The following Microsoft Basic example demonstrates the use of the FATS 
indexing commands:
REM FATS 02.30
REM (c) GCS Software, Udo Gertz 1993-1998
REM
REM Test program (Microsoft Basic / Quick Basic Compiler)
REM
REM Build the test data file customer.dat.
REM
REM 19-03-2009 U.Gertz
REM Needed Object Files
REM ===================
REM
REM Up to version 6.0 of the basic compiler all strings were administered
REM in the data segment of the application. Starting from the version 7.0
REM the entire memory can be used by strings (compiler flag /Fs).
REM
REM Therefore you must use the appropriate interface when linking with FATS.
REM To link FATS to your programs you will need the following object modules:
REM
REM FATS.OBJ The FATS module for MS-DOS
REM FATS_MB6.OBJ MS-Basic interface for NEAR-strings, *or*
REM FATS_MB7.OBJ MS-Basic interface for FAR-strings (/Fs)
REM
REM The following libraries are included on the distribution diskette to
REM call the FATS Workstation Engine (FATS_WE.EXE):
REM
REM FATSMB6R.LIB interface for NEAR-strings, *or*
REM FATSMB7R.LIB interface for FAR-strings (/Fs)
REM
REM If you want to make calls to the extended version of FATS (FATSXWE.EXE),
REM you have to use the libraries FATSXB6R.LIB or FATSXB7R.LIB.
REM
REM If you like to use the resident module FATS.COM to make the FATS calls,
REM the object module fatsmb7t.obj provides the FABS PLUS compatible
REM function FABSMB2.
REM
REM
REM Linking a MS Basic Program with FATS
REM ====================================
REM
REM To compile and link a application that calls FATS, use ONE of the
REM following methods:
REM
REM 1. METHOD: Linking FATS to the program
REM
REM BC TST1ENG6 /Lr
REM LINK TST1ENG6 FATS.OBJ FATS_MB6.OBJ
REM
REM or Basic 7.x and FAR-strings:
REM
REM BC TST1ENG6 /Lr /Fs
REM LINK TST1ENG6 FATS.OBJ FATS_MB7.OBJ
REM
REM 2. METHOD: Calling the Workstation Engine (FATS_WE.EXE)
REM
REM BC TST1ENG6 /Lr [/Fs]
REM LINK TST1ENG6 FATSMB[6 oder 7]R.LIB
REM
REM or if you own the extended version of FATS: (FATSXWE.EXE)
REM
REM LINK TST1ENG6 FATSXB[6 oder 7]R.LIB
REM
REM
REM Calling FATS
REM ============
REM
REM FATS commands are executed with the function FATSBASIC :
REM
REM FATSBASIC( szCmnd$, uFATSError%, dwRecno&, nKeyLen% )
REM
REM Parameter Usage:
REM
REM szCmnd With this command string you specify the actual
REM FATS command. The available commands are described
REM in the user manual.
REM
REM nErrorcode Your application must always pass this variable as
REM the status parameter on a FATS call. After the
REM FATS call, the application should always check the
REM value of this variable. FATS returns a errorcode of
REM 0 after a successful operation. FATS indicates any
REM errors which occur during processing by returning a
REM nonzero value in the errorcode variable.
REM In the manual you can find a list of all FATS
REM errorcodes and their possible causes.
REM
REM dwRecno Record number (output), long integer
REM
REM nKeyLen Length of key value (output), integer
REM
REM The FATSBASIC subroutine does the actual call to FATS
REM and returnes the length of a found key in the nKeyLen
REM variable. This value should be used to assign to the
REM key string variable the value SPACE$(nKeyLen%). Until
REM your application assigns some value to the string
REM variable, it has a length of 0.
REM The FATSGETKEY subroutine copies the key value from
REM the previous FATS call to the key string variable:
REM
REM If nKeyLen% > 0 Then
REM szFATSkey$ = Space$( nKeyLen% )
REM Call FATSGETKEY( szFATSkey$ )
REM Else
REM szFATSkey$ = ""
REM End If
REM -------> Activation of Network Operation
REM
REM FATS is standardly equiped for the network environment.
REM Nearly all commands can be executed both in single workstation
REM and network environment. With the 
"Y" Auto Refresh command you
REM determine the behavior of FATS accessing all index files.
REM Normally it is sufficient to apply this instruction one time at
REM the program start whereby the specified access mode will apply
REM to all coming opened files, i.e. they are accessed either with
REM network (Y\2) or single workstation access (Y\0).
REM CALL FATSBASIC( "Y\2", ERRORCODE%, RECNO&, KEYLEN% )
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
REM "C" Create Indexfile
REM
REM With this command you create an index file, whereby a possibly
REM already existing file with the same name is deleted.
