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Plb-0320.cfm v1.0


plb-t010.cfm
 

ANSI Standard PL/B Language and Visual PL/B

FILELIST

NOTE TO OUR READERS
This web resource is written for our own use. But we feel strongly that the PL/B language should be shared with the software community. So feel free to use this at will! BUT PLEASE... if you find errors or omissions or have a better way to do something. TELL US! Dialog helps us all. Send e-mail to: support@mmcctech.com
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FILELIST:    -    This is a SUNBELT ONLY language feature.

CONCEPT OF USE

The FILELIST instruction is a method for updating multiple indexes to the same text file. In traditional PL/B programming, you'd define TWO (or more) indexed files and process them separately. One file would be the primary and the other(s) would be secondary indexes. Records would be WRITTEN into the primary file then the secondary record keys would be INSERTED into the secondary index(s).

With a FILELIST you still define the multiple files, but you list them inside a FILELIST container:
WORK_ORDER_FILES  FILELIST
WO_HEADER            IFILE 
WO_PART_ISI          IFILE  
                  FILELISTEND
Note the following things concerning the IFILE statement within a FILELIST. OPENING FILES

Once the files are defined, they are opened in two ways. First, the files can be opened in one shot at the FILELIST level. That is, using the above example the open would be:
	OPEN 	WORK_ORDER_FILES

Secondly, the files can be opened individually by name. Again using the example the opens would be:
	OPEN	WO_HEADER,{filename},{mode}
	OPEN	WO_PART_ISI,{filename},{mode}
Note the following things concerning the IFILE statement within a FILELIST. INDEX KEYS

For the FILELIST processing to work, the runtime must know the key structure of all of the files which are members of the FILELIST. These keys are obtained from the .ISI file iteslf. You can get the keys into the file in two ways.

First, you can prep the file using a key. The key must be in the form "n-n". In a non-filelist prep you can give the key as just a length. That is: As a point of standards, it would be good practice to always PREP indexed files using the second format. This is true even if the file is not used in a FILELIST. It doesn't impose any limits and it does insure that when a FILELIST is added to the system later, the index will be ready. (The exception is where the programs must be compatible with non-Sunbelt compilers.)

Second, you can use the SUNINDEX or SUNIDXNT to externally create the ISI file.

NOTE:When you create the ISI file with the index utility, you can later re-index the file using the "R" parameter. You CANNOT use the "R" index parameter when the file was prepped internally, regardless of how you specify the keys.

An example of the "R" method would be: Again, when you create the ISI file with a PREP within the program, the FILELIST will work but you cannot SUNINDEX using the "R" parameter. SUNINDEX reports that there are no key specifications in this type of file.

OTHER NOTES

You can PREP any individual file by name, even when the file is defined within in a FILELIST.

You CANNOT directly write or update or delete records to a file which is defined within a FILELIST. If you want to write to an individual file that's part of a FILELIST, you'll have to define it again and separately outside of the FILELIST.

READ, READKS, READKP may all be done to the individual file names. They are NOT done at the FILELIST level since the reads address a specific record, not the collection of records identifed by the FILELIST group.

FILEIO may be used in place of the READ, READKS, READKP. If you try to do a FILEIO for WRITE or UPDATE operations you will get a runtime error.


This is a stub that was used for testing.... it's left here as a reminder only:





