I believe that you will end up overwriting the next record, not appending. So if you start with a file 

afoo
bfoo
cfoo
dfoo

[download]
you should end up with 
afoo
abar
cfoo
cbar

[download]

(untested)

--MidLifeXis

In reply to Re^2: Using read/write to update a file by MidLifeXis
in thread Using read/write to update a file by PackerX

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