For the paranoid, Mad Mimi allows for setting up an SPF (TXT) record like so:

"v=spf1 include:auth.madmimi.com ~all"

A genuine case would be where your domain already has an SPF record in place for some other email service provider (e.g. self-hosted email, Google Apps). In this case, I believe, it'd be better to include Mad Mimi's domain in the SPF record.

So, when I asked them how, this is what they told me to do:

"v=spf1 include:auth.madmimi.com include:_spf.google.com ~all"

Let me remind you, Mad Mimi folks always tell, "you don't need SPF or DKIM from us". So, it's your call.

Continue reading "Set up SPF record for Mad Mimi" on Aahan Krish's Blog.

1.  www.amazon.com/Ubuntu-Unleashed-2013-Covering-12-10/dp/0672336243/
2.  www.amazon.com/dp/0672336243/
3.  amzn.com/0672336243/
4.  www.amazon.com/gp/product/0672336243/
5.  amzn.to/14N3BFC/
6.  www.amazon.com/exec/obidos/ISBN/0672336243/
7.  www.amazon.com/exec/obidos/ASIN/0672336243/

So, which should you use? While can't go wrong with any of them (as Amazon will most likely, make sure that the URLs stay intact with at least some form of redirection) it's better to stick with a reliable link that's least likely to be changed. Right? Read on...

(NOTE: Everything you are going to read below is my opinion backed by some logic, or just that, an opinion.)

1. It's the canonical link to a specific product on Amazon.com, and fortunately, it's the default link that Amazon shows you. Unless you know what you are doing, you should be using this URL to link to products on Amazon.

But the product slug name you see in the URL (i.e. Ubuntu-Unleashed-2013-Covering-12-10) is the least of your concerns. Actually, replace it with some text, and you'll still be taken to the same product page. For example, try this:

www.amazon.com/sdfsdff/dp/0672336243/

2. Clearly, the product slug name in the URL is negligible, which hints us at:

www.amazon.com/dp/0672336243/

This the URL I recommend using, as it's canonical, short and precise.

3. That's a shortlink provided my Amazon:

4. and 5. refer to the product link and shortlink provided to Amazon Associates (Affiliates).

6. and 7. I am not sure where Amazon references to these links. I just know that they work.

All links have the ID of the product, which is either the product's Amazon Standard Identification Number (ASIN) or International Standard Book Number (ISBN) identifier, and therefore can be deemed reliable, all alike.

But... like I said earlier, since it's both canonical and short, I always use this URL structure:

www.amazon.com/dp/[ASIN_ID]/
www.amazon.com/dp/[ISBN_ID]/

Sources:

• Creating Short Amazon Affiliate Links (AMZN.COM)
• Amazon Affiliate Link Structure

Continue reading "Linking to a product on Amazon.com (the right way)" on Aahan Krish's Blog.

The Ubuntu Unleashed 2013 Edition, which I am reading as of the time of writing this post, has a good reminder:

When setting a password, the common advice is to make sure that it has a mixture of letters and numbers to make it more secure. For instance, a good example of a historically recommended style of password is T1a5c0p. Although this might seem like garbage at first glance, the easy way to remember it is by remembering the phrase This Is A Good Choice Of Password, shortened to Tiagcop, and finally substituting some of the letters with similar-looking numbers.

There are some reasons why this might not be the best recommendation anymore because computer systems are much faster than they used to be. It is a true statement that the longer a password is, the harder it is to break. For this reason, the newest recommendation is to use a passphrase consisting of at least four words, perhaps something like green monkeys chortle often. There is no doubt that a password the length of four common words combined together would be harder to break than the T1a5c0p example. From that perspective, it seems like a no-brainer. On the other hand, a longer password that does not use any words found in a dictionary would be even better [...]

— Chapter - 1: Step-by-Step Installation: A Quick Aside on Passwords

Kinda makes sense, doesn't it?

Continue reading "Short & complex vs. Long passwords: Long passwords win every time" on Aahan Krish's Blog.

And they are...

