Code is Love

I recently found my 3G card, a Sierra Wireless Aircard 860 I use to connect to my cell carrier, not working after well over a year of flawless execution. Poking through syslog I found:

‘cs: warning: no high memory space available!’

and indeed, the card was not recognized when you put it in, which was new and unusual. After some trial and error and a lot of googling, this solved my problem:

Add this to /etc/pcmcia/config.opts

include memory 0x40000000-0x40000fff

Boom - now it works. Slide the card into the slot and instantly the TTy is assigned and I’m good to go.

My Hardware:
Dell Latitude D620
Sierra Wireless Aircard 860

Here’s a less than elegant solution to get a summary of the number of emails per domain that have mail sitting in your postfix queue.

#!/bin/sh
postqueue -p|egrep '^([[:space:]])+([[:alnum:]]|.|-|_)+@([[:alnum:]]|-)+.([[:alnum:]]+|.|-)*([[:alpha:]]){2,4}$’|awk ‘{ print $1 }’
|awk -F@ ‘{ print $2 }’|sort|uniq -i -c
| awk ‘BEGIN {sum=0} {sum += $1} {print $0} END {printf(”—————————n “sum” Total E-mails that are properly formattedn”)}’

Thank you, awk

I’ve been reading about the estarling, a digital photo frame that will sit on a wireless network and grab photos from an RSS feed, on say, Flickr, or Picasaweb. What a fantastic idea this is — and really it’s the product I’ve been waiting to come to market for a long time if its features work as promised. Imagine: stick it in the home of your grandparents, parents, etc. - and _you_ can send the photos to their frame - keeping them up to date with all the latest photos from the lives of their family and friends.

To go along with this, I wanted a simple screen saver for my new install of Ubuntu Feisty-Fawn that did the same thing — grabbed latest images from an RSS feed on the web and then serve them when the screen was locked, or the system idle for more than a few minutes. It seemed like every Mac in my office has been taunting me with a feature like this, but maybe all those photo slideshows I’ve been seeing are from local images.

So, this is nothing short of a hack, but if you want this functionality on your desktop, maybe you’ll think it’s worth it like I did. The end result is Gnome Pictures Screen Saver with a modified version of bashpodder that grabs the latest photos from any feed(s) I specify to become the content for my screensaver.

The script takes a config file which consists of the URL to the feed you want to subscribe to and the xsl file which pulls out the URLs to the photos themselves from the feed. Currently RSS feeds/xsl transformations from Gallery, Picasaweb, and Flickr have been tested. When it runs, it checks the feed against files previously downloaded and only downloads the new stuff. It could be run from cron or perhaps when you log in. I suggest running it by hand the first time to make sure it is doing what you expect.

Package available in this thread:

Prerequisite pkg: libwww-perl (I used GET instead of wget - long story)

To install:

$tar -xzvf rss_photos.tar.gz

Edit rss_photos.sh and change the values of CONF_FILE and LOG_FILE to a permanent location. Create the CONF_FILE you just specified.

# Lines in CONF_FILE should be of the pipe-delimited format:
# |
# e.g.
# http://api.flickr.com/services/feeds/photos_public .gne?id=YOURIDHERE&lang=en-us&format=atom|parse_flickr_enclosure.xsl


Obviously, you will need to enable the “Pictures Folder” screen saver in Gnome for this to work - the script simply grabs photos for the screen saver.

I was really surprised that I couldn’t find a how-to to configure Gnome’s Terminal program to have various profiles to connect to different hosts. For those familiar, I was looking for something PuTTY like, where when I launched the program, I would have a list of hosts to connect to, rather than just opening a local shell and running the same ssh commands to different hosts each time I need to login to a remote system. Yes, I have heard that PuTTY runs on linux, but I really wanted to use Gnome Terminal since I use it every day and want to use more standard tools in my daily Linux life.

What I did find, however, was the Gnome Terminal Launcher Applet. This is an applet that runs in your Gnome tray/panel with a drop down menu for each of your terminal profiles. Sweet! I ran into a problem though: if I just put “ssh ” in the profile, ssh wouldn’t use my keys already in memory thanks to keychain and the ssh agent, of course. So, here’s where my hack comes into play — and might save you the same minor hassle.

