Kutuma's Ramblings

DIY tripod for the iPhone

2011-10-03T22:08:00.001+01:00

Do you need to make a short video explaining how to do something with your hands? A drawing, assembling some lego, playing with your Nintendo DS? Well, I needed, and since the only video camera I have is my iPhone, I needed a tripod for it. So here it is, my homemade iPhone tripod!

Converting a list of IP addresses to countries

2011-09-26T09:05:00.001+01:00

If you have an Excel file with a column filled with IP addresses that need to be converted to countries, here's a way to do it. These instructions were tested on a Mac, but it should work fine in any environment with Python.

Start by downloading the GeoIP City database from MaxMind. They have a free version that you can download here. Download the one in binary format, and uncompress it.

Next, you need the library to access this database format. There's a pure Python library called pygeoip that you can download from google code. To install it, just uncompress it and run the installer: sudo python setup.py install

Next, you need to build a small script to convert the IP addresses to countries. Here's the script I used (note that the countries database should be in the same directory as the script).

#!/usr/bin/env python

import pygeoip, sys
gi = pygeoip.GeoIP('GeoLiteCity.dat')

for line in sys.stdin:
	rec = gi.record_by_addr(line)
	print rec['country_name']

I used this script (geo.py) by copying the IP list from excel to a plain text file (ips.txt), where you get one address per line. Then just run it with something like python geo.py < ips.text and you get a list of countries on your terminal window. Copy/paste to excel and you're done!

If you want more than just the country, just play a bit with the print line. Here's a variation I did to get the state and the city. The output is tab separated so that you can copy it easily to excel:

#!/usr/bin/env python

import pygeoip, sys
gi = pygeoip.GeoIP('GeoLiteCity.dat')

for line in sys.stdin:
	rec = gi.record_by_addr(line)
	print rec['country_name'] + '\t',
	if rec['country_code'] == 'US' and 'region_name' in rec:
		print rec['region_name'] + '\t' + rec['city']
	else:
		print '-' + '\t' + rec['city']

As a side note, I tried another database from hostip.info, but it was only able to convert about half of the IPs I threw at it, so I recommend going with the one from MaxMind...

Mobile Trends and Numbers - Infographic

2011-08-10T17:27:00.001+01:00

Here's an infographic that I designed for OutSystems. It shows some of the impressive numbers around mobile adoption and mobile in the enterprise:

Via: OutSystems

What's wrong with ScrumBut?

2011-01-19T00:16:00.000Z

When I talk to other Agilists about SCRUM, I usually get two very extreme reactions to this methodology:

On one side, I get people that say you've got to follow all the rules. That's what SCRUM is! There is no but!

On the other side, I get people saying that there's no such thing as a one size fits all methodology, so you always need to adapt SCRUM for your particular scenario.

Now, I don't agree that you need to blindly follow all the rules of SCRUM. That's not Agile at all... remember the 1st rule in the Agile Manifesto? "Individuals and interactions over processes and tools". Seems clear to me that, if your team agrees that some part of SCRUM can be improved, the Agile Manifesto is there to back you up.

But...

Just because it is ok to change SCRUM, doesn't mean you should. Failing to properly implement SCRUM is not a valid excuse to change the process "to fit your organization". That's the the type of attitude that gives ScrumBut a bad name!

Before adapting SCRUM to your organization, you need to implement and use original SCRUM for a while. It's only when you finally get SCRUM running smoothly on your organization (and that will take some time!) that you and your team can move to phase 2: Analyze the process, do retrospectives, and improve the process to better suite your needs.

And that's when the real fun of Agile and SCRUM begins!

Giving Gantt charts some Agile love!

2010-06-26T19:24:00.005+01:00

Gantt charts have a really bad reputation these days. They're strongly associated with the waterfall methodology, are considered an evil tool that managers use to micro-manage teams, and are usually classified as outdated delusions of certainty about projects that are subject to lots of change.

But still, I love Gantt charts! They're a great way to keep everybody in synch with the overall timeline of a project, team allocation, and how the project dates relate to other important dates.

My secret to make Gantt charts successful is easy: Keep It Simple!

Here are a few tips on how to achieve Gantt Nirvana:

You have to be able to produce the Gantt really quickly. The problem with most Gantt charts is that creating them is a project in itself. And that means that by the time you publish them, they're already out-of-date.
It must be really easy to change the Gantt. The Gantt's main purpose is communication. So when the project changes, the Gantt must also change.
Gantt's don't work well with lots of data. Forget about the never-ending WBSs. It's too much detail and too much work. User stories are more than enough detail.
Assign to teams, not individuals. It's up to the team to organize how they solve problems. Besides, it means a lot less work for you!
Gantt's don't scale well vertically. Don't make a stair case of user stories if they all belong to the same project. Show them one after the other, with the most important first, of course!
Be precise. There's not much point communicating something that's wrong. Take into account the team velocity, vacations, national holidays, ...
Add milestones and releases. Make it obvious when things will be made available. Just because a user story is completed next week, that doesn't mean it will be available in production.
Worry about the future. Retrospectives are important learning tools, but usually it's more important to communicate were we are heading. Focus on that.

At OutSystems, we used our own Agile Platform to automate the entire process of creating the Gantt. All I have to do is click a button, and hey presto! Here's how they look:

Beating the Delivery Deadline!

2010-05-23T22:59:00.000+01:00

I'm a product delivery manager at OutSystems. In a nutshell, my job is to make sure new versions of the Agile Platform are released on time, with quality, and with all the features agreed upon.

Last Friday we released version 5.1 beta of the Agile Platform! And yes, it was released on time, with quality, and with everything the stakeholders were expecting! Cool, hum?

And if you're wondering, this wasn't a one time lucky shot. This is the 4th version since I'm a delivery manager that we've pulled this off!

Actually, this shouldn't be anything to be amazed about... But the fact of the matter is that it is so unusual, that it surprises most people I know in the software industry. So I decided to share some principles I follow to make sure we ship on time:

Embrace change: One of the most anticipated features on 5.1 are the Wizards. Funny enough, the wizards weren't part of 5.1 when it started! This could've been a major stress factor, but it wasn't! From the moment we understood it was the right decision, we were more than thrilled to make it happen!
Don't add, swap: It's really easy to add a bunch of features to a version, just so see its ship date delayed over and over. Swapping puts a price on features and forces everyone to prioritize. This keeps everyone focused on shipping the most important things first!
Say 'No': It happens on every version. The end date gets near and everybody wants to add just one more thing. It's much easier to say "yes", but you'll regret it for much longer. I usually put it like this: Is it worth it to miss the ship date to add this last minute feature? It usually isn't...
Know your teams: 5.1 got out on time because we were able to predict how long it would take to build! And the reason we were able to predict this (even with so much change!) is because we studied past versions to learn how long we take to do stuff. And not just the time software takes to build, we also consider interactions with other teams, user feedback, meetings, ...
Establish design rules: It's really easy to derail when developing software. Establishing good design rules (visions, goals, guidelines, ...) is a great way to make sure everyone is on the same page. To be honest, I usually don't come up with these rules. The teams do! I just help teams stick to them.
Get out of the way: I'm always available to give help and advice to my teams. But once I feel they're on track, I get out of the way. This is actually much harder to do than it seems, but once you have this level of trust with your teams, it's pure bliss - for both the manager and the team!
Ship: There's always last minute bugs. There's always a reason to stop the presses and hold the version. Turns out most last minute bugs only occur when the planets are aligned and it's raining in the Kalahari... so ship anyway! You can fix it tomorrow!

These might seem like easy enough tips, but to each of them there's a lot of preparation, trust, and discernment going on! Not only that, there's a huge requirement to make any of these tips work:

You need amazing teams working with you!

Lucky for me, I work with the best teams on the planet!

It's not about the numbers!

2010-04-25T20:29:00.004+01:00

When an organization is small, everyone knows what's going on. People have the full context, communication is easy, and so is evaluating performance. Everything is natural, very ad-hoc, and mostly qualitative.

When the company grows, formalism starts to impose itself. Some evaluation forms (aka Excel files) appear, and goals and metrics are agreed upon. Still, when evaluation time arrives, everybody is very well aware that things changed since the day the goals were written, and a more qualitative approach is used once again.

When the company gets big, people don't know each other so well, and they don't have all the organization's context at the top of their heads. To make sure everybody is aligned and working for the same grand objective, metrics are put in place. Big mistake!

Don't get me wrong. Metrics are good. The problem is turning metrics into goals and evaluations. Once you do that, people will try to make the number blindly, even if they have to go against the organization's best interest. To put it a single sentence:

Metrics are tools, not goals!

As with every tool, some care must be taken with metrics. Here's a few hints to make sure your metrics are helping you:

Understand the metric: Not only the formula to obtain the metric, but why are you getting the current values.
Question the values: It's really easy to measure wrong. Check your numbers. Measure twice, cut once.
Question the metric: Don't assume the current metric is adequate. Mistakes are made. Things change. More information is available. Be extra critical with metrics!
Study the derivative: More important than the number, is the derivative. More important than knowing the current numbers, is knowing next month's.
Don't trust all stats: You need a big sample of values to trust statistics. Don't trust averages and the like if the sample is small.
Don't use metrics as a direction: Use them as guidance.
Talk to people: Don't trust yourself to analyze the results. Talk to the people that measure. Talk to the people that affect the metric.

