Web: PATH_INFO and front-controller routing (#121)

bin/serve.php

@@ -72,15 +72,21 @@ function handleConnection($conn, string $docroot): void
         $path = '/example.php';
     }
 
-    $script = $docroot . $path;
+    $scriptName = $path;
+    $pathInfo = '';
+    if (preg_match('#^(.+\.php)(/.*)?$#', $path, $pm)) {
+        $scriptName = $pm[1];
+        $pathInfo = $pm[2] ?? '';
+    }
+
+    $script = $docroot . $scriptName;
     if (!is_file($script)) {
         respond($conn, 404, 'text/plain', "Not Found\n");
 
         return;
     }
 
-    $scriptName = $path;
-    $requestUri = $path;
+    $requestUri = $scriptName . $pathInfo;
     if ('' !== $query) {
         $requestUri .= '?' . $query;
     }
@@ -90,6 +96,11 @@ function handleConnection($conn, string $docroot): void
     putenv('REQUEST_BODY=' . $body);
     putenv('SCRIPT_NAME=' . $scriptName);
     putenv('REQUEST_URI=' . $requestUri);
+    if ('' !== $pathInfo) {
+        putenv('PATH_INFO=' . $pathInfo);
+    } else {
+        putenv('PATH_INFO');
+    }
 
     $code = file_get_contents($script);
     if (false === $code) {

lib/Web/Superglobals.php

@@ -98,6 +98,15 @@ private static function populateServer(
             }
         }
         self::setStringEntry($server, 'REQUEST_URI', $requestUri);
+
+        $pathInfo = getenv('PATH_INFO');
+        if (false === $pathInfo || '' === $pathInfo) {
+            $pathInfo = self::derivePathInfo($scriptName, $requestUri);
+        }
+        if ('' !== $pathInfo) {
+            self::setStringEntry($server, 'PATH_INFO', $pathInfo);
+        }
+
         self::setStringEntry($server, 'GATEWAY_INTERFACE', 'CGI/1.1');
         self::setStringEntry($server, 'SERVER_SOFTWARE', 'PHP-Compiler-VM');
 
@@ -139,6 +148,26 @@ private static function populateFormEncoded(HashTable $ht, string $body): void
         }
     }
 
+    /**
+     * Derive PATH_INFO from REQUEST_URI path suffix after SCRIPT_NAME (front-controller pattern).
+     */
+    public static function derivePathInfo(string $scriptName, string $requestUri): string
+    {
+        $path = parse_url($requestUri, PHP_URL_PATH);
+        if (!is_string($path) || '' === $path) {
+            $path = $requestUri;
+            $q = strpos($path, '?');
+            if (false !== $q) {
+                $path = substr($path, 0, $q);
+            }
+        }
+        if ($path === $scriptName || !str_starts_with($path, $scriptName)) {
+            return '';
+        }
+
+        return substr($path, strlen($scriptName));
+    }
+
     private static function setStringEntry(HashTable $ht, string $key, string $value): void
     {
         $v = new Variable(Variable::TYPE_STRING);

test/real/cases/web_path_info.phpt

@@ -0,0 +1,11 @@
+--TEST--
+Web: PATH_INFO from REQUEST_URI (front-controller routing)
+--ENV--
+SCRIPT_NAME=/index.php
+REQUEST_URI=/index.php/admin/dashboard
+REQUEST_METHOD=GET
+--FILE--
+<?php
+echo isset($_SERVER['PATH_INFO']) ? $_SERVER['PATH_INFO'] : '';
+--EXPECT--
+/admin/dashboard

test/real/cases/web_path_info_cgi_env.phpt

@@ -0,0 +1,12 @@
+--TEST--
+Web: PATH_INFO from CGI PATH_INFO env var
+--ENV--
+SCRIPT_NAME=/index.php
+REQUEST_URI=/index.php/other
+PATH_INFO=/from-cgi
+REQUEST_METHOD=GET
+--FILE--
+<?php
+echo isset($_SERVER['PATH_INFO']) ? $_SERVER['PATH_INFO'] : '';
+--EXPECT--
+/from-cgi