如何自动确定项目使用哪些PHP扩展？

Question

Is there a way to automatically find out which PHP extensions are used by a particular project you have the source code of?

When migrating a website from a one server to another, I often find myself wondering what PHP extensions should I enable for the website to function normally. Yes, this use case would probably be irrelevant if the project used Docker or had an exhaustive install guide, but it's not always the case.

I was thinking of a script that went through all of the .php files and looked for specific function calls or classes, for exeample:

• new mysqli( or mysqli_connect(: mysqli
• imagecreate( or imagepng or imagejpeg or ... : gd
• curl_init( : curl

Does a similar script already exist? If not, would it make sense to write it?

Answer 1

^{Writing as answer as requested by OP in their comment}

glenscott/php-dependencies

Although not a complete solution, this will lessen the manual work you'll have to do: https://github.com/glenscott/php-dependencies

A few caveats are;

• Your source code and its dependencies must lie under one directory -- included/required files outside this directory are not scanned
• As it stands, only function dependencies are found. This means that class dependencies are not checked.

You can read the blog post by the author here: http://www.glenscott.co.uk/blog/finding-function-dependencies-in-your-php-applications/

To run

You can do these via the command line or through a web browser.

• Step 1) Getting PHP environment details: php get-env-functions.php

• Step 2) Find dependencies: php scan-dependencies.php