REM After the file is created it will be opened with the opening
REM flags defined with the command Auto Refresh (Y) and can be
REM accessed under the file number you specified.
REM
REM Max. 200 primary keys per data record can be administered in an
REM index file, the max. key length amounts to 240 characters.
REM
REM Full path names must be specified using forward slashes (/)
REM instead of Backslashes (\), because FATS normally uses the
REM Backslash character as delimiter.
REM You may change the delimiters by placing the desired character
REM as the first character of the command string,
REM e.g. szCmnd = "&C&C:\ARTICLES.KEY&1&1&A&1". Any character with
REM an Ascii code less then 48 will be accepted.
REM
REM The syntax of the command string:
REM
REM szCmnd = "C\{Filename}\{KeyLength}\{KeyCount}\{KeyType}\{FileNo}"
REM
REM FileName filename, perhaps with an additional path
REM (e.g. C:/DATA/ARTICLES.KEY or ARTICLES.KEY)
REM
REM KeyLength Maximum key length (1-250)
REM If you choose to have more than one key for
REM this index file, you may specify the length
REM for each key (separated by a semicolon ";")
REM to conserve diskette space.
REM Otherwise, the maximum length applies to all
REM keys, i.e. every key will occupy the maximum
REM space.
REM
REM KeyCount Number of primary keys (1-200)
REM
REM KeyType Key type (A = Ascii text, I = Integer)
REM
REM FileNo File number (1-40)
PRINT "Creating Index File ..."
CALL FATSBASIC( "C\CUSTOMER.KEY\5;25\4\A\1", ERRORCODE%, RECNO&, KEYLEN% )
IF ERRORCODE% <> 0 GOTO ENDE
REM ========================================================================
REM Insert Records
REM ========================================================================
PRINT
PRINT "290 records will be inserted into the data file."
PRINT "For each record 4 keys will be stored in the index file."
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$
REM "I" Insert Record
REM
REM This command is used to insert the primary keys of a new
REM data record into the index file. After the insert, the
REM record number of the new record is returned in the "RECNO"
REM variable. You can use this record number to write the data
REM record to the data file.
REM
REM The number of keys included in the command string must equal
REM the number of primary keys you specified in the
REM Create Indexfile (C) command.
REM
REM The length of the transferred keys may not exceed the maximum
REM key length specified with the Create Indexfile (C) command.
REM Variable length keys will be padded with the Ascii char 0 to
REM the maximum key length.
REM
REM The syntax of the command string:
REM
REM szCmnd = "I\{FileNo}\{KeyStr1}[\{KeyStr2}[\{KeyStr3}]]"
REM
REM FileNo File number
REM
REM KeyStr# Key value
CMND$ = "I\1\"
CMND$ = CMND$ + RTRIM$(CUSTID$) + "\" + RTRIM$(NAME$) + "\" + RTRIM$(JOB$) + "\" + RTRIM$(ZIP$ + CITY$)
CALL FATSBASIC( CMND$, ERRORCODE%, RECNO&, KEYLEN% )
IF ERRORCODE% <> 0 GOTO ENDE
PRINT NAME$; " --> RecNo "; RECNO&
PUT #2, RECNO&
NEXT X
CLOSE #1
REM "K" Close Indexfile
REM
REM This command closes the index file with the specified
REM file number.
REM
REM If you have activated the cache algorithm with the command
REM Auto Refresh (Y), the possibly still in the cache buffers
REM presented data are automatically written on the disk.
REM
REM If the cache is inactive after every FATS command all
REM changed data are written on the disk. Therefore closing of
REM a file is necessary only before terminating the application.
REM
REM If you omit the parameter "FileNo", then all opened index
REM files are closed. This version is recommended before the
REM termination of the application program.
REM
REM The syntax of the command string:
REM
REM szCmnd = "K\{FileNo}"
REM
REM FileNo File number
CALL FATSBASIC( "K\1", ERRORCODE%, RECNO&, KEYLEN% )
REM ========================================================================
REM Search
REM ========================================================================
REM "O" Open Indexfile
REM
REM With this command you open an existing index file with
REM the opening flags defined with the command Auto Refresh (Y).
REM After the file was opened it can be accessed under the
REM file number you specified. An index file already opened
REM with the same file number is closed before this command
REM is executed.
REM
REM Full path names must be specified using forward slashes (/)
REM instead of Backslashes (\), because FATS normally uses the
REM Backslash character as delimiter.
REM You may change the delimiters by placing the desired character
REM as the first character of the command string, e.g.
REM szCmnd = "&O&C:\ARTICLES.KEY&1". Any character with an Ascii
REM code less then 48 will be accepted.
