How do I run PHP files using XAMPP on Linux?

PHP Interview Questions with Solutions: Prepare for PHP Interview

PHP Interview Questions with Solutions: Prepare for PHP Interview

Prepare for PHP Interviews. Set Variable With php.ini File. Logic & Output Behind PHP Code Segment. Class Concept, Error & Functions in PHP. Start PHP Now!

Description
In this course you will be introduced with some tricky questions that everyone face during their interview. In each solutions I have included some useful functions which we generally use at the time of development also. I have covered the following area in my course with Questions, Attractive Presentations and Practical Solutions that will help you to understand the logic behind PHP in a different way.

Some useful functions
PHP error types
Class concept
Access specifiers public, private and protected
Set variable with php.ini file
Operators introduced in PHP7
Logic and its output behind some code segment
Basic knowledge
PHP7, XAMPP Server, Notepad++
What will you learn
This course is build for the person who is facing interviews. Every question is well explained with the practical solution through videos. So that everybody can prepare themselves for the tricky questions asked during interviews
To continue:

Advantages of Hiring PHP Developer for your Website Project

Advantages of Hiring PHP Developer for your Website Project

PHP - Hypertext pre-processor, a scripting language used by many people in developing web pages, but most of us are unaware even of the full form. To train someone and make them learn this whole language is as difficult and time-consuming as it is...

PHP - Hypertext pre-processor, a scripting language used by many people in developing web pages, but most of us are unaware even of the full form. To train someone and make them learn this whole language is as difficult and time-consuming as it is to learn the language yourself. That’s why PHP developers are there to make your life easy. This article will give us the advantages and requirements of Hire PHP Developer for our very own website project.

First of all, let us understand the value the right developer brings to the project and why it is important for your business.

A website is a major component of any company/business and is very important for its face value, the way it represents the company on the internet is critical for any business to succeed. This is the reason why companies are looking for PHP developers who can develop their webpage.

If you're planning to do an online business, your PHP programmer will be the first person to transfer your thinking onto the webpage. You should, therefore, employ developers from PHP to make your hypothetical idea a reality.

With this software programming language, PHP developers all-around can easily build website frameworks, web content management systems, web template systems, and various other web-based designs.

Some of the reasons why we need to outsource these developers are:

Not everyone is the best in each field, all of us have our specific skills and talents hence, PHP developers are also the best at what they do. The time and money spent on the training of the in house employees would be saved if the professional PHP developers are hired. Instead of multitasking, if the employees were to focus on what they’re good at it would increase productivity too.

The PHP developers would be much more professional than the in-house workers. It would lead to the seriousness of work. Hence, on-time delivery is guaranteed with hired PHP developers.

In addition to these benefits, you would also be able to track your project through every stage in constant communication with your online team. These advantages make it incredibly popular and smart to hire a PHP developer.

The PHP developers have in-depth knowledge of PHP, HTML and various frameworks in terms of technical capabilities. Hiring PHP developers are advised to give your website a professional look based on PHP.

Much of web success depends on the involvement of social media. The developer can add to your social networking pages a feature that explicitly redirects visitors. In addition, SEO experts also suggest better connections to the website's social network.

Just like a tailor stitches our dresses according to our preferences and is ready to make last-minute changes. A PHP developer will also be available at the nick of your call to make the website just the way you want it to be and have a customized solution for every problem.

Read also: Why & How to Hire Dedicated PHP Developer

At some point in your business, you’re going to have problems regarding your webpage due to the rapidly changing technology, instead of struggling with ideas like these and not being able to come up with an appropriate solution a PHP web developer could help us with our problems just like any technician would help us with the problems we face in our offices or any architect would help us with designing the structure of a building or any interior designer would help us with setting up our home. The PHP development company are hubs of workers who would help us overcome these problems and are always there.

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How To Install Linux, Nginx, MySQL, PHP (LEMP stack) on Ubuntu 18.04?

How To Install Linux, Nginx, MySQL, PHP (LEMP stack) on Ubuntu 18.04?

This guide demonstrates how to install a LEMP stack on an Ubuntu 18.04 server. The Ubuntu operating system takes care of the first requirement. We will describe how to get the rest of the components up and running.

