Announcement

**Ian Cairns** · 6 Jul 2001, 03:29 PM

This is just a simple, untested record retrieval. You need to have some information about
record lengths to do a proper job. You also need to know the structure of the Time stamp
variables (CreationTime, etc.)

Code:

'######################################################################################
#COMPILE EXE
'#INCLUDE "WIN32API.INC"

TYPE HeaderStruc
  dbName             AS STRING * 32
  Flags              AS INTEGER
  Version            AS INTEGER
  CreationTime       AS LONG
  ModificationTime   AS LONG
  BackupTime         AS LONG
  ModificationNumber AS LONG
  AppInfoOffset      AS LONG
  SortInfoOffset     AS LONG
  dbType             AS LONG
  Creator            AS LONG
  IDseed             AS LONG
  nextRecordListID   AS LONG
  NumberOfRecords    AS INTEGER
END TYPE

TYPE RecordStruc
  RecordOffset  AS LONG
  RecordInfo    AS LONG ' Attrib as Byte, ID AS 3 BYTES
END TYPE
'######################################################################################
FUNCTION PBMAIN() AS LONG
  LOCAL header     AS HeaderStruc, _
        recInfo    AS RecordStruc, _
        record     AS STRING, _
        ndx        AS LONG, _
        fhandle    AS LONG, _
        fileLen    AS LONG, _
        recNo      AS LONG, _
        nextOffset AS LONG

  DIM recInfo(1:1) AS RecordStruc
  fhandle = FREEFILE
' Open a file with a fixed name
  OPEN "myfile.pdb" FOR BINARY AS # fhandle

' Retrieve the header
  GET # fhandle, 1, header
  IF header.NumberOfRecords < 1 THEN
    MSGBOX "No data in your file"
    FUNCTION = 0
    EXIT FUNCTION
  END IF
  
' Retrieve the Record Structure Info for each record, place in array
  REDIM recInfo(1:header.NumberOfRecords)
  FOR ndx = 1 TO header.NumberOfRecords
    GET # fhandle, , recInfo(ndx)
  NEXT ndx
  
' What is not mentioned is the length of a record.
' Without that knowledge, it becomes more difficult,
' but not impossible to display.
  fileLen = LOF(fhandle)
' .ie. let us look at the contents of the first record.
  recNo = 1
' find the offset of the next record in the file.
' If this is the last record, then set the offset to read to the end of the file.
  nextOffset = fileLen + 1
  FOR ndx = 1 TO header.NumberOfRecords
    IF recInfo(ndx).RecordOffset > recInfo(recNo).RecordOffset THEN
      nextOffset = MIN&(nextOffset, recInfo(ndx).RecordOffset )
    END IF
  NEXT ndx
' Place file file pointer
  SEEK fhandle, recInfo(recNo).RecordOffset
' Read the data into a record string
  GET$ # fhandle, nextOffset - recInfo(recNo).RecordOffset, record
' and Display it - Binary data may display unreadable characters!
  MSGBOX "Record: " + record
  
  CLOSE # fhandle
  
END FUNCTION
'######################################################################################

regards,

------------------
[email protected]

**Ariel Benzakein** · 6 Jul 2001, 09:45 PM

Thanks, that helped a bit. However, I'm just having trouble
reading the header. For example, in the Palm documentation
for the PDB format it says that the number of records is stored
as a WORD value, and the creation times are stored as DWORD
values. When I read the data into variables I have DIMmed in
this manner, it is not returning accurate values (i.e. it is
reporting 77 records when it should be 68, and the times are
not accurate).

Any ideas?

**Lance Edmonds** · 7 Jul 2001, 02:40 AM

www.wotsit.org lists 2 files outlining the PDB format:

http://www.wotsit.org/download.asp?f=pdb

http://www.wotsit.org/download.asp?f=pdb-fmt

------------------
Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

**Ariel Benzakein** · 8 Jul 2001, 05:56 AM

Thanks.. those don't tell me any more than the Palm API
docs though. But I have at least figured out what the
problem is... the Motorola processors save DWORD values in a
different format that Intel processors. So all I need to do
now is figure out a way to convert it.

