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From: ericp@beach.csulb.edu (Eric Pederson  CSE)
Newsgroups: comp.databases
Subject: Re: So does Clipper do it ?
Message-ID: <1991May23.182713.5914@beach.csulb.edu>
Date: 23 May 91 18:27:13 GMT
References: <77135@eerie.acsu.Buffalo.EDU> <24910@well.sf.ca.us> <29638@hydra.gatech.EDU>
Organization: Cal State Long Beach
Lines: 28

In article <29638@hydra.gatech.EDU> jgb@prism.gatech.EDU (James G. Baker) writes:
>In article <24910@well.sf.ca.us> kms@well.sf.ca.us (Kelly Stanonik) writes:
>>Well, first of all, what version of Clipper are you trying to use?  Second
>>of all you can index on a function to display the update bar.  I personally
>>shy away from this approach since it places garbage in your index key, but
>>it will work. 
>
>Very true.  BUT, you can use low-level file calls to change to index
>expression in the .NTX file.  fopen, fread, fwrite.  I have an index routine
>that does an INDEX ON expression+stat_bar() TO index_file and then calls
>a function to clean up the index_file.  (Places a null right after it finds
>"expression".  Might seem a bit dangerous, but it works.  Of course your
>stat_bar() needs to handle what ever type expression is and return 0 or ""
>appropriately after to displays the status bar.

If you use INDEX ON stat_bar(expression) and

FUNCTION stat_bar
PARAMETERS X

... stat bar code ...

RETURN X

You don't have to worry about the type of expression.

Eric Pederson - CSULB
ericp@beach.csulb.edu