Databases, Systems & Networks

When content for a webpage is created and published, image optimization is probably the last thing an author knows about. Well, it is an acceptable mistake if an author’s example is taken into consideration in this context. But, it should be in the “Absolutely-To-Do” list of an SEO Vancouver specialist before posting the graphical parts of web based content.

According to the SERP feature history of Mozcast Feature Graph, Google images search ranking is 3^rd in the list with 32.4% of organic search results following Adwords – Side of 42.6% search results (2^nd in the list) and Adwords – Top of 58.3% search results (1^st in the list) respectively.

In this post, I’ll try and explain certain small SEO steps which can improve the visibility of your webpage with the help of image optimization:

1. Naming of the Image Files: Even if it sounds absurd, a proper image file name plays a generous role in image optimization. According to google, a file name of “Testing Audi A8” does well than “IMG_909”.

2. Character size of File-name: 3-5 words file name is optimal for an image file.

3. Format of Image Files: When it boils down to the format of an image, JPEG steals the show. Instead of putting a PNG file in your webpage, try putting JPEG for better results.

4. ALT Text: ALTernate Text is a great visibility influencer. Generally, every image should have an ALT text with it which should be descriptive enough for the crawlers.

5. Do Not Stuff your image’s ALT Text with keywords. It is considered as a bad practice nowadays. Keyword stuffing is being target by google and everyone should avoid this dangerous habit.

6. User Experience should be the primary concern of every SEO activities we do. Google has become user centric and it is always better to perform the activities taking the requirements of random potential user in the mind. This part should be taken care of carefully. The quality of images should be good yet it should not take more than 2-3 seconds to get loaded in a decent internet connection.

7. Placement of Images: yes, the placement of images in a web page also decides the faith of the page. It is talked about and a proven fact that if the text surrounding the image is matching or, of relevance, it has a greater chance to get pumped up in the search ranking.

After performing above given steps, the changes of your webpage getting visible in google search results get higher than ever. Please the context of this article in mind. It is also very possible that image optimization does not yield you expected results but for this to happen, you might blame the content associating it as well. Image optimization should be your only way to get ahead but it surely gives you an admirable edge over the others.

Factors such as Image metadata, Dimensions of images and, such things are also said to be crucial factors for SEO Vancouver purposes but there is no definite proof of it. However, it is always advisable to keep an account on all of the relevant factors for better results.

Source: sotra.ca

Send email notifications using Gmail SMTP

Using Gmail SMTP: Suppose you want to configure a Linux app to send out email messages from your server or desktop. The email messages can be part of email newsletters, status updates (e.g., Cachet), monitoring alerts (e.g., Monit), disk events (e.g., RAID mdadm), and so on. While you can set up your own outgoing mail server to deliver messages, you can alternatively rely on a freely available public SMTP server as a maintenance-free option.

One of the most reliable free SMTP servers is from Google’s Gmail service. All you have to do to send email notifications within your app is to add Gmail’s SMTP server address and your credentials to the app, and you are good to go.

One catch with using Gmail’s SMTP server is that there are various restrictions in place, mainly to combat spammers and email marketers who often abuse the server. For example, you can send messages to no more than 100 addresses at once, and no more than 500 recipients per day. Also, if you don’t want to be flagged as a spammer, you cannot send a large number of undeliverable messages. When any of these limitations is reached, your Gmail account will temporarily be locked out for a day. In short, Gmail’s SMTP server is perfectly fine for your personal use, but not meant for commercial bulk emails.

With that being said, let me demonstrate how to use Gmail’s SMTP server in Linux environment.

Google Gmail SMTP Server Setting

If you want to send emails from your app using Gmail’s SMTP server, you need to adjust the security setting of the Gmail account to be used. Go to the Google account settings, and enable the option to allow less secure apps, which is off by default.

Then you will need to provide your app with the following details.

