Coredump

View hidden files in Mac OS X

2011-09-04T10:19:00.001+08:00

Just plunk the following in a file:

Change the file's mode to executable, then invoke using

view-hidden.sh yes

Hidden files (including "dot" Unix files) will be viewable in Finder.

Create Kerberos keytab file for single sign-on

2011-06-03T13:59:00.000+08:00

On a Windows 200[38] server:

Cars 2 trailer, in LEGO

2011-05-20T13:07:00.000+08:00

ZOMGWTFBBQ! I'm *almost* through in my LEGO City Space collection (just one more set!). Will this be the next one?

PS. Yesterday's post was my 666th. Just saying.

Paean to the letterpress

2011-05-19T10:39:00.000+08:00

(I missed the smell of ink and the sound of rolling presses. Heidelbergs, Bodoni and Blueback are personal favorites. I loved the way I can lay out pages on a grid, and then mess it up by extending beyond the column guides {the old technician laying out the leads always threw a fit!}. Photogravures were "cutting-edge" and novelties. {Yes, Pagemaker was still in its infancy when I started, and I didn't want anything to do with Ventura Publisher.} {I'm showing my age...:P})

Letterpress from Naomie Ross on Vimeo.

Customize fatal error messages in Perl CGI apps

2011-05-18T10:35:00.001+08:00

We all know Carp and CGI::Carp, and they're quite useful when catching errors in your apps. But, the messages are butt-ugly, sorry to say. CGI::Carp to the rescue. It has some nifty functions that can be used to make the error messages friendlier.

To set a custom message when fatal errors are encountered:

use CGI::Carp qw(fatalsToBrowser warningsToBrowser set_message);

### Custom fatals browser message
BEGIN {
sub handle_errors {
my $msg = shift;
my $err_mail = "Error%20message:%0A%0A\
-------------------------------------------------------------------------------%0A\
$msg%0A\
-------------------------------------------------------------------------------%0A";
my $err_msg = "

Encountered an error:

\
$msg\

Click here to send a report.

";
print($err_msg);
}
set_message(\&handle_errors);
}

(Side note: The mailto URI scheme has some great extensions as well.)

Robot Sunday: "I'm doing Science and I'm still alive"

2011-05-15T13:12:00.002+08:00

(Okay, technically, GLaDOS is *not* a robot but an AI, but this is still cool.)

Roll your own package, RPM repo, part 2

2011-05-12T11:19:00.000+08:00

(Part I, building the package, is over here.)

Part II. Create the repository

Prepare the environment in the server where the repository will be stored. Note: All commands from hereon, unless otherwise stated, are by root.
```
mkdir -p /srv/RPMS/{i386,i586,x86_64,noarch}
```

Add the package created from Part I.

cp ~username/builds/RPMS/noarch/this-package-1.0-0.1.noarch /srv/RPMS/noarch/

Generate the repository metadata.
```
createrepo -v /srv/RPMS
```

Sign the metadata and add the repository key.

cd /srv/RPMS/repodata
gpg -ba repomd.xml
gpg -a --export key-id > repomd.xml.key

Add as an installation source. (In this case, I'm using SuSE zypper.) Add the key to the trusted keyring.
```
zypper service-add -t YUM file:///srv/RPMS alias
```
Test by installing the package.
```
zypper in this-package
```

Roll your own package, RPM repo, part 1

2011-05-11T17:45:00.001+08:00

(This is more a note to myself than anything else. Surely, there are lots of references out there on the net... ;))

Part I. Build the package

Prepare the build environment.

mkdir -p builds/{BUILD,RPMS,SOURCES,SPECS,SRPMS}

Add the sources to be built.

mkdir builds/BUILD/this-package-1.0 && cd builds/BUILD
tar czvf ../SOURCES/this-package-1.0.tgz this-package-1.0
cd ..

