slackbuilds/system/vlock

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.

There's also a screensaver, based on libcaca.

vlock has two particular options that this SlackBuild reserves to the
wheel group:

  -n,--new

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

and
  -s,--disable-sysrq

              Disable the SysRq mechanism (enabled by stock Slackware
        kernels) while consoles are locked. This option only works if
        the -a, --all option given.

If you would like to set an alternative group, you may pass the
VLOCK_GROUP variable to the SlackBuild like this:

VLOCK_GROUP=users ./vlock.SlackBuild