I'm sure the list goes on and on. What is your advice for working with metrics? Do you have any stories of metrics gone wrong?

Sprint review meeting: It's all about Marketing!

2009-11-01T22:19:00.006Z

I attend a lot of Sprint Review meetings, and sometimes I leave those meetings a bit sad...

It's not that the team hasn't done a great job! Quite the opposite. The teams I work with do miracles! But, like most engineers, they sell themselves short.

Sprint Review Meetings are all about Marketing! Your team needs to sell the work done during the Sprint to the audience!

Here are a few tips to effectively market your work:

Show the value of what you did: Don't explain how you did it, and don't go into excruciating technical detail about what you implemented... explain the benefits of what you did!

Do: "By improving the reticulating splines performance, customers have a much smoother checkout process"
Don't: "We improved reticulating splines speed by using a really smart b-tree structure"

Make a big fuss about what you did: Don't hide the great work you did in a bullet list with all the details of the Sprint. Pick 3 to 5 key points, and make a slide for each of them.

Do:
Don't:

Make a real world demo: Be smart with your seed data. Use real data whenever possible, or some really clever examples to make your demo more effective.

Do: "Peter Smith bought a Mega Chair and paid it with a Visa card"
Don't: "Customer A bought Product 1 and paid with card X"

Talk about the entire Use Case: Even if you don't demo it all, explain how the user got to the point of the demo and what the user is trying to achieve. It will make understanding your demo much easier.

Do: "Peter Smith was navigating at our web site to buy a chair. He did a search for chairs, and clicked the 1st result on the list. What you see here is the page present to him at that stage."
Don't: "Assume Customer 1 is at this page"

Make a clean demo: The demo should be as near to reality as possible. Avoid launching the command line, use batch files, or employ other kind of odd gizmos during your demo.
Don't dwell on what you didn't do: If your team made a commitment to this sprint that it wasn't able to keep, mention it, give a one sentence justification, and move along. Be prepared to answer any questions that may arise, but don't spend the time you have to talk about what you did, speaking about what you didn't do.

What other tips would you add to this list? How do you turn your Sprint Review meetings into huge successes?

When is enough good enough?

2009-10-27T16:25:00.006Z

We all love perfect products! Those products that you actually feel pleasure just for using. And naturally, we all want to make our own products perfect!

But perfection comes at a price. Generally speaking, the closer you want to get to perfection, the more it will cost you. And the cost increase isn't linear!

(the smiling faces represent the mood of your "average user")

This means you have to be careful when investing on perfection. In most scenarios, there's simply not enough time to make everything perfect. Nothing new here, right? It's just the old quantity vs. quality dilemma. You either do 1 perfect thing, or you do 2 "good enough" things.

If you take this into a software product scope, there are a few guidelines that can help deciding how perfect your feature needs to be:

How many times will the feature be used? Rarely used features can be a bit uncomfortable, and seldom used features can be good enough. Perfection should be saved for those features that are used all the time!
Who will be using the feature? Features targeted at one particular user can get away with a hack. For features existing users are craving for, a quick "good enough" solution may be better than a delayed perfect solution. If you're aiming for first time users, you should go for perfection, to make sure they stick around for more.
How unique is the feature? Is this something every other product does? Is it always done the same way? Unless this is really core to your product, you probably should stick to good enough and go with the crowd. But if this is something truly unique to your product, polish it up for perfection!
Is the feature demo-able? If this is something you'll be wanting to show at a prospect demo or at a room with 400 people, going for perfection is a good investment.
Is the feature sell-able? Is this one of those features that has the potential to enchant customers? Better yet, is this a feature customers will be talking about to your prospects? If so, by all means make it perfect!

These are just a few things to consider. I bet there's lots more! What factors do you take into consideration when deciding how much effort you should invest on a feature?

PS: The same principle can be applied to a bunch of other areas of a software product, like documentation and marketing. Anyone care to make a blog post about those? :-)

The Secret of Agile Speed

2009-09-06T20:52:00.003+01:00

Here's an introductory video on how Agile improves your projects' speed.

Reading burndown charts

2009-07-10T22:55:00.003+01:00

Burndown charts are a fairly common tool used in Agile projects to measure the velocity of a team. It usually contains two sets of data, the actual missing effort and the expected missing effort.

The thing is, looking at a burndown chart is useless, unless you have a very good understanding of what’s going on with the project.

Here’s a sample of a burndown chart:

At first glance, it seems things aren’t bad. Although there is a “saw” look to it, every couple of weeks things go back to normal. The drops seem to occur at the end of each iteration (assuming 2 week iterations). But the thing is, the chart doesn’t show us why the drops occur!

One reason might be poor self management by the team. They only close the stories at the end of the iteration. This is a good scenario, because it means you can quickly coach the team to have more fine grained stories, so you can have better visibility on the project.

Another reason for these drops might be that, at the end of each iteration, the team reviews the backlog and realizes it will miss the date. With that in mind, they remove the last items from the backlog, and the project gets back on track. This is way more problematic!

The team is assuming the project is about 1/2 weeks late (marked by the dotted red line), so they cut 1/2 weeks worth of work from the backlog. But the reality is that the project is 5 weeks late! (marked by the dotted blue line).

The consequence of this is that the team will have to cut about half of the backlog to finish the project on time! This can obviously have catastrophic implications for the project....

There are several ways to deal this problem, but the important thing is that action is taken as soon as possible. And to be able to quickly understand what is going on, you cannot trust on the burndown chart alone. You need a very good understanding of what is going on with the project.

Analyzing Movable Type search logs

2009-05-09T12:09:00.009+01:00

The OutSystems blog uses Movable Type. I was curious to see what type of searches were being made on the blog, so I downloaded the logs from MT's back-office and started thinking how I could analyze them.

I wanted to generate CSV files, so I could open them in Excel or Numbers. At first I considered Python, because it has good CSV support. But most of the work would consist in parsing the MT log file, so then I considered Perl. The problem with Perl is that I can never remember the syntax, so in the end I decided to just use the Unix command line.

I started out by checking unique sentences in the file:

grep "Search: query for" logfile.csv | cut -d \' -f 2 | tr '[A-Z]' '[a-z]' | sort | uniq -c | sort -nr | sed 's/ *$[0-9]*$ $.*$/\2, \1/' > sentences.csv

Here's what this does:

grep "Search: query for" logfile.csv - Get all the lines from the log that are searches
cut -d \' -f 2 - Extract the content of the search. This might not work if the content has ' on it, so be advised.
tr '[A-Z]' '[a-z]' - Turn everything to lowercase.
sort - Group the sentences (for uniq -c to work).
uniq -c - Count the unique occurrences of each sentence.
sort -nr - Sort by numbers, in reverse order.
sed 's/ *$[0-9]*$ $.*$/\2, \1/' - Transform the result into a CSV file.
> sentences.csv - Save to sentences.csv.

Turns out this wasn't very useful, because there are a lot of different sentences. One of them kind of stand out, but it accounted for about 5% of the searches. So I've added a bit of awk to do the same for the words, instead of the sentences:

grep "Search: query for" logfile.csv | cut -d \' -f 2 | tr '[A-Z]' '[a-z]' | awk '{for (i=1;i<=NF;i++) print $i}' | sort | uniq -c | sort -nr | sed 's/ *$[0-9]*$ $.*$/\2, \1/' > words.csv

The awk script splits the sentences into words. This issue a more interesting result: 26% of the searches include the word "Agile"! Note that this counts words like "and" and "the", but it's easy enough to remove them.

There's some more fun stuff you can do with this! Use Wordle to create a word cloud:

Or you can check where the accesses come from. If you have an IP geolocation DB, you can try this:

grep "Search: query for" $1 | cut -d , -f 2 | sort | uniq | awk '{print "SELECT country_name FROM ip_group_country where ip_start <= INET_ATON(\""$1"\") order by ip_start desc limit 1;"}' | mysql --skip-column-names -B -uGeoDBUser -pGeoDBPwd GeoDB | sort | uniq -c | sort -nr | sed 's/ *$[0-9]*$ $.*$/\2, \1/' > geo.csv

You can then open the file and make a nice chart! Have fun!

Great employee care!

2009-03-04T19:00:00.005Z

I had a baby boy a few days ago. Because of that, I'm on leave from work. And, to my surprise, today I got a gift delivered to my house.

It was a gift from the company I work for, OutSystems! It was a plant for my wife, a cigar for me, and a bunch of stuff for the baby, including some diapers, a blanket and some baby shoes.

My company treats me pretty good on a regular basis, but for some reason this attention they had really hit a chord. It was a really thoughtful gesture, and I truly appreciate the gift!

This is even more meaningful if you consider the tough times we're going through. To me, this sends a clear message that OutSystems is devoted to great employee care, even in the middle of the current crisis.

Thank you OutSystems!

Sharing a mouse and a keyboard between computers

2009-02-14T13:13:00.002Z

I have a Mac at home. Considering I spend most of my computer time @ work, the poor computer was feeling kind of lonely.

