Shell Programming and Scripting

#!/bin/ksh
#scriptname:locktty
#writed by :javalee
#email:javalee@tom.com
#homepage:www.linuxsir.org
#script start...
reset;clear    
info="System will be locked!!! Press Waitting....."
print "\n\n\n\n\n\n\n"
for i in 9 8 7 6 5 4 3 2 1 0;do
	print -n "                \a$info$i\r"
	sleep 1
done
clear
trapper () {     
trap ' ' 2 3 20  
}
while :  ;do
	trapper  
	print "\n\n\n\n\n\n\n\n\t\t\tPlease enter unlock code:"
	stty -echo      
	read input
	case $input in
		123)	print "\t\t     Hello $USER,Today is $(date +%T)\n"
		stty echo       
		break ;;         
		*)
		clear
		continue ;;     
	esac
done
#script over