Le Wake On Lan sous Linux

#!/bin/sh
# /// revision-script 1.0 \\\
# Author : Clément ROGER
# Author : Be4free.com
# Author : <clement.be4free AT gmail DOT com>
# Licence : Under GPL
# If you modify this script or if you want to add functions please email 
# your version to clement.be4free AT gmail DOT com

function wol_install {
        if [ ! -d "/var/lib/wol/" ] ; then  mkdir -p /var/lib/wol/ ; chmod 640 /var/lib/wol/ ; fi
        if [ ! -f "/var/lib/wol/discover" ] ; then  touch /var/lib/wol/discover ; chmod 640 /var/lib/wol/discover ; fi
}

function wol_list {
        mac_list=`cat /var/lib/wol/discover`
        for mac_address in $mac_list ; do
                echo $mac_address | {
                        IFS=";" read mac name
                        echo $name
                }
        done
}



function wol_discover {
        mac_list=`cat /var/log/syslog | grep dhcpd | grep DHCPREQUEST | sed 's/^.*from//' | cut -d " " -f 2,3 | sed 's/\ (/;/' | sed 's/)//' | sort | uniq`
        for mac_address in $mac_list ; do
                cat /var/lib/wol/discover | grep -x $mac_address >> /dev/null 1>&1
                if [ "$?" == 1 ] ; then
                        echo $mac_address >> /var/lib/wol/discover
                fi
        done
}

function wol_wake {
        argv=$1
        cat /var/lib/wol/discover | grep $argv | {
                IFS=";" read mac name
                ether-wake $mac
        }
}

if [ ! -d "/var/lib/wol/" ] || [ ! -f "/var/lib/wol/discover" ] || [ ! -r "/var/lib/wol/discover" ] && [ $1 != "install" ] ; then
        echo "Error : $0 db are not installed, please type '$0 install'"
        exit 1;
fi

case $1 in
        install)
                wol_install
                ;;
        list)
                wol_list
                ;;
        discover)
                wol_discover
                ;;
        wakeall)
                wol_discover
                mac_list=`cat /var/lib/wol/discover | cut -d ";" -f 1`
                for mac_address in $mac_list ; do
                        wol_wake $mac_address
                done
                ;;
        wake)
                if [ "$1" != "" ] ; then
                        cat /var/lib/wol/discover | grep $2 >> /dev/null 2>&1
                        if [ "$?" != "0" ] ; then
                                echo "undiscovered host, please try '$0 discover' first"
                                exit 1;
                        fi
                        wol_wake $2
                else
                        echo "Usage : $0 wake [HOST or MAC_ADDRESS]"
                        exit 1;
                fi
                ;;
        *)
                echo "Usage : $0 list|dicover|wakeall|wake [HOST or MAC_ADDRESS]"
                ;;
esac