Taking the Mac to work allows me to use a bunch of stuff that I really like, for task organization, to do some script development, and so on. But having to swap between keyboards and mouse is a pain.

Along comes Synergy. It allows you to share a mouse and keyboard across computers and it works in a bunch of OSs, so I can have the server running on my windowz box, the client on the Mac, and share the mouse and keyboard between them. And it even allows you to copy paste text between the 2 boxes!

Synergy works pretty good, and I'm using it every working day, but there are a few quirks that are kind of annoying. Here they are, so you can level your expectations on it:

When the host machine is working hard (CPU or HDD) it stops working. This is a bit of a pain, because most of the time I want to go to the Mac when windowz is trashing.
The keyboard layout for the Mac is a bit strange. You get Alt for Command, and the Windows key for Option. This means you use Alt-C to copy on the Mac and Ctrl-V to paste on Windows. It gets a bit confusing.
It's not that tolerant to bandwidth ups and downs. Since my Wifi network at work sucks, this is a problem sometimes.

Still, it is a pretty cool piece a software and well worth the try. And the price is right!

Cleaning up your computer to give away

2008-12-04T22:11:00.000Z

While cleaning up the house, I came up across two old computers that I really don't want. One of them is old enough to recycle, the other one I'll give away for charity. Eitherway, I want the hard-drives to be clean before they leave the house. Not that I have any sensitive stuff on them, but there's probably enough info for some identity theft.

Fortunately, a while ago I came across this tool: Darik's Boot and Nuke. This is basically an image file you download and burn on a CD. You boot the computer you want to recycle/give away/sell with the CD and it just wipes all your hard drives.

I used it with both computers and it worked perfectly. Now I can give them away without concern.

Oh, using this software had an unexpected bonus! Because I had to open the CD drive, it stopped me from sending the computer away with a backup CD in it!

Setting up Cake on a custom folder

2008-09-28T23:01:00.005+01:00

I wanted to try the PHP framework Cake, but if you look at the documentation it assumes you want to install Cake under the /var/www/html folder.

You can obviously install to other folders, but if not done properly, you'll encounter a start page with no images, no styles, and some error messages.

The steps I took to make Cake work in my folder (/home/me/dev/myapp) and to work with the http://localhost/myapp URL where:

Uncompress the latest version of Cake to /home/me/dev/myapp

Edit my /etc/apache2/users/me.conf and add the following (replace braces with chevrons):

Alias /myapp/ "/home/me/dev/myapp/"
{Directory  "/home/me/dev/myapp/"}
 AllowOverride All
 Order allow,deny
 Allow from all
{/Directory}

Edit the .htaccess file in your /home/me/dev/myapp folder and add RewriteBase /myapp/ to it. Should look something like (replace braces with chevrons):

{IfModule mod_rewrite.c}
 RewriteEngine on
 RewriteBase /myapp/
 RewriteRule ^$ app/webroot/     [L]
 RewriteRule (.*) app/webroot/$1 [L]
{/IfModule}

Make sure your /home/me/dev/myapp/app/tmp folder is writable by all
Restart apache

And that's it. After these steps you should be able to access your application and see the default Cake page, including images & CSS.

Mighty Mouse design flaw

2008-09-13T21:31:00.003+01:00

I bought a Mighty Mouse from Apple. I wanted a wireless mouse for my computer, and the Mighty Mouse seemed like the perfect choice for my Mac.

The mouse is beautiful, the buttons work pretty well and the scroll ball is great! But the mouse has a rather annoying design flaw:

You cannot lift the mouse while clicking!

Here's the problem: The mouse detects the button is pressed because you press the body of the mouse against the base of the mouse. When you lift the mouse, there's no longer pressure between the body and the base of the mouse. So our mighty mouse assumes you're no longer pressing the button.

There's somewhat of a work around for this... If you squeeze the mouse, the base does not drop and you can lift the mouse. But since squeezing the mouse brings up Exposé, things can get pretty weird...

This can be a real pain when you're trying to drag files from an end of the screen to another, or when you're trying to make a huge selection... it is one of those design vs. function options that I'm still not sure if Apple's done the right choice.

Hello world in Cocoa-Ruby

2008-08-14T13:08:00.003+01:00

Here's a short video on how to do a "hello world" application in Cocoa-Ruby.

This was based on this japanese video I found on the web.

Killing programs on Windows shutdown

2008-07-03T00:20:00.000+01:00

My Windows computer at the office takes quite some time to restart... so, whenever there's an update or such that requires a restart, I wait for a moment that I'm away from the computer to do so. Turns out that it's not that unusual to return to a dialog box stating that some program has failed to exit with a button to "click to end".

Fortunately there's a workaround for this not so smart behavior. Start regedit (*sigh*), go to HKEY_CURRENT_USER\Control Panel\Desktop and alter the key AutoEndTasks to the value 1.

PS: I'm not really sure if this works, because I'm always away when my computer reboots... but I haven't seen that message again!

PHP on the Mac

2008-06-10T18:44:00.003+01:00

If you have a Mac with Leopard and want to use PHP, most of what you need is already installed. It's just a matter of making it work.

First you need to turn on apache. Just go to your "System Preferences", "Sharing" and turn on "Web Sharing". That's it, apache is running. You can check if all is ok by going to http://localhost.

You'll probably want MySql too. Just go to their site, download and install. No big fuss, but make sure you install the StartupItem if you want MySql to start when the system boots.

Next you must enable PHP. Launch a terminal and use your favorite text editor to edit /etc/apache2/httpd.conf. Look for LoadModule php5_module and uncomment the line. Restart apache with sudo apachectl graceful.

Now let's say your username is john, and you have on your home folder a ~/dev/phpproj where your php code is. One way to make this available (and there's lots of others) is to edit /etc/apache2/users/john.conf and add the following to the bottom of the file (replace [ with "lesser than" and ] with "greater than". Blogger doesn't like those symbols):

Alias /phpproj/ "/Users/john/dev/phpproj/"
[Directory "/Users/john/dev/phpproj/"]
 Options Indexes MultiViews
 Order allow,deny
 Allow from all
[/Directory]

Now you can access http://localhost/phpproj/ to view your app.

At this point you might get a MySql error stating that you /var/mysql/mysql.sock does not exist, just go back to your terminal window and type:

cd /var

sudo mkdir mysql

cd mysql

sudo ln -s /private/tmp/mysql.sock mysql.sock

That's it!

I bought a Mac!

2008-06-10T17:59:00.000+01:00

About a year ago I wrote some reasons why I wasn't buying a Mac. Well, a year has come and gone an I bought a Mac! And so far, I'm very happy with it!

I could go on forever about what's so great about my Mac, how cool it is just to unpack it, how beautiful the hardware and software are, and all that. But you can read about a million posts on the web about that, so I won't bother.

Instead I'm going to focus on the parts that aren't so good. This way people switching from Ubuntu to Mac will know what to expect.

You have to pay for the software: Oh yeah, most software is closed source and payed for. I really miss doing apt-get and it just works, no payment, no registration...
The keyboard is... different: I have a portuguese keyboard. The Mac doesn't have a } anywhere visible on the keyboard! It took me a while to figure I had to type --9!
X11 compatible... kind of: You can run X apps on the Mac. I installed Gimp, and it works. But the UI is a bit clumsy... For starters, the keyboard shortcuts aren't the same for X and Mac (e.g. in Mac you copy with -c, in X with -c). Second, the windows interaction is awkward. In "X mode" you have to click the window to get the focus, then click the button on the window to make it work. Since the Gimp has multiple windows, this is very annoying.
No out of the box NTFS write support: C'mon! I have an external 500Gb HD formatted in NTFS! I had to install MacFUSE from google to make it work!
Only 2 USB ports: Good thing I have a hub!
Strange video output: It has a mini-DVI. Never seen one before. Oh well, I don't have another monitor, so it's not a big problem.

And I can't remember anything else... but I only have the laptop for 4 days!

Don't get me wrong, I love my Mac! But, like all things, it has some downsides. And the biggest one AFAIK is the non-open nature of this platform. Still, if I was going shopping again today, I would still buy the Mac!

Reso. not supported

2008-05-03T15:07:00.002+01:00

I bought a 500Gb Iomega Screenplay HD. I needed some place to backup my photos, and since I don't like watching long videos sitting at the computer, I figured a multimedia drive was the way to go.

I tried it out with a bunch of videos and it seems to work pretty good. It supports enough formats, it has support for subtitles, and it lets me see my photos (though it is a bit slow showing pictures).

Then I tried another video that I really wanted to watch, and I got this error:

Reso. not supported

I must confess it took me a bit to understand that it meant "Resolution not supported"! After I got finally got that, the solution was obvious! Change the resolution of the video.

To do that I used Avidemux. It is very easy to use and has these "Auto" configurations that basically do exactly what you want. All I had to do was open the video, select "Auto/DVD", configure to do a single pass (double pass is the default, but it takes twice as long to convert), and wait. Now I can see the video on my multimedia drive!

Problems with Picasa 2 in Ubuntu

2008-05-01T00:19:00.001+01:00

I've upgraded my Ubuntu installation to Hardy Heron.

