http://johnbokma.com/ John Bokma, a freelance Perl programmer living in Mexico http://johnbokma.com/mexit/2012/04/04/renewing-self-signed-certificate.html Last month the self-signed certificate I created for postfix and dovecot on the virtual private server I use to host this site expired. I was made aware of this fact by the email client I use, Mozilla Thunderbird. Since I was quite busy and had no time to look into this I just made Thunderbird accept [...] 2012-04-04T18:49Z http://johnbokma.com/mexit/2012/03/15/on-duplicate-key-with-if.html Recently, for a project I am working on, I needed a conditional update of one column's value with the value of a different column part of the conditional. Luckily, this is possible and the syntax is what I expected it to be. In my specific case I wanted to keep track of the total times an object was [...] 2012-03-15T23:24Z http://johnbokma.com/mexit/2012/03/15/job-queue-in-mysql.html At the beginning of this year I had a problem: from a Perl program I had to select the oldest row in a MySQL database table to obtain some data and set the time of the row to the current time to prevent other processes to use the same row data immediately. In short: I wanted to update a row in a transaction [...] 2012-03-15T23:24Z http://johnbokma.com/mexit/2012/03/04/kindle-fire-outside-usa-beware.html Last year, a day before Christmas, a Kindle Fire arrived at our house; a Christmas present sent to us by a customer of mine. Esme paid the custom duties and IVA (value added taxes), about 50 USD, and soon we had opened the box and were admiring the brand new Kindle [...] 2012-03-05T01:23Z http://johnbokma.com/mexit/2012/01/13/down-the-grassy-slope.html In the morning I had a hard time getting up; I hadn't slept much during the night. When I looked out the window the gray clouded sky didn't help me much convincing that it was a good day for hiking. After some pondering, should we stay or should we go, I decided to just go, also since the weather might [...] 2012-01-22T01:51Z http://johnbokma.com/mexit/2011/11/01/installing-qt-sdk-ubuntu-lucid-lynx.html Yesterday I tried to install Qt 4.7 via the Linux/X11 64-bit "Online Installer" on Ubuntu 10.04. At first the installation failed since I ran out of space on the partition that has /usr/local/. I had selected the custom installation and added Qt Designer, its documentation, and the Qt [...] 2011-11-02T01:16Z http://johnbokma.com/mexit/2011/09/01/books-received-in-august.html Since I want to relearn C++ programming; I've been programming in this language back in the 90's but soon got more work in Java and Perl programming, I asked for several C++ programming related books. The reason why I want to pick up C++ again is that I would like to do more GUI related programming work. [...] 2011-10-24T20:06Z http://johnbokma.com/mexit/2011/09/01/re-learning-c-plus-plus.html Recently I decided to relearn C++ programming. I used to do some C and C++ programming back in the 90's but somehow I kept getting more and more Perl and Java programming work, so after some time I stopped improving both my C and C++ [...] 2011-10-24T22:01Z http://johnbokma.com/mexit/2011/07/18/adobe-flash-11-on-ubuntu-64-bit.html In the afternoon I installed the beta of the Adobe Flash Player 11 plug-in into the plugins directory of Firefox. Below I have written down the steps I [...] 2011-07-18T23:03Z http://johnbokma.com/mexit/2011/07/18/oracle-java-plug-in-firefox.html While I had installed Oracle Java on Ubuntu 10.04 weeks ago I hadn't had time to install the Java plug-in so Mozilla Firefox could display Java applets even though this is a piece of cake. And since today I had planned to, finally, configure Firefox on a recent fresh install of Ubuntu Lucid Lynx to my [...] 2011-07-18T23:03Z http://johnbokma.com/mexit/2011/07/04/installing-saxon-he-ubuntu.html Because Ubuntu didn't see my manual installation of the Oracle Java JDK as a valid Java alternative I couldn't install Saxon-B using apt-get install. Instead of trying to find a solution to this issue I decided to install Saxon manually as well. And since I was now free in my choice, I decided to install [...] 2011-07-12T22:38Z http://johnbokma.com/mexit/2011/07/04/installing-apache-fop-ubuntu.html Since I had installed Oracle Java installed manually without a single problem I decided to install Apache FOP manually as well. Also because when I tried to install it via sudo apt-get install fop it turned out that Ubuntu didn't see that Java had already been installed, most likely due to a step I hadn't [...] 2011-07-12T22:21Z http://johnbokma.com/mexit/2011/06/29/ssh-client-time-out.html Nearly a week ago I did a fresh install of Ubuntu Lucid Lynx on my development system and I am still installing software I need for my work on it and configuring the system. Today I restored the .ssh folder from backup into my home directory. I have in the config file inside this directory the two following [...] 