Category: WEB SERVER

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PROGRAMMING TOOLS TUTORIALS WEB SERVER

How To Send Header To A Server Using Curl Command

In this article, we will learn how to send header to a server using the curl command. But before we can do that, you need to know what curl is in the first place, right?

So if you do not already know what a curl is, take a look at my earlier post here. What Curl Is & How It Works?

But if you are already familiar with curl, we can go ahead with this tutorial. So here we go!

But before we look at the command, let us try to understand what the Header itself is. Alright? Because knowing about it will help us in learning what the curl needs to do under the hood. Sounds good?

What Is An HTTP Header?

HTTP header is a case insensitive header information that can be sent with every HTTP request and response. So what does this mean? It means that we can pass some extra information between a server and a client computer.

Okay! But what does this extra information looks like?

You see, when you are using the internet, the web pages you look at comes in many shapes and sizes. They could be of different languages, different formats etc. So for example, you could be looking at a web page that is using plain text. Or it could be showing data in JSON format.

How To Send Header To A Server Using Curl Command
How To Send Header To A Server Using Curl Command

So whatever be the case, you need a way to tell the server or client about this when exchanging information. Right? So how do we do that? That is when the Header comes into picture. Because using HTTP headers, we can pass along this type of information.

So what does a typical HTTP header looks like then? Well, it looks something like this:

Accept:application/json
Content-Type:application/json

So a typical HTTP header looks something along these lines. By looking at the above header, it is kind of self explanatory, right? Because it is clearly saying that the client will accept content from the server in JSON format.

So with this idea in our mind, let us now see how to send Header to a server. Alright? Here we go!

How To Send Header To A Server

So to start with, we will see how to send the header shown in previous section to a server. Which means that we are sending in a request to a web server to send data only in JSON format.

So the curl command we need to use to do that is as shown below:

curl -i -H "Accept: application/json" -H "Content-Type: application/json" http://mywebsite.com/data.json

So as you can see from the above code, the curl command is quite simple. Here is what each of these options are doing:

“-i” – This switch is telling the curl tool to display the header information for both request & response.

“-H” – This is the switch that we need to use to send a custom header. What it means is that curl actually sends header info. even without this switch. But by using it, we are explicitly saying curl to use this custom header instead. Makes sense?

So that is it. That is all there is to learn about how to send header to a server. Pretty simple, huh?

But if you are not clear on something or have any question, ask me in the comments below. I will be more than happy to answer your queries.

But otherwise, that is all there is to this article folks. So, see you guys until next time! 😉

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DIGITAL MARKETING TUTORIALS WEB DEVELOPMENT WEB SERVER WORDPRESS

5 Best Domain Name Ideas For Food Blog

domain name ideas for food

Here is a list of domain name ideas you can use to start your own food blog. Now we know that if you are a food blogger looking to start your own blog, then finding a suitable name is a challenge. So to help you on this, we have come up with a short list of domain names that you can use for your blogs.

We will go through each of these blog domain names and discuss its advantages. These are all domain names best suitable for a food blog and available for registration. So, using one of these names should give a meaningful character to your blog.

5 best domain name ideas for food blog

What do we need to look for when coming up with a blog name?

There are lots of challenges we need to overcome when we are trying to come up with a name for a food blog. So let us discuss this first. Now since this is a new food blog, your visitors will be unfamiliar with it. Therefore, you need to have a brand name that is catchy, creative and easy to remember. In this way, when your visitor visits your website, it’s name will get registered in his mind.

Here is a little exercise for you

I want you to recollect how many brands and names you came across today? Every brand names you had come across the entire day, I want you to try and recollect them. Done? Now tell me, how many of those names were you already familiar with? And how many “new” brand names did you come across today?

Did you make a list of it?

So here is the thing. Most of the familiar names you recollected were because of their extensive marketing. They would have been promoting their brand names regularly and as a result, it has become a house hold name now. And that is the reason you were quickly able to recollect most of the well known brands. But you can’t take this path because you need to spend a lot of money for that. Because advertising needs money.