I had some new photos to check, so after installing the system the 1st thing I did was get Picasa. I ran the software, it started scanning my hard drive, and it just didn't go past the 5th photo folder on my hard drive (I've got about 400 photo folders).

I immediately cursed the new Ubuntu release, because after my upgrade to Gutsy Gibbon I also had problems with Picasa.... but turns out that this time the problem wasn't in Ubuntu, it was in Picasa.

The symptoms of the problem are:

Hard disk always on
Computer stand still... even the mouse moves slow
No matter how long you wait (I left the computer working over night) nothing happens

The solution is a bit drastic, but it works. Basically Picasa is generating huge invalid Picasa.ini files, and those are messing the system. All you have to do is delete the invalid files. One easy way to spot them is by their size:

find . -size +512 -name Picasa.ini

To make Picasa get back on track, just delete them. You can use xargs to do this:

find . -size +512 -name Picasa.ini | xargs rm

or (if you have directory names with strange characters):

find . -size +512 -name Picasa.ini -print0 | xargs -0 rm

Note that this will not destroy any of your photos, but it will destroy any changes you made to the photos in Picasa, like crops, tunnings, ...

Registry entry for Java Preferences

2008-04-01T22:25:00.003+01:00

Java Preferences in Windows are stored in the registry entry:

HKLM\Software\Javasoft\Prefs\

and

HKCU\Software\Javasoft\Prefs\

There, now I don't have to dig this information on the net again!

What can you see with a 60mm telescope?

2008-03-30T22:31:00.003+01:00

Like every other geek, I love astronomy and most things related to space. I never truly pursued this topic, apart from the odd article on NGS, but now I get to use a telescope on the weekends.

The telescope ain't that much, but it ain't that bad either. It's a 60mm Konus, with equatorial mount and a motor (which basically means I can point at an object, turn on the motor and the motor will make up for Earth's rotation).

One of the things I would like to know is what can you see with such a telescope. Oddly enough, I still wasn't able to find a comprehensive list on the net... so here's what I was able to see so far: (I've only used the telescope 3 times, so I hope the list will grow in the future!)

Moon: Excellent view, great contrast on the craters. I plan to look at it with a lot more detail.
Saturn: I was able to see the rings without a problem. I still wasn't able to see the Cassini Division, but I'll keep trying. I was able to see a bit of the texture of the planet, but it's mostly a small white ball. I was also able to see one of the moons of Saturn (Dione, I believe).
Mars: I've seen it without much detail, because right now it is way up in the sky and therefore a bit uncomfortable to watch. Still, it is rather small, and the only detail I was able to see was that it was only partly lit by the Sun.
Orion Nebula: You can see the trapezium cluster without a problem, as well as the nearer 3 stars. But the nebula itself is rather faint, and you can only see the brightest part. And even that is only a small blur.

Next, I plan to see the Sun (I'll need to buy a filter), Jupiter and some other Messier objects. (I'd really like to see the Whirlpool Galaxy, but I still wasn't able to spot it... don't even know if it is visible with my telescope!)

Creating an SVN repositoy

2008-02-18T21:18:00.003Z

I do a bunch of personal projects and, in the spirit of keeping it all under source control, I always create an SVN repository for all of them (even if I don’t finish them… after all, I suffer from NADD). Because I like to automate everything, here’s the script I use to startup projects:

#!/bin/sh
TMPDIR=/tmp/svntmpdir
REPODIR=/home/rsc/Documents/repositories
REPOURL=file://$REPODIR

if [ $1 == ""] ; then
    echo Usage: $0 {repository name}
    exit 1
fi

echo Creating directory structure
echo $TMPDIR
mkdir $TMPDIR
mkdir $TMPDIR/trunk
mkdir $TMPDIR/branches
mkdir $TMPDIR/tags
echo Creating repository $1
svnadmin create $REPODIR/$1
cd $TMPDIR
svn import $REPOURL/$1 -m "Initial structure"
echo Checking out
cd -
svn co $REPOURL/$1/trunk $1
echo Cleaning up
rm -Rf $TMPDIR
echo Done!

MySQL fails to start on Gutsy

2007-12-01T21:16:00.000Z

For some reason, mySql wasn't starting up on my machine. It was easy enough to find the cause just by looking at the log. Apparently there was no /var/run/mysqld directory where mySql could write to. So I created the directory, gave the required permissions and didn't give it a second thought.

Turns out that when I rebooted my computer, mySQL wasn't starting again! The directory wasn't there anymore! Because I don't want to have to create the directory and start mySQL by hand each time the computer restart, here's what I did:

sudo gvim /etc/init.d/mysql

Just after the 'start') string I added the following content:

'start')
  # Create directory in /var/run
  if [ ! -d "/var/run/mysqld" ]; then
      mkdir /var/run/mysqld
      chown mysql.mysql /var/run/mysqld
  fi
  # All done

Changing the default gateway using Network Manager

2007-11-29T22:29:00.000Z

I have an oddball network configuration at home. I have a wireless D-Link router that connects to a Huawei router that in turn connects to the internet. So far so good.

The problem is that I want to use the D-Link router DHCP Server, but I want to use the Huawei router as default gateway... and there is no way to specify that in the D-Link router.

The solution I had so far implied setting the connection manually in Ubuntu, and that works fine... Apart from the fact that I have no fast way of setting up a VPN! So I decided to give it one more go with Network Manager, and turns out it is pretty easy to change the default gateway for a particular interface.

To do that, just create a file in /etc/network/if-up.d/ and call it gwconfig for instance.

sudo gvim /etc/network/if-up.d/gwconfig

In that file, check for the interface that you want (e.g. eth1), delete the default gateway that is messing up your system (e.g. 192.168.0.10) and add the the one you really want (e.g. 192.168.1.1).

#!/bin/sh

if [ "$IFACE" = "eth1" ]; then
 route delete default gw 192.168.1.10
 route add default gw 192.168.1.1
fi

Make sure you make the file executable and you're done.

sudo chmod a+x /etc/network/if-up.d/gwconfig

Set the network to Roaming Mode, and all should work fine. If it doesn't, try to disable and re-enable the network on Network Manager.

Btw, I still wasn't able to make the VPN work with this configuration... more on that later.

Greasemonkey tips

2007-11-22T21:45:00.000Z

Greasemonkey is a great Firefox add-on that allows you to add custom JavaScript to any web page. This simple concept allows you to do extraordinary changes to a web page and you can find a lot of pre-made scripts around. But if you want to do your own scripts, there's a few things that you should know before you start...

Registering events
Let's say you want to catch a button click. Here's how to do it:

var button = document.getElementById(buttonId);
button.addEventListener('click', myFunction, false);

Don't do stuff like button.onclick = "myFunction()" or even button.onclick = myFunction. It won't work.

Accessing element properties
Suppose you want to add some information to a link that you created to use during the onclick event. You must do it with:

lnk.setAttribute("attrName", value);

and fetch it with:

lnk.getAttribute("attrName");

Doing lnk.attrName or lnk["attrName"] will not work, and will return null when you access it.

Parameters in Event Handlers
Let's say you registered an event like mentioned above. The event always receives a MouseEvent argument, so you should declare the function like myFunction(evt). This is important because if you by accident register as an event handler a function that takes a boolean paramenter, like myFunction(flag), flag will always be "true" when called from the event.

Stopping the bubble
Assuming you defined your function like mentioned earlier, myFunction(evt), you can stop the event from bubbling by calling

evt.preventDefault();

Testing functions
Because Firebug is such a great tool to debug your scripts, you may want to check for Grasemonkey functions before you use them. Do it with something like:

if (typeof(GM_getValue) != "undefined")

And you should be able to run the script outside Greasemonkey for easier debugging.

More tips
Well, so far these were the problems I faced! :-) I'll update this as I keep discovering Greasemonkey's idiosyncrasies.

Upgrading to Gutsy Gibbon

2007-11-01T23:11:00.000Z

Ubuntu has launched a new release last October, Gutsy Gibbon. I was really eager to try it out, so I clicked the magic button to do the upgrade, just like I did last April.

Turns out that this time things weren't so easy... For some reason my Update Manager had been giving me trouble for a couple of weeks. And the Gutsy upgrade was the worst time for things to go really bad.

To start with, the upgrade seemed to stop at some point for no apparent reason. Because the upgrade script is made in Python I decided to try to figure out what was going on. For some inexplicable reason, the confirmation dialog was freezing the installation... so I removed the call to the dialog and things seemed to move forward.

Obviously my happiness didn't last long, and the process stopped at the middle of the installation. No chance but to boot the computer and be prepared for the worst. Turns out the computer booted OK, Ubuntu loaded, but the system was so mixed up with new and old stuff, that X didn't start and apt-get was unable to recover the situation... oh well...

Still, I had text mode so I was able to backup all the things that I should have backed up earlier. I booted Windows and downloaded the Gutsy CD. And then I reinstalled everything.

Internet privacy with Firefox

2007-08-24T21:46:00.000+01:00

If you don't want your girlfriend to know what you're watching online, you can use Firefox profiles to clear your footsteps. Here's how:

Start by printing this page, because you'll have to close Firefox in order for this to work. Next, launch Firefox with the -p option. If you're in Ubuntu, you can do this by pressing Alt-F2 and typing firefox -p at the "Run Application" window.