Introduction

The LEMP software stack is a group of software that can be used to serve dynamic web pages and web applications. This is an acronym that describes a Linux operating system, with an Nginx (pronounced like “Engine-X”) web server. The backend data is stored in the MySQL database and the dynamic processing is handled by PHP.

This guide demonstrates how to install a LEMP stack on an Ubuntu 18.04 server. The Ubuntu operating system takes care of the first requirement. We will describe how to get the rest of the components up and running.

Step 1 – Installing the Nginx Web Server

In order to display web pages to our site visitors, we are going to employ Nginx, a modern, efficient web server.

All of the software used in this procedure will come from Ubuntu’s default package repositories. This means we can use the apt package management suite to complete the necessary installations.

Since this is our first time using apt for this session, start off by updating your server’s package index. Following that, install the server:

sudo apt update
sudo apt install nginx

On Ubuntu 18.04, Nginx is configured to start running upon installation.

If you have the ufw firewall running, as outlined in the initial setup guide, you will need to allow connections to Nginx. Nginx registers itself with ufw upon installation, so the procedure is rather straightforward.

It is recommended that you enable the most restrictive profile that will still allow the traffic you want. Since you haven’t configured SSL for your server in this guide, you will only need to allow traffic on port 80.

Enable this by typing:

sudo ufw allow 'Nginx HTTP'

You can verify the change by running:

sudo ufw status

This command’s output will show that HTTP traffic is allowed:

OutputStatus: active

To                         Action      From
--                         ------      ----
OpenSSH                    ALLOW       Anywhere
Nginx HTTP                 ALLOW       Anywhere
OpenSSH (v6)               ALLOW       Anywhere (v6)
Nginx HTTP (v6)            ALLOW       Anywhere (v6)

With the new firewall rule added, you can test if the server is up and running by accessing your server’s domain name or public IP address in your web browser.

If you do not have a domain name pointed at your server and you do not know your server’s public IP address, you can find it by running the following command:

ip addr show eth0 | grep inet | awk '{ print $2; }' | sed 's/\/.*$//'

This will print out a few IP addresses. You can try each of them in turn in your web browser.

As an alternative, you can check which IP address is accessible, as viewed from other locations on the internet:

curl -4 icanhazip.com

Type the address that you receive in your web browser and it will take you to Nginx’s default landing page:

http://server_domain_or_IP

If you see the above page, you have successfully installed Nginx.

Step 2 – Installing MySQL to Manage Site Data

Now that you have a web server, you need to install MySQL (a database management system) to store and manage the data for your site.

Install MySQL by typing:

sudo apt install mysql-server

The MySQL database software is now installed, but its configuration is not yet complete.

To secure the installation, MySQL comes with a script that will ask whether we want to modify some insecure defaults. Initiate the script by typing:

sudo mysql_secure_installation

This script will ask if you want to configure the VALIDATE PASSWORD PLUGIN.

Warning: Enabling this feature is something of a judgment call. If enabled, passwords which don’t match the specified criteria will be rejected by MySQL with an error. This will cause issues if you use a weak password in conjunction with software which automatically configures MySQL user credentials, such as the Ubuntu packages for phpMyAdmin. It is safe to leave validation disabled, but you should always use strong, unique passwords for database credentials.

Answer Y for yes, or anything else to continue without enabling.

VALIDATE PASSWORD PLUGIN can be used to test passwords
and improve security. It checks the strength of password
and allows the users to set only those passwords which are
secure enough. Would you like to setup VALIDATE PASSWORD plugin?

Press y|Y for Yes, any other key for No:

If you’ve enabled validation, the script will also ask you to select a level of password validation. Keep in mind that if you enter 2 – for the strongest level – you will receive errors when attempting to set any password which does not contain numbers, upper and lowercase letters, and special characters, or which is based on common dictionary words.

There are three levels of password validation policy:

LOW    Length >= 8
MEDIUM Length >= 8, numeric, mixed case, and special characters
STRONG Length >= 8, numeric, mixed case, special characters and dictionary                  file

Please enter 0 = LOW, 1 = MEDIUM and 2 = STRONG: 1

Next, you’ll be asked to submit and confirm a root password:

Please set the password for root here.

