Juan Valencia's website

I fight a merciless and endless war against a part of myself that is mediocre, ridden with self-doubt, and lazy. It always tries to stop me, it always tries to control me. It dominated me for many years. Years in which I lived a stagnant life with no future.

But the last years has been a journey of madness. After living in 8 different places in three different cities (4 after this website was started); after experiencing poverty, hunger and risks; and after facing every last one of my fears, including failure and loneliness, I found out that I wouldn't give up fighting, I found out that I still felt alive, probably more than I ever felt before. Not everything was bad, I also experienced my happiest and my most intense moments during these years. Even on the verge of desperation I ended up starting my website, when I couldn't pay for food anymore, leave alone for an Internet connection.

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Categories: Thoughts

This isn't a guide about how to create regular expressions (although I would like to make one). These are a few regular expression that I made some time ago, when I had access to a list of names, addresses, phone numbers, etc. They were formatted in very different ways (special the phone numbers) so, the simpler regular expressions that I was using before that, had to be improved. I also talk about to use this regular expressions to validate input fields in PHP scripts.

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Categories: PHP, Programming

Copyright © Juan Valencia Escalante. Some rights reserved, check the license at the bottom of this page.

This is the old photo that I had in the Contact section of the website. Since I am planing to post a few extra photos I am starting the section with this one, and I will replace it from the contact section with a photograph of me.

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Categories: Photography

Life is full of disappointments, broken plans and shattered expectations, and these can cause emotional reactions that lead to actions that we wouldn't normally do. Part of the growth of a person is learning how to deal with life's curve balls. It does sound very obvious, but that doesn't always make it easy, in the heat of the moment one feels the almost uncontrollable urge to do of the hook things. In my own personal experience, a stream of emotions cross my head, and all of them must be controlled.

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Categories: Thoughts

I'll take a little deviation from the usual posts just to share and leave this as a reminder of how not to implement security.

The captcha generating function at Sony doesn't generate an image, just some text and changes its style. I am sure that this script will not last long in there, but here, have some fun:

http://pro.sony.com/bbsc/jsp/forms/generateCaptcha.jsp 

They do "disable" the mouse, but you can see the source code from the menu, or pressing CTRL+U in about any browser, or CTRL+A (select all), CTRL+C (copy) CTRL+V (paste). Or, if you have a terminal with curl installed:

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Categories: Commands, Linux

I find sad how many online systems are out there unprotected against even the simplest type of attack, SQL injections. This is a guide and a set of examples about the use of prepared MySQL statements in PHP. If you want to see how an SQL injection attack works you can read the previous article An SQL injection attack. There is a similar guide to this but using the regular structured functions from the MysqlI library at Prepared MySQL statements in PHP (structured examples).

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Categories: MySQL, PHP, Programming

I find sad how many online systems are out there unprotected against even the simplest type of attack, SQL injections. This is a guide and a set of examples about the use of prepared MySQL statements in PHP. If you want to see how an SQL injection attack works you can read the previous article An SQL injection attack. There is a similar guide to this but using the object oriented interface of MysqlI in the examples at Prepared MySQL statements in PHP (object oriented examples).

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Categories: MySQL, PHP, Programming

Since I wrote two different guides about the use of prepared MySQL statements in PHP, and one of the reasons for use this is to prevent SQL injection attacks, I am going to write a little about these attacks that many websites has suffer and continue to suffer even today. More than define what this attack is, the objective is to show how it works.

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Categories: MySQL, PHP, Programming