The profiles window will appear with only one profile called "default". Create a new one (let's call it private), select it and start Firefox. Next, go to "Edit", "Preferences" and in the "Privacy" tab untick all the "History" options. Tick the "Always clear my private data when I close Firefox", click the "Settings" button and tick all the boxes. Your private profile is now ready!

Now close Firefox and open it again with the -p option. Select the "default" profile and set the "don't ask me on startup" option. Run Firefox and make sure you have the old profile back (with history and all). Of course I'm assuming that's what you want by default.

From now on, each time you want to navigate to websites you don't want your girlfriend to know about (say, because you want to surprise her with a valentines gift), just execute Firefox by typing firefox -p private.

Sending emails via Gmail with Python

2007-08-22T23:20:00.000+01:00

Whenever I need to send files from work to home I use gmail. Usually this email message consists of one single file (that may be a tarball) and has the file name for subject. In the "Automate Everything" spirit, I decided to build a script to do this task for me.

The first thing I had to do was find out how to send an email with an attachment via gmail. It wasn't too hard to find this information around the web, but it still took me the best part of an hour. So here's a simple Python script that sends an email with an attachment:

#!/usr/bin/python

import smtplib
from email.MIMEMultipart import MIMEMultipart
from email.MIMEBase import MIMEBase
from email.MIMEText import MIMEText
from email import Encoders
import os

gmail_user = "your_email@gmail.com"
gmail_pwd = "your_password"

def mail(to, subject, text, attach):
   msg = MIMEMultipart()

   msg['From'] = gmail_user
   msg['To'] = to
   msg['Subject'] = subject

   msg.attach(MIMEText(text))

   part = MIMEBase('application', 'octet-stream')
   part.set_payload(open(attach, 'rb').read())
   Encoders.encode_base64(part)
   part.add_header('Content-Disposition',
           'attachment; filename="%s"' % os.path.basename(attach))
   msg.attach(part)

   mailServer = smtplib.SMTP("smtp.gmail.com", 587)
   mailServer.ehlo()
   mailServer.starttls()
   mailServer.ehlo()
   mailServer.login(gmail_user, gmail_pwd)
   mailServer.sendmail(gmail_user, to, msg.as_string())
   # Should be mailServer.quit(), but that crashes...
   mailServer.close()

mail("some.person@some.address.com",
   "Hello from python!",
   "This is a email sent with python",
   "my_picture.jpg")

Dual monitor in Ubuntu

2007-08-15T14:44:00.000+01:00

I bought a new 32'' LCD TV. A Samsung LE32S62. The TV comes with a VGA connection, so obviously I had to connect my laptop to it!

The first challenge was making Ubuntu work with dual monitor. I did a few searches on the web and found a few instructions on how to do this. I ended up with a rather simple configuration. Just edit the /etc/X11/xorg.conf file and add the following under the "Device" section. (NOTE: I'm using an nVidia graphics card. This may be different for your card)

Option "TwinView" "on"
Option "TwinViewOrientation" "RightOf"

Next restart X (Ctrl-Alt-Backspace) and you should end up with dual monitor. This isn't exactly brilliant, because the TV ended up as the main monitor, and I would prefer to have the laptop as the main monitor. But after a bunch of failed tries I just gave up. After all, I don't think I'll use this setup a lot of times. (but I am thinking on recovering my old computer to use it as a media center!)

Here's a couple of pics of the setup:

Setting up xorg.conf with gvim

Watching a movie with VLC

Back to basics: Vi

2007-08-12T14:29:00.000+01:00

I've been doing a lot of programming in Ubuntu, mostly in PHP (my sister's in law web site), Perl and Python. I tried a lot of editors and (so called) IDEs, but was never happy with any of them. So I went back to basics: using Vim.

Now, I can ear the screams of Emacs users and the cries of all of you who only learned the :q! shortcut to exit Vi as soon as possible, but here's my view on things:

Emacs users: I tried using Emacs. I really did. And I actually used it for a long time while I was in college. But after using Vi for a while I had a really hard time both remembering the shortcuts and configuring Emacs to behave like I wanted to. So I just stuck with Vi.

:q! users: Vi is not that hard. Really! It does need a bit getting used to, but the freedom of not using the mouse and all those small shortcuts that you think you'll never use but turn out to be extremely useful make up for the learning curve.

To speed up your learning curve, here are the two secrets to loving Vi:

A proper .vimrc file
Knowing the right commands

Because there are so many "right commands" I'll leave that to a later post. Let's focus on the .vimrc file for now. And just to get your expectations in the right place, I'm not a Vim power user. If you look the web for .vimrc files you'll find files with hundreds of lines of code. Mine has 25, including comments... But it makes Vim behave like I want, so it's enough. Just go through the code and comments and you'll be able to understand what the configurations do. If not, drop me a line.

NOTE: The last 2 lines are wrong! Instead of [ you should have <. And instead of ] you should have >. But Blogger does a really bad job with these 2 characters....

" Turn on syntax highlight
syntax on
" Set tabs to 4 in size and make sure autoindent is on
set tabstop=4
set autoindent
" Make backspace work as in most editors
set backspace=indent,eol,start
" Black background and white foreground
highlight Normal guibg=black
highlight Normal guifg=white
" Make the default window size 50x80
set lines=50
set columns=80
" Store temp and swap files in this directory
set directory=/tmp/
" Show the status line
set ls=2
" Set the status line to:
" Filename [Modifed & Readonly Status] line number/total lines column (#buffer)
" More info at:
" http://www.winterdom.com/weblog/CommentView,guid,3372fa1e-966e-4389-b2ba-bb2ce527f52a.aspx
let &stl="%f %([%R%M]%)%=%l/%L %c (#%n)"
" Map Ctrl-Ins and Shift-Ins to clipboard copy paste (FIX THIS!!!)
map [C-Insert] "+y
map [S-Insert] "+gP

Objects in Perl? Use Python!

2007-08-11T16:00:00.000+01:00

I've been meaning to try Python for a while. I'm kind of a sucker for programming languages, and knowing a bunch of languages allows me to choose the right tool for the right job. Turns out that this week I had the perfect opportunity to check out Python.

The task at hand was analyzing patterns in a bunch of XML files. I had 270Mb of XML files, and the largest file was 32Mb. Because I was pretty sure I was executing the analysis more than once (errare humanum est and I want to improve the analysis in the future) I decided to use SAX to read the files.

Having decided to use SAX I then decided to use Perl to do the job. I'm pretty familiar with it and was able to quickly find a SAX sample. Besides, I had a few string matches and replacements to do, and Perl is a great language for that.

Turns out that using SAX in Perl demands that you use and define objects in Perl. And it turns out that defining objects in Perl is... well, terrible! I really hated the syntax, bless and the way attributes were defined. It all looks like a big hack! To add insult to injury, the perlSAX has a few quirks when changing handlers. This is mandatory to make your SAX code maintainable... So I dropped Perl and went for Python.

To my surprise the transition was really easy. I was able to convert my Perl code to Python very quickly, with only a few doubts now and then on specific stuff. Here's what I gained from the transformation:

I learned Python (finally!)
Better SAX handlers (the quirks that happen in Perl don't happen in Python)
Clearer attribute access (if you have an object with a reference to an array of references and want to print it in Perl... things can get weird)
Clearer object definition and usage (no bless!)
Fewer lines of code (from ~250 to ~150)
Same performance (I was worried about this, but both scripts took the same time to execute!)

I still love Perl. If I want to parse a bunch of text files, do text transformations and the like it will be my 1st choice.

But whenever I need to do something a bit more complex that requires complex data types or OO programming, from now on I'll definitely turn to Python!

Web Testing

2007-07-29T21:54:00.000+01:00

Last week I updated my sister's in law web site to have expanding folders. The solution I implemented is far from perfect but it does the trick. And since I used the prototype framework for the JS code, I figured it shouldn't have any problems in either IE or Firefox. I was wrong...

Turns out I forgot to test the web site in IE, and the first time my wife went there to take a look, it didn't work. Apparently nextSiblings doesn't work properly in IE... so instead of:

my_element.nextSiblings()

I had to do:

Element.nextSiblings(my_element)

This is really a pain for me because it means I have to test the site in both IE and Firefox all the time. And since I use Ubuntu, that didn't seem like an easy task. Wrong again!

There's a project called IEs4Linux that allows you to run IE on any computer that runs Wine. So I followed the instructions on the website, installed the thing, and in about 5 minutes (mostly because of download times) I was running IE 6 on my Ubuntu machine. I actually found out and solved the above problem all in Ubuntu. Sweet!

Use source control. Always!

2007-07-22T14:16:00.000+01:00

So you're doing this simple project, you have a bit of PHP, a bit of mySQL, you add a dash of really cool JavaScript, you publish it to the server and... BANG! Everything stops working!

Guess what? It happened to me this week. Because of a rather simple thing, actually. In my development machine I have mySQL 5, and the server machine has mySQL 4. My beautiful queries were all failing.

It actually took me about 2 minutes to fix the problem. Get the latest running version from source control (I'm currently using SVN) publish it and that's it. And during those 2 minutes I just kept thinking, "I'm *so* glad I have this in source control!"