But on the other hand, let us look into your list of the new brand names you had came across. It might not be a long list. But it is still something you were able to recollect and write it down. So that is by itself surprising isn’t it?

But can you realize why you were able to recollect that new brand name? The answer will most likely be because it was easy, memorable and creative! So these are the same 3 things I had listed earlier that you need to use while coming up on your own food blog’s name! Correct?

So you saw the pattern here. You now know exactly what you need to do come up with a successful brand and domain name.

So with this in mind, let us start going through each one of the domain name ideas that you can use right away for your food blog.

Domain Name Idea For Food Blog #1

Buy Domain Name: Foodfossil.com

Now this is one of the interesting domain name ideas for food blog. Because it is simple, cheesy and easy to remember as well.

Also everyone who has been using an automobile will be very familiar with the term fossil. It is literally how the fuel is obtained for the said automobile.

Now, if we consider humans to be like automobile, what is the fuel we need? Yes, you got it right. It is the food!

So combining the word food with its intended activity as a fuel for body, foodfossil.com makes so much sense! Also, since this is a .com domain name, it is easy to remember!

Domain Name Idea For Food Blog #2

Buy Domain Name: foodassemble.com

Now this ia very unique domain name idea for a food blog to use. We are all familiar with how a car is made right? It is made up of individual parts that gets assembled in a factory. So the end product – the car is assembled in a factory. Now just like that, even we assemble our food by making use of its ingredients.

So when you use a name like foodassemble.com for your food blog, it signals the process of the preparation of food. So what do you guys think of this name? Doesn’t it sound cheeky, professional and still easy to remember? 😉

Food Blog Domain Name Idea #3

Buy Domain Name: platesofaroma.com

Now far some reason, you don’t want to use keyword like food for your domain name, we have an alternative for that. You can simply use this new domain name platesofaroma.com.

I think by now you are already able to figure out how this is a good name. If we simply break the domain name of this food blog, we get three words plates + of + aroma.

Aroma, if you are not a native English speaker simply means smell. So when I say plates of aroma, I simply mean delicious smelling food in a plate. See again, this domain name is very easy to remember. You are making your website’s visitor imagine a plate of food. And this food is something that is delicious and best smelling. And this food is served on a plate for you to eat up!

Now that is a sight to remember isn’t it. Also, everytime he comes into a similar kind of situation for real, he will remember youf blog!

Win-win for you if you use this domain name for your food blog, isn’t it? 😉

Food Blogger Domain Name Idea #4

Buy Domain Name: mealartist.com

Now this is a domain name that is on point! It clearly describes you, a food blogger’s mastery over your food art.

This domain name is simply a combination of two words meal and artist. Here, the word meal simply tells that the subject is about food. On the other hand, the word artist would mean that you are an expert in it.

Also, since this domain name uses two most familiar words, anyone will be able to remember it easily.

Domain Name Idea For A Food Blog #5

Buy Domain Name: Eggpotato.com

So this is an interesting domain name for a food blog, right? What we are doing here is to combine two food items. Eggs and Potatoes and forming a domain name out of it. Now since egg and potato scramble is a common food item everywhere, it is easier to remember.

Aslo, it comes as a surprise to us that this domain is still available in a .com extension!

So, if you are just starting out a new blog and unsure about a name, this is the one you should mostly be picking up!

Conclusion

So, these were the top 5 domain names you can use to create your food blog. As a food blogger, the domain name ideas you use should match the content you plan to post in the blog. So make sure that you pick the right name depending on what you plan to write.

Also as a food blogger, your reputation in the social media only increases if you can come up with innovative recipes. So, keep these things in mind when registering a domain name for your website.

So with that, I will end this article now. Hope you liked some of the domain names I have listed here. If you still have any questions or suggestions, do let me know in the comments below.