2011-07-12T18:52Z http://johnbokma.com/mexit/2011/06/24/oracle-java-jdk-installation-ubuntu.html In the evening I installed the Oracle Java JDK on Ubuntu Lucid Lynx. Since Oracle Java is no longer available via the default repositories I decided to manually install Java instead of adding a repository and possibly installing an older version. Since I need Java to run programs like Apache Ant, Apache [...] 2011-07-12T16:56Z http://johnbokma.com/mexit/2011/06/24/installing-vlc-media-player-ubuntu.html In the evening I installed VLC media player 1.1.10 "The Luggage" on Ubuntu 10.04 LTS. The latter I had freshly installed yesterday on my Dell Vostro 200 ST. Instead of installing the outdated 1.0.6 version that comes with Lucid Lynx I decided to install VLC, at my own risk, from a Personal Package Archive [...] 2011-07-12T01:34Z http://johnbokma.com/mexit/2011/06/24/emacs-anti-aliased-fonts.html On the previous installation of Ubuntu on my Dell Vostro I used a snapshot version of Emacs to have much better looking anti-aliased fonts while editing. Today, in the afternoon, when I checked the default version of Emacs on my fresh installation of Lucid Lynx I was pleasantly surprised to discover [...] 2011-07-12T01:34Z http://johnbokma.com/mexit/2011/07/09/utorrent-server-64-bit-linux.html In the evening I decided to install the 64 bit 3.0 alpha of µTorrent Server on my Dell Vostro 200 ST running Ubuntu 10.04 Lucid Lynx. Earlier this week I had checked if the program would even run on my computer, which it seemed to do without any problems. And today I wanted to install it for real and [...] 2011-07-11T01:22Z http://johnbokma.com/mexit/2011/06/29/making-org-mode-pdf-export-work.html A week ago I received "The Org Mode 7 Reference Manual", published by Network Theory Ltd as a reward for some Perl programming help I had given. I had already been reading parts of the book and so far Org mode for Emacs looks very, very useful to me, especially since I still keep todo lists on paper [...] 2011-07-06T18:23Z http://johnbokma.com/mexit/2011/06/24/subversion-apache-ssl-ubuntu.html In the afternoon I installed Subversion on my Dell Vostro running Lucid Lynx. Yesterday I had done a fresh install of Ubuntu Lucid Lynx 10.04.02 LTS and in order to be able to do some work I really had to make the SVN repositories I keep my work in available via https [...] 2011-07-10T23:43Z http://johnbokma.com/mexit/2011/06/08/ Today, while still preparing for the reinstall of a more recent version of Ubuntu I wrote a small bash script to backup each MySQL database to a separate file. I have not much experience with writing bash scripts and at first wanted to write the program in Perl. But after firing up Emacs and typing the [...] 2011-06-09T00:19Z http://johnbokma.com/mexit/2011/05/02/ The 23rd of April "alex" posted a message to the Dutch Linux Usenet group nl.comp.os.linux.installatie with the subject "Install Hypervm " centos". In the message "alex" asked for help since he couldn't make it work. Since I had installed CentOS in Microsoft Hyper-V several times the past year I replied [...] 2011-05-03T01:45Z http://johnbokma.com/mexit/2011/03/10/ And this time, finally, I was right: 2 boxes from Amazon. One box contained two books ordered the 10th of February in return for the Perl programming help I had [...] 2011-03-12T01:11Z http://johnbokma.com/mexit/2011/03/09/the-little-bookworm.html In the evening we wanted to watch a movie in our basement. The basement has 2 sections: one part is my office and the other part has a couch and a monitor. The latter is used to watch movies on by connecting it to Esme's laptop, a Dell Inspiron 1525. A Muscle Rack, functioning as a bookcase, is used [...] 2011-03-11T21:48Z http://johnbokma.com/mexit/2011/03/09/date-manip-arguments-must-be-valid-dates-bug.html Today, a Perl program, part of a parallel site crawling project I am working on for a customer, reported the following issue (reformatted for easy [...] 2011-03-11T21:24Z http://johnbokma.com/mexit/2011/03/07/ In the early evening I decided to check the substrate of a terrarium in which I keep a centipede collected the 6th of November last year near the town of El Limón Totalco, Veracruz. I hadn't seen the centipede for months and was worried that it had died even though I've kept the substrate about as moist [...] 2011-03-10T01:15Z http://johnbokma.com/mexit/2010/08/15/ While we were living in the town of Coatepec we went on several walks close to this town. Due to time constraints I haven't been able yet to write about most of those walks; a blog entry of a single walk can take between one and two days to write, including sorting through a lot of photos. Since in that [...] 