Listen to experience. Use source control. Always!

Video Editing and Ubuntu

2007-06-29T21:18:00.000+01:00

Last weekend I had to edit a video for work. It was nothing too fancy. I had about 45 minutes of video on tape and I wanted to save parts of it to my computer (the takes). Then I wanted to cut the takes into pieces (the scenes), edit it as I pleased and add some background music.

Let me go straight to the conclusion: I gave up and did it all in Windows. How depressing...

I was able to capture the video to disk without problems (I think I used Kino for that), but the editing part was really bad.

I tried out Pitivi but it just hang after a few clicks. Then I tried Kino but unfortunately it is too basic. No ability to add the background music (actually I think there's a way, but 2 audio channels is still to limited).

Then I found Cinelerra. I tried everything to make Cinelerra work properly, I even fixed the dreaded startup error regarding the shmmax parameter. And although the software looks very promising, it is full of bugs that make it completely unusable... It's a shame really.

I did manage to do a test video in Cinelerra. The video had cuts, background music, the works. But while doing this video the preview was out of synch (and that makes editing really hard), I had to restart the software at least 20 times (no kidding) and when I got to work with my new video to show my colleagues what a great editor I was, I couldn't make it play on a Windows machine!

So I went back to my Windows partition, installed VirtualDub and another video editor I can't remember the name right now and was able to do the job hassle free... 1 down for free (as in speech) software. :-(

PS: To fix the dreaded startup error regarding the shmmax parameter edit the file /etc/sysctl.conf and add the following:

# make cinelerra happy
kernel.shmmax = 2147483647

You'll need to reboot for the changes to take effect.

Why I am not buying a Mac

2007-06-13T14:22:00.001+01:00

Yearly this year I was strongly considering buying a Mac. The design is so cool, OSX seems like a great OS, they have TextMate and people I know that own Macs don't miss a chance to tell me how great it is.

But as time went by I changed my mind. Here's some of the reasons why this happened:

The $$$ factor: I don't really need a Mac. Actually, I don't even need a new PC. It's a way too expensive whim.
iPod: I own an iPod. I love it. It's a great MP3 + video player but it does have its flaws, specially when it comes to iTunes. There's just some things it won't do right (like podcast handling) and it has a few bugs that cause my artwork to vanish from time to time. Fortunately Media Monkey solves my problem, but it does make me wonder about other Apple software.
It burns: A friend of mine has a MacBook Pro. The hand rest heats to a point where it is actually uncomfortable to rest your hands. This is an issue to me because I actually use the hand rest to... well, rest my hands! I returned a laptop because of this same problem, so it's a no go for me.
Safari: I downloaded Safari for Windows. It crashes as soon as I type something in an input box. Again my faith in Apple software went downhill.
Ubuntu: When I first considered buying a Mac I was using Windows. My machine was getting slower and slower by the day, so I believed I needed a new machine... Now I use Ubuntu and that problem is gone. And Ubuntu may not be as cool as OSX, but it is a cool enough OS.
Fanatics: The legion of Apple fans makes me more uncomfortable than reassured. They always assume Steve Jobs is right and that everything about Apple is great. This means they have a high tolerance to problems and that they don't talk about those problems. This is not an exclusive problem of Apple, it's a problem that occurs every time a technology issue is turned into a religious war (think Emacs vs Vi!).

With all this in mind I'll save my $$$ and keep this not so fast machine for at least another year.

Scribus vs Inkscape

2007-06-13T00:43:00.000+01:00

My sister in law is having an exhibit next week. To help her out I did the paper invitations during the weekend. This was the first time I needed to do something like this in Ubuntu, so I did a test drive on two applications.

Due to an article on Full Circle Magazine I decided to give Scribus a go. I already new Inkspace by name so I also gave it a try.

The short of it: Use Inkscape. If you want to know why, here's the details.

Scribus
Scribus annoyed me a bit. The first bad experience was with the "new document" menu. It doesn't save your settings! I was doing a few experiments so I had to start new documents quite often... and typing all the settings all the time is a drag (I had to change 4 values for the margins and 1 value for the units).

The next thing I disliked was the line tool. When you draw a line it stays red (because it is selected) and wider than the line you actually draw. Pretty bad for WYSIWYG. Also, moving the thing around had some odd behaviors....

The next problem was undo. Not sure what it actually did... Sometimes it worked, sometimes it didn't... sometimes it did odd things. Like after moving the line, undoing deleted the line. Pretty bad.

The final annoyance was with the snap to guides. I set the option but it did nothing... it just kept not snapping. I gave up at this stage.

Inkspace
No questions asked when the software starts, the document is already there and it actually has the settings I wanted to use. Not bad.

Drawing lines was also as I expected, and after a web search on how to snap to the guides, it worked OK. And undo did what I expected.

After I did a bit of work on the actual invitation, I decided to move the files around to organize my folders. Turns out Inkspace stores the pictures as references, so I lost all the pictures I had in the drawing (about 9 pictures). Restoring the references seemed like a drag, but since the save format is SVG I was able to use a text editor and perform a simple find and replace! Not bad.

Then I wanted to add a new page. I wasn't able to find out how to do it! Fortunately there is the concept of layers, so I just used one layer for each page. I could have used another document, but since the invitation isn't that complex this solution was good enough.

Time to print! This was another surprise. You actually need to know the lp command details and how CUPS works to do some basic printing tasks (like printing more than one copy in normal mode). So much for a grandma friendly application. But at the end of the day I managed to print everything without a problem and the invitations were sent on time.

Here's the final result:

Printing to PDF

2007-06-07T17:35:00.000+01:00

If you need to print something to PDF in windows, you can do it with doPDF. I know there's a lot of other software that does exactly the same thing, but this one got my attention because:

It is small (about 1Mb)
It is free (as in beer)
It is easy to use...
...but has advanced features for when you need them

In about 5 minutes (including download and installation) I had just what I wanted: a Word document printed in PDF, page size A4, 150 dpi's. Cool!

VPN in Ubuntu

2007-05-27T22:37:00.000+01:00

After my previous attempt at creating a VPN in Ubuntu I reverted all my work because I was rather unhappy with the results. After digging a bit more I found out I could actually use pptpconfig, as long as I didn't actually clicked the "Start" button. Here's the trick:

Start by installing pptpconfig. Add the following to your /etc/apt/sources.list file:

# James Cameron's PPTP GUI packaging
deb http://quozl.netrek.org/pptp/pptpconfig ./

Then install the app:

sudo apt-get update
sudo apt-get install pptpconfig

Now run it (sudo pptpconfig) and configure your VPN. In the "Routing" options, select "Client to LAN". Lets assume you called your new configuration MyVPN.

You can close pptpconfig. Go over to /etc/ppp/ip-up.d/ and create a new file called vpnroute (sudo gedit vpnroute). Assuming that the network you want to connect to uses IPs like 192.168.0.*, add this to the file:

#!/bin/sh
if [ "${PPP_IPPARAM}" = "MyVPN" ]; then
   route add -net  192.168.0.0 netmask 255.255.255.0 dev ppp0
fi

Don't forget to make it executable, or it won't work:

chmod a+x vpnroute

And that's it. To start your VPN run:

sudo pon MyVPN

To stop it run:

sudo poff MyVPN

VPN in Ubuntu using Network Manager

2007-05-27T12:23:00.000+01:00

UPDATE: I found a better way to connect to a VPN. Check this post.

Imagine you have a Windows Network at work and you're stuck at home waiting for the plummer to fix the sink. No problem, just connect via VPN to your workplace, launch a Remote Desktop and in no time you're working in that piece of code you must deliver yesterday. Being this such a useful and common scenario, how come it is so hard to set up in Ubuntu?

Here's how I managed to connect to my workplace via VPN using Ubuntu. Let me say upfront that I'm not particularly happy with the result, and I'll try to do it some other way in the near future. But if you're desperate this will do. This is not an How To, but rather a step by step description of the tries and failures. Maybe it can help someone that finds the same error messages I've encountered. Well, here goes:

First I tried pptpconfig. Everything seemed to be properly configured, but all I got was the error message:

Cannot determine ethernet address for proxy ARP (Update: Actually this is not a problem. Just add noproxyarp to the pppd parameters.)

So I decided to install the Network Manager PPTP package:

sudo apt-get install network-manager-pptp

And restarted everything that depended on the package:

sudo /etc/dbus-1/event.d/25NetworkManager restart
sudo /etc/dbus-1/event.d/26NetworkManagerDispatcher restart
killall gnome-panel
nm-applet &

The killall and nm-applet commands are there to restart the Network Manager icon on your gnome panel. If for some reason the Network Manager icon does not appear (happened to me) just execute:

sudo /etc/dbus-1/event.d/25NetworkManager start
killall gnome-panel
nm-applet &

If you click the Network Manager icon now, you should have a "VPN Connections" entry. Just configure your own VPN connection and it should appear in the list of VPNs. Click it. If it works, you're in luck. If it doesn't, keep reading.

To keep an eye on what's going on with the VPN connection, just tail syslog:

sudo tail -f /var/log/syslog

That's how I found this error message:

(...) no currently active network device, won't activate VPN.

