Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!yale!cmcl2!husc6!unix!ace!ric
From: ric@ace.sri.com (Richard Steinberger)
Newsgroups: comp.lang.c
Subject: Locking a terminal
Summary: Shell script to lock a term
Keywords: lock, tty
Message-ID: <ric.652635631@ace>
Date: 6 Sep 90 15:40:31 GMT
Sender: news@unix.SRI.COM
Lines: 41

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


------------------------------cut here--------------------------------

#!/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'