New password:

Re-enter new password:

For the rest of the questions, you should press Y and hit the ENTER key at each prompt. This will remove some anonymous users and the test database, disable remote root logins, and load these new rules so that MySQL immediately respects the changes we have made.

Note that in Ubuntu systems running MySQL 5.7 (and later versions), the root MySQL user is set to authenticate using the auth_socket plugin by default rather than with a password. This allows for some greater security and usability in many cases, but it can also complicate things when you need to allow an external program (e.g., phpMyAdmin) to access the user.

If using the auth_socket plugin to access MySQL fits with your workflow, you can proceed to Step 3. If, however, you prefer to use a password when connecting to MySQL as root, you will need to switch its authentication method from auth_socket to mysql_native_password. To do this, open up the MySQL prompt from your terminal:

sudo mysql

Next, check which authentication method each of your MySQL user accounts use with the following command:

SELECT user,authentication_string,plugin,host FROM mysql.user;

Output+------------------+-------------------------------------------+-----------------------+-----------+
| user             | authentication_string                     | plugin                | host      |
+------------------+-------------------------------------------+-----------------------+-----------+
| root             |                                           | auth_socket           | localhost |
| mysql.session    | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE | mysql_native_password | localhost |
| mysql.sys        | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE | mysql_native_password | localhost |
| debian-sys-maint | *CC744277A401A7D25BE1CA89AFF17BF607F876FF | mysql_native_password | localhost |
+------------------+-------------------------------------------+-----------------------+-----------+
4 rows in set (0.00 sec)

In this example, you can see that the root user does in fact authenticate using the auth_socket plugin. To configure the root account to authenticate with a password, run the following ALTER USER command. Be sure to change password to a strong password of your choosing:

ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'password';

Then, run FLUSH PRIVILEGES which tells the server to reload the grant tables and put your new changes into effect:

FLUSH PRIVILEGES;

Check the authentication methods employed by each of your users again to confirm that root no longer authenticates using the auth_socket plugin:

SELECT user,authentication_string,plugin,host FROM mysql.user;

Output+------------------+-------------------------------------------+-----------------------+-----------+
| user             | authentication_string                     | plugin                | host      |
+------------------+-------------------------------------------+-----------------------+-----------+
| root             | *3636DACC8616D997782ADD0839F92C1571D6D78F | mysql_native_password | localhost |
| mysql.session    | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE | mysql_native_password | localhost |
| mysql.sys        | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE | mysql_native_password | localhost |
| debian-sys-maint | *CC744277A401A7D25BE1CA89AFF17BF607F876FF | mysql_native_password | localhost |
+------------------+-------------------------------------------+-----------------------+-----------+
4 rows in set (0.00 sec)

You can see in this example output that the root MySQL user now authenticates using a password. Once you confirm this on your own server, you can exit the MySQL shell:

exit

Note: After configuring your root MySQL user to authenticate with a password, you’ll no longer be able to access MySQL with the sudo mysql command used previously. Instead, you must run the following:

mysql -u root -p

After entering the password you just set, you will see the MySQL prompt.

At this point, your database system is now set up and you can move on to installing PHP.

Step 3 – Installing PHP and Configuring Nginx to Use the PHP Processor

You now have Nginx installed to serve your pages and MySQL installed to store and manage your data. However, you still don’t have anything that can generate dynamic content. This is where PHP comes into play.

Since Nginx does not contain native PHP processing like some other web servers, you will need to install php-fpm, which stands for “fastCGI process manager”. We will tell Nginx to pass PHP requests to this software for processing.

Note: Depending on your cloud provider, you may need to add Ubuntu’s universe repository, which includes free and open-source software maintained by the Ubuntu community, before installing the php-fpm package. You can do this by typing:

sudo add-apt-repository universe

Install the php-fpm module along with an additional helper package, php-mysql, which will allow PHP to communicate with your database backend. The installation will pull in the necessary PHP core files. Do this by typing:

sudo apt install php-fpm php-mysql

You now have all of the required LEMP stack components installed, but you still need to make a few configuration changes in order to tell Nginx to use the PHP processor for dynamic content.