• Outgoing mail server (SMTP server): smtp.gmail.com
• Use authentication: yes
• Use secure connection: yes
• Username: your Gmail account ID (e.g., « alice » if your email is [email protected])
• Password: your Gmail password
• Port: 587 (TLS) or 465 (SSL)

Exact configuration syntax may vary depending on apps. In the rest of this tutorial, I will show you several useful examples of using Gmail SMTP server in Linux.

Send Emails from the Command Line

As the first example, let’s try the most basic email functionality: send an email from the command line using Gmail SMTP server. For this, I am going to use a command-line email client called Mutt.

First, install Mutt as follows.

For Debian-based system:

$ sudo apt-get install mutt

For Red Hat based system:

$ sudo yum install mutt

Create a mutt configuration file (~/.muttrc) and specify in the file Gmail SMTP server information as follows. Replace <gmail-id> with your own Gmail ID. Note that this configuration is for sending emails only (not receiving emails).

$ vi ~/.muttrc

set from = "<gmail-id>@gmail.com"
set realname = "Dan Nanni"
set smtp_url = "smtp://<gmail-id>@smtp.gmail.com:587/"
set smtp_pass = "<gmail-password>"

Now you are ready to send out an email using mutt:

$ echo "This is an email body." | mutt -s "This is an email subject" [email protected]

To attach a file in an email, use « -a » option:

$ echo "This is an email body." | mutt -s "This is an email subject" [email protected] -a ~/test_attachment.jpg

Using Gmail SMTP server means that the emails appear as sent from your Gmail account. In other words, a recipient will see your Gmail address as the sender’s address. If you want to use your domain as the email sender, you need to use Gmail SMTP relay service instead.

Another note is that if you are concerned about placing your SMTP password in the plain-text .muttrc file, you can encrypt the password using GnuPG.

Lire la suite…

If you are running the Apache Web Server or your web hosting provider running Apache based web server, you can use .htaccess configuration file to restrict access to your website. This could be a very important issue from security stand point of view especially if your server is being attacked or hacked from any specific or range of IP addresses.

Now, restricting access method works in two ways. First, you can restrict access to certain IP addresses and allow others. Second, you can restrict access to everyone but few IP addresses only. On this post, I will focus on both method and will try to explain as much as I can.

Restrict Certain IP Addresses

If you want to restrict specific IP addresses from accessing your site, you can use the following lines on your .htaccess file.

order deny,allow
deny from 123.4.5.6
deny from 654.3.2.1
allow from all

These lines above will block “123.4.5.6” and “654.3.2.1” IP addresses from accessing your site. You can add as many IP addresses as you want on this “deny from” list. One interesting fact is, Apache web server gives you lot more flexibility in terms of blocking IP addresses. Take a look at the following lines.

order deny,allow
deny from 123.4.5.
allow from all

If you observe it carefully, you will see that the fourth set of digit is missing on this IP address. It means, if any IP address that matches the first three set of digits will be blocked. So basically anyone with IP address like “123.4.5.1” or “123.4.5.244” won’t be able to access your site as in both IP address matches with the first three (123.4.5.) sets of digits blocked by the Apache web server.

Allow Specific IP Addresses

Think of about a site that you built for a very specific purpose and for very few people, where you do not want everyone to show up. Apache allows you to do that as well.

For an example, lets assume that you built a site that you want one of your friend to be able to access and his IP address is “123.4.5.12”. Simply write the following line on your .htaccess file and you are good to go.

order allow,deny
allow from 123.4.5.12
deny from all

In this case Apache will block all IP addresses except your friends IP address. This is as simple as it can get and I hope you got the basic idea.

Note: On all of my example I used either “allow from all” or “deny from all” at the bottom, this is very important. You must declare either one of these line based on your requirement or things might get little more complicated.

Also remember that all blocked IP addresses would be forwarded or shown an “403 Forbidden” error message. You can definitely customize this message as well but that’s something I will talk about in another post.

Source: iftekhar.net

Source: Xmodulo

Virtual hosting refers to the technique that allows a physical server to host more than one website domain (e.g., site1.com, site2.com). Virtual hosting is prevalent in shared web hosting environments, where typically hundreds or more of websites or blogs are packed on a single dedicated server to amortize server maintenance cost.

