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This article mainly explains "how to dynamically view and load PHP extensions". The content in the article is simple and clear, and it is easy to learn and understand. Please follow the editor's train of thought to study and learn how to dynamically view and load PHP extensions.

Dynamically view and load PHP extensions

After compiling and completing the configuration of php.ini, we successfully installed an extension of PHP. However, PHP also provides us with two functions that can view the status of extensions and load extensions that are not configured in php.ini during dynamic operation. Next, let's take a look at their use.

Check to see if the extension echo extension_loaded ("redis") has been loaded

A very simple function that checks whether an extension has been loaded. It returns a Boolean value, true if the extension is loaded, and false if the extension is not loaded.

In the PHP-FPM web page, we can use the phpinfo () function to view the current PHP status and expand the relevant information. In the CLI command-line script, we can use the php-m command to view the loaded extensions.

Dynamically load extension

First, we turn off the loading of the redis extension in php.ini and need to open enable_dl=1 at the same time, so we can use the dl () function to load an extension dynamically.

Dl ("redis")

Echo extension_loaded ("redis")

/ / 1

Yes, the dl () function is a function used to dynamically load extensions. However, there are many restrictions on its use, which is not a safe function. So in PHP7, its configuration in php.ini, enable_dl, is turned off by default. We also try not to load extensions in this way in a production environment.

In addition, this function is valid only for CLI environments in PHP7. That is, in PHP-FPM 's web environment, this function is useless, even if you have opened enable_dl in php.ini.

The directory loaded by the extension is based on the default extension directory of PHP. In the windows environment, note that the extension is .dll file. When the extension fails to load, not only does this function return false, but it also generates an error message for E_WARNING. Finally, this function is also unavailable in PHP safe mode.

To sum up, we should try not to use the ability to dynamically load extensions in a production environment. This can be used as one of our learning materials, when you don't want to load too many extensions at once on your local computer, and when you need to test some functions and need some special extensions, then consider using this feature for local testing.

Thank you for your reading, the above is the content of "how to dynamically view and load PHP extensions". After the study of this article, I believe you have a deeper understanding of how to dynamically view and load PHP extensions, and the specific use needs to be verified in practice. Here is, the editor will push for you more related knowledge points of the article, welcome to follow!

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