# Script to enforce a 10 minute break every half hour from typing - 
# Written for someone (Uwe Hollerbach) with Carpal Tunnel Syndrome.

# If you type for more than 20 minutes straight, the script rings
# the bell after every character until you take a 10 minute break.

# Author: Don Libes, NIST
# Date: Feb 26, '95

spawn $env(SHELL)
set start [clock seconds]	;# when we started our current typing period
set stop [clock seconds]	;# when we stopped typing

set typing 1200		;# twenty minutes, max typing time allowed
set notyping 600	;# ten minutes, min notyping time required

interact -nobuffer -re . {
    set now [clock seconds]

    if {$now-$stop > $notyping} {
	set start [clock seconds]
    } elseif {$now-$start > $typing} {
	send_user "\007"
    }
    set stop [clock seconds]
}