I googled for a while and found that if you want to use Network Manager to take care of your VPN, you cannot have a Wireless Connection manually configured. Oh boy... So I opened the manual configuration, saved my current configuration and in the properties of the Wireless connection ticked the box "Enable roaming mode". Because I have a somewhat odd configuration of routers at home, I also had to reconfigure all the routers, but I won't bother you with that.

My main problem with the roaming mode is that it stores the WEP password in the keyring. That's all fine and safe, but it means that when I login, besides having to enter my username and password I also have to put my keyring password! Very annoying!

On with the show. Connect VPN. More mysterious errors in syslog:

LCP terminated by peer (+ bunch of characters blogger won't let my type)

This is a funny one! First because it was a bit lost in the middle of a bunch of error messages. Second because, at least to me, it means absolutely nothing! Using a bit of intuition I thought it might be an authentication problem, so I just ticked all the boxes in the "Authentication" tab in the VPN configuration dialog and... it worked! I have a VPN connection to my workplace!

Just for wrap up, here's what I didn't like about all this:

It's a lot of work for something so common.
Because the WEP is in the keyring I must enter the keyring password each time I login.
I must use roaming for my wireless connection. This means the router must do the configuration, and my routers suck at that.
PPTP logs are there for the people who know the code or the protocol by heart.
~~I'll probably just revert to my old configuration and try a new way of connecting via VPN.~~I got back to my old configuration and managed to configure the VPN in a different way.

Ubuntu, NVidia and Automatic updates

2007-05-26T11:59:00.000+01:00

So you have your Ubuntu system up and running, you click the button to do an innocent software update and suddenly... Bye bye X! What happened?

Well, during my upgrade to Feisty I installed the NVidia drivers' packages and they were updated. And since for some reason Ubuntu's NVidia drivers still don't work, I lost my X! So, once again, it's back to w3m to download and install the NVidia drivers from NVidia's website...

This is easy to solve, but I would rather that it didn't happen again. So I removed the Ubuntu packages from my installation.


sudo apt-get remove nvidia-glx
sudo apt-get remove nvidia-kernel-common

After doing this you must reinstall the NVidia drivers, because removing these packages also deletes a bunch of required files. As a bonus, you win about 100Mb of free space. :-)

Automate Everything!

2007-05-20T12:06:00.000+01:00

The other day, while waiting for another computer reboot or something similar, I grabbed The Pragmatic Programmer from the shelf. I already read the book, so I was just quickly browsing the tips in the book when I found this one: "Automate Everything". (you can find it by looking for "Don't Use Manual Procedures" in the previous link).

I already do this at work, but I started thinking it would be a really good idea to start applying this principle to my home projects. Take my sister's in law website. Here's the procedure I use to upload it to the server:

Open googleanalytics.txt and copy the contents
Open pageend.php and paste googleanalytics.txt content
Open gFTP
Open KeePassX to fetch the site's password
Use gFTP to transfer some of the directories in the development folder (this actually counts as about 10 steps!)
Check if I didn't make a mistake in the gFTP 10 steps!
Open pageend.php and remove googleanalytics.txt content

Some notes on these procedures: I never did steps 1, 2 and 7. It was too much work so I never actually got Google Analytics to work until yesterday. I'm not kidding about step 5 being about 10 steps... I actually uploaded the folders one by one to make sure I got all the right files and that the .svn folders weren't copied. This may seem rather stupid, but since I executed this procedure about once a month it wasn't really a problem, just a nuisance.

Still I decided to automate everything. I did a shell script and right now I have a one step procedure to upload the site:

Run ./publish.sh

And what did I gain with this 2 hour or so investment?

I learned more about bash programming
I learned how sed works
I learned about wput
I got Google Analytics working on the website
I'll be doing no more mistakes while uploading the site
I can make small changes to the site without thinking about the dreaded upload process
I feel like a better geek! :)

Sandboxie

2007-05-12T18:40:00.000+01:00

Are you looking for the best free text editor? Looking for the best wma to mp3 converter? It is quite easy to find free software to do these tasks, the problem is that after you install and test them all, your Windows installation is suddenly filled with registry entries and software you really don't want!

A while a go while browsing LifeHacker I read an article about a software that promised to end these troubles: Sandboxie. So I gave it a try.

I had some wma files to convert to MP3 files and found this free converter, so I installed Sandboxie and run the installer of the software. Everything went OK and the software was installed. I then run the free converter inside the Sandboxie and converted the files. Sure enough the converted files only appeared in the special folder selected by Sandboxie to be the sandbox.

I copied the MP3 files to a real folder on disk, turned off and cleared the contentes of the sandbox. And my Windows installation was exactly what it was before I installed the converter!

I only wished I knew about this software before testing 14 different text editors and totally trashing my Windows installation.

Upgrading to Feisty

2007-04-28T21:30:00.000+01:00

With all the media coverage Ubuntu Feisty is getting in slashdot, digg and others, I started thinking about doing the upgrade myself. I was just thinking how great it would be if there was just a simple button to click when I got the usual desktop notification from the Update Manager. And guess what? It had a button to upgrade to Feisty! So I clicked it.

What I loved about the upgrade:

The button!
The warnings about low disk space at the start, and not 20 minutes into the installation
The download speed (it took about 25 minutes to download... I didn't know my ISP could do 900kb/s!)
After the upgrade, stuff that wasn't working on my box started working again (Picasa)

What I didn't like so much:

The warning about the disk space tells you how much space you need to free up, not how much space you need free (who reads the fine print anyway?)
There are dialog boxes in the middle of the installation. It was late at night when I started the installation, and the estimated time was 45 minutes, so I went to sleep. When I woke up there was a question waiting for me and 40 more minutes of installation time.
My NVidia graphics adapter wasn't working after the upgrade. And installing it with apt-get didn't work either. I had to get the drivers from the NVidia web site, not an easy task when all you have is a text console and w3m.

But all in all everything went fine and I've been using my brand new Ubuntu release since morning. If you're using Ubuntu, click the button!

3 Cheers for Open Source!

2007-04-21T23:02:00.000+01:00

I'm a great user and adept of free software, but I must confess that I'm more attracted to the "free beer" side of things rather than the "free speech".

But for some reason each time I change a bit of open source code and make things work just like I want them to, it gives me an enormous satisfaction! There's 3 episodes that I really enjoyed on my open source adventures:

1. I patched the linux kernel! It was just a small patch to make my CD-Rom drive work, but it was tremendously rewarding to see the little light blink on that drive! (I didn't publish this one because it was a really old cartridge 1x CD-Rom drive)

2. I patched Kannel. This was amazing because I did the patch at the same time someone asked for it on the mailing list. So I send it to the mailing list and it is now part of the Kannel code!

3. I've been trying out Total Commander on Windows. It's a really good file manager and has an iPod Plugin. Turns out the plugin doesn't work with newer iPods. But since the source is available at the author's site, I downloaded it and fixed the problem! (I'm now talking with the author to get the patch published)

The funny thing is I believe I would've done the same even if the software wasn't free as in "free beer". Actually I would be thrilled to be able to fix some bugs and annoyances in some paid applications. Unfortunately I don't have access to the source code, so I'll just have to live with them...

Wacom Graphire 4

2007-04-06T16:29:00.000+01:00

I bought a Wacom Graphire 4! I'm an engineer, not a designer, but I do like to make the occasional drawing and I was on the lookout for a pen tablet for a while.

I bought it yesterday and installing it was as smooth as you would expect... just plug it in and it works, add a few drivers and you can use all features (so far I only installed it on Windows). I was very happy to see that neither the pen nor the tablet need bateries. Just plug in to the USB port and everything is working.

I installed Corel Painter Essentials 3 (it is bundled with the pen tablet) and started sketching. It's really awkward when you start, because you keep doing "mouse gestures" all the time. I raised my hand, moved it to the left and when I placed it down again I was surprised to see the pointer going way to the left instead of staying in the same place!

But I eventually got used to it and draw the mouse that you see here... My very first pen tablet drawing!

OutSystems Express Edition

2007-03-28T20:00:00.000+01:00

If you're looking for a fast way to build an enterprise application, if you want to be able to change it even faster and if you want it for free, OutSystems Express Edition is the answer!

I've got to be honest here. I work for OutSystems so you may consider my opinion to be a little biased. But the great thing is that by subscribing to the beta program you can see for yourself how fast it is to create a web application using the OutSystems Platform.

So go ahead! Register now for the beta program, wait impatiently for the "Welcome to the Beta program email", take a look at the bundled IT Asset Manager and build your own web application!

Don't forget to send us all your feedback about the OutSystems Express Edition so we can improve the product! And feel free to exchange ideas with other OutSystems users at the OutSystems Community!

Happy developing!

Change Gnome Splash Screen

2007-03-07T23:00:00.000Z

So you just changed your entire Gnome theme, your Ubuntu installation is finally that great shade of blue you really love, you customized your login screen to use transparent png's and it just sparkles and... After you login the gnome splash screen is still Ubuntu brown!

Don't worry! It can be fixed... and tested! Just create an image (jpg or png) and copy it to /usr/share/pixmaps/splash/. Now launch a terminal window and type gconf-editor. This will launch the Gnome Configuration Editor.

