Printing to a matrix printer from PostgreSQL

• Posted: July 31, 2010
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• Author: Melvin
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• Filed under: English,Howto,Open source,Software
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• Tags: No tags set for this entry.

Recently I found an interesting piece of code again which I would like to share with you. I produced the code about a year ago for a project which needed offline data logging.

I used the piece of code to print a line to a matrix printer from PostgreSQL. The matrix printer was connected to the database server and supplied with endless paper. I used a matrix printer, because you can print directly to the device.

With the method, described below, it’s possible to print with a SQL query or print something initiated by a trigger. Using this method you can log specific data ‘offline’.

The print_line method consists of three files; print_line.c which contains the code to address the printer, a Makefile to compile the print_line.c file and a print_line.sql file which creates the function in SQL.

print_line.c

Makefile
MODULES = printhash
PGXS := $(shell pg_config --pgxs)
include $(PGXS)

print_line.sql
CREATE FUNCTION print_line(text) RETURNS integer
AS '/usr/local/libexec/print_line.so', 'print_line'
LANGUAGE C STRICT;

Installation:
mkdir /home/user/print_line
cd /home/user/print_line
unzip print_line.zip
make
cp print_line.so /usr/local/libexec/
// open postgresql command line client and execute:
# \i /home/user/print_line/print_line.sql

Usage:
SELECT print_line('Hello World!');

Download:
Download print_line.zip

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Artikel in Linux Magazine

• Posted: May 29, 2010
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• Author: Melvin
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• Filed under: Diversia,Games,Stories
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• Tags: No tags set for this entry.

Deze week is een interview met mij over Diversia in Linux Magazine verschenen.

“Verder spraken we voor deze editie met de ontwikkelaar van Diversia, een open source-variant op Second Life. Waarom Diversia wel een succes wordt, terwijl Second Life langzaam verandert in een spookstad, legt projectleider Melvin Rook uit in een rijk geïllustreerd artikel.”

Inmiddels heb ik ook al veel positieve en leuke reacties op het artikel ontvangen.

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Synology DS1010+ NAS

• Posted: April 10, 2010
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• Author: Melvin
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• Filed under: English,Hardware,Open source
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• Tags: No tags set for this entry.

A while ago I decided to buy a Synology DS1010+ to backup my data. People keep me asking why I bought a Synology. Well, next to the fact it runs on open source software, Linux and has wide variety of features, I guess the following video explains everything.

More information on Synology NAS systems can be found at www.synology.com

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