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DJANGO PYTHON TUTORIALS WEB DEVELOPMENT WEB SERVER

Django Web Framework Beginner Tutorial – Introduction

A very big sum python function
Writing a very big sum function in Python programming language

What is Python Django?

Django is a Python based web development framework. It is a collection of libraries and tools that can be used to develop websites and web applications. Django uses Python as its primary backend programming language.

Learn more about Frontend & Backend components of a web app here

Why use Django Web Development Framework for developing a web app?

In the early days of internet, not many programming languages or supporting libraries were available for the development of websites. So, every website developer was writing many frequently used components repeatedly.

Python Django Web Development Framework

These included features like user authentication, database read/write, Cross Site Scripting (XSS)/malware protection code, database injection prevention code etc.

Every time a new website was built, web developer had to rewrite these pieces of code over and over again. This results in an increase in time to complete the project. It also exposes the website to certain vulnerabilities due to bad testing or bad design.

In order to overcome these, developers started to create a common web development framework. This contained all the frequently used components like authentication, session management code etc. These were later made available to others as part of the web framework libraries.

Soon enough, these libraries started being developed in different programming languages as well. Django is one such web application development framework that was developed using the Python programming language.

Why Use A Web Development Framework Like Django?

The main advantage of using Django is the number of readily available components it comes with. All the bells and whistles required to develop a basic web application is present in Django. Module like user management, admin dashboard, session management component, protection against XSS, CORS support are all readily available. This makes Django one of the quickest web development framework to get started with. You can go live with a website in no time because of this.

In addition to this, Django also comes with framework extensions such as Django Rest Framework (DRF) that can be also used to enhance the capabilities of a Django Web Application.

All these features of Django makes it one of the most appealing “all batteries inclusive” web app development framework in the tech industry.

In addition to this, if you are already familiar with the Python programming, then using Django becomes very easy.

Django is not the only Python web development framework. There exists other Python based web development frameworks like Flask, web2py and many more. But what makes Django different and easier to get started with is its all inclusive battery modules we discussed earlier.

Who is currently using Python Django Web Framework in real world?

Some of the top tech companies using Python Django includes Instragram, Quora, Mozilla, Disqus, National Geographic, Last.fm etc.

This was a theoretical introduction of Django. In the upcoming articles, we will get our hands dirty by using Django to develop a few simple web apps. This should give you a clear idea on the advantages of Django and why it is extremely useful.

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TUTORIALS VPS WEB DEVELOPMENT WEB SERVER

Things To Consider When Designing & Developing A Website

So you have decided to design and develop your own website? Great! But are you aware of all the things that you need to keep in the back of your mind when designing and developing your website? In this article, we will list some of the most important thing you need to consider when developing your website in 2019 & 2020.

1. Domain Name

The internet today is made up of over a billion of websites and web applications. With so many options at the tip of their hand, your website visitors will not be able to remember your website until and unless its name stands out from the crowd. So, pick a catchy website domain name that is easier for your website visitors to recollect in the future. Use the Namecheap’s search bar extensively to identify an easy to remember and available domain name. Ideally, a .com domain name is preferable over other domain name extensions as most of the non technical visitors by default assume the domain name to end with a .COM extension. It is also advisable not to use a name that is too long to remember or too many non interpret able characters such as vooooooooz.com (Here, it will be very difficult for your users to remember how many o’s are there in the domain name).

2. Web Hosting

Web hosting is the web server provider where your website will reside or hosted finally after web development activity is done. Where you host your website is very important as that becomes an important criteria in determining your website visitors satisfaction! Confused? You see, your website visitors will be very happy when your websites loads as quickly as possible. If it takes more than 10 seconds to load a web page, your website visitors will get frustrated and might close your website rather than waiting for it to completely load. As a result, the speed at which your web server delivers your website to its visitors plays a vital role in determining the ultimate customer satisfaction.

So how to determine which is the best web server to use?