Create a shell script in your home directory called terminal-helper with the following contents:

#!/bin/sh
. .bash_profile
ssh $1


so I get the benefit of the keychain lines pre-existing in my .bash_profile when it is sourced, and it just connects to whatever host I pass to the script (thanks, Diego, for removing some obvious clunkiness from the original implementation). In my Gnome Terminal profiles, on the “Title and Command” tab, I specify “Run command as a login shell”, “Run a custom command instead of my shell”, and then specify the command:
/home/myuser/terminal-helper <yourusernamehere>@<yourhostnamehere>

Now I can connect to whatever host I have created a profile for just by clicking on a drop down menu. 10-15 keystrokes per host saved! Heh. Enjoy.

So, I finally decided it was time to upgrade to a modern Linux distro — and I was pushed by the fact that some experimentation with dmraid from way back had left my system in a sorry state. A coworker was already running Fedora Core 6 on his laptop and while I don’t always love Fedora for it’s lack of longevity per release, I am a bit addicted to the bleeding edge.

In the last week I have installed FC6 Twice. Once on a homebrew desktop:

Asus K8N-E
AMD Athlon 64 3400
1 GB RAM
2 200 GB Maxtor SATA 133 Drives in dmraid mirror config through motherboard based controller
OEM Graphics card w/ nVidia Corporation NV34 [GeForce FX 5200]
Onboard Gb NIC
etc.
etc.

and a laptop:
Dell Lattitude d620
Intel Core 2 Duo T7200
nVidia Corporation Quadro NVS 110M / GeForce Go 7300
Broadcom Corporation Dell Wireless 1390 WLAN Mini-PCI Card
1 GB RAM
80 GB 5400 RPM SATA drive

The first install had a number of small hiccups — some related to hardware installed that was, well, kinda broken, and some minor anaconda explosions. None of these were that big a deal, but one lesson learned would be don’t configure an IP on your system if you are them going to add extra repositories to install from (this part has another network config screen, and it clearly didn’t like that I had already chosen to give myself a fixed IP). Run with dhcp until after the install, then set your static IP.

The second install went great — until I ran into a problem luckily already witnessed in my office — a stupid Linksys device that couldn’t handle the TCP window scaling properly. Thank you: “echo 0 > /proc/sys/net/ipv4/tcp_window_scaling”. The symptom was HORRENDOUSLY slow network performance before making this tweak (think downloading a few rpm updates all day).

I knew that eye-candy in gnome was finally working because I had stumbled across this news a while back, so I had to try it. Fedora comes pre-installed with the compiz package which, so long as your graphics card supports it, does some nice GUI effects, like rubbery windows, each desktop on it’s own side of a rotating cube, etc.. Really cool stuff, and to my amazement it mostly worked right out of the box. Linux is finally catching up in the UI world to the likes of Apple, so for the people who don’t generally live at the command line, this is a big deal. Nice work, everybody who had a hand in design/coding/testing/documenting/etc./etc.. This rocks. Amazing stuff.

A couple bumps in the compiz road that were/are being faced: the closed-source NVidia driver is necessary for those of us with nVidia chipsets as far as I can tell. None of this really works on the Xen kernel, currently. Also, running said nvidia driver causes IRQ conflicts with the Broadcom/Dell WiFi, and the wi-fi is currently unusable with either the ndiswrapper or the reverse engineered bcm43xx driver. Note: ndiswrapper works for some indeterminate amount of time before either dropping the wireless or freezing the whole system requiring hard reboot.

Another thing I discovered in all of this is Beryl. Whoa Cool. It basically takes the GUI effects in your desktop to the next level.

So, if you haven’t seen what desktop Linux has been up to in a while, go out of your way to see all the new stuff in Compiz and/or Beryl on a system near you - you won’t be disappointed.

On Linux, you can get a ton of information about the physical hardware you are running right from the command line. Simply cat’ing /proc/cpuinfo will give you lots of gory details about the processors you have installed. Unfortunately, it gets a little confusing thanks to hyperthreading, dual cores, etc.. So here’s a simple command to find out how many physical processors you have installed.

$ dmesg | grep "Physical Processor" | awk '{ print $5 }' |sort -nu|wc -l

Ok, so most of you are wondering why I’d be even bothering to do double interpolation in Bash rather than a real language. Well, I already had some scripts in progress and I didn’t want to start from scratch. What is double interpolation and why would I bother?

In my case, I knew that I was going to have a dynamic list (an array), and that for every array member, there would be a number of other things I would need to know about it (yes, like a multi-dimensional array).

done


The beauty of what we have here is that we don’t need to reconfigure the script to add or remove servers, just maintain a simple config file.