Thread: Pico vs Vi(m) read lock question

The following places a read lock over cf.buffer

Code:

% lockf "/home/nh/cf.buffer" sleep 10000 &

Now here' s what I'm mystified by. I run this and then i fire up the Vi(m) editor. The editor warns me that the file is read only and then refuses to let me modify the file. But when I dot he same thing with Pico, I get no warning and the Pico editor will not only let me write to cf.buffer but also save the changes.

Why is this?

lockf places an advisory (or voluntary) lock, not a mandatory one. This means that applications that aren't aware of this form of locking (as pico apparently is) simply ignore it.