symfony · nicolas-grekas · Aug 3, 2023 · Dec 5, 2022
diff --git a/src/Symfony/Component/Process/CHANGELOG.md b/src/Symfony/Component/Process/CHANGELOG.md
@@ -4,6 +4,8 @@ CHANGELOG
 6.4
 ---
 
+ * Add `PhpSubprocess` to handle PHP subprocesses that take over the
+   configuration from their parent
  * Add `RunProcessMessage` and `RunProcessMessageHandler`
  * Support using `Process::findExecutable()` independently of `open_basedir`
 

diff --git a/src/Symfony/Component/Process/PhpSubprocess.php b/src/Symfony/Component/Process/PhpSubprocess.php
@@ -0,0 +1,164 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Process;
+
+use Symfony\Component\Process\Exception\LogicException;
+use Symfony\Component\Process\Exception\RuntimeException;
+
+/**
+ * PhpSubprocess runs a PHP command as a subprocess while keeping the original php.ini settings.
+ *
+ * For this, it generates a temporary php.ini file taking over all the current settings and disables
+ * loading additional .ini files. Basically, your command gets prefixed using "php -n -c /tmp/temp.ini".
+ *
+ * Given your php.ini contains "memory_limit=-1" and you have a "MemoryTest.php" with the following content:
+ *
+ *     <?php var_dump(ini_get('memory_limit'));
+ *
+ * These are the differences between the regular Process and PhpSubprocess classes:
+ *
+ *     $p = new Process(['php', '-d', 'memory_limit=256M', 'MemoryTest.php']);
+ *     $p->run();
+ *     print $p->getOutput()."\n";
+ *
+ * This will output "string(2) "-1", because the process is started with the default php.ini settings.
+ *
+ *     $p = new PhpSubprocess(['MemoryTest.php'], null, null, 60, ['php', '-d', 'memory_limit=256M']);
+ *     $p->run();
+ *     print $p->getOutput()."\n";
+ *
+ * This will output "string(4) "256M"", because the process is started with the temporarily created php.ini settings.
+ *
+ * @author Yanick Witschi <[email protected]>
+ * @author Partially copied and heavily inspired from composer/xdebug-handler by John Stevenson <[email protected]>
+ */
+class PhpSubprocess extends Process
+{
+    /**
+     * @param array       $command The command to run and its arguments listed as separate entries. They will automatically
+     *                             get prefixed with the PHP binary
+     * @param string|null $cwd     The working directory or null to use the working dir of the current PHP process
+     * @param array|null  $env     The environment variables or null to use the same environment as the current PHP process
+     * @param int         $timeout The timeout in seconds
+     * @param array|null  $php     Path to the PHP binary to use with any additional arguments
+     */
+    public function __construct(array $command, string $cwd = null, array $env = null, int $timeout = 60, array $php = null)
+    {
+        if (null === $php) {
+            $executableFinder = new PhpExecutableFinder();
+            $php = $executableFinder->find(false);
+            $php = false === $php ? null : array_merge([$php], $executableFinder->findArguments());
+        }
+
+        if (null === $php) {
+            throw new RuntimeException('Unable to find PHP binary.');
+        }
+
+        $tmpIni = $this->writeTmpIni($this->getAllIniFiles(), sys_get_temp_dir());
+
+        $php = array_merge($php, ['-n', '-c', $tmpIni]);
+        register_shutdown_function('unlink', $tmpIni);
+
+        $command = array_merge($php, $command);
+
+        parent::__construct($command, $cwd, $env, null, $timeout);
+    }
+
+    public static function fromShellCommandline(string $command, string $cwd = null, array $env = null, mixed $input = null, ?float $timeout = 60): static
+    {
+        throw new LogicException(sprintf('The "%s()" method cannot be called when using "%s".', __METHOD__, self::class));
+    }
+
+    public function start(callable $callback = null, array $env = [])
+    {
+        if (null === $this->getCommandLine()) {
