This is what I do on 5.0/i386.
I have this line in /etc/ttys:
ttyC5 "/bin/Lock" vt220 on secure
To lock the computer I run this executable /bin/Lock:
#!/bin/sh
pass=sparken
exe=/bin/Lock
fifo=/var/Lock
case "$1" in
ttyC*) t=/dev/$1
tty=$t exec $exe exe < $t > $t 2> $t ;;
exe) ;;
*) echo > $fifo
exit ;;
esac
mknod -m 0666 $fifo p
for i in eof intr kill quit susp start stop \
dsusp lnext reprint status; do
stty $i undef
done
stty -echo
while :; do
jot 200
echo -n computing
cat < $fifo > /dev/null
focus=$(wsconsctl display.focus)
t=${tty#/dev/ttyC}
wsconsctl display.focus=$t > /dev/null
map=$(wsconsctl keyboard.map | grep Cmd_)
map2=$(echo "$map" | sed 's/=.*/= x/')
wsconsctl keyboard.map+="$map2"
while :; do
read -r r
[ _"$r" = _"$pass" ] && break
echo -n .
done
wsconsctl keyboard.map+="$map"
wsconsctl $focus > /dev/null
done