Write the spec file using the skeleton below.
```
vi SPECS/this-package.spec
```

Build and sign the package.

gpg --export -a key-id > KEYS/RPM-GPG-KEY-username
vi ~/.rpmmacros

%_signature gpg
%_gpg_path /home/username/.gnupg
%_gpg_name User Name (key-id) 
%_gpgbin /usr/bin/gpg

rpmbuild -ba --clean --sign SPECS/this-package.spec

Test and verify.

sudo rpm -ivh ~username/builds/RPMS/noarch/this-package-1.0-0.1.noarch.rpm
rpm -Vp ~username/builds/RPMS/noarch/this-package-1.0-0.1.noarch.rpm

Remove version numbers from package names

2011-05-03T19:52:00.003+08:00

/bin/rpm -qa | sed 's/-[0-9].*//'

is wrong.

Use this instead:

/bin/rpm -qa --qf "%{n}\n"

Mad props to ssatoh and rhonda.

That is all.

Check printer status via SNMP

2011-05-01T13:31:00.000+08:00

So we're asked to monitor several "critical" printers. Instead of accessing the printers' administrative console using `curl` (a kludge, yes), we opted for SNMP -- easier, but unfortunately less secure for the printers. SNMP OIDs for the printer are readily available so this looked easy enough.

To get the printer console's display, for example, one just issues:

/usr/bin/snmpwalk -v1 -On -c $community_string $printer_address \
 1.3.6.1.2.1.43.16.5.1.2 | awk -F: '{print $NF}' \
 | sed 's/\"//g;/^$/d;s/^\s//'

Fortunately, most of the steps (getting the OID from the printer MIB, rehashing the output into something usable by Nagios) are already done for use by a nifty little shell script, check_snmp_printer.sh.

Adding a local YaST repo

2011-04-27T13:09:00.001+08:00

Adding a local package repository to be used by YaST is straightforward.

Create and populate the directory tree:

mkdir -p /srv/suse/RPMS/{i586,i686,x86_64,noarch}

Generate the RPM header information using createrepo (from the package with the same name):
```
createrepo /srv/suse/RPMS
```

Digitally sign the header file:

cd /srv/suse/RPMS/repodata && gpg -a --detach-sign repomd.xml

Add as an installation source in YaST:

/usr/bin/zypper service-add -t YUM /srv/suse/RPMS/ repo-alias

Robot Sunday: Assembly-line robots -- LEGO, of course

2011-04-24T10:22:00.003+08:00

Remember this? Well, an AFOL constructed a working model of an industrial robotics line. Now that's dedication.

Space-Earth flute duet

2011-04-20T22:44:00.000+08:00

To honor Yuri Gagarin, astronaut Cady Coleman, aboard the International Space Station, duets with Jethro Tull founder, Ian Anderson, somewhere on Earth, in a wonderful rendition of Johann Sebastian Bach's "Bourrée in E minor".

Rube Goldberg plus LEGO plus balls

2011-04-18T13:07:00.000+08:00

Equals awesomesauciness, or "The Great Ball Contraption" goodness. Whatever you call it, this video is worth the eight minutes.

A 'Blocumentary'

2011-04-07T14:10:00.000+08:00

(That LEGO fever, it's still raging!)

AFOL A Blocumentary from AFOL on Vimeo.

Passion combines with creativity in this documentary that features a selection of AFOLs (Adult Fans Of LEGO) from the Pacific NorthWest.
Directed by Jess Gibson

LEGO ship in a bottle

2011-04-06T20:15:00.002+08:00

It's LEGO fever over here! :)

What's next, a terrarium?

Sumo vs Karate

2011-04-04T11:15:00.004+08:00

Sumo vs Karate, a set on Flickr.

LEGO martial arts face-off!

From Series 2 and Series 3.

Awesome combo

2011-04-04T09:22:00.000+08:00

Settlers of Catan + LEGO = awesomesauce!

[Via The Brothers Brick.]

Robot Sunday: Surgical robot folds paper plane

2011-04-03T09:38:00.001+08:00

This is precision.

LEGO multimeter

2011-03-18T16:13:00.000+08:00

Who says LEGO minifiguresare just toys? An electronics hobbyist built an ohmmeter out of LEGO bricks and minifigures.