------------------

**Lance Edmonds** · 8 Jul 2001, 06:10 AM

Right, the old little-endian (Intel) vs big-endian (Motorola) problem... You should be able to just reverse the byte order to get an Intel Dword.

For example, if you load the big-endian DWORDS into a string, you can use STRREVERSE$ and convert back to DWORD, ie:

Code:

#COMPILE EXE
FUNCTION PBMAIN
    a??? = &H0FFEEDDCC ' big-endian value
    b??? = CVDWD(STRREVERSE$(MKDWD$(a???)))
    MSGBOX HEX$(a???) & "=>" & HEX$(b???)
END FUNCTION

There are other ways, such as assembling the value with pointers, etc, but this is fairly fast and quite simple.

------------------
Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

**Ariel Benzakein** · 8 Jul 2001, 06:43 AM

Thanks Lance.. I wasn't aware of the string reverse function and
was doing it the "hard way" ....

------------------

**Florent Heyworth** · 8 Jul 2001, 07:02 AM

Here's another way:

Code:

#COMPILE EXE
FUNCTION PBMAIN
    a??? = &H0FFEEDDCC ' big-endian value
    b??? = a??? 'Copy
    ! bswap a??? 'Byte swap
    MSGBOX HEX$(b???) & "=>" & HEX$(a???)
END FUNCTION

Cheers

Florent

------------------

**Ariel Benzakein** · 8 Jul 2001, 07:55 AM

Well this code works (thnaks guys) but I still can't seem
to make it into a decimal number that makes sense.

------------------

**George Bleck** · 8 Jul 2001, 04:15 PM

I'm only glossing over this thread, but what if you created a union between a decimal number and a dword, then make the big endian swap as neccessary in the dword and the decimal equivelent through the union will be corrected.

------------------
George W. Bleck
Senior System Engineer
KeySpan Corporation

**Ariel Benzakein** · 8 Jul 2001, 06:55 PM

A union?

------------------

**Lance Edmonds** · 8 Jul 2001, 07:54 PM

Technically it would work (although you still need to go through the byte reversal procedure), but why bother with that arrangement as it would offer less advantage than the techniques outlined above?! Makes no sense to me... sorry!

------------------
Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

**Ariel Benzakein** · 8 Jul 2001, 08:16 PM

Well using the technique above I'm still not pulling out the
correct values. I know what they should be since I created the
database on my Palm device. I also double checked in Windows
with a program I have that displays the data in the PDB files.

I must be missing something really obvious.

**Lance Edmonds** · 8 Jul 2001, 10:07 PM

How about posting the binary of the values, aalong with the expected integer representations - maybe we can correlate them and suggest a solution.

------------------
Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

**Ariel Benzakein** · 9 Jul 2001, 08:08 PM

OK Lance... thank you to you and everyone else who has been
trying to help me. I feel a little bad about it, like you guys
are doing my work for me.. but I am really getting frustrated
trying to figure this out.

I posted my PDB file to the following URL: http://www.seekersofwisdom.com/EMPIN.PDB

(note that the filename, EMPIN.PDB is upper case). It's a
small (4k) file.

Here is what the values SHOULD be:
DB Name: EMPIN
Attributes: 0x0008
Version: 0
Creation Date: -1217854540
Modfication Date: -1217854540
Last Backup Date: -1217854540
Modification Number: 0
AppInfoArea: 624 (Size = 158) (not important, not sure what its for)
SortInfoArea: 0 (not important)
Database Type: DB99
Creator ID: DBOS
UniqueIDSeed: 0
NextRecordListID: 0
NumberOfRecord: 68

This information is pulled from my table with a reliable Windows
tool I have to read PDB database information.

I can also post my code here if that would be helpful... the
error could always be coming out of something I'm doing there.

**George Bleck** · 9 Jul 2001, 09:28 PM

Not sure if this is helpfull but I found a PDB list program and it's source code written in C.

