"Michael Ju. Tokarev" wrote: > > Well, I see two common locking mechanisms: > > lckpwdf way is creating /etc/.pwd.lock file to lock > both passwd and shadow > > other way used in shadow-utils (if lckpwdf is not > available?) and pwdb is to create passwd.lck and > shadow.lck files With either method you're basically saying that all files that deal with modifying the passwd and shadow files need to agree to check for the existance of the lock before doing anything. Besides the fact that this approach can lead to obvious race issues, why not use POSIX 1 advisory locks (or 'discretionary file locks' as the fcntl man page calls them)? They're cross-platform and placed on the file itself so no race issues can exist as long as everybody plays ball. Since that's a requirement for both approaches I would think that this is a far better solution. Cooper -- If you can read this you're probably not dead yet. - Johnny The Homicidal Maniac 7 -