Ideally, your web server must be located as close to your website visitor as possible. So for example, if your website visitors are mostly from the United States (US), you should host your website in a server located within the US. If your website is located in a far away location such as Australia, the amount of time required to deliver the web pages of your website from the server ot your website visitor will increase a lot!

What if your website visitors are coming from all across the world?

If you have a very generic website that appeals to all the people across the world, chances are you will have visitors coming into your website from across the globe round the clock. In such a case, where should we host the website? Well, the answer for this is to host your webserver across the globe!

Wait…what???

Yeah, you heard it right. If you are getting visitors from across the world, you will still need to deliver your web pages from the web server closer to your user’s location! But how to do that? Allow me to introduce you to the “Content Delivery Network” or CDN for short.

What does a Content Delivery Network or CDN do?

Content Delivery Network or CDN is a type of web service provided by certain set of CDN service providers whose main job is to host copies of your website across multiple web servers around the world. They will take care of determining where your website visitors are coming from and decide upon which CDN web server to use to serve web pages to them. In that way, you are ensuring that all of your visitors coming from across the world will get the same quality of website access as every other user from any other location in the world.

If you are just beginning with your website, you dont normally need to go for a CDN until you are able to determine the geographical locations from where majority of your website user base is located at. So, we will revisit again regarding CDN in the future and ignore it for now.

So now that we understand that our web servers need to be very fast and located closer to the website’s userbase, where do we look for a web server and how to determine a web hosting provider?

How to choose a web hosting provider?

There are different types of web hosting providers in the market. Some of them provide us with a managed hosting where they will manage the entire web server related issues and you will only need to worry about your website related parts. They also usually host not just your website on their server, but many other websites from other website owners as well in the same server. So, in other words, you will be sharing your website’s web server with other websites and hence they are usually called as the Shared Web Hosting service providers. One of the best example of such a Shared Web Hosting provider is the Namecheap shared hosting provider as shown below.

Shared Hosting with Namecheap

Using a shared hosting provider has its own set of advantages and disadvantages. One of the main advantage of using a shared hosting provider is that in that case the webmaster (aka website owner or website maintainer) need not worry about maintaining the web server part as it will be taken care of by the shared hosting service provider. On the other hand, one of the main disadvantage of a shared hosting provider is that since the same web server will be shared with other websites as well, the speed of the web server will be nondeterministic and usually slower. If one of the website in that shared hosting server gets high traffic, the other websites in the same server will be affected with its response time, thereby frustrating its users.

If you do not want to go for shared hosting, there are other types of web servers available to you. One such option is the Virtual Private Server (VPS).

In case of a Virtual Private Server (VPS), you will be the sole person in control of an entire virtual private server and it will not be shared with anyone else. This results in an increase and deterministic response time, all the time by your website to your website visitors. The other advantage of a VPS server is that since you have access to the complete VPS computer, you can install any software that you choose to, something that may not be possible when using a shared web hosting service provider. The downside, however is that this VPS will not be managed by the service provider and you will be completely responsible for maintaining the VPS server. There are many Virtual Private Server (VPS) providers in the market that are highly competitive and cost effective. One such service provider is the Vultr VPS service provider which provides a VPS server for as low as $2.5 per month! We highly recommend this VPS server if you are looking in to a VPS server option.

3. Design A Responsive Website For Mobiles

Now that we have covered the infrastructure part of a website – domain name and the web server, let us now start looking into the design aspects of a website.

Over 70% of the website traffic these days come from smartphones and tablets. As the mobile data rates continue to fall along with the fall of smartphone prices with excellent technical specs, this number of mobile visitors is only going to increase in the future. So what does this mean to your website?

Make your website responsive and mobile friendly!

What do we mean by a responsive website?

In the early days of web development, where there were not many devices with varying form factor – that is the size of the screen did not vary a lot, designing a website for these computer devices where reasonably easy. But with the advent of smartphone since 2007 – the year iPhone was launched, most of the website traffic started coming from these smartphones and every year this is only increasing. With the introduction of smartphones, web developerf faced a new challenge – huge range of smartphone computing device screen sizes!

