#!/bin/sh
set -x  # Used for debugging
IDLE_TIME=$((60*1000)) #a minute in milliseconds

screen_saver(){
# My screensaver function
    cmatrix -abs
}

sleep_time=$IDLE_TIME
triggered=false

while sleep $(((sleep_time+999)/1000)); do
    idle=$(xprintidle)
    if [ $idle -ge $IDLE_TIME ]; then
        if ! $triggered; then
            screen_saver
            triggered=true
            sleep_time=$IDLE_TIME
        fi
    else
        triggered=false
        sleep_time=$((IDLE_TIME -idle+100))
    fi
done

./screensaver.sh

screen_saver(){
     cmatrix -abs && fg
}