Sixth installment: establishing wifi connections from the command line

Reader's Digest condensed version

Want to get on a wifi network fairly quickly and painlessly from the command line? Try network-manager's command-line cousin, cnetworkmanager. A command like sudo cnetworkmanager -C essid-of-network --unprotected (for unprotected networks) will do it. For further details on how I discovered this and for further remarks on cnetworkmanager's capabilities, read below.

Unabridged version

Trailing edge technologist that I am, I'm also a fan of minimalist desktops. I've used mainly ion2/3, dwm, and evilwm for day-to-day computing--though I've tried out many others like JWM, icewm, fluxbox, blackbox, twm, openbox, etc.

After my netbook's keyboard went on the fritz subsequent to having water squirted on it by a loved one (I can say she's a loved one in hindsight), I decided to dig out an old laptop and press it back into service. It is, of course, a single-core machine with a Celeron 2.4 Ghz CPU and only 512 MB RAM. So, another ideal candidate for a minimalist desktop.

I wanted to get the machine up in a hurry so I chose to install a lighter-weight *buntu on it--namely, Lubuntu. That variant uses the lightweight LXDE desktop.

After I'd gotten it set up and used it for awhile, I decided to try paring back the system resource usage yet further. The main means toward that end was to install the evilwm window manager which, though I understand it is not quite as lightweight as dwm, nevertheless looked like a good choice for this machine.

It took some trickery to be able to load into the evilwm desktop once the machine was booted. Lubuntu, you see, uses the LXDM login manager, and I was unable to create a valid menu entry for an evilwm session. So I used the quick and dirty method: cobble together an .xinitrc for evilwm, kill LXDM, then issue startx from the command line.

I'm in the initial stages of possibly replacing LXDE with evilwm on this laptop, but I've gotten at least partway there. I want to recount in this entry how I managed to get wifi connections working under evilwm. But first, a relevant digression.

I used to use command-line routines on another old laptop some years ago when connecting to wifi networks. That involved using commands such as iwlist and iwconfig, then issuing a dhcp request on the wifi NIC. At a certain point, however, my trusted command line routines stopped working for reasons I could not understand.

Searching for alternatives, I discovered wicd. I actually doubted it would work since, as I understood it, wicd was simply a series of python scripts that invoked the same command-line binaries I'd been unsuccessfully attempting to use.

But wicd did work, and to my delight, I even discovered that it had a curses, terminal interface: I thus needed not be bothered with using a pesky gui utility to employ wicd. I subsequently came to rely on wicd for establishing and managing wifi connections.

Getting back to evilwm; those who are familiar with that window manager will be aware how minimalistic it is: there are no taskbars, no system trays, no pop-up menus. No, all evilwm does is display the desktop background you specify and allow you to open graphical applications (invoked from a terminal or by using something like xbindkeys and gmrun).

That sparseness presented an issue with wifi connections once I started switching from LXDE to evilwm: you see, Lubuntu has set up this system such that it uses network-manager for managing wifi connections, and network-manager, in turn, expects there to be a system tray in which it can reside. Given that architecture, I could see no way in which I could use network-manager for my wifi connections while running evilwm.

My first assumption was that my old standby, wicd, would allow me to manage wifi connections under evilwm. So I installed it. But it would not, no way, no how, allow me reliably to connect to wifi networks.

I am uncertain why this problem exists. I read that it was related to some conflict with network-manager, and that the solution was to uninstall network-manager. But doing that did not resolve my problems: wicd would, for the most part, give me a "bad password" error and would not connect to the network: perhaps once in every thirty tries I could get on-line, but the other twenty-nine times, I would get the bad password error.

Short story long, I had to abandon wicd and look into other ways of connecting my laptop to wifi networks using command line utilities. My attempts at finding an alternative to wicd finally resulted in the discovery that there is actually a command line version of network-manager called cnetworkmanager.

The happy ending to this story is that cnetworkmanager's man page is fairly simple and easy to comprehend for the non-specialist. I was, in very short order, able to bring up my wifi network connection using cnetworkmanager. Below are salient details.

In order to find the name of your wifi network interface and, at the same time, scan for essid's of detected networks, the command cnetworkmanager -a -d run in a terminal does the trick (-a is the option that lists available networks, -d is the switch that tells you the names of wifi interfaces on the machine being used). With that information it is fairly simple--though super-user privileges are required for this--to a network as follows.

For WPA-encrypted networks, the command sudo cnetworkmanager -C essid-name --wpa-pass=password will do the trick. For unencrypted networks, sudo cnetworkmanager -C essid --unprotected does the job.

It's a bit clunky, but provides a workable solution that gets me by for now.