How to check if extension is loaded in php

PHP is a popular open source scripting language that is widely used to develop dynamic websites, web applications, server-side scripts, etc. PHP users can extend the functionality of PHP by adding extensions, which provide PHP with a rich set of libraries and APIs to use. However, in some cases, the user may need to check whether PHP has loaded the extension. This article will explain how to check whether PHP has loaded an extension.

1. Use phpinfo() to check extended information

The most common method is to use the phpinfo() function. This function will generate a page with details about PHP configuration and installation. You can find a list of loaded extensions and search for the extension that interests you. Here is how to use the phpinfo() function:

1. Create a php file named phpinfo.php and contain the following code:

<?php
phpinfo();
?>

2. Upload the file into the root directory of your web server.
3. Enter the following URL in your web browser: http://yourdomain.com/phpinfo.php
4. In the page that opens, you can find the list of loaded extensions.

2. Use the get_loaded_extensions() function

The get_loaded_extensions() function can be used to obtain the list of currently loaded PHP extensions. The following is an example of using the get_loaded_extensions() function:

<?php
$loaded_exts = get_loaded_extensions();
print_r($loaded_exts);
?>

Executing this script will return a list of names of all extensions currently loaded.

3. Use the extension_loaded() function

Use the extension_loaded() function to check whether the specified extension has been loaded. The following is an example of using the extension_loaded() function:

<?php
if (extension_loaded(&#39;pdo_mysql&#39;)) {
echo "pdo_mysql extension is loaded";
} else {
echo "pdo_mysql extension is not loaded";
}
?>

In this example, it will be checked whether the pdo_mysql extension has been loaded. If loaded, "pdo_mysql extension loaded" will be output, otherwise "pdo_mysql extension not loaded" will be output.

4. Use the command line to check extensions

Use the command line to check whether certain extensions are enabled. The following is an example of using the command line to check for extensions:

php -m | grep -i pdo_mysql

Executing this command will return a prompt as to whether the pdo_mysql extension is enabled. If enabled, the word pdo_mysql will be returned, otherwise nothing will be returned.

Summary

In this article, we introduced four methods to check whether PHP has loaded an extension. These methods are: using the phpinfo() function, using the get_loaded_extensions() function, using the extension_loaded() function, and using the command line to check for extensions. No matter which method you choose, knowing how to check whether an extension is loaded will help improve the efficiency and accuracy of PHP development.

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