What is /etc/.pwd.lock for ?

["G. Crimp" <ye416@freenet.victoria.bc.ca>]

Hi,

	I deleted /etc/.pwd.lock on a test box I play with.  It was dated 15
apr.  I thought it was just a stale lock file from the last time I created a
user.  Rebooting the same machine to an install of Red Hat, I discovered
that the same file existed in /etc of the RH system.  The time stamps on the
files correspond to the dates I installed the respective systems.

	I think now that it was not a stale file, but can't find what
purpose it serves.  Its name would suggest it has something to do with
passwords, but nonw of the man pages associated with passwd or shadow make
mention of it.  The shadow man pages speak of file locking without giving
details (ie, not specifically naming the log file).

	Does anyone know what the file is for, or failing that, where I
might look, aside from the above man pages, to learn more ?

	Thanks,

	Gerald