Analysing random files

[Anton Lasich]

Hello

Logically one should be able to determine a pattern in a random
access file to grab the data in it. Is there an easy way or has
someone written an algo for this?

Problem is a client has an old database stored in a random
file. It is peculiar and no-one knows the record structure...

Thanks
Anton


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[Michael Mattias]

Um, no, at least I've never heard of an algorithm, especially in a PC environment, where random files are nothing more than a stream of bytes.

One thing I've done is to write a program to try different values as the record length, then look at the data and see if it makes sense:

 FOR RecLen=1 to 100
   OPEN "Mystery" FOR RANDOM AS #1 LEN=RecLen
   FIELD #1, RecLen AS X$
   NumRecs = LOF(1) \ RecLen
   FOR J = 1 TO NumRecs
    GET #1,J, X$
    PRINT X$
    IF J MOD 10 = 0 THEN
     K$ = INPUT$(1)  ' pause the screen each ten records 
    END IF
   NEXT J
   CLOSE #1
 NEXT RecLen

Hopefully, you'll see a pattern at some value of RecLen.

Happy hunting.

MCM

[Paul Squires]

Anton,

We have two programs at work that have this functionality
built in. One is called WinIdea (made by CaseWare) and the
other is ACL (Audit Command Language). They both have an
"analyze" feature that allows you to figure out the record
structure.



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Paul Squires
[email protected]

[Lance Edmonds]

Paul, that sounds interesting! Do you have a URL or contact detail for those programs?

Thanks!


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