I have uploaded it to my website if you care to compare it to what you are working on.

http://www.blecktech.com/listfull.zip

Hope that helps...

------------------
George W. Bleck
Senior System Engineer
KeySpan Corporation

**Ian Cairns** · 10 Jul 2001, 03:24 PM

This should be enough to keep you going for a while.
This post contains the date/time conversions.
Credit for most of this goes to Egbert Zijlema's Julian Date routines.

I moved away from the ASM byteSwap conversion due to compile errors.

Code:

'###########################################
#COMPILE EXE
#REGISTER NONE
#INCLUDE "WIN32API.INC"
DECLARE FUNCTION DateToJulian(inDate AS STRING) AS DWORD
DECLARE FUNCTION JulToDate(BYVAL Jul AS DWORD) AS STRING
DECLARE FUNCTION SecondsToTime(BYVAL inSeconds AS DWORD) AS STRING

TYPE HeaderStruc
  dbName             AS ASCIIZ * 32
  Flags              AS WORD
  Version            AS WORD
  CreationTime       AS DWORD
  ModificationTime   AS DWORD
  BackupTime         AS DWORD
  ModificationNumber AS DWORD
  AppInfoOffset      AS DWORD
  SortInfoOffset     AS DWORD
  dbType             AS STRING * 4
  Creator            AS STRING * 4
  IDseed             AS DWORD
  nextRecordListID   AS DWORD
  NumberOfRecords    AS WORD
END TYPE

TYPE RecordStruc
  RecordOffset  AS DWORD ' 4 <offset to record 0 from the beginning of the file>
  RecordAttrib  AS BYTE  ' Attrib as Byte
  ID            AS STRING * 3
END TYPE

TYPE WordStruc
  byte0 AS BYTE
  byte1 AS BYTE
END TYPE

TYPE dWordStruc
  word0 AS WordStruc
  word1 AS WordStruc
END TYPE
'###########################################
FUNCTION PBMAIN() AS LONG
  LOCAL header     AS HeaderStruc, _
        recInfo    AS RecordStruc, _
        record     AS STRING, _
        ndx        AS LONG, _
        fhandle    AS LONG, _
        fileLen    AS LONG, _
        recNo      AS LONG, _
        nextOffset AS LONG, _
        NoRecs     AS WORD, _
        firstRec   AS WORD, _
        recordLen  AS WORD, _
        Created    AS DWORD, _
        fieldOffset AS DWORD, _
        sortOffset AS DWORD, _
        buffer     AS STRING, _
        tString    AS STRING, _
        bufferLen  AS DWORD, _
        dataOffset AS DWORD, _
        testValue  AS DWORD, _
        noFields   AS WORD, _
        fldPtr     AS DWORD, _
        baseDate   AS LONG

LOCAL inDate AS STRING, julDate AS LONG, remainder AS DWORD, testDate AS LONG

' Dates are calculated in seconds from Jan 1, 1904 = Julian Date: 2416481
  baseDate = 2416481

  DIM recInfo(1:1) AS RecordStruc
  fhandle = FREEFILE
' Open a file with a fixed name - Zero-based Offset
  OPEN "EmpIn.pdb" FOR BINARY AS # fhandle BASE = 0

' Retrieve the header
  GET # fhandle, 0, header
  IF header.NumberOfRecords < 1 THEN
    MSGBOX "No data in your file"
    FUNCTION = 0
    EXIT FUNCTION
  END IF
' Mark the position from which to read record Info.
  dataOffset = SEEK(fhandle)

  NoRecs = header.NumberOfRecords
  CALL SwapWord(noRecs)
  Created = header.CreationTime
  CALL SwapDword(Created)

' Convert Creation Date to Display Date
  testValue = Created \ (60*60*24)  ' days
  remainder = Created - testvalue * (60*60*24)
  testDate = baseDate + testValue
  inDate = JulToDate(testDate)
  inDate = inDate + " - " +  SecondsToTime(remainder)

