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VLOCK(1)		       Linux User's Manual			VLOCK(1)

NAME
     vlock - Virtual Console lock program

SYNOPSIS
     vlock [ -hv ]

     vlock [ -acns ] [ -t <timeout> ] [ plugins... ]

DESCRIPTION
     vlock is a program to lock one or more sessions on the Linux console.  This
     is  especially useful for Linux machines which have multiple users with ac-
     cess to the console.  One user may lock his or her session(s)  while  still
     allowing  other  users to use the system on other virtual consoles.  If de-
     sired, the entire console may be locked and virtual console switching  dis-
     abled.

     By  default,  only  the  current  VC (virtual console) is locked.	With the
     -a,--all option all VCs are locked.  The  locked  VCs  cannot  be	unlocked
     without  the  invoker's  password	or the root password.  The root password
     will always be able to unlock any or all sessions, unless disabled at  com-
     pile time.

     Please note that it is entirely possible to completely lock yourself out of
     the  console with the -a,--all option if you cannot remember your password!
     Unless you are able to kill vlock by logging in remotely via a serial  ter-
     minal or network, a hard reset is the only method of ``unlocking'' the dis-
     play.

     When  locking  the entire console display it is sometimes still possible to
     kill vlock using the Secure Access Key (SAK) or  other  commands  that  are
     available	through  the  SysRq  mechanism.  When the -s,--disable-sysrq and
     -a,--all options are given the SysRq mechanism is disabled while  vlock  is
     running.  See /usr/src/linux/Documentation/sysrq.txt for more details.

     vlock  works  for	console  sessions primarily.  To lock the entire console
     display from an X session use the -n,--new option.  This  will  make  vlock
     switch to an empty virtual console to lock the display.

     The  options  -n,--new,  -s,--disable-sysrq,  and -t,--timeout only work if
     vlock is compiled with plugin support.  See the PLUGINS  section  for  more
     information.

OPTIONS
     -a,--all

	    Lock all console sessions and disable VC switching.

     -c,--current

	    Lock the current session (this is the default).

     -n,--new

	    Switch to a new virtual console before locking all console sessions.

     -s,--disable-sysrq

	    Disable  the SysRq mechanism while consoles are locked.  This option
	    only works if the -a,--all option given.

     -t,--timeout <seconds>

	    Specify the timeout for the screensaver  plugins.	See  vlock-plug-
	    ins(5) for more information.

     -h,--help

	    Print a brief help message.

     -v,--version

	    Print the version number.

ENVIRONMENT VARIABLES
     The following environment variables can be used to change vlock's behavior:

     USER

	    If	this  variable	is when vlock is run as root (uid 0) vlock locks
	    the screen as this user instead of root.   The  root  password  will
	    still  be  able  to  unlock  the session, unless disabled at compile
	    time.

     VLOCK_ALL_MESSAGE

	    If this variable is set and all consoles  are  locked  its	contents
	    will be used as the locking message instead of the default message.

     VLOCK_CURRENT_MESSAGE

	    If	this variable is set and only the current consoles is locked its
	    contents will be used as the locking message instead of the  default
	    message.

     VLOCK_MESSAGE

	    If	this  variable	is  set its contents will be used as the locking
	    message instead of the default.  This overrides the former two vari-
	    ables.

     VLOCK_PLUGINS

	    If this variable is set it is interpreted as a space separated  list
	    of plugins that will be loaded when vlock starts additionally to the
	    ones listed on the command line.

     VLOCK_TIMEOUT

	    Set  this  variable  to specify the timeout (in seconds) after which
	    the screen saver plugins (if any) will be invoked.	If this variable
	    is unset or set to an invalid value or 0 no timeout  is  used.   See
	    vlock-plugins(5) for more information about plugins.

     VLOCK_PROMPT_TIMEOUT

	    Set  this  variable  to  specify the amount of time (in seconds) you
	    will have to enter your password at the password  prompt.	If  this
	    variable  is  unset  or  set  to an invalid value or 0 no timeout is
	    used.  Warning: If this value is too low, you may not be able to un-
	    lock your session.

FILES
     ~/.vlockrc

	    This file is read by vlock on startup if it exists.  All  the  vari-
	    ables mentioned above can be set here.

SECURITY
     See the SECURITY file in the vlock distribution for more information.

SEE ALSO
     vlock-main(8), vlock-plugins(5)

AUTHORS
     Michael K. Johnson <http://danlj.org/mkj/>

     Frank Benkstein <frank-vlock@benkstein.net>

Linux				  28 July 2007				VLOCK(1)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=vlock&sektion=1&manpath=FreeBSD+Ports+15.1.quarterly>

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