PEAR, PECL, and Composer: The Ultimate PHP Framework and Dependency Manager
Lynda Up and Running with PHP: PEAR, PECL, and Composer
PHP is one of the most popular and widely used programming languages for web development. It offers a rich set of features, a large community of developers, and a vast ecosystem of tools and frameworks. However, PHP also has some challenges and limitations that can make it difficult to manage complex projects, reuse code, and maintain quality standards.
lynda Up and Running with PHP: PEAR, PECL, and Composer
That's where PEAR, PECL, and Composer come in. These are three powerful tools that can help you enhance your PHP skills, streamline your workflow, and improve your productivity. In this article, you will learn what these tools are, how they work, and how you can use them in your PHP projects. You will also learn how to create and distribute your own packages and extensions using these tools.
This article is based on the lynda course "Up and Running with PHP: PEAR, PECL, and Composer" by Joseph LeBlanc. This course is designed for intermediate to advanced PHP developers who want to learn how to use these tools effectively. By the end of this course, you will be able to:
Install and configure PEAR, PECL, and Composer on your system
Use PEAR packages and channels to add functionality to your PHP applications
Use PECL extensions and libraries to access low-level features and optimize performance
Use Composer packages and repositories to manage dependencies and autoload classes
Create and distribute your own PEAR packages, PECL extensions, and Composer packages
Getting Started with PEAR
PEAR stands for PHP Extension and Application Repository. It is a framework and distribution system for reusable PHP components. It provides a standard structure for organizing code, a set of coding guidelines, a library of useful packages, and a command-line interface for installing and managing packages.
PEAR packages are collections of PHP files that provide specific functionality or solve common problems. For example, there are PEAR packages for database access, email handling, web services, testing, encryption, logging, caching, etc. You can browse the official PEAR website (https://pear.php.net) to find the available packages.
PEAR channels are alternative sources of PEAR packages. They allow you to access packages that are not hosted on the official PEAR website. For example, there are channels for Symfony (https://pear.symfony.com), Zend Framework (https://pear.zend.com), Horde (https://pear.horde.org), etc. You can browse the official PEAR channel list (https://pear.php.net/channels) to find the available channels.
How to install and configure PEAR on your system
To use PEAR, you need to have PHP installed on your system. You also need to have access to the command-line interface (CLI) of your operating system. To install PEAR, you can use the following steps:
Download the PEAR installer script from https://pear.php.net/go-pear.phar and save it in a folder of your choice.
Open the CLI and navigate to the folder where you saved the script.
Run the command php go-pear.phar to start the installation process.
Follow the instructions on the screen to customize the installation options. You can accept the default values or change them as needed.
Wait for the installation to complete. You should see a message saying "PEAR installation is complete."
To configure PEAR, you can use the following steps:
Open the CLI and run the command pear config-show to see the current configuration settings.
If you want to change any of the settings, you can use the command pear config-set followed by the name and value of the setting. For example, to change the default PEAR channel, you can use the command pear config-set default_channel pear2.php.net.
If you want to see the available settings, you can use the command pear config-help.
How to use PEAR packages and channels
To use PEAR packages, you need to install them on your system. You can use the following steps:
Open the CLI and run the command pear search followed by a keyword or a package name to find the available packages. For example, to find packages related to database access, you can use the command pear search database.
If you want to see more details about a package, you can use the command pear info followed by the package name. For example, to see more details about the DB package, you can use the command pear info DB.
If you want to install a package, you can use the command pear install followed by the package name. For example, to install the DB package, you can use the command pear install DB.
If you want to update a package, you can use the command pear upgrade followed by the package name. For example, to update the DB package, you can use the command pear upgrade DB.
If you want to uninstall a package, you can use the command pear uninstall followed by the package name. For example, to uninstall the DB package, you can use the command pear uninstall DB.
To use PEAR channels, you need to register them on your system. You can use the following steps:
Open the CLI and run the command pear channel-discover followed by a channel URL to register a channel. For example, to register the Symfony channel, you can use the command pear channel-discover pear.symfony.com.
If you want to see more details about a channel, you can use the command pear channel-info followed by a channel name. For example, to see more details about the Symfony channel, you can use the command pear channel-info pear.symfony.com.
If you want to install a package from a channel, you can use the command pear install followed by a channel name and a package name. For example, to install the YAML package from the Symfony channel, you can use the command pear install pear.symfony.com/YAML.
If you want to update a package from a channel, you can use the command pear upgrade followed by a channel name and a package name. For example, to update the YAML package from the Symfony channel, you can use the command pear upgrade pear.symfony.com/YAML.
