Steganography app hides a messages in plain sight

BlackBox is an application that makes use of steganography. You have the ability to hide messages within Bitmap (BMP) files with no changes to the image or even the any of its properties, such as its file size. Useful for people who would like to send anonymous messages.

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Noob’s guide to manual photography

Some might ask why you would want or need to modify camera settings manually when the camera can do it for you â??just fine.â?? If you really want to end up with expressive photographs instead of mere snapshots, this beginner’s guide is a must-read. I personally didn’t really get into photography until I learned the manual controls. Check it out.

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An Introduction to AJAX

AJAX (Asynchronous JavaScript and XML) is the latest boom in the Web development world. AJAX helps developers narrow the gap between desktop and web applications — Google Earth, Flicker and MS Outlook Express Web Version are some of the applications powered by AJAX.

Asynchronous means that you can make a request to a server and perform other actions while the server is processing your request — and on the arrival of the response required actions can be performed — as opposed to conventional web applications, in which the user has to sit back and stare at the blank screen while the server is processing the request.

AJAX Architecture :
Figure 2

Source : Topcoder

How to create a patch

Generating patches, files containing the difference between files, is the domain of diff programs.
Creating Patch :

diff -Naur olddir newdir > new-patch

Note: the symbol > will redirect the output to the file new-patch.

To apply the patch
go to olddir and do :

patch -p1 <new-patch

And if you want some files to be excluded from doing a diff use -x option like

diff -Naur -x *.o olddir newdir > new-patch
this will exclude .o files when doing a diff

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Searching with find

The find command is one of the darkest and least understood areas of Linux, but it is also one of the most powerful. The biggest problem with find is that it has more options than most people can remember — it truly is capable of doing most things you could want.

The most basic usage is this:

find -name "*.txt"

That query searches the current directory and all subdirectories for files that end in .txt.

Source :


Creating Firefox Extension

Learn by example

Everyone has a good idea at one time or another to implement a new feature in a web browser. Well, with the goodness that is Mozilla Firefox, now you can do just that. You need to have a vague understanding of XUL and Javascript, but you certainly don’t need to be a master of either.
The author explains how the extensions break down in a nutshell, using BugMeNot as an example


Related Post : If you want to develop firefox extension

Vim tips: Using viewports

A really useful feature in Vim is the ability to split the viewable area between one or more files, or just to split the window to view two bits of the same file more easily. The Vim documentation refers to this as a viewport or window, interchangeably.
You may already be familiar with this feature if you’ve ever used Vim’s help feature by using :help topic or pressing the F1 key. When you enter help, Vim splits the viewport and opens the help documentation in the top viewport, leaving your document open in the bottom viewport.
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Article By: Joe ‘Zonker’ Brockmeier
Also Emacs Tips : Buffer & windows

vi survival guide

A comprehensive guide to a famous text editor “vi”, written in vi itself.

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graph plotting with gnuplot

Gnuplot is a free, command-driven, interactive, function and data plotting program.
Here i’ m providing a quick reference guide for plotting graphs (as many of us don’t bother to go in detailed documentation).
On Unix/Linux systems start Gnuplot by simply typing:

first the formal syntax :

plot {[ranges]}
{[function] | {“[datafile]” {datafile-modifiers}}}
{axes [axes] } { [title-spec] } {with [style] }
{, {definitions,} [function] …}

To plot functions simply type: plot [function] at the gnuplot> prompt
gnuplot> plot sin(x)
gnuplot> splot sin(x*y/20)
gnuplot> plot sin(x) title ‘Sine Function’, tan(x) title ‘Tangent’

Now for plotting data points firstly data points should be written in text file with axis ranges as columns.Data files should have the data arranged in columns of numbers. Columns should be separated by white space (tabs or spaces) only, (no commas). Lines beginning with a # character are treated as comments and are ignored by Gnuplot. A blank line in the data file results in a break in the line connecting data points. ‘
Plotting a graph from data file “” , do
gnuplot>plot “”

Now customizing the plot :

set xlabel “x-axis data” # will set a label “x-axis data” in graph
set ylabel “y-axis data”
set title “x vs y” # will set title for graph
set xrange [0.001:0.005] # Change the x-axis range:
set yrange [20:500] # Change the y-axis range:
set logscale # plot using log scale
set autoscale #let gnuplot determine ranges
plot “” with lines #will join data points with lines
plot “” smooth csplines with lines #will join plot graph using smooth curves

Gnuplot can mathematically modify your data column by column:
to plot sin( col.3 + col.1 ) vs. 3 * col.2 type:

plot ‘force.dat’ using (3*$2):(sin($3+$1))

To print graph (this will store graph in post script(.ps) file do this before plotting graph:

set output “”
set terminal postscript
plot “” using lines

This will save the graph in
For more help type ‘help’ in gnuplot mode :

A simple guide to GNU plot
Introduction to GNU plot

Useful Windows XP DOS Commands & Tricks

Typing DOS commands on the Windows Command Line prompt is a most efficient and faster way of doing things in Windows XP. Here’s a run-down of the most useful DOS commands available in Windows XP. Some of these DOS commands even do not have an visual alternative. Digital Inspiration has a nice roundup of 10 very useful commands and tricks that can help you get things done quickly from the command line.
Useful Windows XP DOS Commands & Tricks [Digital Inspiration]

Related resources on Microsoft Website:
List of DOS Commands with Examples

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