2010-08-16T02:57Z http://johnbokma.com/mexit/2010/04/28/ In the morning, just after I woke up, Esme told me that the Compaq computer wasn't working. She thought it had died, which wouldn't have been a big surprise since the motherboard, an Asus K8S-LA (Salmon), had nearly killed the north bridge about 2 years ago. Ironic, since I specifically bought the Compaq [...] 2010-04-29T03:45Z http://johnbokma.com/mexit/2010/03/31/ One of my most favorite Firefox add-ons is Copy URL+. For one reason or another the maximum version of Firefox it supports hasn't been updated for quite some time. So each time I want it installed on a computer with a fresh install of Firefox I have to update the maxVersion in the install.rdf [...] 2010-04-01T03:50Z http://johnbokma.com/mexit/2010/03/22/ I just closed my AdSense account and removed all AdSense related code off my site. The reason? Tired of having to ask in a public forum if someone can please assist in helping me out. Yes, you're reading that correctly, nowadays Google insists that you ask for help in a public forum, where you have to [...] 2010-03-23T06:25Z http://johnbokma.com/mexit/2010/03/15/ If you use the subdl command-line tool for downloading subtitles you probably have noticed that it suddenly stopped working a few days ago. Instead of a list of subtitle files to download I got the following [...] 2010-03-16T02:00Z http://johnbokma.com/mexit/2010/02/17/ In the afternoon I decided that in the evening I was going to install Ubuntu 9.10, also known as Karmic Koala, on my mother-in-law's computer. But I needed something easy to put a backup on of the /home directory, which has two accounts, one for Esme and one for her mother. Since we have an old 256MB [...] 2010-02-19T00:54Z http://johnbokma.com/mexit/2010/02/11/ The past two days I've been working on a small project which required the generating of a PDF file with a barcode and some other text data, and a watermark image. Today I decided to do a clean install on Ubuntu 9.10 AMD64 running in VirtualBox of all programs I use to convert an XML file, via an intermediate [...] 2010-02-12T03:37Z http://johnbokma.com/mexit/2010/02/05/ Just after 10 in the morning Esme, Alice and I went out for our appointment with Naolí Vinaver Lopez, our midwive, who lives just outside of Xalapa. Since I wanted to take my digital photo camera with me, and the rechargeable batteries have become very unreliable - especially the Energizer AA 2500 mAh [...] 2010-02-11T18:32Z http://johnbokma.com/mexit/2010/02/02/ Today Esme and I went to Xalapa. We left Alice with her grandmother, Esme's mother, who has been staying with after her mother passed away. We went to Xalapa for two reasons: first I had to do some paperwork in order to get my FM2 visa, and second, I wanted to see Avatar [...] 2010-02-11T18:41Z http://johnbokma.com/mexit/2010/01/27/changing-the-mysql-prompt.html For example the following command will show the current database name between parentheses in the prompt, which is quite useful if you switch often between [...] 2010-01-28T02:20Z http://johnbokma.com/mexit/2010/01/27/sql-from-text-file.html Today I was working on a Python project for a customer, and had to add some additional tables to an existing MySQL database. I normally add the SQL statements to a text file, using the extension 'sql' and feed this file to the mysql client program as [...] 2010-01-28T02:20Z http://johnbokma.com/mexit/2010/01/21/ In the afternoon I finished "Into the heart of Borneo" by Redmond O'Hanlon (ISBN 0-394-75540-5). Back in the 90's I had read the Dutch translation of this story, and I loved it. Hence sometime ago I had added the book to my Amazon wish list and later on asked for it to be ordered in exchange for some [...] 2010-01-23T01:02Z http://johnbokma.com/mexit/2010/01/05/activeperl-wxwidgets-dll-issue.html Last week I decided to update a development environment, Windows XP Professional running in a virtual machine, with the latest version of ActivePerl and WxWidgets. However, when I had installed the Wx package via the Perl package manager the application I am developing didn't start but reported the following [...] 2010-01-06T02:23Z http://johnbokma.com/mexit/2009/12/30/alice-broke-her-arm.html "John! John! John!" that was how I woke up around noon, Esme calling loud several times my name. I was still in the bed: I had a cold for a few days now and hadn't been able to sleep most of the [...] 2010-01-20T23:15Z http://johnbokma.com/mexit/2009/09/26/python-downgrading-beatifulsoup.html Yesterday, a customer of mine emailed me that the Python program I had written for him didn't work. The last line of the traceback [...] 2009-09-27T22:29Z