If you want to uninstall a package from a channel, you can use the command pear uninstall followed by a channel name and a package name. For example, to uninstall the YAML package from the Symfony channel, you can use code>pear uninstall pear.symfony.com/YAML.
How to create and distribute your own PEAR packages
If you want to create and distribute your own PEAR packages, you need to follow the PEAR standards and guidelines. You can use the following steps:
Create a folder for your package and name it according to the PEAR naming convention. For example, if your package name is MyPackage, you should name the folder MyPackage.
Create a PHP file for your package and name it according to the PEAR naming convention. For example, if your package name is MyPackage, you should name the file MyPackage.php.
Write your PHP code in the file and follow the PEAR coding standards. You can find the PEAR coding standards at https://pear.php.net/manual/en/standards.php.
Create a package.xml file in the folder and fill it with the metadata of your package. You can use the command pear package to generate a template for the package.xml file. You can find the documentation for the package.xml file at https://pear.php.net/manual/en/guide.developers.package2.php.
Test your package and make sure it works as expected. You can use the command pear run-tests to run unit tests for your package. You can find more information about testing PEAR packages at https://pear.php.net/manual/en/guide.developers.testing.php.
Package your package and create a tarball file. You can use the command pear package to create a tarball file from your package.xml file.
Distribute your package and upload it to a PEAR channel or a website of your choice. You can also submit your package to the official PEAR website for review and approval. You can find more information about distributing PEAR packages at https://pear.php.net/manual/en/guide.developers.distributing.php.
Getting Started with PECL
PECL stands for PHP Extension Community Library. It is a repository of PHP extensions that provide low-level functionality and access to external libraries. PHP extensions are compiled modules that extend the core functionality of PHP. They can offer better performance, more features, and more integration than PHP code.
PECL extensions are collections of C files that implement specific functionality or wrap external libraries. For example, there are PECL extensions for encryption, compression, image processing, database access, networking, etc. You can browse the official PECL website (https://pecl.php.net) to find the available extensions.
How to install and configure PECL on your system
To use PECL, you need to have PHP installed on your system. You also need to have access to the command-line interface (CLI) of your operating system. To install PECL, you can use the following steps:
Download the PECL installer script from https://pear.php.net/go-pear.phar and save it in a folder of your choice.
Open the CLI and navigate to the folder where you saved the script.
Run the command php go-pear.phar to start the installation process.
Follow the instructions on the screen to customize the installation options. You can accept the default values or change them as needed.
Wait for the installation to complete. You should see a message saying "PEAR installation is complete."
To configure PECL, you can use the same steps as for configuring PEAR. You can use the commands pecl config-show, pecl config-set, and pecl config-help to see and change the configuration settings.
How to use PECL extensions and libraries
To use PECL extensions, you need to install them on your system. You can use the following steps:
Open the CLI and run the command pecl search followed by a keyword or an extension name to find the available extensions. For example, to find extensions related to encryption, you can use the command pecl search encryption.
If you want to see more details about an extension, you can use the command pecl info followed by the extension name. For example, to see more details about the mcrypt extension, you can use the command pecl info mcrypt.
If you want to install an extension, you can use the command pecl install followed by the extension name. For example, to install the mcrypt extension, you can use the command pecl install mcrypt.
If you want to update an extension, you can use the command pecl upgrade followed by the extension name. For example, to update the mcrypt extension, you can use the command pecl upgrade mcrypt.
If you want to uninstall an extension, you can use the command pecl uninstall followed by the extension name. For example, to uninstall the mcrypt extension, you can use the command pecl uninstall mcrypt.
To use PECL libraries, you need to link them to your PHP code. You can use the following steps:
Edit your php.ini file and add the extension directive for the PECL library. For example, to enable the mcrypt library, you need to add the line extension=mcrypt.so (for Linux) or extension=php_mcrypt.dll (for Windows) to your php.ini file.
Restart your web server or PHP process to load the PECL library.
Use the functions and classes provided by the PECL library in your PHP code. For example, to encrypt a string using the mcrypt library, you can use the function mcrypt_encrypt().
How to create and distribute your own PECL extensions
If you want to create and distribute your own PECL extensions, you need to have some knowledge of C programming and PHP internals. You can use the following steps:
Create a folder for your extension and name it according to the PECL naming convention. For example, if your extension name is MyExtension, you should name the folder MyExtension.