FILELIST Examples
.......................................................
.  TESTPREP                                 10/17/2001
.    ÚÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ¿
.    ³          TEST ISI PREPS TO SEE HOW TO DEFINE THE KEY           ³
.    ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ
.
         INCLUDE   Z:COMMON
         INCLUDE   REVISION.DBS
.
.............................................
.   The following EQU's are to allow the test program
.   to be compiled with and without various sections
.   of code just to see what happens.
.
PREP_ROUTINE    EQU    0
WRITE_ROUTINE   EQU    0
UPDATE_ROUTINE  EQU    1
READ_ROUTINE    EQU    1
.
NUL            DIM    1
.
.....................................
.        Define the files in the list.
.        Note that the NAME= parameter is NOT used.
.        Instead, the files will be PREPPED or OPENED individually
.
IFILE_LIST  FILELIST
IFILE          IFILE        ;primary file
IFILE2         IFILE        ;secondary index
            FILELISTEND
.
I_RECORD    LIST
I_KEY          DIM    15   ;primary record key
I_DATA         DIM    20   ;We'll just put a timestamp here.
I_SEQUENCE     FORM    4   ;This will be the secondary index key
I_DOT          INIT  "."   ;just to show end of record when listing.
            LISTEND
.
         WINSHOW                 ;we'll run this on the main screen
         INCLUDE   COLR-BAR      ;mmcc's color information (not required)
.
         DISPLAY   "TESTPREP BEGINS"
.
.........................
.
  %IF PREP_ROUTINE > 0
         DISPLAY   "PREP ZZ-ISI2 secondary index"
         PREP      IFILE2,"ZZ-ISI","ZZ-ISI2", "36-39", "40"
.
         DISPLAY   "PREP ZZ-ISI  primary index"
         PREP      IFILE, "ZZ-ISI","ZZ-ISI",  "1-15","40"
.
...............
.    Create a group of test records counting up.
.
         MOVE      " 20",I_SEQUENCE     ;starting 2ndary key.
         MOVE      "100",NWK03          ;starting unique part of prime key
         LOOP
           PACK    I_KEY, NWK03," A B C ",SPACES     ;build up the key
           CALL    WRITE_FILELIST       ;write the LIST & increment NWK03
           IF (NWK03 > 110)             ;is this enough for the test?
               BREAK                    ;yep... stop now
           ENDIF
           ADD     "10",NWK03           ;increment PRIMARY KEY
         REPEAT
.
...............
.    Create a SECOND group of test records counting down.
.    This should give a nice mix of records
.
         MOVE      "151",NWK03          ;second group of primary keys
         LOOP
           PACK    I_KEY, NWK03," A B C ",SPACES    ;build up key
           CALL    WRITE_FILELIST       ;write the LIST & increment NWK03
           IF (NWK03 < 110)             ;is this enough for the test?
               BREAK                    ;yep... stop now
               BREAK
           ENDIF
           SUB     "8",NWK03            ;decrement PRIMARY key
         REPEAT
.
         DISPLAY   "CLOSE IFILE"        ;first set of records are done
         CLOSE     IFILE
         CLOSE     IFILE2
.
         KEYIN     "Original PREP & WRITE done.  Tap any key ",*+,REPLY,*-
  %ENDIF
.
.........................
.    Second test will re-open the files which were prepped above.
.    We'll just write another group of records.
.
  %IF WRITE_ROUTINE > 0
         DISPLAY   "Write routine... see how to open existing files ":
                   "for I/O."
.
         DISPLAY   "OPEN ZZ-ISI2 secondary index"
         OPEN      IFILE2,"ZZ-ISI2"      ,"ZZ-ISI2", "36-39", "40"
.
         DISPLAY   "OPEN ZZ-ISI  primary index"
         OPEN      IFILE, "ZZ-ISI"       ,"ZZ-ISI",  "15","40"
.
         MOVE      " 20",I_SEQUENCE         ;start 2ndary key at same point
         MOVE      "500",NWK03              ;new group of prime keys
         LOOP
           PACK    I_KEY, NWK03," A B C ",SPACES    ;build up key
           CALL    WRITE_FILELIST       ;write the LIST & increment NWK03
           IF (NWK03 > 520)             ;is this enough
               BREAK                    ;yep... stop now
           ENDIF
           ADD     "10",NWK03           ;increment prime key
         REPEAT
.
         DISPLAY   "CLOSE IFILE"
         CLOSE     IFILE
         CLOSE     IFILE2
.
         KEYIN     "OPEN and WRITE routine done.  Tap any key ",REPLY
  %ENDIF
.
..............................................
.        This routine reads back the primary key file.
.        The data and the secondary key are displayed for each record.
.        The user can enter a different secondary key.
.        If they do, then the files are updated.
.        That should take care of both ISIs.
.
  %IF UPDATE_ROUTINE > 0
         DISPLAY   "Update routine... ":
                   "See how the indexes are updated."
.
         DISPLAY   "OPEN ZZ-ISI2 secondary index"
         OPEN      IFILE2,"ZZ-ISI2"      ,"ZZ-ISI2", "36-39", "40"
.
         DISPLAY   "OPEN ZZ-ISI  primary index"
         OPEN      IFILE, "ZZ-ISI"       ,"ZZ-ISI",  "15","40"
.
         DISPLAY   "You can change the secondary key on any record ":
                   "by keying a new value."
.
         LOOP
           READKS  IFILE;I_RECORD
           BREAK IF OVER
.
           DISPLAY "KEY:",*HON,*LL,I_KEY,   *PL,*HOFF:
                   " D:", *HON,*LL,I_DATA,  *PL,*HOFF;
.
           MOVE    I_SEQUENCE,NWK04
           KEYIN   " Seq:",*HON,*DVRV=I_SEQUENCE,*HOFF," ";
           IF (I_SEQUENCE != NWK04)
               DISPLAY " UPDATE"
               CALL    UPDATE_FILELIST
             ELSE
               DISPLAY SPACE
           ENDIF
         REPEAT
.
         DISPLAY   "CLOSE IFILEs"
         CLOSE     IFILE
         CLOSE     IFILE2
.
         KEYIN     "OPEN and UPDATE routine done.  Tap any key ",REPLY
  %ENDIF
.
...................................
.        This routine just opens the files one at a time and displays
.        all of the records on screen for confirmation
.
  %IF READ_ROUTINE > 0
         MOVE      "ZZ-ISI",FILENAME
         DISPLAY   "Read back PRIMARY index:",*HON,*LL,FILENAME,*PL,*HOFF
         OPEN      IFILE,FILENAME,READ
         LOOP
           READKS  IFILE;TITLE_LINE
           BREAK IF OVER
           DISPLAY *HON,*LL,TITLE_LINE,*PL,*HOFF
         REPEAT
         KEYIN     "Tap any to read back ISI2",*+,REPLY,*-
.
...................................
.
         MOVE      "ZZ-ISI2",FILENAME
         DISPLAY   "Read back SECONDARY index:",*HON,*LL,FILENAME,*PL,*HOFF
         OPEN      IFILE,FILENAME,READ
         LOOP
           READKS  IFILE;TITLE_LINE
           BREAK IF OVER
           DISPLAY *HON,*LL,TITLE_LINE,*PL,*HOFF
         REPEAT
         DISPLAY   "End of readback "
  %ENDIF
.
         KEYIN     "End of TESTPREP ",*+,REPLY,*-
         STOP
.
................
.
write_filelist
         CLOCK     TIMESTAMP,I_DATA
         ADD       "12",I_SEQUENCE
         DISPLAY   "  Write key:",*HON,*LL,I_KEY,*PL,*HOFF:
                   " ",*HON,I_SEQUENCE,*HOFF
         WRITE     IFILE_LIST; I_RECORD
         RETURN
.
................
.
update_filelist
         CLOCK     TIMESTAMP, I_DATA
         UPDATE    IFILE_LIST;I_RECORD
         RETURN


v1.10

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