP1
LABEL1:

REM  -------> print all customers, sorted in ascending order by JOB

PRINT
PRINT "Two columns - JOB and NAME are displayed, sorted in ascending"
PRINT "order by the JOB field."
PRINT
INPUT "Please press the [ENTER] key ...", X$

CMND$="F\3\1"
LOOP2:
  CALL FBSVBDOS(CMND$, ERRORCODE%, RECNO%, ADRKEY%)
  IF ERRORCODE% <> 0 GOTO LABEL2
  GET #2,RECNO%
  PRINT JOB$;" ";NAME$;" --> RecNo ";RECNO%
  CMND$="N\1"
  GOTO LOOP2
LABEL2:

REM  -------> print list with records sorted by ZIP and CITY

PRINT
PRINT "Three columns - ZIP, CITY and NAME are displayed, sorted in"
PRINT "descending order by ZIP then CITY."
PRINT
INPUT "Please press the [ENTER] key ...", X$

CMND$="L\4\1"
LOOP3:
  CALL FBSVBDOS(CMND$, ERRORCODE%, RECNO%, ADRKEY%)
  IF ERRORCODE% <> 0 GOTO LABEL3
  CALL FABSGETKEY(FABSKEY$, ADRKEY%, 25)
  GET #2,RECNO%
  PRINT ZIP$;" ";CITY$;" ";NAME$;" --> RecNo ";RECNO%
  CMND$="E\4\"+STR$(RECNO%)+"\1\"+FABSKEY$
  GOTO LOOP3
LABEL3:

ENDE:

REM  -------> close index file

CALL FBSVBDOS("K\1", ERRORCODE%, RECNO%, ADRKEY%)

CLOSE #2
END


REM  -------> SUB: get the return key value from FATS

SUB FABSGETKEY (FABSKEY$, ADRKEY%, KEYLEN%)
  FABSKEY$=""
  CALL GFSEG(FSEG%)
  ADRKEY=ADRKEY%
  IF ADRKEY < 0 THEN ADRKEY=ADRKEY+65536!
  FOR X=ADRKEY TO ADRKEY+KEYLEN% - 1
    DEF SEG=FSEG%
    KCHAR=PEEK(ADRKEY)
    DEF SEG
    FABSKEY$=FABSKEY$+CHR$(KCHAR)
    ADRKEY=ADRKEY+1
  NEXT X
END SUB