source: projects/initscripts/tags/initscripts-8.91.3/rc.d/init.d/random @ 1108

#!/bin/bash
#
# random        Script to snapshot random state and reload it at boot time.
#
# Author:       Theodore Ts'o <tytso@mit.edu>
#
# chkconfig: 2345 20 80
# description: Saves and restores system entropy pool for higher quality \
#              random number generation.

# Source function library.
. /etc/init.d/functions

random_seed=/var/lib/random-seed

# See how we were called.
case "$1" in
  start)
        # Carry a random seed from start-up to start-up
        # Load and then save 512 bytes, which is the size of the entropy pool
        if [ -f $random_seed ]; then
                cat $random_seed >/dev/urandom
        else
                touch $random_seed
        fi
        action $"Initializing random number generator: " /bin/true
        chmod 600 $random_seed
        dd if=/dev/urandom of=$random_seed count=1 bs=512 2>/dev/null
        touch /var/lock/subsys/random

        ;;
  stop)
        # Carry a random seed from shut-down to start-up
        # Save 512 bytes, which is the size of the entropy pool
        touch $random_seed
        chmod 600 $random_seed
        action $"Saving random seed: " dd if=/dev/urandom of=$random_seed count=1 bs=512 2>/dev/null
        
        rm -f /var/lock/subsys/random
        ;;
  status)
        # this is way overkill, but at least we have some status output...
        if [ -c /dev/random ] ; then
                echo $"The random data source exists"
        else
                echo $"The random data source is missing"
        fi
        ;;
  restart|reload)
        # do not do anything; this is unreasonable
        :
        ;;
  *)
        # do not advertise unreasonable commands that there is no reason
        # to use with this device
        echo $"Usage: $0 {start|stop|status|restart|reload}"
        exit 1
esac

exit 0