By default, what the operating system of these smartphones do – such as the iOS of iPhone or Android is to shrink the size of a website to just fit enough into the screen size of the smartphone.

However, problem with such a scheme is that many of the links and buttons of the websites where user was supposed to take action on, became extremely difficult to click on thereby reducing the user experience (UX) of the website. This can be extremely frustrating to your website visitors and hence, an alternative design had to be thought of to handle mobile visitors to the website. This is when the Responsive Website Design was born!

In a Responsive Web Design, the website is designed in such a way that the size of the buttons, links, texts or images and the overall layout of the web page are determined depending on the size of the device’s screen and rendering accordingly, automatically!

The advantage now is that the visitors of your website need not have to fight with their smartphones and tablets to interact with your website. So always build your website using responsive design strategy.

One of the easiest way to design a responsive website if you do not have the time to learn every aspect of a responsive design is to use a frontend website framework such as Twitter’s Bootstrap. Using Bootstrap framework while building the frontend of your website will ensure that your website is always responsive!

4. Search Engine Optimization (SEO)

Finally, we also need to ensure our website is optimized for search engines such as Google, Bing, Yahoo, DuckDuckGo etc.

What is Search Engine Optimization (SEO)?

Most of the people use search engines such as Google or Bing to find answers to their queries. In return, the search engine will display a list of websites that is expected to answer those queries. In the early days of our website, when not many people will know about its existence will mostly end up on our website mainly through these search engines. If our website has answers to the queries asked by the search engine’s users and the searach engine thinks our website’s answers are better than other websites’ answers, it will display our website link above other websites, there by increasing the probability of the search engine user to click our link and visit our website.

So then, what are the parameters that we need to take care of to ensure the search engine such as Google places our website at the top of the search result? It is these set of parameters that becomes the basis of Search Engine Optimization (SEO).

Search Engine Optimization (SEO) as the name suggests, is the optimization methodology used on our websites to ensure that the search engines can easily traverse throughout our website’s web pages, analyze the content of our website for quality and hopefully determine the best position of our website in its results displayed to its users. The position given to our website in the search result for a particular query is called the search engine ranking of our web page for that query.

Our aim hence, will always be to figure out a way to get our articles to the top of as many search query results as possible. This is usually achieved by ensuring quality of the content of the website, ease of navigation across the web pages throughout the website – both for search engine bots as well as our website users, proper use of appropriate HTML tags depending on the content, easy readable hyperlinks & URLs, good amount of highly authoritative websites linking back (aka backlinks) to our web pages there by signalling the search engines that our articles are highly recommended by them etc.

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HTML JAVASCRIPT LAMP PHP STATIC WEBSITES TUTORIALS WEB DEVELOPMENT WEB SERVER

Beginners Tutorial – What Is A Website?

A website example

We have all heard about different websites present on the internet such as Google, Youtube, Facebook, Twitter etc. But what exactly is a website? What is it made up of?

Imagine you just found a 100 year old book in your attic that contains a wealth of information about the world wars. It also has a collection of photographs that revealed some secrets that are lesser known to the public. You wanted to share this information with the world, but how?

One way is to go to the newspapers and get it published, but it can still not reach all the people across the world. What would be an easy and best possible way to share this information to people around the world? Publish it on the internet!

When you publish it on the internet, anyone from around the world having a computer or a smartphone with an access to the internet will be able to consume your content.

You can publish this information on social networking websites such as Facebook, Twitter or Youtube or create your own website to publish it.

A website example

So, a website, simply put, is a collection of information present in different formats such as texts, images, videos, graphs that is published on the internet to helps its users consume them.

