Below I’ve embedded my first attempt at a screencast, which I’m putting on here to solicit feedback upon but also to make notes for myself about lessons learned in the process.

Takeaways from this first experience:

• it’s harder than it looks!
• I will either need to pre-script the audio or re-record the audio track over the video — attempting to cold-record the audio admits far too many flubs
• I need to set my video encoding resolution better for Youtube (I think they’re HD is 1280×720)

Anyway, there you go. Click through for a larger version to make it easier to read what’s going on.

(As a moderate Twitter user but total geek, I’ve been meaning to write this for a while. Hopefully someone finds some usefulness in it.)

(Before someone comments, I know this could be done with a command line Twitter client, or I could just write one Python/PHP/etc. program to do it, but that would entirely be missing the point. Command line tools are extremely powerful and fun to use once you get some experience with them!)

The original idea for this came from The Apple Blog, but it has been heavily modified.

My desktop tends to be quite busy, and even with two 24″ screens, I find that I’m constantly out of screen real estate and don’t want to have yet another client open to display my Twitter stream. GeekTool to the rescue. GeekTool allows you to display the output of a shell script or a URL or file to the screen and refresh it at some defined frequency.

First, here’s a screenshot of what it looks like having my most recent 15 tweets visible on the screen, and what this tutorial is going to cover:

From Diminished Effect Pics

And here’s the command that creates it (GeekTool refreshes it every 4 minutes):

curl -s -u username:password http://twitter.com/statuses/friends_timeline.rss | egrep “<title>|<pubDate>” | head -n 31 | tail -n 30 | sed -E ’s/^[ ]+//’ | sed -n -E ‘1h;1!{;/<title>.+<\/pubDate>/ !H;g;/<title>.+<\/pubDate>/ {;s/<title>(.+)<\/title>.+<pubDate>.+([0-9]{2}:[0-9]{2}:[0-9]{2}).+<\/pubDate>/\2 – \1/g;p;n;h;};h;};$p’ | sed -E ’s/$/<br>/’ | /Users/scott/bin/modtime.py | /opt/local/bin/w3m -dump -cols 170 -T text/html

First a tiny bit about shell scripting for those unfamiliar. When you are in a terminal session (ie. run terminal.app on your Mac, from the /Applications/Utilities folder) you can run commands by typing them in and pressing enter. If you want to run multiple commands, passing the output from the first into the second and so on, you use the | (pipe) symbol. That way, the only output you will see at the end is the output from the last command.

The first segment of the shell script is this:

curl -s -u username:password http://twitter.com/statuses/friends_timeline.rss

The curl program fetches the contents of a URL. The -s option tells it to do it silently (ie. only display the output of the URL, not a progress meter as it is pulling the data). The -u option tells curl to use the following username:password combination — your Twitter username and password. Run that in the terminal program and you’ll see all of your recent Twitter timeline with a lot of extra information.

The next command in the chain is:

egrep “<title>|<pubDate>”

grep (and egrep) look for certain lines in their input and pass *only* those lines to their output. In this case we’re looking for lines that contain the tag <title> which contains the contents of a Twitter post or the tag <pubDate> which follows after each Twitter message with the timestamp (GMT) of when that message was sent.

Run the combined version of the first 2 commands in the terminal to see the difference in the output:

curl -s -u username:password http://twitter.com/statuses/friends_timeline.rss | egrep “<title>|<pubDate>”

Okay, now I only want to see the 15 most recent posts in my timeline…the next 2 commands take care of that:

head -n 31 | tail -n 30

The head command says “only print out the top 31 lines”, that is, the first line which we don’t actually want and then 15 <title> and <pubDate> pairs. The tail command says “only take the last 30 lines (of the 31)” so that gets rid of the first line we didn’t want anyway. (It only came in because it has a <title> tag in it.)

Now we start some real processing:

sed -E ’s/^[ ]+//’

sed is a stream editor; basically it will find text that you identify with a regular expression (regex) and replace it with other text. This first invocation of sed says “find the text identified by ^[ ]+ and replace it with nothing”. The symbols ^[ ]+ mean, “one or more contiguous spaces, starting at the beginning of the line”. This deals with the issue that there are 4 spaces at the beginning of every line that we don’t want/need.

