Another one where I post a partial answer to my own question. The problem seems to be that I have made an assumption about how filehandles behave. The code for Copy will open and close the file if given a filename but not if given a filehandle. This makes sense. What surprised me was that closing the file would release the lock. I was thinking that if I had obtained the lock by using filehandle XX then I would have to close it through XX to release the lock. I didn't do an explicit close and was expecting the lock to exist until the end of the script

In summary the sequence of events is:

opened as XX # by me
locked as XX # by me
opened as YY # by copy
closed as YY # by copy and the lock is released

Copy says "Note that passing in files as handles instead of names may lead to loss of information on some operating systems; it is recommended that you use file names whenever possible." - which is how I got into this mess in the first place

In reply to Re: flock question by Odud
in thread flock question by Odud

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