Stefan Monnier wrote:
> When I'm AC-plugged, I like my /etc/init.d/network script to start my wifi
> card automatically. But when I'm on battery, I'd rather not start it
> automatically (I can always start it manually if I really want it).
>
> Does anybody have an idea how to do that?
> Can the `auto' lines in /etc/network/interfaces be parameterized by a little
> script that says whether or not to auto-config the interface at boot?
>
I do something like this. The problem I wanted to solve was that I
didn't want the wireless interface to be activated when the wired
interface was already up. I added a pre-up line in my interfaces file.
Here's the section that defines my wireless card:
iface eth-wlan inet dhcp
pre-up [ -z "$(ifconfig eth-lan | grep 'inet addr:')" ] && true
pre-up /sbin/iwconfig eth-wlan essid <ESSID snipped>
pre-up /sbin/iwconfig eth-wlan enc on
pre-up /sbin/iwconfig eth-wlan key <MY KEY snipped>
My wired interface is named "eth-lan" and the wireless "eth-wlan", BTW.
So that first line checks to see if eth-lan has an IP address or not.
If it does not have an IP, then the line returns true and the interface
is allowed to come up. If eth-lan does have an IP, it will return false
and the eth-wlan interface will fail when attempting to come up.
Honestly, I'm not 100% sure why I have the "&& true" bit on there. It
might not be necessary.
Anyway, if you can provide a set of commands (or a script) that can
detect when you're AC plugged, you should be able to do something similar.
Thanks,
Rick Reynolds