The next line is both more interesting and much harder to explain in detail:

sed -n -E ‘1h;1!{;/<title>.+<\/pubDate>/ !H;g;/<title>.+<\/pubDate>/ {;s/<title>(.+)<\/title>.+<pubDate>.+([0-9]{2}:[0-9]{2}:[0-9]{2}).+<\/pubDate>/\2 – \1/g;p;n;h;};h;};$p’

I won’t get into the gory description, but basically sed is intended to process lines one-at-a-time, but in this case I need the time from the second line of each pair added to the beginning of the first line. This mini-program in sed achieves that (and takes out the title and pubDate tags). As an example, it takes this:

<title>hodgman: But so many of the film’s reviews really seem to have the anti-nerd knives out.</title>
<pubDate>Sat, 07 Mar 2009 15:46:59 +0000</pubDate>

And turns it into this:

15:46:59 – hodgman: But so many of the film’s reviews really seem to have the anti-nerd knives out.

If you wish to proceed with any more customization before putting your command into GeekTool, you’ll need 2 things: a little programming experience and to have Xcode installed on your system. It’s a free download from Apple to get the most recent version. The additional customization will convert the time from GMT to your timezone and also clean up the output of some of the tweets a little bit. Continue on if interested, otherwise skip to the end.

The final sed command:

sed -E ’s/$/<br>/’

…does a little bit of processing to add a <br> to the end of each line. It is needed to make the final command recognize that it should print each tweet on a new line.

The next command fixes the problem with the time (still in GMT):

/Users/scott/bin/modtime.py

Now, I admit, this is a cheat. I did it because I can’t quite figure out how to do the time conversion on the command line yet, so I wrote a small Python program to do it. Here’s the code for this program (the 3 lines inside the for loop should of course be indented, but WordPress is not allowing me to do it easily):

#!/usr/bin/python

import sys
from datetime import time, timedelta, date, datetime
from time import timezone

output = “”

for text in sys.stdin:
t = time(int(text[0:2]),int(text[3:5]),int(text[6:8]))
adjtime = datetime.combine(date.today(),t) – timedelta(seconds=timezone)
output += adjtime.strftime(“%H:%M”) + text[8:]

print output

That turns the example line above into:

10:46 – hodgman: But so many of the film’s reviews really seem to have the anti-nerd knives out.

The last command:

/opt/local/bin/w3m -dump -cols 170 -T text/html

…does some text processing to get rid of html entities and turn them back into readable symbols. Note that w3m is not installed on a Mac by default, but can be installed easily using MacPorts (beyond the scope of this post).

Putting it all together:

Now open up GeekTool (it’s a preference pane, so you’ll find it in System Preferences) and select “New Entry” and put your assembled command into the command box and fill out the location section to your satisfaction and set the refresh rate (I use 4 minutes). You can see my setup below:

From Diminished Effect Pics

I hope this quick tutorial provides value to anyone in the Apple AND Twitter AND GeekTool AND command-line-fearless group of potential readers. Leave any questions in the comments and I’ll try to respond to them.

So who all of the readers of this blog uses Google Reader for their daily blogging enjoyment?  Further, who uses the shared items feed?

I ask because I currently only have Petter, Tom, Stacey and Chutz as ‘reader sharing users’ in my Google contacts.  If there are any other of you out there, please let me know so I can add you to my Gmail address book.  The last few months have only reinforced my belief that the sharing feature is probably the best part of Google’s RSS reader.  I consider it the ‘person’ filter of the world.  For example, Petter is an excellent critical thinker and developer and he reads blogs which seem centered on those topics and when he shares an item from one of the 100+ items that he might scan over in a day, I know that it must have a particular significance.

I don’t exactly know where I sit on the whole seal hunt thing that is being widely debated in Canada these days.  I honestly don’t know even half as much as I probably should about the whole situation.

What I do know however, is that I really don’t like the actions and accusations of the anti-seal-hunt people — the group I know of as the Sea Shepherd Conservation Society (I will not link to them…they are stupid).  On Saturday their boat was raided by the RCMP and the captain and first officer were arrested for their dangerous use of the ship in ramming a Canadian Coast Guard vessel.

Of course, as soon as the rest of the crew gets back to shore we hear stories about how they were all innocent, why, in fact it was the Coast Guard that rammed them!  (Forgetting the evidence I’m about to describe, seriously, how likely does this sound?)  After which their boat was taken into custody in, get this, an act of piracy!

