compress a file

[Nancy Palmquist]

On 12/16/2014 8:19 AM, tob at b-e-s-t.com wrote:
>   
> One of my transaction files needs to be broken into 2 parts-active/inactive.
> After I write out the inactive I would like to then compress the file.
> But I want to save all the internal fp fields such as @cd, at cb,etc.
> Is there a way to do this when I do a lookup free or any other way?
> thanks
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Are you familiar with non-filepro files?

The logic to do this is to use the file like a non-filepro file. You 
will need two non-filepro files with a map that has 20 characters added 
to the front of the file.

One file will be pointing at the existing key file you want to 
compress.  One will be pointing at a new file - I might make it a key in 
the same file but with a qualifier name, like keynew.  Then it is easy 
to see if it is working correctly.

Get rid of all indexes - remember how they are built.

You will also have to be sure you copy the Zero record to the new file, 
there is one in every filepro file.

Make backups of everything before you start.

Then write a quick bit of logic (by the way you could make this do both 
things you want at the same time.  Compress and archive, just make one 
more non-filepro file.  But that can be done first to remove all the 
archive records in the normal filepro way but you will lose the 20 bytes 
of overhead data.)

Then go through the file record by record and copy record zero first to 
the new file, then copy every record that has data in the critical 
fields.  There is no kind of free chain in a non-filepro file so it can 
not tell what records are null and what are not so you have to test it 
as you go. (BTW if you are making an archive at the same time, copy the 
zero record to that file first also.)

That should do it.  BTW - do not modify any data, just copy the entire 
record to the new file.

I am sure if you understand non-filepro files this will make perfect 
sense.  Remember a non-filepro file has no overhead bytes so when you 
copy the record you get all the bytes copied not just the 21-end bytes 
like you do with a filepro file copy.

Relocate the new keys where you want them in the right filepro files.
Then run freechain on the new key files to make sure filepro understands 
it correctly.  Build indexes on the new key files.

Nancy

-- 
Nancy Palmquist
Owner
Virtual Software Systems - www.vss3.com
(412) 835-9417