How to set up DNS in Ubuntu
You can add hostname and IP addresses to the file /etc/hosts for static lookups.
You can add your DNS Server Ip address for name lookups to /etc/resolv.conf.
For example If you want to add the DNS server at IP address 8.8.8.8
sudo vi /etc/resolv.conf
If you have GUI use the following command
gksudo gedit /etc/resolv.conf
enter the following details
search test.com
nameserver 8.8.8.8
Here You can see how to simulate the celebrated open-source electronics prototyping platform Arduino with Proteus. To simulate the core of Arduino platform we need only a few components: the atmega328P Microcontroller, a Crystal and two Capacitors
Ping is used to check if a machine is up, Most of the hackers are using ping for finding the hackable machine. The hacking chances can be reduced by blocking ping.
in ubuntu ping can be disable by adding following line to /etc/init.d/networking (network init script)
echo 1 >/proc/sys/net/ipv4/icmp_echo_ignore_all
to re-enable
echo 0 >/proc/sys/net/ipv4/icmp_echo_ignore_all
Install package called build-essential is the best way
build-essential contains a list of packages which are essential for building Ubuntu packages including gcc compiler, make and other required tools.
Open A terminal and type the following
$ sudo apt-get update
$ sudo apt-get upgrade
$ sudo apt-get install build-essential
You can test Installation with following
$ gcc -v
$ make -v
Now, you should able to compile software using C / C++ compilers.
You can also use Synaptic Package Manager for installing build-essential
Tact switches are widely used as digital input devices. Normally one tact switch requires one digital I/P pin of a microcontroller but if you want to interface a matrix of such switches (say a 16 digit keypad), assigning a digital I/O pin for each key won’t be a good idea. You need to think about the way to minimize the required number of digital I/O pins of microcontroller. A very popular method is a keypad matrix where the keys are arranged into rows and columns so that a 4×4 (16) tact switches can be interfaced to a microcontroller using only 4+4 = 8 I/O pins
Wkhtmltopdf is a command line utility for converting webpage / html to PDF.
How to install wkhtmltopdf in Ubuntu / Debian
$ sudo apt-get install wkhtmltopdf
Usage:
$ wkhtmltopdf –help
This will provide help for using wkhtmltopdf
If you want to Convert website home page to a PDF document
$ wkhtmltopdf www.keralalinux.com keralalinux.pdf
This will convert the home page of www.keralalinux.com to a file named keralalinux.pdf.
Page orientation can be change using -O option
$ wkhtmltopdf -O Landscape www.keralalinux.com keralalinux.pdf
This will change page orientation to landscape
Page size can be change using -s option
$ wkhtmltopdf -s A4 www.keralalinux.com keralalinux.pdf
This will change page size to a4 it will support A4, letter etc.
Add table of contents to the pdf document with -t option
$ wkhtmltopdf -t www.keralalinux.com keralalinux.pdf
The Eye of GNOME image viewer is the official image viewer for the GNOME Desktop environment. With it, you can view single image files, as well as large image collections.
The Eye of GNOME supports a variety of image file formats. The GdkPixbuf library determines which file formats Eye of GNOME can load and save. If the appropriate plugins are installed on your system, Image Viewer will be able to open more image formats than those listed below. The following list is the default supported file formats for reading:
Open a terminal
$ eog <imagefile>
Here you can see a tutorial about the layout of Arduino Shied
This tutorial assumes an understanding of Cadsoft Eagle. For more information about Eagle, see the Eagle Tutorials section below. Here are the steps to make your own Arduino shield:
One More tutorial You can see here
This is for beginners
If you want to change your password, just open a terminal
then type
$ passwd
( this will ask for current password, enter your current password, now it will ask for now password enter new password and repeat it.)
$ passwd -d username for deleting password
Nice drawings of the Arduino UNO and Mega 2560
If you’re looking to make your own shield for the Arduino platform, you’ll definitely need to know where all the pins and holes are located on the Arduino. After doing a quick search, I was unable to find an accurate technical drawing of the new Arduino UNO and Arduino Mega 2560.