\   backslash
`   backtick
*   asterisk
_   underscore
{}  curly braces
[]  square brackets
()  parentheses
#   hash mark
+   plus sign
-   minus sign (hyphen)
.   dot
!   exclamation mark

So, (note to self) keep that in mind the next time you write something in Markdown.

PS: Here's the complete Markdown syntax documentation in Markdown, which you could use as a style guide.

Continue reading "Characters that have a special meaning in Markdown formatting syntax" on Aahan Krish's Blog.

It's no less loved by professionals who want to keep themselves on the cutting edge.

Started as a 50-50 joint venture between biggie publishers O'Reilly and Pearson, Safari Books Online is now a staggering library of Technology & Business-related books, including those by other leading publishers such as Addison-Wesley, Prentice Hall, Peachpit, John Wiley & Sons, Microsoft Press, Adobe Press, Cisco Press, Manning Publications, Packt, SAS Publishing, IBM Press, FT Press and Focal Press.

So, why exactly am I talking about it? 'cause I loved it!

I expect Safari Books Online and Lynda.com to play a very important role in my learning process.

It's a great feeling to have immediate access to almost every book recommended to you by fellow experts, and I am experiencing it right now. I am overwhelmed.

I went with the "5-Slot Bookshelf" subscription for a start (signed-up the day before yesterday), and plan to upgrade only if I need to.

SBO and Lynda are two services I'd blindly recommend to anyone.

Continue reading "Safari Books Online — A staggering digital library of Technology books" on Aahan Krish's Blog.

GRUB 2 is the default boot loader and manager for Ubuntu. When there are multiple operating systems installed on a machine (dual-booting), GRUB presents a menu and awaits user input.

Otherwise (i.e. only Ubuntu is installed), it transfers control over to the Linux kernel which automatically boots Ubuntu without ever showing the boot menu. Of course, you can hold down the SHIFT key (or sometimes ESC) early in the boot process until the menu displays.

So, in order to modify the boot order, or anything that deals with the boot menu, you'll have to modify the related GRUB configuration files. And there are many ways to achieve what you want, so lets check 'em out.

Option - I: Using menu position — '/etc/default/grub' is the primary configuration file for changing menu display settings in GRUB. So, start by making a copy (backup) of the file.

sudo cp /etc/default/grub /etc/default/grub.bak

Open the file via a text editor of your choice (gedit, nano, vi, vim, emacs, etc.) like so:

sudo gedit /etc/default/grub

The line GRUB_DEFAULT=0 in the file tells GRUB to select the first menu item to boot (menu items are zero-indexed).

But how do you find the position of the menu item (OS) you want to boot by default? Easy! Simply restart your system, and start counting when the boot menu appears. If the operating system that you want to boot first is listed at number 5 in the boot menu, you'd modify the line to GRUB_DEFAULT=4, and save the file.

Lastly, run this command:

sudo update-grub

This command runs the GRUB 2 configuration scripts and updates the '/boot/grub/grub.cfg' file with the updated boot order configuration. Restart your PC to test. More info here.

Option - II: Using exact menu entry — For some background, '/boot/grub/grub.cfg' is the main GRUB 2 configuration file. It is automatically generated by grub-mkconfig using templates from /etc/grub.d and settings from /etc/default/grub (more info here). Since it is a product of various scripts, it should not normally be edited directly. But we'll use it for some info; NOT edit it, but use it.

Open the terminal (CTRL + ALT + T) and issue this command:

grep menuentry /boot/grub/grub.cfg

As you can see in the image below, the output shows every line containing our catchphrase 'menuentry'. Look even closer, you'll notice that the text between single quotes after the catchphrase are actually the menu entries in the boot menu, and represent different OS options.

I am dual-booting Windows 8 alongside Ubuntu (evident from the output), and I want it to boot by default. So, I select the menu entry text in between the quotes (corresponding to the OS I want to boot up by default) — in my case, Windows 8 (loader) (on /dev/sda1) — and copy it for the next step.

Now, open '/etc/default/grub' in your text editor (take a backup first):

sudo gedit /etc/default/grub

Replace GRUB_DEFAULT=0 with GRUB_DEFAULT="Windows 8 (loader) (on /dev/sda1)" (notice the double quotes!) and save the file.

