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Motion is a program that monitors the video signal from one or more cameras and is able to detect if a significant part of the picture has changed. Or in other words, it can detect motion.

The program is written in C and is made for the Linux operating system.

Motion is a command line based tool. It has absolutely no graphical user interface. Everything is setup either via the command line or via a set of configuration files (simple ASCII files that can be edited by any ASCII editor).

The output from motion can be:

* jpg files
* ppm format files
* mpeg video sequences

Source:
http://www.lavrsen.dk/foswiki/bin/view/Motion/WebHome

n2n is a layer-two peer-to-peer virtual private network (VPN) which allows users to exploit features typical of P2P applications at network instead of application level. This means that users can gain native IP visibility (e.g. two PCs belonging to the same n2n network can ping each other) and be reachable with the same network IP address regardless of the network where they currently belong. In a nutshell, as OpenVPN moved SSL from application (e.g. used to implement the https protocol) to network protocol, n2n moves P2P from application to network level.

The main n2n design features are:

* An n2n is an encrypted layer two private network based on a P2P protocol.
* Encryption is performed on edge nodes using open protocols with user-defined encryption keys: you control your security without delegating it to companies as it happens with Skype or Hamachi.
* Each n2n user can simultaneously belong to multiple networks (a.k.a. communities).
* Ability to cross NAT and firewalls in the reverse traffic direction (i.e. from outside to inside) so that n2n nodes are reachable even if running on a private network. Firewalls no longer are an obstacle to direct communications at IP level.
* n2n networks are not meant to be self-contained, but it is possible to route traffic across n2n and non-n2n networks.

Source:
http://www.ntop.org/n2n/

PacketFence is a fully supported, Free and Open Source network access control (NAC) system. PacketFence is actively maintained and has been deployed in numerous large-scale institutions over the past years. It can be used to effectively secure networks – from small to very large heterogeneous networks. PacketFence has been deployed in production environments where thousands of users are involved. Among the different markets are :

* banks
* colleges and universities
* engineering companies
* manufacturing businesses
* school boards (K-12)

.. and many more!

Released under the GPL, PacketFence offers an impressive amount of features.

Source:
http://www.packetfence.org

It is an alternative for a NetworkManager who some time makes me crazy when it doesn’t work as I like. And I have to kill it for work.

Wicd is an open source wired and wireless network manager for Linux which aims to provide a simple interface to connect to networks with a wide variety of settings.

Some of Wicd’s features include:

1. No Gnome dependencies (although it does require GTK), so it is easy to use in XFCE, Fluxbox, Openbox, Enlightenment, etc.
2. Ability to connect to wired (Ethernet only, no PPPoE/DSL support yet) and wireless networks
3. Profiles for each wireless network and wired network
4. Many encryption schemes, some of which include WEP/WPA/WPA2 (and you can add your own)
5. Remains compatible with wireless-tools
6. Tray icon showing network activity and signal strength
7. A full-featured console interface

There are instructions for installing Wicd on Ubuntu, Debian, Arch, Fedora, Slackware, and Gentoo on the downloads page, although it should work on any Linux distro.

Source:
http://wicd.sourceforge.net/

Open1X is an open source implementation of the IEEE 802.1X protocol. This project includes support for the supplicant, while other projects (e.g., FreeRADIUS) provide support for the authentication server.

Source:
http://open1x.sourceforge.net

LiVES is a Video Editing System. It is designed to be simple to use, yet powerful. It is small in size, yet it has many advanced features.

And the most important thing is … LiVES is a Free, Open Source video editor *and* a VJ tool.

Source:
http://lives.sourceforge.net/

Scribus is an Open Source program that brings award-winning professional page layout to Linux/UNIX, Mac OS X, OS/2 Warp 4/eComStation and Windows desktops with a combination of “press-ready” output and new approaches to page layout. Underneath the modern and user friendly interface, Scribus supports professional publishing features, such as CMYK color, separations, Spot Colors, ICC color management and versatile PDF creation.

Manual (Spanish) written by Antonio Cobo Cuevas, Profesor of informatics in I.E.S. Fuente de la Peña (jaen)

shebang/hashbang/haspling is…

#! <- The first two characters used in Unix-like in a script file, they're read by the program reader looking for the interpreter of this script, that is specified after the shebang. For example:

#! /bin/sh

Edit your .vimrc settings file to include the following line:

set enc=utf-8

And you should be able to edit a UTF-8 file in Windows using gvim.
For Linux, just set the locale to utf-8 such as:

export LANG=en_SG.UTF-8

Source: http://research.mosuma.com/faq/howto/vim-utf8

Some times we need to limit the traffic that uses some applications. In my case, when I download big files. So:

If we use wget, It is doted with –limit-rate option that permits set the limit of traffic.

