source: projects/initscripts/tags/initscripts-8.91.0/sysconfig/network-scripts/net.hotplug @ 1108

#!/bin/sh

. /etc/sysconfig/network-scripts/network-functions

if [ "$INTERFACE" = "" ]; then
    exit 1
fi

case $ACTION in
add|register)
    # Don't do anything if the network is stopped
    if [ -f /dev/.in_sysinit ] ; then
        exit 0
    fi
    if [ ! -f /var/lock/subsys/network ]; then
        exit 0
    fi
    
    case $INTERFACE in
        # interfaces that are brought up as a part of configuration
        ppp*|ippp*|isdn*|plip*|lo*|irda*|dummy*|ipsec*|tun*|tap*)
            exit 0
            ;;
        # interfaces that are registered then brought up
        *)
            export IN_HOTPLUG=1
            if [ -x /sbin/ifup ]; then
                addr=$(get_hwaddr ${INTERFACE})
                if [ -n "$addr" ]; then
                        nconfig=$(get_config_by_hwaddr ${addr})
                        [ -n "$nconfig" ] && INTERFACE=$nconfig
                fi
                exec /sbin/ifup $INTERFACE
            fi  
            ;;
    esac
    ;;

remove|unregister)
    case $INTERFACE in
        # interfaces that are brought down as part of deconfiguration
        ppp*|ippp*|isdn*|plip*|lo*|irda*|dummy*|ipsec*|tun*|tap*)
            exit 0
            ;;
        *)
            export IN_HOTPLUG=1
            if [ -x /sbin/ifdown ]; then
                exec /sbin/ifdown $INTERFACE
            fi
            ;;
    esac
    ;;

*)
    exit 1 ;;

esac