This is done on the server block level (server blocks are similar to Apache’s virtual hosts). To do this, open a new server block configuration file within the /etc/nginx/sites-available/ directory. In this example, the new server block configuration file is named example.com, although you can name yours whatever you’d like:

sudo nano /etc/nginx/sites-available/example.com

By editing a new server block configuration file, rather than editing the default one, you’ll be able to easily restore the default configuration if you ever need to.

Add the following content, which was taken and slightly modified from the default server block configuration file, to your new server block configuration file:

server {
        listen 80;
        root /var/www/html;
        index index.php index.html index.htm index.nginx-debian.html;
        server_name example.com;

        location / {
                try_files $uri $uri/ =404;
        }

        location ~ \.php$ {
                include snippets/fastcgi-php.conf;
                fastcgi_pass unix:/var/run/php/php7.2-fpm.sock;
        }

        location ~ /\.ht {
                deny all;
        }
}

Here’s what each of these directives and location blocks do:

  • listen — Defines what port Nginx will listen on. In this case, it will listen on port 80, the default port for HTTP.
  • root — Defines the document root where the files served by the website are stored.
  • index — Configures Nginx to prioritize serving files named index.php when an index file is requested, if they’re available.
  • server_name — Defines which server block should be used for a given request to your server. Point this directive to your server’s domain name or public IP address.
  • location / — The first location block includes a try_files directive, which checks for the existence of files matching a URI request. If Nginx cannot find the appropriate file, it will return a 404 error.
  • location ~ \.php$ — This location block handles the actual PHP processing by pointing Nginx to the fastcgi-php.conf configuration file and the php7.2-fpm.sock file, which declares what socket is associated with php-fpm.
  • location ~ /\.ht — The last location block deals with .htaccess files, which Nginx does not process. By adding the deny all directive, if any .htaccess files happen to find their way into the document root they will not be served to visitors.

After adding this content, save and close the file. Enable your new server block by creating a symbolic link from your new server block configuration file (in the /etc/nginx/sites-available/ directory) to the /etc/nginx/sites-enabled/ directory:

sudo ln -s /etc/nginx/sites-available/example.com /etc/nginx/sites-enabled/

Then, unlink the default configuration file from the /sites-enabled/ directory:

sudo unlink /etc/nginx/sites-enabled/default

Note: If you ever need to restore the default configuration, you can do so by recreating the symbolic link, like this:

sudo ln -s /etc/nginx/sites-available/default /etc/nginx/sites-enabled/

Test your new configuration file for syntax errors by typing:

sudo nginx -t

If any errors are reported, go back and recheck your file before continuing.

When you are ready, reload Nginx to make the necessary changes:

sudo systemctl reload nginx

This concludes the installation and configuration of your LEMP stack. However, it’s prudent to confirm that all of the components can communicate with one another.

Step 4 – Creating a PHP File to Test Configuration

Your LEMP stack should now be completely set up. You can test it to validate that Nginx can correctly hand .php files off to the PHP processor.

To do this, use your text editor to create a test PHP file called info.php in your document root:

sudo nano /var/www/html/info.php

Enter the following lines into the new file. This is valid PHP code that will return information about your server:

<?php
phpinfo();

When you are finished, save and close the file.

Now, you can visit this page in your web browser by visiting your server’s domain name or public IP address followed by /info.php:

http://your_server_domain_or_IP/info.php

You should see a web page that has been generated by PHP with information about your server:

If you see a page that looks like this, you’ve set up PHP processing with Nginx successfully.

After verifying that Nginx renders the page correctly, it’s best to remove the file you created as it can actually give unauthorized users some hints about your configuration that may help them try to break in. You can always regenerate this file if you need it later.

For now, remove the file by typing:

sudo rm /var/www/html/info.php

With that, you now have a fully-configured and functioning LEMP stack on your Ubuntu 18.04 server.

Conclusion

A LEMP stack is a powerful platform that will allow you to set up and serve nearly any website or application from your server.