Lastly, run this command:

sudo update-grub

This command runs the GRUB 2 configuration scripts and updates the '/boot/grub/grub.cfg' file with the updated boot order configuration. Restart your PC to test. More info here.

I prefer Option - II over I. But there's an even better one.

Option - III: Simply boot the OS you booted the last time — For this, open '/etc/default/grub' in your text editor (take a backup first):

sudo gedit /etc/default/grub

Replace GRUB_DEFAULT=0 with GRUB_DEFAULT=saved. Then add this line right below GRUB_SAVEDEFAULT=true and save the file. More info here.

Lastly, run this command:

sudo update-grub

This command runs the GRUB 2 configuration scripts and updates the '/boot/grub/grub.cfg' file with the updated boot order configuration.

How it works? For example, lets say I restarted my system now, selected Windows 8 from the boot menu, I worked on it for a while, and shutdown the system. Later on when I start my PC, GRUB will boot Windows 8 by default. And then, if I select Ubuntu the next time, GRUB will boot Ubuntu by default starting from that point. Get the idea?

Option - IV: GRUB-Customizer, the graphical alternative — People were using StartUp-Manager until its development halted at some point in 2011. Now we have GRUB-Customizer.

Installing GRUB-Customizer is easy. First add the PPA to your system's software sources:

sudo add-apt-repository ppa:danielrichter2007/grub-customizer
sudo apt-get update

And this command installs the package from the PPA:

sudo apt-get install grub-customizer

SCREENSHOTS:

Continue reading "Change Boot Order When Dual-Booting Ubuntu With Another OS" on Aahan Krish's Blog.

sudo apt-add-repository ppa:jtaylor/keepass
sudo apt-get update

Now lets install KeePass (automatically downloaded from the PPA we just added):

sudo apt-get install keepass2

(Just know that KeePass is available from the official Ubuntu Package archive/repository, and can be installed easily via the Ubuntu Software Center, but it's not always the latest version.)

Now install the xdotool package (for simulation of X11 keyboard/mouse input) available from the official Ubuntu Package archive/repository:

sudo apt-get install xdotool

This package is necessary for the auto-type hot key function (Ctrl + V) in KeePass to work in Ubuntu. This is something most people miss, and complain that KeePass is broken in Ubuntu.

Continue reading "Installing KeePass Password Manager On Ubuntu" on Aahan Krish's Blog.

I have only been able to setup VirtualBox on Ubuntu (tested on 12.04 & 12.10) by following these exact steps.

Before you do anything, make sure your system is up-to-date by issuing the command:

sudo apt-get update && sudo apt-get upgrade

Install linux-headers package: Programs (like VirtualBox) attempting to use kernel services check for Linux kernel headers. You can easily install the Linux kernel headers for currently running kernel version by issuing the following commands:

sudo apt-get install linux-headers-$(uname -r)

Next install the 'DKMS' package to ensure that the VirtualBox host kernel modules (vboxdrv, vboxnetflt and vboxnetadp) are properly updated if the linux kernel version changes during the next apt-get upgrade (i.e. system update).

sudo apt-get install dkms

Now we are ready to install VirtualBox. So go ahead and download the latest stable package for your Linux distribution here. Double click the downloaded .deb file and install as usual.

The installer creates the system user group 'vboxusers' during installation. Any system user who is going to use USB devices from VirtualBox guests must be a member of that group. So, we need to add our Ubuntu user to the 'vboxusers' group.

sudo usermod -aG vboxusers username

(Don't forget to replace 'username' in the above command with yours.)

One last thing. You might also want to install the VirtualBox Extension Pack as it enables support for USB 2.0 devices, among a few others. You can download it here, and install then install it in two ways:

• Double-click on the package file, and let the VirtualBox Manager guide you through the process.

• Start Oracle VirtualBox from Ubuntu Dash, then go to File → Preferences, select Extensions tab in the settings window, and click Add package button as shown in the screenshot below (source).

Before you create a virtual machine, be sure to restart your PC.

