the website of xero harrison

atom editor linux install

2014-05-08T15:33:06-04:00

atom is a "hackable text editor for the 21st century" created by the team at github. it's designed to be customizable, but also usable without needing to edit a config file.

this quote really sums it up perfectly:

because we spend most of our day in a text editor, the single most important feature we wanted in an editor was extensibility. atom is built with the same open source technologies used by modern web browsers. at the core of atom is chromium, the open source project behind google chrome. with that comes all the power and innovation being developed for the web. but more importantly, extending atom is as simple as writing javascript and css, two languages used by millions of developers each day.
atom.io

cron jobs

2014-04-15T12:55:11-04:00

cron jobs are automated scripts that run at a specified date/time, or on a specified interval.

anything that can be executed in the terminal on the server can be run as a cron job (this includes commands, applications, scripts, etc).

crontab is the command used to create/view/modify/remove cron jobs.

crontab -l lists all scheduled jobs
crontab -e allows you to edit jobs
crontab -r will delete *all* your active jobs!

once the crontab file has been edited the cron daemon will automatically read it and update it's job que to match the file. you should see the message:
crontab: installing new crontab

git with the program

2013-01-13T22:42:00-05:00

git is a distributed revision control and source code management (SCM) system with an emphasis on speed. git was designed by linus torvalds, of linux fame, for managing the development of the kernel. every git working directory is a fully fledged repository, complete with revision tracking abilities independent of a network or centralized server. git is 100% open-source, freeware, and distributed under the GNU general public license v2.

mysql string replacements

2013-01-11T08:51:33-05:00

sometimes you find the need to do mass string replacements in your mysql/maria databases. here's how i do it:

UPDATE your_table
SET your_field = REPLACE(your_field, 'old_value', 'new_value')
WHERE your_field LIKE '%old_value%'

SQL select into statement

2009-08-14T11:14:00-04:00

have you ever had a database table that you needed to clone? you can use any number of convoluted methods such as: manually coping and pasting rows in the database manager, running lots of queries/stored procedures, or writing a script to cycle though each row copying data from one table to the next. all of these methods are inferior and far more complex then the method i'm going to show you.

introducing the select into query...
this method should be used if the table you want to clone exists, but the new table douse not. the select into query will create the new table for you, copying all the column names, properties, and data. if you want to make an exact clone of the table you can select * into the new table. but if you only want a few specific columns, you can declare only the ones you want. the syntax is elegantly simple...

SELECT *
INTO [new-table]
FROM [old-table]

inline SQL statements

2008-10-26T19:25:00-04:00

the world of database programming can be a dark and treacherous journey. when you first set out, your quest seems manageable. but as time progresses your start to realize you need more queries, more tables, etc, etc, to achieve your goal. well today i’m going teach you a little trick that might help you need one less stored procedure then you thought...

sometimes it’s true, you actually do need two queries to get the job done. but other times you can circumvent this by using something like a "join" or "inner join" query to merge two tables together and pull your results from both.

but the optimizer in you says that still isn’t enough...

PQ torus knot

2008-09-15T01:15:00-04:00

here we go again, another papervision3D demo featuring math permeated lines. this time im working with a classic piece of code known as the PQ torus. the vague idea is that you have 2 numbers (P + Q) that are used in the algorithm to define the knot. in general, given P + Q mutually prime, the line wraps meridionally around the torus P times and wraps the longitudinally around it Q times. i was having some trouble grasping exactly how this was going to be achieved, until i read this article on blackpawn’s website. he really breaks down the algo to a very simplistic level...