Re: finding a suitable key

Reading the responses I figured out that I really was not making myself
clear the first time. I'll try again, if I may. Let's say we have an
externally described file. The DDS specification looks approximately
like this:
A       R FIL_REC
          FIL_KEY       4S      TEXT('unique primary key')
          FIL_DTA      80A      TEXT('the data')        
        K FIL_KEY

We do have some records already there:
FIL_KEY FIL_DTA
------- -------------------------------
 1      'one'
 4      'record FOOBAR'
 0      'null record'
 99     'some record'
 2      'BAR'

Now, let's suppose we need to insert a record... We want to find a
unused primary key for it. What I do now is approximately:

FFil    UF A E       K DISK
DKey      S                4S 0
C               DoW     *In40 = *Off
C               Add     1               Key
C       Key     Chain   Fil_Rec                         40
C               EndDo
C               Move    Key             Fil_Key
C               Move    Data            Fil_Dta
C               Write   Fil_Rec

This kinda gets the job done and we happily add a record with key '3'
(we skipped the '1' and '2' here) there. I don't really like this code,
because it takes a few lines to write and has to chain through the whole
file to find the next unused key. It doesn't recognize keys of 0. And it
changes the buffers (whatever was in Fil_Dta is modified). I was just
wondering if this could be written easier/better/smarter? Any ideas?

                        Kind regards, Juris.
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