Chapter 3. Using the PHP scripting language

Hypertext Preprocessor (PHP) is a general-purpose scripting language mainly used for server-side scripting, which enables you to run the PHP code using a web server.

3.1. Installing the PHP scripting language

This section describes how to install PHP.

Procedure

  • To install PHP, use:

    # yum install php

3.2. Using the PHP scripting language with a web server

3.2.1. Using PHP with the Apache HTTP Server

In Red Hat Enterprise Linux 9, the Apache HTTP Server enables you to run PHP as a FastCGI process server. FastCGI Process Manager (FPM) is an alternative PHP FastCGI daemon that allows a website to manage high loads. PHP uses FastCGI Process Manager by default in RHEL 9.

This section describes how to run the PHP code using the FastCGI process server.

Prerequisites

  • The PHP scripting language is installed on your system.

Procedure

  1. Install the httpd package:

    # yum install httpd
  2. Start the Apache HTTP Server:

    # systemctl start httpd

    Or, if the Apache HTTP Server is already running on your system, restart the httpd service after installing PHP:

    # systemctl restart httpd
  3. Start the php-fpm service:

    # systemctl start php-fpm
  4. Optional: Enable both services to start at boot time:

    # systemctl enable php-fpm httpd
  5. To obtain information about your PHP settings, create the index.php file with the following content in the /var/www/html/ directory:

    echo '<?php phpinfo(); ?>' > /var/www/html/index.php
  6. To run the index.php file, point the browser to:

    http://<hostname>/
  7. Optional: Adjust configuration if you have specific requirements:

    • /etc/httpd/conf/httpd.conf - generic httpd configuration
    • /etc/httpd/conf.d/php.conf - PHP-specific configuration for httpd
    • /usr/lib/systemd/system/httpd.service.d/php-fpm.conf - by default, the php-fpm service is started with httpd
    • /etc/php-fpm.conf - FPM main configuration
    • /etc/php-fpm.d/www.conf - default www pool configuration

Example 3.1. Running a "Hello, World!" PHP script using the Apache HTTP Server

  1. Create a hello directory for your project in the /var/www/html/ directory:

    # mkdir hello
  2. Create a hello.php file in the /var/www/html/hello/ directory with the following content:

    # <!DOCTYPE html>
    <html>
    <head>
    <title>Hello, World! Page</title>
    </head>
    <body>
    <?php
        echo 'Hello, World!';
    ?>
    </body>
    </html>
  3. Start the Apache HTTP Server:

    # systemctl start httpd
  4. To run the hello.php file, point the browser to:

    http://<hostname>/hello/hello.php

    As a result, a web page with the “Hello, World!” text is displayed.

3.2.2. Using PHP with the nginx web server

This section describes how to run PHP code through the nginx web server.

Prerequisites

  • The PHP scripting language is installed on your system.

Procedure

  1. Install the nginx package:

    # yum install nginx
  2. Start the nginx server:

    # systemctl start nginx

    Or, if the nginx server is already running on your system, restart the nginx service after installing PHP:

    # systemctl restart nginx
  3. Start the php-fpm service:

    # systemctl start php-fpm
  4. Optional: Enable both services to start at boot time:

    # systemctl enable php-fpm nginx
  5. To obtain information about your PHP settings, create the index.php file with the following content in the /usr/share/nginx/html/ directory:

    echo '<?php phpinfo(); ?>' > /usr/share/nginx/html/index.php
  6. To run the index.php file, point the browser to:

    http://<hostname>/
  7. Optional: Adjust configuration if you have specific requirements:

    • /etc/nginx/nginx.conf - nginx main configuration
    • /etc/nginx/conf.d/php-fpm.conf - FPM configuration for nginx
    • /etc/php-fpm.conf - FPM main configuration
    • /etc/php-fpm.d/www.conf - default www pool configuration

Example 3.2. Running a "Hello, World!" PHP script using the nginx server

  1. Create a hello directory for your project in the /usr/share/nginx/html/ directory:

    # mkdir hello
  2. Create a hello.php file in the /usr/share/nginx/html/hello/ directory with the following content:

    # <!DOCTYPE html>
    <html>
    <head>
    <title>Hello, World! Page</title>
    </head>
    <body>
    <?php
        echo 'Hello, World!';
    ?>
    </body>
    </html>
  3. Start the nginx server:

    # systemctl start nginx
  4. To run the hello.php file, point the browser to:

    http://<hostname>/hello/hello.php

    As a result, a web page with the “Hello, World!” text is displayed.

Additional resources

3.3. Running a PHP script using the command-line interface

A PHP script is usually run using a web server, but also can be run using the command-line interface.

Prerequisites

  • The PHP scripting language is installed on your system.

Procedure

  1. In a text editor, create a filename.php file

    Replace filename with the name of your file.

  2. Execute the created filename.php file from the command line:

    # php filename.php

Example 3.3. Running a "Hello, World!" PHP script using the command-line interface

  1. Create a hello.php file with the following content using a text editor:

    <?php
        echo 'Hello, World!';
    ?>
  2. Execute the hello.php file from the command line:

    # php hello.php

    As a result, “Hello, World!” is printed.

3.4. Additional resources

  • httpd(8) — The manual page for the httpd service containing the complete list of its command-line options.
  • httpd.conf(5) — The manual page for httpd configuration, describing the structure and location of the httpd configuration files.
  • nginx(8) — The manual page for the nginx web server containing the complete list of its command-line options and list of signals.
  • php-fpm(8) — The manual page for PHP FPM describing the complete list of its command-line options and configuration files.