schroot: snapshot chroots

According to its manual page “schroot allows the user to run a command or a login shell in a chroot environment”. As many others (chroot, lxc, docker, vserver) it is a OS virtualizer. Often, these “chroot environments” are known as “jails”. A jail is much faster that a full virtualizer as vmware, virtualbox, etc.

In that recipe we explore a interesting feature: jail snapshoting

Introducción a Ogre3D

Esta receta se explicará de forma breve que es Ogre3D.

nautilus: list folder before files

Current nautilus Debian version (3.14) has a bug in preferences. It is not possible to set
the option “put folders before files”.

That command sets it:

$ gsettings set org.gnome.nautilus.preferences sort-directories-first true

multi machine Vagrantfile

A Vagrantfile to generate several machines:

Each machine has a different configuration via salt provision.

Installing veewee on Debian sid

# apt-get install ruby-nokogiri libxml2-dev
# gem install veewee

Useful LaTeX packages and their main commands

  • setspace — set space between lines
    • \singlespacing
    • \onehalfspacing
    • \doublespacing
  • textpos — absolute positioning of text on the page
    • \textbox
  • geometry — flexible and complete interface to document dimensions
  • enumitem — Control layout of itemize, enumerate, description
  • titlesec — Select alternative section titles
  • titletoc — alternative headings for toc/lof/lot (better than fancyhdr)
  • listings — typeset source code listings using LaTeX
  • versions — optionally omit pieces of text
  • acronym — expand acronyms at least once
  • crop — support for cropmarks
  • hyperref — extensive support for hypertext in LaTeX
  • multicol — intermix single and multiple columns
  • tocbibind — add bibliography/index/contents to Table of Contents
  • caption / caption2 — customising captions in floating environments
  • xcolor — driver-independent color extensions for LATEX and pdfLaTeX

[under construction]

Arrancar grub en un equipo con UEFI

— [ edit | raw ] migrated from node/1709
Suponiendo que acabáis de instalar una Debian o que, aunque ya la tenías funcionando, w8 ha hecho de las suyas, os veis en una situación en la que no tenéis grub y lo que es peor, ni siquiera podéis arrancar vuestra Debian desde el menú de arranque. En este caso, lo que hay que hacer es lo siguiente:

Keep repeating a command until it fails

That may be useful to make some kind of stress testing or to “ensure” the command is doing right.

Pretty simple:

$ while ./command; do true; done

Autenticación básica en IceGrid

— [ edit | raw ]

Esta receta muestra cómo proporciona, de una forma sencilla, un mecanismo de autenticación a IceGrid.

Fixing damaged /var/lib/dpkg/available

Sometimes the file /var/lib/dpkg/available is corrupted. When you use the package managing tools you get messages similar to these:

dpkg: warning: parsing file '/var/lib/dpkg/available' near line 1128 package 'dash':
 missing description
dpkg: warning: parsing file '/var/lib/dpkg/available' near line 2687 package 'login':
 missing description

Usually this is not a big issue but it may be annoying. To fix it, just execute next commands:

# mv /var/lib/dpkg/available /root/
# touch /var/lib/dpkg/available
# sh -c 'for i in /var/lib/apt/lists/*_Packages; do dpkg --merge-avail "$i"; done'

Seen at http://askubuntu.com/questions/109994/dpkg-error-parsing-file-var-lib-dpkg-status-near-line-6449