But just like you, there are millions of people who are sharing information on the internet, so how do you make your contents accessible from other people’s information? This problem is very similar to having thousands of building in a city and needing to find a particular building. How do we do that? We will discuss about this in the future articles

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HTML JAVASCRIPT LAMP PHP PYTHON TUTORIALS WEB DEVELOPMENT WEB SERVER

Basic Structure Of A Web App/Website

A website or a web app is usually made up of the following 3 web components:

These components are arranged as shown in the following diagram.

Structure Of A Web App
Location of the web app components on the internet

Web App Back-End component

All the core logic of a web app or website is usually implemented in the web app’s back-end component. This includes all the algorithms of the web app, code to perform any storing and retrieval of data from the database, url based route handling etc. All these code forms the back-end of a web app or website and runs on a specialized computer called the web server.

Backend component of the above image

The code for back-end programming can be written using several different programming languages such as PHP, Python, Java, Javascript, Ruby etc. Each of these programming languages comes with their own advantages and disadvantages like for example choosing a language like Python comes with the great benefit of having several readily available libraries useful for data crunching activities, however they can be relatively slow compared to other programming languages. So which backend programming language to choose largely depends on the type of functionalities required for the particular web app that is going to be developed.

Web App Front-End Component

All the visual and interactive elements of a web app or website comes under the Web app’s front-end component. Whenever the user of a web app or website visits the website, he will only see and interact with the web app’s front-end component. So as far as he is concerned, a web app for him is usually just the front-end component. It is what he sees and interacts with in his web browser.

Front end component of the above image

However, these front-end components will not usually store all the relevant data of a web page within itself but instead, will query for them by sending requests to the web app’s back-end component that was discussed earlier. These requests are usually sent using the HTTP protocol.

The programming languages used to write web app’s front end component includes HTML, CSS & Javascript. Among these, HTML is a markup language that a web browser will use to interpret what HTML components needs to be drawn on the browser screen to represent the website. CSS is a styling language used to customize the style (like change the color, size, background color etc.) of these HTML components. Finally Javascript is a programming language that can be used to add interactive functionalities to these HTML components.

With the help of these 3 programming languages, your front end should be highly interactive and user friendly for any non technical person to start using your web app.

Database component

A database is a specialized software used to store and retrieve data efficiently on a computer or a server. The database can sit in a web server along side the server software or can be present in its own seperate dedicated database server.

Database component

Databases are usually used in a web app (or website) to store all relevant data of that web app such as user data, session data, web app specific data etc. There are many different forms of databases available such as relational databases, NoSQL databases, Document Oriented databases, Graph databases etc. Each of these variants of databases have certain unique features that are useful in certain specific situations. The most common database type used in web apps are usually relational databases such as MySQL, PostgreSQL. However Document Oriented databases such as MongoDB are also used frequently.

So these 3 components forms the fundamental elements of a web application. Of course there can be more than these 3 components required as your web app continues to grow. You may need to add multiple servers, load balancers to manage higher traffic, caching mechanisms etc. We will discuss more on these modules further in future articles, but having the knowledge of above three fundamental components of a web app should give you the best start to learn and start working on the development of your first web application.

Do comment below if you liked the article or if you have any questions regarding the above topic and I will be happy to answer your questions. Until then, happy learning! 🙂

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JAVASCRIPT STATIC WEBSITES TUTORIALS WEB BROWSER WEB DEVELOPMENT WEB SERVER

This one value in Javascript is not equal to itself!

We know that Javascript supports all kinds of values such as strings, numbers, constants etc. All these values are deterministic values in that their weights always remains the same. For example, an integer value of 25 is always equal to 25 in Javascript no matter what. Similarly a string value of “Hello” is also always equal to another string “Hello”.

In other words, these values in Javascript can always be compared with another value to determine if they are the same or different. To understand this better with an example, let us open up our browser console. In my case I am using Google Chrome browser console where we will create 3 variables with these values:

We can note from the above Javascript demo video that when the variable a and c are compared, since both their values are same holding a value of 2, they return true when compared with each other. On the other hand when variable a was compared with b, since their values were different, the comparison resulted in a return value of false.