You are not a web hosting company? Sure, virtual hosting can still be useful to you. For example, you can place multiple websites of yours on one VPS that you rent out, saving on your VPS cost. To serve multiple domains on a VPS, you just need to configure as many virtual hosts on its web server, and point the domains to the static IP address of your VPS.

Due to its usefulness, virtual hosting is supported by all modern web server software such as Apache, Nginx, Lighttpd, IIS. In this tutorial, I will demonstrate how to create and enable virtual hosts in Apache HTTP server under Linux environment. There is slight difference in the configuration between Debian-based and Red Hat-based systems. I will highlight the difference along the way.

Before I start, I assume that Apache HTTP server is already installed on your Linux server. If you haven’t, refer to our tutorials for Debian or Red Hat based systems, and install Apache server before proceeding.

As an exercise, let’s create a virtual host for domain abc.com on Apache web server.

Step One: Create Document Root Directory for Abc.com Domain

Start by creating a directory which will hold the web pages for abc.com. This directory is known as « document root » for the domain. Following the common practice, let’s organize all document root directories under /var/www, and name them after the corresponding domains. Also, create a dedicated log directory for abc.com under /var/log.

$ sudo mkdir /var/www/abc.com
$ sudo mkdir /var/log/apache2/abc.com (Debian, Ubuntu, Mint)
$ sudo mkdir /var/log/httpd/abc.com (Fedora, CentOS, RHEL)

Create a test webpage for the domain:

$ sudo vi /var/www/abc.com/index.html

Change the ownership of the document root directory to the user that Apache web server runs as.

On Debian, Ubuntu or Linux:

$ sudo chown -R www-data:www-data /var/www/abc.com

On Fedora, CentOS or RHEL:

$ sudo chown -R apache:apache /var/www/abc.com

Lire la suite…

Source: Xmodulo

Have you ever wanted to live stream a video feed from your webcam for someone else? You could use any existing video chat software such as Skype, Google+ Hangouts. However, if you do not want to rely on any third-party streaming infrastructure, you can set up your own webcam streaming server in house.

In this tutorial, I will describe how to live stream video from webcam by using VLC. VLC is an open-source, cross platform media player which can handle virtually all video and audio formats. VLC can also run as a streaming server supporting various streaming protocol such as RTP, HTTP, RTSP, etc.

Before attempting to set up webcam streaming on your own, you need to understand the huge potential security risk of streaming a webcam over the Internet. Anyone can tap into your streaming feed unless you properly access control the streaming server, and encrypt the streaming traffic. I’ll briefly mention several security protections against threats towards the end of the tutorial.

Install VLC on Linux

Before setting up a streaming server with VLC, install VLC first.

To install VLC on Debian, Ubuntu or Linux Mint:

To install VLC on Fedora, first enable RPM Fusion’s free repository, and then run:

To install VLC on CentOS or RHEL 6, first set up EPEL repository, and then use the following commands:

Verify Webcam Device on VLC

Next, verify whether a webcam device is successfully detected on your Linux system and VLC.

To do so, first find out the device name of your webcam with the following command. In this example, the device name of the webcam is /dev/video0.

/dev/video0

Now use the following command to test video from your webcam. Replace « video0 » with your own device name.

If your webcam is successfully detected by VLC, you should see a video stream of yourself.

Configure Webcam Streaming on VLC

Assuming that your webcam is successfully recognized by VLC, I am going to show how to configure webcam streaming. In this setup, webcam is streamed over HTTP in WMV format.

To configure VLC for webcam streaming, first launch VLC.

Choose « Streaming » from VLC menu.

On the screen, choose webcam/audio device name (e.g., /dev/video0 for webcam, and hw:0,0 for audio). Click on the checkbox of « Show more options ». Make a note of value strings in « MRL » and « Edit Options » fields. We will use these strings later in the tutorial. Click on « Stream » button at the bottom.

Lire la suite…