F_GETLK Working?

[Jeff Epler]

Because strings are immutable, this line
    rv = fcntl.fcntl(lock_file, fcntl.F_GETLK, flk)
can't modify the value of flk.  Instead, the value you want is returned
in rv.  Try changing the last 2 lines to
    locked = struct.unpack('hhllhl', rv)[0]
    print locked
on my system, this prints 2, which is the value of F_UNLCK.

Jeff