Navigate to apps >> gnome-session >> options and change the splash_image to your image name. That's it!

Now to test it without logging out. First install Xnest: sudo apt-get install xnest. Now go to a terminal window and type gdmflexiserver --xnest.

This will launch another login session inside a window, so you don't have to keep logging in and out to test your new splash screen!

Beryl: Desktop Fireworks

2007-03-02T18:51:00.000Z

If you want to make your Ubuntu desktop really come to live, Beryl is the answer. It's an accelerated OpenGL desktop manager that gives you a lot of ~~bells and whistles~~ visual feedback on your window manager operations.

Installing is not as simple as you might wish, but it isn't too hard either. On the Beryl wiki there's an entry on how to install Beryl on Ubuntu and you can basically follow that.

The only notes I have on the installations steps are:

I had an error message while starting Beryl. As a consequence I had no window manager! The message was:

beryl: No GLXFBConfig for depth 32

After doing some searches on the web I found a post that gave a solution to this problem. Just add the following to "Device" section on your /etc/X11/xorg.conf file:

Option "AddARGBGLXVisuals" "True"
Option "DisableGLXRootClipping" "True"

Also I skipped the entire "Configuring Beryl" section and just added beryl-manager to my Startup Programs in System > Preferences > Sessions

Next you have to configure Beryl. There's a ton of options, animations, keyboard shortcuts, themes, etc, etc that you can tweak with to make your desktop look exactly like you want it to! And if you have a bit of patience and 28Mb of spare memory to run Beryl, it's really worth the trouble.

Touchpad in Ubuntu

2007-02-24T13:37:00.000Z

Ubuntu installations come with a mouse setup software, but it is a generic software that only allows you to setup stuff like double-click timeout, pointers, speed, etc. If you have a touchpad and want to setup other parameters like tapping speed, you'll have to install GSynaptics:

sudo apt-get install gsynaptics

After installing the software you can find it in the System/Preferences/Touchpad menu. Try to click it and you'll get an error message!

GSynaptics couldn't initialize.
You have to set 'SHMConfig' 'true' in xorg.conf or XF86Config to use GSynaptics

To fix this you need to edit your /etc/X11/xorg.conf file (e.g. sudo gedit /etc/X11/xorg.conf) and find a section like:

Section "InputDevice"
    Identifier     "Synaptics Touchpad"
    Driver         "synaptics"
    Option         "SendCoreEvents" "true"
    Option         "Device" "/dev/psaux"
    Option         "Protocol" "auto-dev"
    Option         "HorizScrollDelta" "0"
EndSection

Before the EndSection add an option with the code Option "SHMConfig" "on".

Now you need to restart X. Make sure you save all your work, because restarting X will log you out. Now press ctrl-alt-backspace. Login and you should now be able to run System/Preferences/Touchpad.

If you still have problems using your touchpad, refer to this complete guide.

Google Earth on Ubuntu

2007-02-19T19:22:00.000Z

Google Earth is a great software to explore your home planet and your neighborhood. But if you have an nVidia video card in Ubuntu you may experience some... rather strange results!

To solve this problem all you have to do is update to the latest nVidia drivers. But if you're lazy like me you're probably asking "Isn't there an easier way?".

Well, the answer is both yes and no. You do have to update the nVidia drivers, but Alberto Milone has a great script called Envy that does all the hard work for you.

Just follow the instructions on the website and in 5 minutes you should have Google Earth running without a scratch!

ICDSoft Appraisal

2007-02-13T23:19:00.000Z

If you're looking for a hosting server, my advice goes to ICDSoft. I host my sister's in law website there and it has all the features I need (PHP, MySql, Ruby, email accounts galore, ...) and I never had a problem with it.

Of course not having problems isn't good enough reason to recommend a hosting service. That's the minimum they can do for you! The reason why I recommend ICDSoft is for their support. Let me tell you about my two experiences with them:

Ticket 1: I tried to place a Rails application on the website. For some reason I wasn't able to make it work, so I decided to contact support. In 5 minutes I had a reply with all the required instructions to make my application work.

Being new to Rails I didn't really understand the response... So I told them something like "I couldn't make it work. Please poke my code and see what is wrong. And fixe it while your at it". And can you believe it? They did look into my code, corrected my scripts, changed the permissions to make it all work and sent me a reply with all they had done... In less than 45 minutes! Now that is great support...

Ticket 2: Still working on my sister's in law Rails version of the website I decided to use RMagick to resize the images and create the thumbnails. I uploaded the website to my account to test it and it didn't work. ICDSoft doesn't have RMagick installed.

So I contacted support. I don't know how long they took to reply, but I think it was about 5 minutes like the first time. The reply said something like "We're talking to the sysadmins and we will contact you soon". And they did!

Less than 30 minutes later I had a reply stating that the sysadmins had installed RMagick. I tested my website again and RMagick was really working!

As a client, my feeling was that they were there working just for me! They edited my code, they installed a package on the server because I asked them to. Never a support service made me feel this pampered!

Compiling Drivel in Ubuntu

2007-02-07T10:45:00.000Z

So you want to use Drivel to add your posts to Blogger, right? By this time you probably noticed that Drivel doesn't work with the new version of Blogger. Shame...

If you look around you'll probably find rumors that the CVS version of Drivel supports the new Blogger login... This is not true, but if you care to compile Drivel anyway here are the steps to do it:

Get CVS: sudo apt-get install cvs

Get the gnome development environment: sudo apt-get install gnome-devel

Install libsoup. This should be easy, something like sudo apt-get install libsoup2.2-dev. Unfortunately it's not so easy. The Ubuntu version of libsoup is 2.2.96 and Drivel needs version 2.2.97! You must go to Debian and search for the needed packages. I've downloaded and installed this one, plus dependencies.

For some reason during the installation of the libsoup dependencies (the libxml) I had to do a apt-get install -f. This made some libs disappear, so I had to run sudo apt-get install gnome-devel again.

Now get the Drivel source from CVS. Instructions on how to do this can be found at their site.

Now just type ./autogen.sh followed by make.

You can now start hacking the code and add support for the new Blogger Login API! :)

Registry Tips

2007-02-06T14:00:00.000Z

Here's some tricks you can use to make the Windows Registry work for you:

Add a command to the context menu

Add a key to the HKEY_CLASSES_ROOT\[EXTENSION]\shell with the name of the application you'll be using (e.g. SourceEdit). In the default value, insert the name you want to appear in the context menu (e.g. "SourceEdit").

Inside the currently created key, add another key called "command". In the default value of the command key, add the command that will be invoked (e.g. "c:\Program Files\Source Edit\SrcEdit.exe" %1).

Note: [EXTENSION]can be "*" for all files.

Setting command completion in cmd

In the key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Command Processor set the value of CompletionChar to 9.

Setting an application path to launch from the "run" window

In the key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths create a new key with the name of the application you want to launch (e.g. ue.exe). Set the default entry to the application you REALLY want to launch (e.g. c:\Program Files\UltraEdit\uedit32.exe).

.reg Files

Adding an entry:

REGEDIT4

[HKEY_CURRENT_USER\DummyTree]
"ValueToBeRemoved"="Value"

Removing a tree:

REGEDIT4

[-HKEY_CURRENT_USER\DummyTree]

Remove an entry:

REGEDIT4

[HKEY_CURRENT_USER\DummyTree]
"ValueToBeRemoved"=-

Vertically align images

2007-02-01T22:12:00.000Z

Ever tried to vertically align an image inside a div? I tried to find an easy solution for this problem but couldn't find anything that worked on the web, so here's the solution I found.

But first, let me go back to the problem. Imagine you're creating a photo gallery website. Being a Web 2.0 kind of guy you place the thumbnails inside divs, something like:

<div class="thumb">
 <img src="mythumb.jpg" />
</div>

Your css might look something like:

.thumb {
 width: 120px;
 height: 120px;
}

.thumb img {
 vertical-align: middle;
}

If your thumbs aren't all the same size (and 120x120) this approach will not work! All your thumbs will be top aligned instead of middle aligned.

The problem here is that the image is being aligned relatively to the height of the contents of the div rather than to the div height. To solve this problem we have to make sure the content of the div has the same height as the div itself.

The hack you can use to "fool" the div is to create an empty image with height 100%:

<div class="thumb">
 <img width="0" height="100%" />
 <img src="mythumb.jpg" />
</div>

The first image has no width nor source, to make sure it stays invisible. Because the height is 100% it will have the same height as the div (120px in this case). This means the content of the div has 120px height, so the "mythumb.jpg" image will be properly aligned.

I tried this trick with Firefox 2.0 and IE 7.0 and it worked fine. If you find any browser where this doesn't work, please let me know.

Image Size on Ruby

2007-01-31T20:50:00.000Z

If you need to know the dimensions of an image file in ruby, for example because you want to set the "width" and "height" properties of an image on a web page, here's how to do it:

Start by getting libimage-size. If you're using Ubuntu you can fetch it using sudo apt-get install libimage-size-ruby.

You can now use the ImageSize class to fetch the width and height of your image. There are several ways of doing this, so here's one:

open(image_path) do |fh|
      img_size = ImageSize.new(fh)
end
puts "Width: #{img_size.get_width} Height: #{img_size.get_height}"