RHEL4.4

is_available ()
{
    LC_ALL= LANG= ip -o link | grep -q $1
    [ "$?" = "1" ] || return 0

    alias=`modprobe -c | awk "/^(alias|install)[[:space:]]+$1[[:space:]]/ { print \\$3 }"`
    if [ -z "$alias" -o "$alias" = "off" -o "$alias" = "/bin/true" ]; then
        return 2
    fi
    HOTPLUG=`cat /proc/sys/kernel/hotplug`
    echo "/etc/hotplug/firmware.agent" > /proc/sys/kernel/hotplug
    modprobe $1 > /dev/null 2>&1 || {
      echo "$HOTPLUG" > /proc/sys/kernel/hotplug
      return 1
    }
    echo "$HOTPLUG"  > /proc/sys/kernel/hotplug
    # if it is a mainframe ccwgroup device, configure it before
    # trying to rename it:
    configure_ccwgroup_device
    if [ -n "$HWADDR" ]; then
       local curdev=`ip -o link | awk -F ':' -vIGNORECASE=1 "/$HWADDR/ { print \\$2 }"`
       if [ -z "$curdev" ]; then
          return 1
       fi
       rename_device "$1" "$HWADDR" "$curdev"
    fi
    LC_ALL= LANG= ip -o link | grep -q $1
    return $?
}