Example:
# wget –limit-rate=50k http://lexo.lx-networks.net/testingfile.gz

This example limits wget to uses 50KBps maximum of download traffic.

But … ¿what’s up when we need use other application that it hasn’t the same option like this? Don’t worry, looking for it option I found a solution to do it.

trickle: is a portable lightweight userspace bandwidth shaper. It can run in collaborative mode (together with trickled) or in stand alone mode.

It works by taking advantage of the unix loader preloading. Essentially it provides, to the application, a new version of the functionality that is required to send and receive data through sockets. It then limits traffic based on delaying the sending and receiving of data over a socket. trickle runs entirely in userspace and does not require root privileges.

Example:
# trickle -s -d 120 -u 100 firefox

This example limits to firefox uses 120KBps for download and 100KBps for upload of traffic.

These are simple methods, because we can use traffic control at kernel level.

If you have this problem maybe other program is using the snd resource, so, you need know which is the program is using it. You can do it with lsof, and kill the process.

~# lsof | grep pcm ; lsof | grep dsp
xmms 17613 lexo mem CHR 116,8 12785 /dev/snd/pcmC0D0p
xmms 17613 lexo 10u CHR 116,8 12785 /dev/snd/pcmC0D0p

~# fuser -v /dev/snd/*
USER PID ACCESS COMMAND
/dev/snd/controlC0: lexo 5468 F…. mixer_applet2
lexo 18351 F…. xmms
/dev/snd/pcmC0D0p: lexo 18351 F…m xmms
/dev/snd/timer: lexo 18351 F…. xmms

* /etc/init.d/alsa-utils reset card

Hace tiempo que no me veía en la necesidad de hacer uso de MySQL y he olvidado como crear usuarios con full privileges para una db.

Aquí les dejo la linea que se ocupa para de crear un usuario test con password tester, con full access a la db test y con capacidad para acceder desde cualquier lugar(mientras el servidor y firewall lo permita cuando se cuenta con alguno).

mysql> GRANT ALL PRIVILEGES ON test.* TO 'test'@'%' IDENTIFIED BY 'tester';

Recuerden que hay que entrar por consola usando el cliente mysql y como administrador.

En esta ocasión escribo un pequeño tuto que trata acerca de como cambiar la mac address de una interfaz de red. Y si que debo confesar que me fue muy útil, en aquellos tiempos en que mi cuenta wifi no solo se validaba por un usuario y contraseña.

Para aquellos que creían darle seguridad a sus redes inalámbricas haciendo uso de los “MAC FILTERS”, ahora ya no sera una opción para conseguir seguridad en nuestras redes.

Este es un ejemplo de como modificar la mac address de nuestra primer tarjeta de red identificada como eth0, en GNU/Linux. Le pondremos la mac 00:1e:68:ab:b4:4a.

ifconfig eth0 down
ifconfig eth0 hw ether 00:1e:68:ab:b4:4a
ifconfig eth0 up

Ahora para aquellos FreeBSD aquí les va el ejemplo.

ifconfig xl0 down
ifconfig xl0 link 00:1e:68:ab:b4:4a

Como ven para ambos casos es necesario dar de baja la interfaz antes de hacer el cambio de mac address. Pues es posible que de estar activa, no tendremos permiso del sistema para hacer el cambio.

Para aquellos que nos gusta hacer uso de la linea de comandos para la reproducción de streaming media y no contamos con una conexión directa a Internet, y que hacemos uso de un HTTP Proxy tendremos por defecto problema para la reproducción de estos.

Pero… haciendo uso de algunas facilidades que MPlayer nos provee para pasar a través de nuestro HTTP Proxy, permitiéndonos escuchar y ver streaming media. Y lo podremos hacer de la siguiente manera:

Ejemplo 1:

mplayer http_proxy://proxy:port/http://prov.com:80/stream.asf

Ejemplo 2:

export http_proxy=http://proxy:port
mplayer http://prov.com:80/stream.asf

Ejemplo 3:

export http_proxy=http://proxy:port
wget ftp://prov.com/something.avi -O – | mplayer -

En el ultimo ejemplo quien se encarga de pasar a través del HTTP Proxy es la aplicación wget, y por medio de un pipe pasamos esto al MPlayer, y es así como podemos conseguir la reproducción.

Para distros basadas en Red Hat tenemos el archivo /etc/redhat-release, para Slackware tenemos /etc/slackware-version, y bueno creí que en Ubuntu sería algo así(/etc/debian-* o tal vez /etc/ubuntu-*), pero no, la manera en que podemos ver que versión se encuentra instalada es con la ayuda del siguiente archivo: /etc/lsb-release

Así es que con un:

cat /etc/lsb-release

Podremos conocer que versión de Ubuntu se encuentra instalada.