copy file in use

Hi All!
I have an application that continously records audio for several hours.
I want to be able to listen to recorded material but not necessarily in real time.
I have tried to just copy the file being recorded to a new file with overwrite and the copy obviously gets done (filesize changes) but when I try to listen to the copied file my player just 'blinks' and nothing more happens. If I however close the recording, the copy also gets playable. My idea is that copying a file in use just creates another file in use.
If this is the case how can I close the copied file?
If you have any other idea on how to solve this I would like to hear from you!

Gunnar

re: copy file in use

I would guess that the copy is copying junk data when you are writing to the original file.
Have you tried opening the file and being sure to set the permisisions to allow read by other opens?