Add script to index pgaes, for faster lookup by php.net

Author: afilina

.gitignore

@@ -0,0 +1,4 @@
+var/
+!var/.gitkeep
+
+vendor/

README.md

@@ -8,6 +8,13 @@ The legacy documentation is maintained by Zend and the community.
 
 Ideally, we'd love to see everyone running the latest version of PHP! But to achieve this, someone has to read the old documentation to ensure the application's compatibility with the new PHP version.
 
+## Indexing
+
+This project comes with a script to create an index of which manual page exists for which PHP version. The resulting file will be supplied to php.net in order to speed up lookup.
+
+- Generate the autoload file: `composer install`
+- Execute using `php bin/indexpages.php`
+
 ## FAQ
 
 __Q: Where are the translations?__

bin/indexpages.php

@@ -0,0 +1,8 @@
+<?php
+declare(strict_types=1);
+
+require 'vendor/autoload.php';
+
+use App\Command\IndexPages;
+
+(new IndexPages())->execute();

composer.json

@@ -0,0 +1,7 @@
+{
+  "autoload": {
+    "psr-4": {
+      "App\\": "src/"
+    }
+  }
+}

src/Command/IndexPages.php

@@ -0,0 +1,37 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Command;
+
+class IndexPages
+{
+    public function execute()
+    {
+        $legacyUrlsIndex = [];
+        foreach ([4, 5] as $versionNumber) {
+            $filenames = $this->getHtmlFilenames($versionNumber);
+
+            foreach ($filenames as $filename) {
+                $uri = $this->filenameToUri($filename);
+                $legacyUrlsIndex[$uri][] = $versionNumber;
+            }
+        }
+
+        file_put_contents('var/legacyurls.json', json_encode($legacyUrlsIndex));
+    }
+
+    /**
+     * @return string[]
+     */
+    private function getHtmlFilenames(int $versionNumber): array
+    {
+        return glob('php' . $versionNumber . '/**/*.html');
+    }
+
+    private function filenameToUri(string $filename): string
+    {
+        return preg_replace_callback('/^php.*\/.*\/(.*)\.html$/', function (array $matches) {
+            return $matches[1];
+        }, $filename);
+    }
+}