Create a config.m4 file in the folder and fill it with the configuration options for your extension. You can use the command phpize --help to see the available options.
Create a C file for your extension and name it according to the PECL naming convention. For example, if your extension name is MyExtension, you should name the file MyExtension.c.
Write your C code in the file and follow the PECL coding standards. You can find the PECL coding standards at https://www.php.net/manual/en/internals2.codestyle.php.
Create a package.xml file in the folder and fill it with the metadata of your extension. You can use the command pecl package to generate a template for the package.xml file. You can find the documentation for the package.xml file at https://pear.php.net/manual/en/guide.developers.package2.php.
Test your extension and make sure it works as expected. You can use the command phpize to prepare your extension for compilation. You can use the command ./configure --enable-myextension (for Linux) or nmake /f Makefile.win myextension.dll (for Windows) to compile your extension. You can use the command nmake test (for Windows) or make test (for Linux) to run unit tests for your extension.
Package your extension and create a tarball file. You can use the command pecl package to create a tarball file from your package.xml file.
Distribute your extension and upload it to a PECL channel or a website of your choice. You can also submit your extension to the official PECL website for review and approval. You can find more information about distributing PECL extensions at https://www.php.net/manual/en/internals2.pecl.php.
Getting Started with Composer
Composer is a dependency manager for PHP. It allows you to declare and manage the libraries and packages that your PHP project depends on. It also handles autoloading of classes and files for you. Composer is not part of PHP itself, but it is widely used by modern PHP projects and frameworks.
provide specific functionality or solve common problems. For example, there are Composer packages for testing, logging, validation, routing, templating, etc. You can browse the official Packagist website (https://packagist.org) to find the available packages.
Composer repositories are sources of Composer packages. They can be public or private, local or remote. The default repository for Composer is Packagist, but you can also use other repositories such as GitHub, Bitbucket, Satis, etc. You can also create your own repositories for your custom packages.
How to install and configure Composer on your system
To use Composer, you need to have PHP installed on your system. You also need to have access to the command-line interface (CLI) of your operating system. To install Composer, you can use the following steps:
Download the Composer installer script from https://getcomposer.org/installer and save it in a folder of your choice.
Open the CLI and navigate to the folder where you saved the script.
Run the command php installer to start the installation process.
Follow the instructions on the screen to customize the installation options. You can accept the default values or change them as needed.
Wait for the installation to complete. You should see a message saying "Composer installed successfully."
To configure Composer, you can use the following steps:
Open the CLI and run the command composer config followed by a configuration option and a value to set or change a configuration option. For example, to set the default repository for Composer, you can use the command composer config repositories.packagist composer https://packagist.org.
If you want to see the current configuration options, you can use the command composer config --list.
If you want to see the available configuration options, you can use the command composer config --help.
How to use Composer packages and repositories
To use Composer packages, you need to declare them in a composer.json file in your project root folder. You can use the following steps:
Create a composer.json file in your project root folder and fill it with the basic information of your project. You can use the command composer init to generate a template for the composer.json file.
Add a require section to your composer.json file and list the packages that your project depends on. You can use the command composer require followed by a package name and an optional version constraint to add a package to your require section. For example, to add the PHPUnit package with a version constraint of ^9.0, you can use the command composer require phpunit/phpunit ^9.0.
Add a repositories section to your composer.json file and list the repositories that you want to use for your project. You can use different types of repositories such as vcs (for version control systems), pear (for PEAR channels), composer (for Packagist or Satis), etc. For example, to add a GitHub repository for a custom package, you can use something like this: "repositories": [ "type": "vcs", "url": "https://github.com/myusername/mypackage" ]
Run the command composer install to install the packages that you declared in your composer.json file. This will create a vendor folder in your project root folder and download the packages there. It will also create a composer.lock file that records the exact versions of the packages that you installed.
If you want to update the packages that you installed, you can use the command composer update. This will check the latest versions of the packages that match your version constraints and update them accordingly. It will also update your composer.lock file with the new versions.
If you want to uninstall a package that you installed, you can use the command composer remove followed by the package name. For example, to uninstall the PHPUnit package, you can use the command composer remove phpunit/phpunit.
To use Composer packages, you need to include the Composer autoloader in your PHP code. You can use the following steps:
Open your PHP file and add the line require_once __DIR__ . '/vendor/autoload.php'; at the beginning of the file. This will load the Composer autoloader that will handle the loading of the classes and files from the packages that you installed.
Use the classes and functions provided by the packages in your PHP code. For example, to use the PHPUnit framework for testing, you can use the class <c