Provided by: vlock_2.2.2-3_i386 bug

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
       ‘‘unlocking’’ 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
              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-
              plugins(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
              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
              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 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>