Dear Post Office

2011-03-18T10:57:00.000+08:00

First off, I'm a HUGE fan of snail mail and the post office. Back in grade school and high school, I used the post office a lot, corresponding with friends and relatives around the world. I also made friends with postal workers at the University post office. I even collected stamps.

Up to this day, in this age of emails and instant messaging and social networks, I still use the post office. There is this warm feeling you get when you fold paper into an envelope, lick the seal, and rub the stamp.

SMTP transactions, RFC 821, 5321, and 5322 don't sound as exciting as the way mail travels down the chute, over conveyor belts, sorted, stacked, stamped, labelled, tied up and bagged, transported over long distances, down rugged roads, across the rivers and oceans, on to your doorstep or mailbox.

But enough of nostalgia.

I write you today to tell you how much I'm hurt, how I feel so disappointed and betrayed.

You see, the packages I expected to arrive a month ago is still not here. I'm used to delays in the delivery. I'm used to the postman doing his rounds only once a week to save on fuel. Those things happen. But a month?

I have confirmed with the sender that the packages have been dispatched promptly. I have no reason to not believe their word. I waited two weeks (the usual time it takes for things like this to arrive) before finally paying you a visit to find out what's holding it up. Your workers said, no, there was nothing for me. So I waited some more. And waited.

Two more visits to you, and the parcel still wasn't there. Now what do you want me to think? I have heard of stories of mails getting lost, envelopes opened then resealed haphazardly (for inspection?), fragile objects getting squashed and munged beyond recognition. Those things haven't happened to me, in all my years of dealing with you. Well, not until now.

The parcel, by the way, is just a bunch of books -- nothing of value to any of your workers. (Not unless they are into science fiction, in which case, I would gladly lend them mine, if only they tell me.) I have received several parcels from the same sender in the past without any hitches. So I'm wondering what could be different now.

I'm not sure how we can resolve this. I've accepted the fate of my books, and could only hope that they are in better hands. I hope whoever got -- stole-- them would give them the love and care they deserve. I know, I sound O.A.: they're just books anyway. But that's just the point. If this can happen to something as trivial, how much more for more something valuable?

Anyway, I have not completely lost my trust in you. I have already asked the sender to resend the package. I earnestly hope that this time, you won't disappoint me.

I will wait.

Sincerely,

I am and will always be

Your old friend

It's never too late

2011-03-17T09:39:00.001+08:00

I don't quite agree with my good friend that it's too late. There's still time -- there's plenty of time: we, our kids, and the next generations can still make it work.

(Nice video, by the way. And, yeah, let's go beyond Earth Hour.)

Signed up for a national bloggers association

2011-03-16T09:00:00.002+08:00

I recently signed up for the formation of a national bloggers association. The idea generated some hoopla in the social networks, but I guess that's the point: we need a group that will have a single, united voice on issues and policies that affect bloggers and "social" media.

If you want to sign up, head over here and read the draft manifesto.

One small step

2011-03-13T13:20:00.000+08:00

In a Martian landscape. (I know, wrong allusion, but it captures the thought. ;))

(I didn't realize they can breathe on Mars... Wait, it's a LEGO minifigure, duh!)

Not a minifigure collectible, but from the LEGO City set 3365.

Fonts, 404s

2011-03-07T15:56:00.000+08:00

I made a few cosmetic changes to my new landing page:

It now uses a cool web font, Titillium Text (funny name, heh), using the CSS @font-face property.

It also has an equally cool 404 page that gets served by Amazon S3.

$ curl -I http://www.iandexter.net/something
HTTP/1.1 404 Not Found
x-amz-error-code: NoSuchKey
x-amz-error-message: The specified key does not exist.
x-amz-error-detail-Key: something
x-amz-request-id: 48043A85C5B27307
x-amz-id-2: UlFlcthVTeBk9UF3MxvlpxOS1OtOqbE5VOWt89eQQ8x6EcfsHiPWzeioE3LadVVt
Transfer-Encoding: chunked
Date: Mon, 07 Mar 2011 07:52:23 GMT
Server: AmazonS3

Nifty LEGO minifigure, too!

Go check it out!