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.\"	@(#)lock.1	8.1 (Berkeley) 6/6/93
.\"
.Dd $Mdocdate: July 24 2019 $
.Dt LOCK 1
.Os
.Sh NAME
.Nm lock
.Nd reserve a terminal
.Sh SYNOPSIS
.Nm lock
.Op Fl np
.Op Fl a Ar style
.Op Fl t Ar timeout
.Sh DESCRIPTION
.Nm
requests a password from the user, reads it again for verification
and then will normally not relinquish the terminal until the password is
repeated.
.Pp
The options are as follows:
.Bl -tag -width Ds
.It Fl a Ar style
The specified
.Bx
Authentication login
.Ar style
(as specified in
.Pa /etc/login.conf )
will be used to authenticate the user.
If the particular
.Ar style
requires a challenge/response handshake or a special prompt, the
user may enter the name of the
.Ar style
to get the standard prompt for that
.Ar style .
.It Fl n
Lock the terminal forever.
This overrides
.Fl t
and is the default on
.Ox
unless
.Fl t
is specified.
.It Fl p
A password is not requested, instead the user's current login password
is used.
If the user has an S/Key key, they may also use it to unlock the terminal.
To do this the user should enter
.Qq s/key
at the unlock
.Dq Key:
prompt.
The user will then be issued an S/Key
challenge to which they may respond with a six-word S/Key one-time
password.
.It Fl t Ar timeout
Unlock the terminal after
.Ar timeout
minutes unless
.Fl n
is also specified.
When used in this manner
.Nm
should be invoked so that the user is safely logged out
if the timeout elapses:
.Pp
.Dl $ lock -t 15 || exit
.El
.Sh SEE ALSO
.Xr skey 1 ,
.Xr login.conf 5
.Sh HISTORY
The
.Nm
command first appeared in
.Bx 2 .
.Sh AUTHORS
.An Kurt Shoens .