Description:

The LockDev methods act on device locks normally located in /var/lock.
The lock is acquired creating a pair of files hardlinked between them
and named after the device name (as mandated by FSSTND) and the
device's major and minor numbers (as in SVr4 locks). This permits to
circumvent a problem using only the FSSTND lock method when the same
device exists under different names (for convenience or when a device
must be accessable by more than one group of users).

The lock file names are typically in the form LCK..ttyS1 and
LCK.004.065, and their content is the pid of the process who owns the
lock.