File::NFSLock - perl module to do NFS (or not) locking

Program based of concept of hard linking of files being atomic
across NFS. This concept was mentioned in Mail::Box::Locker (which
was originally presented in Mail::Folder::Maildir). Some routine
flow is taken from there -- particularly the idea of creating a
random local file, hard linking a common file to the local file,
and then checking the nlink status. Some ideologies were not complete
(uncache mechanism, shared locking) and some coding was even
incorrect (wrong stat index). File::NFSLock was written to be light,
generic, and fast.