REM
REM The syntax of the command string:
REM
REM szCmnd = "O\{FileName}\{FileNo}"
REM
REM Filename filename, perhaps with an additional path
REM (e.g. C:/DATEN/ARTICLES.KEY or ARTICLES.KEY)
REM
REM FileNo File number
CALL FATSBASIC( "O\CUSTOMER.KEY\1", ERRORCODE%, RECNO&, KEYLEN% )
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 Customers"
PRINT "surname and forename."
PRINT
INPUT "Please press the [ENTER] key ...", X$
REM "F" Search First
REM
REM This command enables your application to retrieve the
REM record number corresponding to the first key value for
REM the specified key number.
REM
REM The syntax of the command string:
REM
REM szCmnd = "F\{KeyNo}\{FileNo}"
REM
REM KeyNo Key number
REM
REM FileNo File number
CMND$ = "F\2\1"
LOOP1:
CALL FATSBASIC( CMND$, ERRORCODE%, RECNO&, KEYLEN% )
IF ERRORCODE% <> 0 GOTO LABEL1
FATSKEY$ = SPACE$( KEYLEN% )
CALL FATSGETKEY( FATSKEY$ )
GET #2, RECNO&
PRINT NAME$; " "; JOB$; " --> RecNo "; RECNO&
REM "A" Search Next After
REM
REM With this command your application can retrieve the record
REM number corresponding to the first key value which is greater
REM than the key value you specify.
REM If a duplicate key exists, the next higher record number of
REM the next duplicate will be returned. The key value you specify
REM with "KeyString" don't have to be a valid key in the index file.
REM
REM Unlike the "Search Next" command, this command can be used in
REM a network environment.
REM
REM The syntax of the command string:
REM
REM szCmnd = "A\{KeyNo}\{RecNo}\{FileNo}\{KeyString}"
REM
REM KeyNo Key number
REM
REM RecNo Record number
REM
REM FileNo File number
REM
REM KeyString Key value
CMND$ = "A\2\" + STR$( RECNO& ) + "\1\" + FATSKEY$
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 FATSBASIC( CMND$, ERRORCODE%, RECNO&, KEYLEN% )
IF ERRORCODE% <> 0 GOTO LABEL2
GET #2,RECNO&
PRINT JOB$; " "; NAME$; " --> RecNo "; RECNO&
REM "N" Search Next
REM
REM With this command your application can retrieve
REM the record number corresponding to the first key
REM value which is greater than the key value recently
REM returned by one of the search commands, which have
REM to be executed as the latest command.
REM If a duplicate key exists, the next higher record
REM number of the next duplicate will be returned.
REM
REM Each modification of the index file by inserting or
REM deletion of keys makes an internal pointer invalid
REM that is necessary for this instruction. You better
REM use the command Search Next After (A) because this
REM can happen in the network environment from any station.
REM
REM If there is no key in sequence FATS will return an
REM errorcode of 15.
REM
REM The syntax of the command string:
REM
REM szCmnd = "N\{FileNo}"
REM
REM FileNo File number
CMND$ = "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$
REM "L" Search Last
REM
REM This command enables your application to retrieve the
REM record number corresponding to the last key value for
REM the specified key number. If duplicates exist for the
REM last key value, the record number returned identifies
REM the last duplicate, that is, the one inserted most
REM recently.
REM
REM The syntax of the command string:
REM
REM szCmnd = "L\{KeyNo}\{FileNo}"
REM
REM KeyNo Key number
REM
REM FileNo File number
CMND$ = "L\4\1"
LOOP3:
CALL FATSBASIC( CMND$, ERRORCODE%, RECNO&, KEYLEN% )
IF ERRORCODE% <> 0 GOTO LABEL3
FATSKEY$ = SPACE$( KEYLEN% )
CALL FATSGETKEY( FATSKEY$ )
GET #2, RECNO&
PRINT ZIP$; " "; CITY$; " "; NAME$; " --> RecNo "; RECNO&
REM "E" Search Previous Before
REM
REM With this command your application can retrieve the record
REM number corresponding to the first key value which is less
REM than the key value you specify.
REM If a duplicate key exists, the next lower record number of
REM the previous duplicate will be returned. The key value you
REM specify with "KeyString" don't have to be a valid key in the
REM index file.
REM
REM Unlike the "Search Prev" command, this command can be used in
REM a network environment.
REM
REM The syntax of the command string:
REM
REM szCmnd = "E\{KeyNo}\{RecNo}\{FileNo}\{KeyString}"
REM
REM KeyNo Key number
REM
REM RecNo Record number
REM
REM FileNo File number
REM
REM KeyString Key value
CMND$ = "E\4\" + STR$( RECNO& ) + "\1\" + FATSKEY$
GOTO LOOP3
LABEL3:
ENDE:
REM --------> Close index file
CALL FATSBASIC( "K\1", ERRORCODE%, RECNO&, KEYLEN% )
CLOSE #2
END
© 2008 
GCS Software, Udo Gertz