Creating A Virtual Machine

This is easy. Once the machine has been rebooted post the installation, you may start Oracle VM VirtualBox from Ubuntu Dash, and proceed to creating a virtual machine by clicking the New button in Oracle VM VirtualBox Manager window. The following steps are pretty much self-explanatory.

Once the virtual machine has been created, right-click on the just-created virtual machine, select Settings, and via Storage tab in the new window that pops up, add the ISO file of the OS you want to install in the VM (Virtual Machine). Also check all other settings and make any changes if necessary (for example, video memory, CPU allocation, adding shared folders, enabling clipboard, etc).

Then start the VM, and installation of the operating system should begin. Once done, restart the VM, and when the guest OS is fully up, install VirtualBox Guest Additions by going to Devices → Install Guest Additions....

What is Guest Additions anyway? It's a special software package designed to be installed inside a VirualBox virtual machine after the guest operating system has been installed.

The package consists of device drivers and system applications that optimize the guest operating system for better performance and usability (e.g. mouse pointer integration, shared folders, better video support, host/guest communication, Shared clipboard, automated logons, etc).

If the gui of the OS installed on a virtual machine is laggy, try disabling Hardware Virtualization (see below).

Continue reading "Installing The Latest Version Of VirtualBox On Ubuntu (or Ubuntu-Based Distro)" on Aahan Krish's Blog.

In short, 'base64' encoding is a way of representing binary data as text (ASCII string format) so that it's more easily stored or transmitted over media that is specifically used for textual data (e-mail, HTML form data, CSS, et cetera).

Further Reading: wikipedia.org, stackoverflow.com

Use: Most commonly, images are encoded in base64 when embedded in HTML, CSS, and XML, to decrease the number of browser requests and thereby the loading time of a web page.

But my use case of base64 is to reference a contact's photo in a vCard (.vcf) file to import contacts with photos into Google Contacts.

Disadvantages of base64:

• Base64 string is much bigger than binary data in size. For example, the base64 text string of an encoded image is always bulkier than the image itself. So, base64 is a big no-no for large images, and if you have to, gzip compression and caching of documents (e.g. CSS file) should be of great help.

• If you change the image but keep the same name, you'll still need to change the base64 string. Maintenance is going to get tougher.

Converting (Encoding) An Image File To Base64

In Windows: Steven Benner's Encode64 Utility should do the job.

If you prefer command line (DOS commands), download the base64.exe utility by John Walker, drop it in the directory containing the image file(s) you want to encode. Then use the following commands.

To encode image and output the base64 string to a text file (don't forget to cd to the image directory first):

base64.exe -e image.jpg example.txt

To decode the base64 string in a text file to an image:

base64.exe -d example.txt image.jpg

For help:

base64.exe --help

In Linux: Simply issue the following commands (again, cd to the image directory first). Tested in Ubuntu 12.10.

To encode image and output the base64 string to a text file:

base64 --wrap=0 gcs.png > gcs.txt

In the above command --wrap=0 is used to disable wrapping of the output base64 text string. It's optional.

To decode the base64 string in a text file to an image:

base64 -d gcs.txt > gcs

You can then check the image's properties to find the image type, and then rename the file to include the proper extension.

For help:

base64 --help

Online Conversion Tools: Google is your best friend. There are lots of them, and here's one for a start.

PHP: Have PHP installed on your PC, or a server that you can quickly FTP into? Great! Simply create a base64.php file with the following code, and access it via your browser:

<?php echo base64_encode(file_get_contents('/path/to/image/bg.jpg')); ?>

Your browser should now show the base64 encoded text string for the image 'bg.jpg'.

That's all I know, for now.

Continue reading "Convert (Encode) An Image File To Base64 String" on Aahan Krish's Blog.

That's the hard way (above). Now, how about a fast and easy way?

To install fonts in Ubuntu, create a new directory named .fonts in your home directory (/home/username), if it doesn't exist already, and simply copy all your fonts there. That's it!

Continue reading "Installing Fonts In Ubuntu - The Quick And Easy Way" on Aahan Krish's Blog.

MathJax seems to be a promising one, considering the fact that it's used on the Mathematics Stack Exchange site.

