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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  access  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  desired,	 the  entire console may be locked and virtual
       console switching disabled.

       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
       compile 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	terminal or network, a hard reset is the only method of	 ``un-
       locking'' the display.

       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 ses-
	      sions.

       -s,--disable-sysrq

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

       -t,--timeout <seconds>

	      Specify the timeout for the screensaver plugins.	See vlock-plu-
	      gins(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  be-
       havior:

       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	 pass-
	      word  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  mes-
	      sage.

       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
	      variables.

       VLOCK_PLUGINS

	      If this variable is set it is interpreted	as a  space  separated
	      list  of plugins that will be loaded when	vlock starts addition-
	      ally 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	 time-
	      out  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 time-
	      out is used.  Warning: If	this value is too low, you may not  be
	      able to unlock your session.

FILES
       ~/.vlockrc

	      This  file  is  read  by vlock on	startup	if it exists.  All the
	      variables	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+15.0>

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