LOCK(1) BSD Reference Manual LOCK(1)
lock - reserve a terminal
lock [-p] [-t timeout]
Lock requests a password from the user, reads it again for verification
and then will normally not relinquish the terminal until the password is
repeated. There are two other conditions under which it will terminate:
it will timeout after some interval of time and it may be killed by some-
one with the appropriate permission.
-p A password is not requested, instead the user's current login
password is used.
-t timeout The time limit (default 15 minutes) is changed to timeout
The lock command appeared in 3.0BSD.
4.4BSD June 6, 1993 1