Okay, now I need to learn LaTeX, so here's my notes - focusing on Linux (which is my dev environment).

Learning LaTeX

• LaTeX on Wikibooks
• Wikipedia: Displaying a formula

The info provided in there is just enough to get the job done for me.

Tools

• Texmaker - A free, modern and cross-platform LaTeX editor for Linux, Mac OS X and Windows.

• TeXstudio - Texmaker with some added features (e.g. spell checking).

• Gummi - Open source LaTeX editor for Linux featuring a live preview pane.

• OTHERS: Kile, TeXmacs, LyX (& eLyXer - LyX to HTML converter), and more.

• LibreOffice Math (LibreOffice Writer → File → New → Formula) works as a nice WYSIWYG editor. You can save content in MathML format, and use it as it is (MathJax also supports MathML alongside LaTeX), or convert it to LaTeX using some tool available on the web.

Continue reading "LaTeX For Beginners: Resources & Tools" on Aahan Krish's Blog.

The same applies for Google Blogger as well, considering the fact that the blogging platform uses Picasa for storage.

Now that's all well and good. But the question is, what's the URL of the 50 megapixel image?

In Picasa an image's URL looks like this:

https://lh4.googleusercontent.com/-oBrqCxqM0zY/UH8FEyCR58I/AAAAAAAAAZE/I5mrns0s9Fg/s800/Twilight-Frost-by-Phil-Jackson-Wallpaper.jpg

See s800 in the URL? It can be any number from 0 to 2048, but the standard values include s144, s288, s400, s640, s800, s1600 and s2048. It's this number that decides the size of your image (e.g. s800 in URL means that the size of the image shown will be 800 px on the longest side) - s# is, in other words, the size factor.

If the maximum number you can use in the URL is 2048, how can you get Picasa to show the Original 50 megapixel image? Obviously s8176 wouldn't work.

The number is 0. Yes, replace the size factor in the URL with s0, and that's the URL of the original size image you uploaded, right there!

https://lh4.googleusercontent.com/-oBrqCxqM0zY/UH8FEyCR58I/AAAAAAAAAZE/I5mrns0s9Fg/s0/Twilight-Frost-by-Phil-Jackson-Wallpaper.jpg

It's the same with Blogger as well. For example, in case of Blogger, the URL would look like:

http://2.bp.blogspot.com/-oBrqCxqM0zY/UH8FEyCR58I/AAAAAAAAAZE/I5mrns0s9Fg/s0/Twilight-Frost-by-Phil-Jackson-Wallpaper.jpg

Continue reading "URL Of Original Image (Up To 50 Megapixels) In Picasa / Blogger" on Aahan Krish's Blog.

gedit-markdown is a plugin for Gedit that adds support for Markdown (or Markdown Extra) in the default Gnome text editor, including Markdown to HTML conversion, syntax-highlighting and preview.

Resources:

• gedit-markdown: support for Markdown language in gedit (Developer's site)
• Gedit/MarkdownSupport - GNOME Live!
• Gedit/Plugins - GNOME Live!
• html2text - A Python script, converts HTML to Markdown
• Showdown - Markdown to HTML converter (Check the 'example' folder)

Continue reading "gedit-markdown: Markdown To HTML Conversion and Preview In Gedit" on Aahan Krish's Blog.

Well, the following images are self-explanatory, but if you find them difficult to follow, head over to How-To Geek's comprehensive tut.

The rest of the process is pretty straightforward, really. And as for restoring your system image at a later time, this should be helpful:

Continue reading "Create A System Image (Snapshot) In Windows 7" on Aahan Krish's Blog.

But first, I had to find the location of the default wallpapers in Ubuntu, which is (at least in Ubuntu 12.04):

/usr/share/backgrounds

or here in older versions of Ubuntu:

/usr/share/wallpaper

And when you set a custom background, the image file is stored in:

/home/{USERNAME}

By the way, this is the wallpaper I was talking about earlier - Twilight Frost by Phil Jackson (1920 x 1280)

Continue reading "Where Are The Default Wallpapers Located In Ubuntu?" on Aahan Krish's Blog.