File open'ness

Is there a way to know if a File is already opened (by any process, be it the actual process or other processes) on OS X? Does OS X actually give this possibility?

i have to say i was wondering about file locking on osx, this is what i found:

i don’t know if this is implemented in File.

from what i see here to check if a file is already opened, kust try to open it in exclusive mode, and it will propably fail with an error, and you will know.

I already read that Technote. What they are describing there is a cooperative locking mechanism that only works for the applications that participate, called “advisory locking”.

On OS X, there is no way to “definitively” lock a file like on windows, where your application can be the only one still being able to access the file.

I think it is also not possible to find out if the file is open by another process or not.

it has to be possible since osx has lsof

and underneath all that gui stuff os osx is the bsd kernel.