  MSGBOX "Program: " + header.dbName + CHR$(13) + _
         "Creation Time: " + inDate + CHR$(13) + _
         "database Type: " + header.dbType + CHR$(13) + _
         "Creator: " + header.Creator + CHR$(13) + _
         "No Records: " + FORMAT$(NoRecs)

' Retrieve the Record Structure Info for each record, place in array
  firstRec = 0
  testValue = LOF(fhandle)  ' This will hold the address of the first record
  SEEK # fhandle, dataOffset
  REDIM recInfo(1:noRecs)
  FOR ndx = 1 TO noRecs
    GET # fhandle, , recInfo(ndx)
    CALL SwapDword(recInfo(ndx).RecordOffset)
    IF recInfo(ndx).RecordOffset < testValue THEN
      firstRec = ndx
      testValue = recInfo(ndx).RecordOffset
    END IF
  NEXT ndx

' If there is field Information, then recover it.
  fieldOffset = header.AppInfoOffset
  CALL SwapDword(fieldOffset)
  IF fieldOffset > 0 THEN
    sortOffset = header.SortInfoOffset
    CALL SwapDword(sortOffset)
    IF SortOffset > 0 THEN
      bufferLen = sortOffset - fieldOffset
    ELSE
      bufferLen = testValue - fieldOffset
    END IF
    SEEK fhandle, fieldOffset
    GET$ # fhandle, bufferLen, buffer
' Number of Fields: 2nd dWord
    noFields = CVDWD(MID$(buffer, 5, 2))
    CALL SwapWord(noFields)
    DIM fieldNames(1:noFields) AS STRING
    fldPtr = 9
    FOR ndx = 1 TO noFields
      fieldNames(ndx) = TRIM$(MID$(buffer, fldPtr, 32), ANY CHR$(0,32) )
      IF ndx < noFields THEN
        fldPtr = INSTR(fldPtr+32, buffer, CHR$(&h20,0,&h50) ) + 5
      END IF
    tString =  MID$(buffer, fldPtr+3)
    NEXT ndx

    tString = "No. Fields: " + FORMAT$(noFields)
    FOR ndx = 1 TO noFields
      tString = tString + CHR$(13) + fieldNames(ndx)
    NEXT tString
    MSGBOX tString
  END IF

'Retrieve Record ID of record 3:
  recNo = 3
  testValue = CVDWD(CHR$(0) + recInfo(recNo).ID)
  CALL SwapDword(testValue)
' find the offset of the next record in the file.
' If this is the last record, then set the offset to read to the end of the file.
  nextOffset = LOF(fhandle) + 1
  FOR ndx = 1 TO noRecs
    IF recNo <> ndx AND recInfo(ndx).RecordOffset > recInfo(recNo).RecordOffset THEN
      nextOffset = MIN&(nextOffset, recInfo(ndx).RecordOffset )
    END IF
  NEXT ndx
' Place file file pointer
  SEEK fhandle, recInfo(recNo).RecordOffset
' Read the data into a record string
  GET$ # fhandle, nextOffset - recInfo(recNo).RecordOffset, record

' display Record 3
  tString = "Record 3: " + CHR$(13) + "Test ID: " + FORMAT$(testValue)
  fldPtr = 1
  FOR ndx = 1 TO noFields
    testValue = INSTR(fldPtr, record, CHR$(0))
    tString = tString + CHR$(13) + fieldNames(ndx) + ":  " + MID$(record, fldPtr, testValue - fldPtr)
    fldPtr = testValue + 1
  NEXT ndx
  MSGBOX tString

  CLOSE # fhandle

END FUNCTION
'###########################################
SUB SwapWord(inWord AS WORD)
  DIM tempWord  AS WordStruc

  LSET tempWord = MKWRD$(inWord)
  SWAP tempWord.byte0, tempWord.byte1
  inWord = CVWRD(tempWord)
END SUB
'###########################################
SUB SwapDword(inDword AS DWORD)
  DIM tempdWord AS dWordStruc

