How to find ESSID & signal strength

How to find ESSID & signal strength

[Kai Hendry]

Since there is no "Contact us" details upon:
http://wireless.kernel.org/en/users/Documentation/iw

I'm nervously emailing the mailing list. :}



I want to please ask what is the "canonical" way using your suite of
tools like `iw`, or preferably /proc, to find the ESSID of the AP I'm
connected to and signal strength for my dwm status bar?

https://github.com/kaihendry/Kai-s--HOME/blob/master/bin/dwm_status#L23


Many thanks,

Re: How to find ESSID & signal strength

[Schrober]

On Tuesday 23 April 2013 10:54:59 Kai Hendry wrote:
> Since there is no "Contact us" details upon:
> http://wireless.kernel.org/en/users/Documentation/iw
> 
> I'm nervously emailing the mailing list. :}
> 
> 
> 
> I want to please ask what is the "canonical" way using your suite of
> tools like `iw`, or preferably /proc, to find the ESSID of the AP I'm
> connected to and signal strength for my dwm status bar?
> 
> https://github.com/kaihendry/Kai-s--HOME/blob/master/bin/dwm_status#L23

"Do NOT screenscrape this tool, we don't consider its output stable."

Use nl80211
-- 
Franz Schrober

Re: How to find ESSID & signal strength

[Kai Hendry]

Hi there Schrober,

On 23 April 2013 11:00, Schrober <franzschrober@yahoo.de> wrote:
> "Do NOT screenscrape this tool, we don't consider its output stable."
> Use nl80211

Could you give me a code sample how you would use this "nl80211"
thing, from shell?


Oh while I'm here. Is there no traditional /proc like interface
proposal for wireless information? If not, why not?

Many thanks,

Re: How to find ESSID & signal strength

[Arend van Spriel]

On 04/23/2013 12:14 PM, Kai Hendry wrote:
> Hi there Schrober,
>
> On 23 April 2013 11:00, Schrober <franzschrober@yahoo.de> wrote:
>> "Do NOT screenscrape this tool, we don't consider its output stable."
>> Use nl80211
>
> Could you give me a code sample how you would use this "nl80211"
> thing, from shell?

this popped up earlier. Using shell scripts is a bad idea.  However, 
libnl does provide python bindings. nl80211 is a netlink interface to 
the linux wireless kernel module.

>
> Oh while I'm here. Is there no traditional /proc like interface
> proposal for wireless information? If not, why not?

Because nl80211 is there to provide all the info.

If you do not mind reworking your shell script and want to stick to it 
than the answer is:

$ iw wlanX link

wlanX should be your wireless network interface.

Regards,
Arend

Re: How to find ESSID & signal strength

[Kai Hendry]

On 23 April 2013 12:10, Arend van Spriel <arend@broadcom.com> wrote:
> this popped up earlier. Using shell scripts is a bad idea.  However, libnl
> does provide python bindings. nl80211 is a netlink interface to the linux
> wireless kernel module.

Whoa, isn't progress amazing? Gone are the days of simple file based
interfaces. Now we need libraries and python bindings ! :)

>> Oh while I'm here. Is there no traditional /proc like interface
>> proposal for wireless information? If not, why not?
> Because nl80211 is there to provide all the info.

Well that interface seems to suck. Sorry.

> If you do not mind reworking your shell script and want to stick to it than
> the answer is:
> $ iw wlanX link
> wlanX should be your wireless network interface.

I don't mind reworking my one line of shell, thanks. :-)

Now I wonder how I translate 'signal: -33 dBm' into the typical 5 bars
of wireless signal strength. Any tips?

Kind regards,

Re: How to find ESSID & signal strength

[Kalle Valo]

"Arend van Spriel" <arend@broadcom.com> writes:

> On 04/23/2013 12:14 PM, Kai Hendry wrote:
>> Hi there Schrober,
>>
>> On 23 April 2013 11:00, Schrober <franzschrober@yahoo.de> wrote:
>>> "Do NOT screenscrape this tool, we don't consider its output stable."
>>> Use nl80211
>>
>> Could you give me a code sample how you would use this "nl80211"
>> thing, from shell?
>
> this popped up earlier. Using shell scripts is a bad idea.  However,
> libnl does provide python bindings. nl80211 is a netlink interface to
> the linux wireless kernel module.

I think someone should fork iw which would only provide tabular output
for shell scripts. Shouldn't be too hard, the most difficult part is to
make sure that the output format is extensible when adding new features.

-- 
Kalle Valo

Re: How to find ESSID & signal strength

[Johannes Berg]

On Wed, 2013-04-24 at 13:21 +0300, Kalle Valo wrote:

> I think someone should fork iw which would only provide tabular output
> for shell scripts. Shouldn't be too hard, the most difficult part is to
> make sure that the output format is extensible when adding new features.

You don't even need to fork, just send me patches :-)

Something like a --batch or --script option (to iw) would probably do
it. We'd have to teach each command to be able to do it though, so we'd
want to have some registration about whether a command is already
converted and disallow the other ones, I guess.

johannes