Locking a terminal

[Richard Steinberger]

Someone posted a C program to lock a TTY.  Here is a shell script that 
does the same thing.

I got much of this from a popular Unix book, Sobell's Practical Guide
to the Unix System.  (Don't leave home without it.  The 2nd edition
has this script on p 261, but fails to trap ^Z!).

Note that the trap and stty commands are used to lock out ^C and ^Z.

regards,

	ric steinberger


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#!/bin/sh

# Lock a TTY

trap '' 1 2 3 15
stty -echo susp ''
echo -n "Password: "
read pw_1
echo
echo -n "Again: "
read pw_2
echo
pw_3=				#set to null string
if [ "$pw_1" = "$pw_2" ]
	then
		until [ "$pw_3" = "$pw_2" ]
		do
			echo -n "Lock Password: "
			read pw_3
			echo
		done
	else
		echo "Lock passwords do not match."
fi
stty echo susp '^Z'