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How To: Build an Embedded Linux Distribution From Scratch

Embedded Linux is the use of a Linux operating system in an embedded computer systems such as a mobile phones, personal digital assistants, media players etc.

This tutorial shows you how to install Linux on a target system. Not a prebuilt Linux distribution, but your own, built from scratch. While the details of the procedure necessarily vary from one target to another, the same general principles apply. The result of this tutorial (if you have a suitable target) is a functional Linux system you can get a shell prompt on.

In this tutorial, you will learn about:

  1. Discussion of cross-compilation issues
  2. Review of the components of a Linux system and how they are put together
  3. Detailed steps for building, installing, and configuring the target system

=> Build an embedded Linux distro from scratch (free registration required)

How To Secure Mac OS X Computer ( Hardening Mac )

Apple has released 230 page guide for securing and safeguarding Mac OS X system from the hackers and crackers. The Security Configuration Guides provide an overview of features in Mac OS X that can be used to enhance security, known as hardening your computer. Using this guide you can:

=> Lock down the system.
=> Protect Mac OS x from external attackers.
=> Avoid unauthorized access
=> Secure Mac by hardening your computer.
=> Mac OS X security and much more.

However, guide is heavily depend upon shell prompt (read as terminal) to perform recommended tasks. So you need to have some basic knowledge of terminal. From the Apple site:

Certain instructions in the guides are complex, and deviation could result in serious adverse effects on the computer and its security. The guides should only be used by experienced Mac OS X users, and any changes made to your settings should be thoroughly tested.

Download Mac OS X Security Configuration Guides

Download guide for Mac OS X v10.5 (Leopard) / Mac OS X v10.4 (Tiger) / Mac OS X v10.3 (Panther):

Goosh.org Unix-like Shell For Google

Neat idea:

goosh.org - the unofficial google shell. This google-interface behaves similar to a unix-shell.
You type commands and the results are shown on this page.

=> goosh.org

mplayer: Play All Mp3 Files In Reverse Order

mplayer lacks an option for selecting files in a reverse order. So here is a quick way to playback all mp3 files in reverse order:
$ ls -1 -r *.mp3 > mp3.rev
$ mplayer -playlist mp3.rev


  • -r reverse order while sorting
  • -1 list one file per line
  • -playlist file : Play files according to a playlist file

Let's hear your shell hack in the comments.

Using Color Effectively At a Shell Prompt / Console

Pixelbeat has published a nice article about setting up colorful console under Linux / UNIX. From the article:

I find it very productive working in a terminal environment, as it's efficient and flexible to deal with processes and data, especially text, and especially on remote machines.

Now terminals have advanced in capability over time, with some form of "xterm" being the usual terminal of choice. Therefore one should not restrict programs to their usual monochrome defaults, as colour can be used to greatly ease the parsing of text by humans. We have dedicated sensors and portions of the brain specifically for colour, so we should not ignore them.

Related: Setting up themes and colorful bash prompt

WordPress 2.5 Released

WordPress 2.5 has been released and available for download.The dashboard is cleaner, faster, less cluttered. From the release note:

WordPress 2.5, the culmination of six months of work by the WordPress community, people just like you. The improvements in 2.5 are numerous, and almost entirely a result of your feedback: multi-file uploading, one-click plugin upgrades, built-in galleries, customizable dashboard, salted passwords and cookie encryption, media library, a WYSIWYG that doesn’t mess with your code, concurrent post editing protection, full-screen writing, and search that covers posts and pages.

(Fig. 01: My Dashboard)

(Fig. 02: Writing a post)

scapy – Interactive Packet Manipulation / Generation Tool for Linux / UNIX

Recently I started to play with scapy - a powerful interactive packet manipulation and custom packet generation program written using Python. Please note that this tool is not for a new Linux / UNIX users. This tool requires extensive knowledge of network protocols, packets, layers and other hardcore networking concepts. This tool is extermly useful for
a] Understanding network headers
b] Testing network security
c] Write your own utilities using scapy
d] Decoding protocols etc

From the man page:

You can use this tool to check the security of your own network as it allows to forge or decode packets of a wide number of protocols, send them on the wire, capture them, match requests and replies, and much more. It can easily handle most classical tasks like scanning, tracerouting, probing, unit tests, attacks or network discovery. It also performs very well at a lot of other specific tasks that most other tools can't handle, like sending invalid frames, injecting your own 802.11 frames, combining technics such as VLAN hopping+ARP cache poisoning, VOIP decoding on WEP encrypted channel, etc.

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