  LSET tempdWord = MKDWD$(inDword)
  SWAP tempdWord.word0.byte0, tempdWord.word0.byte1
  SWAP tempdWord.word1.byte0, tempdWord.word1.byte1
  SWAP tempdWord.word0, tempdWord.word1
  inDword = CVDWD(tempdWord)
END SUB
'################################################################
FUNCTION SecondsToTime(BYVAL inSeconds AS DWORD) AS STRING
' Converts Seconds into 24 hour format
  LOCAL hours   AS DWORD, _
        minutes AS DWORD, _
        seconds AS DWORD, _
        tString AS STRING, _
        temp    AS STRING

  seconds = inSeconds
  minutes = inSeconds\60
  seconds = inSeconds MOD 60
  hours = minutes\60
  minutes = hours * 60 - minutes
  temp = SPACE$(2)
  RSET temp = FORMAT$(hours)
  tString = temp + ":"
  RSET temp = FORMAT$(minutes)
  tString = tString + temp + ":"
  RSET temp = FORMAT$(seconds)
  tString = tString + temp
  FUNCTION = tString

END FUNCTION
'###########################################
FUNCTION DateToJulian(inDate AS STRING) AS DWORD
' Originally by Egbert Zijlema
' Returns Julian Date (DWORD) from "String" Date formatted as: MM/DD/YYYY.
  LOCAL year         AS DWORD, _
        month        AS DWORD, _
        day          AS DWORD, _
        Elapsed      AS DWORD, _
        InvalidLeaps AS DWORD, _
        ValidLeaps   AS DWORD, _
        dMonths      AS DWORD

  month = VAL(LEFT$(inDate,2))
  day   = VAL(MID$(inDate,4,2))
  year  = VAL(MID$(inDate,7,4))

  IF month < 3 THEN                      ' January or February?
    month = month + 12                   ' 13th or 14th month ....
    DECR year                            ' .... of prev. year
  END IF

  Elapsed = INT((year + 4712) * 365.25)  ' days in years elapsed
  InvalidLeaps = year \ 100              ' substract century leapdays
  ValidLeaps = year \ 400                ' re-add valid ones
  dMonths = INT(30.6 * (month - 1) + .2) ' days of months elapsed + adjustment
  FUNCTION = Elapsed - InvalidLeaps + ValidLeaps + dMonths + day

END FUNCTION
'###########################################
FUNCTION JulToDate(BYVAL Jul AS DWORD) AS STRING
' Originally by Egbert Zijlema
' Returns "String" Date formatted as: MM/DD/YYYY from Julian Date (DWORD)

  LOCAL help  AS DWORD, _
        Year  AS DWORD,_
        Month AS DWORD,_
        Day   AS DWORD,_
        oText AS STRING * 10

  Jul   = Jul + 68569
  help  = 4 * Jul \ 146097
  Jul   = Jul - ((146097 * help + 3) \ 4)
  Year  = 4000 * (Jul + 1) \ 1461001
  Jul   = Jul - (1461 * Year \ 4) + 31
  Month = 80 * Jul \ 2447
  Day   = Jul - (2447 * Month \ 80)
  Month = Month + 2 - (12 * (Month \ 11))
  Year  = 100 * (help - 49) + Year + (Month \ 11)

  oText = RIGHT$(STR$(Month),2) + "/" _
          + RIGHT$(STR$(Day),2) + "/" _
          + RIGHT$(STR$(Year),4) + "/"
  REPLACE " " WITH "0" IN oText
  FUNCTION = oText
END FUNCTION
'###########################################

regards,

[This message has been edited by Ian Cairns (edited July 10, 2001).]

**Ariel Benzakein** · 11 Jul 2001, 06:34 PM

THANK YOU IAN!!!!

That works beautifully...!

Ariel

------------------

**Ian Cairns** · 11 Jul 2001, 11:03 PM

You are welcome. This is some of what I have to do much of the time.

regards,

------------------
[email protected]

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