This is true for all type of values present in Javascript – be it string, integers, floats, booleans anything you can think of.

However, there exists one special value in Javascript that is never equal to another variable having the same value. In other words its value is never equal to itself. This value is the NaN value!

NaN in Javascript stands for “Not a Number” and it is that one special value in Javascript which does not return true if it is compared with itself.

Why does NaN not equal to itself in Javascript?

Now you might be wondering why a NaN value does not equal to itself? The answer for this lies in the way Javascript language has been designed.

NaN or Not a Number is a special value in Javascript which is used to represent a nonsensical value – that is it is the value returned whenever a non sensical operation is performed. Now this is where it gets interesting. Why does a non sensical value not be the same all the time or at all the place? In other words, why is this happening here:

Why is it returning false?

The answer is that NaN as mentioned earlier is a value that is used to represent a non sensical values. So if the result of an operation performed is something that cannot be represented by ordinary or normal values, Javascript returns a value of NaN.

Now, if two operations results in non sensical values, they are not necessarily equal. Each of these operations can be returning two non sensical values of different weights. However, they both need to be represented by the value of NaN. Hence, the Javascript treats two NaNs as two different values and never equal to each other.

I learnt about this and many other similar anomalies in the book Eloquent Javascript. This is a very good book to learn and understand such interesting things about Javascript so I will definitely recommend this to anyone interesting in learning Javascript in depth.

If you are also aware of any other similar interesting things about Javascript do let me know in the comments below. Until then, happy coding! 🙂

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HTML STATIC WEBSITES TUTORIALS WEB SERVER WORDPRESS

What does Hyper Text Markup Language (HTML) even mean?

HTML is the language used to develop web pages for the world wide web. But what does HTML even mean? We know that HTML stands for Hyper Text Markup Language, but what does each of these terms even signify? This post will try to discuss upon each of these words and their significance in the world of the web.

What is Hyper Text?

Hyper text refers to the ability of web pages to link with each other, within the same website or between websites on the internet.

What is a Markup Language?

HTML is a markup language. But what does markup language even mean? It means that all the building blocks that make up a HTML web page are made up of HTML elements defined by HTML markups. In other words, HTML markups are special tags used to define all the HTML elements that make up a web page. These HTML markups includes tags like <head>, <title>, <body>, <footer> etc.

Why use semantic HTML markups for your web page?

With the recent HTML 5 specification, there has been an increase in the amount of these HTML markups (or tags) defined by the specification so that there are more semantically meaningful HTML markup tags available to define a web page. These new semantically appropriate HTML markup tags help improve the readability and understanding of the sections of these web pages by machines (aka algorithms) such as search engines.

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CMS HTML STATIC WEBSITES TUTORIALS WEB SERVER WORDPRESS

How HTML Anchor Tag Could Be Used To Perform DDOS Attacks

Chinese attackers have been using HTML Anchor tags to perform DDOS attacks across the world these days. This is one such instance where a seemingly benign feature addition done to the HTML technical specification has inadvertently opened a Pandora box of its misuse/abuse by hackers and attackers.

As mentioned in my introductory article to HTML Anchor Tags, Anchor tags are used to link documents present on the word wide web so that users of a web page can easily navigate to a new web page seamlessly from their web browsers.

An example of HTML code using anchor tags looks something like this:

<a href="https://muddoo.com" title="Muddoo Home">Muddoo</a>

While the above code is a standard way of using HTML anchor tags, there are also additional anchor tag attributes one can use to add new features to the anchor tag’s overall functionality. In our previous article we looked at the noopener attribute that ensures that when the respective anchor links are opened in a new window, they are opened in a separate thread all together and have no relationship to the parent web page in anyways. This ensured that Cross Site Script (XSS) attacks could not be made from child web page to the parent page.

