freebsd man page for lock

LOCK(1) 						    BSD General Commands Manual 						   LOCK(1)

NAME
     lock -- reserve a terminal

SYNOPSIS
     lock [-npv] [-t timeout]

DESCRIPTION
     The lock utility 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 someone with the appropriate permission.

     The following options are available:

     -n      Do not use a timeout value.  Terminal will be locked forever.

     -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 minutes.

     -v      Disable switching virtual terminals while this terminal is locked.  This option is implemented in a way similar to the -S option of
	     vidcontrol(1), and thus has the same restrictions.  It is only available if the terminal in question is a syscons(4) or vt(4) virtual
	     terminal.

SEE ALSO
     vidcontrol(1), syscons(4), vt(4)

HISTORY
     The lock command appeared in 3.0BSD.

BSD
								   July 10, 2002							       BSD