So, watching the news last night they showed one of the boat collisions, taken by a crew member of the Sea Shepherd’s boat.  And what could you clearly see, with only a modicum of common sense?  If you watched the motion of the image, and the boats, with respect to the ice, you could see that the only boat that was even moving was the Farley Mowat (the Sea Shepherd’s boat)!  So if only one boat is moving, and there’s a collision, who exactly do we think is responsible?

Just another case of the so-called peaceful protestors doing what they do I guess.  But when you’re weilding a multi-hundred ton boat as a weapon, I totally support the actions of the RCMP.

Oh, and btw, McDonald’s totally needs to start serving baby seal on a bun — McFlubber!  (This was thought of years ago by a group of us in J9, I’ve sent the idea twice to McDonald’s — no response yet.)

Well, it became crushingly evident yesterday that at least one person that I work with at Bishop’s has found my blog, when I was called into an office of my peers and read a paragraph (that I actually do not even remember writing) posted some time ago and speaking very critically of the department for which I now work.  Not that I regret posting anything on here, nor was I wrong in what I said, but the knowledge inevitably causes you to think differently about what you may speak about in the future.

This should be interesting as I have some work-related topics that I plan on posting about in the next couple of weeks.  One would think that working at a university would afford someone with a certain high degree of intellectual freedom as to what they may wish to speak about, but alas I get the sense that those freedoms are only really afforded to faculty, and not staff.  We’ll just see I suppose.

I suppose I should write one of those disclaimers… “all commentary appearing on this blog are the personal insights of Scott Stoddard and have no connection either real or inferred with Bishop’s University or the IT Department at Bishop’s University….blah, blah, blah”.  In short ->  Only my words.  Suck it.

Okay, I’ve seen Google do a lot of smart things over the years — and this one is going to get less press than most — but this is the smartest thing I’ve ever seen them do.

Every web application developer should learn about this; it has all of the hallmarks of a product that could lead to revolutionary change on the web.  Until now, the decision to build a web app depended on not only your ability to code it, but the availability of a server to run it on (can you set one up yourself?  how long will that take? if you do, will it be accessible on the web?  can you solve the myriad of maintenance issues?) and/or your ability to pay someone else to host it.

If you are a developer, free up an hour and watch the six videos from the intro last night, part one below:

I’ve already started coding with their SDK!

Just a reminder to Quebec readers or people who are likely to visit Quebec anytime soon…it is now illegal to drive and talk on a handheld cell phone in this province.  For that matter it’s illegal to drive and use one hand to hold a cell phone (I don’t get that one…I can has cheezburger but I cannot has cell phone!)

Don’t even get me started on the fact that the holding of the phone is not the distraction point of a cell phone conversation, so this law really misses the point entirely.  I suppose however that the alternative would be to make it illegal to talk while driving…I better be quiet with that shit, I don’t want to give this province any ideas.

…to the new blog.  There are some aspects that I have not yet ironed-out, such as commenting.  The way this system should work, I want people to be able to comment without my having to moderate them first…but I also don’t want any comment spam.  I will have to make some additional changes in the next couple of days because right now I have to manually approve each message.

RSS feeds exist:

Blog:  http://diminishedeffect.wordpress.com/feed

Comments: http://diminishedeffect.wordpress.com/comments/feed

Hope you’ll all join in!

I look on with more than mild interest to see how this will turn out.

Personally, I’m in the category that assumes the result will be…clusterfuck.

If unfettered internet access is offered to the 30,000 members of the media then some travesty will occur.  Protests will happen.  People will be killed.  The journalists will report.  And in doing so, should that sufficiently anger or embarass China causing them to block the pipes (or worse, and a significant possibility, they never open them to begin with) the media will still report (you know, that whole ‘free speech is relentless’ thing that we all cherish).  That’s all bad news for China…no matter how you slice it.  I’m almost certain that these Olympics could generate more negative press about the country than positive.

I’m not against the clusterfuck at all.  In fact, I think the country needs a whole host of additional protests, actions and other general forms of defiance.  It’s just that every time China ‘manages’ a situation a lot of people seem to die.  I wonder how many people they’ll be willing to kill with the eyes of the world on them.

I was listening to CBC Radio this morning and the executive producer of Desperate Housewives was paraphrased saying that he’s spending tens of thousands of dollars a week digitally-processing the nipple imprints of his stars out of each episode of the show.  Something about it here.  It is 2008 right?