Re: test for network connection location

[Rupert Swarbrick <rswarbrick@gmail.com>]

Alan <wehmann@fnal.gov> writes:

> I haven't been able to think of a way to put a test in my .vm file
> that would distinguish between when my laptop is connected to the
> internet while at home, versus being connected while at work.  In both
> cases I am interested in fetching mail from the IMAP server at work,
> but I'd like to configure three variables in .vm somewhat differently--
> depending on how the laptop is connected.
>
> While at home I am using wireless, via a modem with the brand name
> 2wire, with a DSL connection supplied by AT&T (formerly SBC).  At work
> I usually connect via an Ethernet cable, but would like to keep the
> option of going wireless.  I'd like to set up an environmental
> variable or some other test that could distinguish between these two
> connections, but haven't come up with anything yet.  Also, I haven't
> yet invented a good search string to use, to find an existing post
> that suggests how to create such a test.

Hi there,

You haven't said what OS you're using, but I think I might have an
idea if you're using linux (which, frankly, is all that I know
about).

Why not use a shell command? For example, this (horrible) elisp
command checks whether the ESSID of the wireless I'm connected to is
PoorStudents (the one at home!)

(defun at-home-p ()
  (string=
    (shell-command-to-string
       "/sbin/iwconfig wlan0 | grep ESSID | awk -F '\"' '{print $2}'")
    "PoorStudents
"))

The slightly lame embedded newline is probably avoidable, but I wrote
this in a hurry...

Rupert