Just like the noopener attribute, we have another attribute associated with the anchor tags that some hackers are misusing to perform DDOS attacks on other websites. This attribute is the “ping” attribute of the anchor tags!

What is HTML Ping Attribute?

Ping is a new attribute of an Anchor tag that was introduced in HTML5 specification. Ping attribute would list a set of one or more URLs that are pinged back whenever a user of a web page follows a hyperlink from that anchor tag.

The idea of introducing Ping attribute to anchor tags was to enable web administrators track clicks on that hyperlink. An example of how this attribute looks like is shown below:

<a href="https://google.com" ping="https://muddoo.com/tracker">Go to Google</a>

So in the above example, whenever a user clicks on “Go to Google” hyperlink, he will be taken to the Google home page, but at the same time, a ping POST message is sent back to the https://muddoo.com/tracker webpage for muddoo.com website to keep track of number of users going to Google through that hyperlink.

But the problem occurred when some of the Chinese hackers started using this innocuous feature to perform DDOS attacks on many websites. They simply created web page with links to standard websites such as Alibaba or Tabao, while using ping back links to their target websites. They specifically targeted people using QQBrowser (from Chinese giant Tencent) to use their web pages to reach standard websites. This resulted in millions of Ping request going back to targeted websites thus acting as a DDOS attack on these websites.

How to prevent Anchor Tag Ping attacks from your web pages?

With good understanding of how the attack is being performed, you must be wondering how you can prevent such DDOS attacks originating from your websites or getting attacked by one. But unfortunately, there are no clear solutions in place as the support for Ping requests are part of HTML 5 specifications so all browsers will be supporting it (well, more or less), so your only best possibilities will be to keep monitoring such activities on your web server and take appropriate action at the right moment.

Hope this article gave good introduction to the possible Ping DDOS attacks happening due to the presence of Ping attribute in the HTML Anchor tags. This article has been part of series of articles that I have been writing about HTML tags with this being the third article on HTML Anchor Tags.

If you would like to take a look at other two articles, you can follow these links:

Introduction To HTML Anchor Tag

What is noopener vulnerability found in anchor tags of HTML?

Until next time, happy coding! 🙂

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What is noopener vulnerability found in anchor tags of HTML?

HTML anchor tags are used to link to different web pages available on the internet. We also frequently use “target” attribute with the anchor tags so that the linked web page is opened in a separate new window. This is achieved by using the anchor tag like this:

<a href="https://muddoo.com" target="_blank"title="Muddoo Home">Home</a>

Note that in the above code we set the “target” value to be _blank, which would result in the linked web page (https://muddoo.com in this case) to be opened in a new window.

However, it has been found that this can leave a possible vulnerability where in the remotely linked web page can take over control of your web page.

Why does this vulnerability happen?

This vulnerability of remotely linked web page taking over your web page (that is having the anchor tag) is because of the following reasons:

  1. In normal scenario, whenever you open a new web page in your browser in a new window, the web page is running in its own separate thread.
  2. Now when we open a link present in that web page, the new linked web page gets opened in a new window due to the presence of “target” attribute of the anchor tag. However, in this scenario, the newly opened web page is also running under its parent’s thread itself instead of its own thread.
  3. As a result, the newly opened external web page has controls over its parent’s thread. There by creating a vulnerable situation!

How to overcome anchor tag’s “target” vulnerability?

We can overcome this “target” thread control vulnerability simply by introducing a new attribute to your anchor tags called the rel=”noopener” attribute.

Thus, the new fixed anchor tag would look something like this:

<a href="https://muddoo.com" target="_blank"title="Muddoo Home" rel="noopener">Home</a>

With this simple change, we can ensure that the newly opened web page runs in it’s own thread there by having no link to it’s parent thread in any way!

Hope you are now aware of this possible vulnerability and ensure you start using the rel=”noopener” attributes to all your web pages’ external links!

Happy coding! 🙂

Note: This article is continuation of my previous article Introduction To HTML Anchor Tag