+            throw new RuntimeException('Unable to find the PHP executable.');
+        }
+
+        parent::start($callback, $env);
+    }
+
+    private function writeTmpIni(array $iniFiles, string $tmpDir): string
+    {
+        if (false === $tmpfile = @tempnam($tmpDir, '')) {
+            throw new RuntimeException('Unable to create temporary ini file.');
+        }
+
+        // $iniFiles has at least one item and it may be empty
+        if ('' === $iniFiles[0]) {
+            array_shift($iniFiles);
+        }
+
+        $content = '';
+
+        foreach ($iniFiles as $file) {
+            // Check for inaccessible ini files
+            if (($data = @file_get_contents($file)) === false) {
+                throw new RuntimeException('Unable to read ini: '.$file);
+            }
+            // Check and remove directives after HOST and PATH sections
+            if (preg_match('/^\s*\[(?:PATH|HOST)\s*=/mi', $data, $matches)) {
+                $data = substr($data, 0, $matches[0][1]);
+            }
+
+            $content .= $data."\n";
+        }
+
+        // Merge loaded settings into our ini content, if it is valid
+        $config = parse_ini_string($content);
+        $loaded = ini_get_all(null, false);
+
+        if (false === $config || false === $loaded) {
+            throw new RuntimeException('Unable to parse ini data.');
+        }
+
+        $content .= $this->mergeLoadedConfig($loaded, $config);
+
+        // Work-around for https://bugs.php.net/bug.php?id=75932
+        $content .= "opcache.enable_cli=0\n";
+
+        if (false === @file_put_contents($tmpfile, $content)) {
+            throw new RuntimeException('Unable to write temporary ini file.');
+        }
+
+        return $tmpfile;
+    }
+
+    private function mergeLoadedConfig(array $loadedConfig, array $iniConfig): string
+    {
+        $content = '';
+
+        foreach ($loadedConfig as $name => $value) {
+            if (!\is_string($value)) {
+                continue;
+            }
+
+            if (!isset($iniConfig[$name]) || $iniConfig[$name] !== $value) {
+                // Double-quote escape each value
+                $content .= $name.'="'.addcslashes($value, '\\"')."\"\n";
+            }
+        }
+
+        return $content;
+    }
+
+    private function getAllIniFiles(): array
+    {
+        $paths = [(string) php_ini_loaded_file()];
+
+        if (false !== $scanned = php_ini_scanned_files()) {
+            $paths = array_merge($paths, array_map('trim', explode(',', $scanned)));
+        }
+
+        return $paths;
+    }
+}
diff --git a/src/Symfony/Component/Process/Tests/Fixtures/memory.php b/src/Symfony/Component/Process/Tests/Fixtures/memory.php
@@ -0,0 +1,3 @@
+<?php
+
+echo ini_get('memory_limit');
diff --git a/src/Symfony/Component/Process/Tests/OutputMemoryLimitProcess.php b/src/Symfony/Component/Process/Tests/OutputMemoryLimitProcess.php
@@ -0,0 +1,28 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Process\Tests;
+
+use Symfony\Component\Process\PhpSubprocess;
+use Symfony\Component\Process\Process;
+
+require is_file(\dirname(__DIR__).'/vendor/autoload.php') ? \dirname(__DIR__).'/vendor/autoload.php' : \dirname(__DIR__, 5).'/vendor/autoload.php';
+
+['e' => $php, 'p' => $process] = getopt('e:p:') + ['e' => 'php', 'p' => 'Process'];
+
+if ('Process' === $process) {
+    $p = new Process([$php, __DIR__.'/Fixtures/memory.php']);
+} else {
+    $p = new PhpSubprocess([__DIR__.'/Fixtures/memory.php'], null, null, 60, [$php]);
+}
+
+$p->mustRun();
+echo $p->getOutput();
diff --git a/src/Symfony/Component/Process/Tests/PhpSubprocessTest.php b/src/Symfony/Component/Process/Tests/PhpSubprocessTest.php
@@ -0,0 +1,75 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Process\Tests;
+
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\Process\PhpExecutableFinder;
+use Symfony\Component\Process\Process;
+
+class PhpSubprocessTest extends TestCase
+{
+    private static $phpBin;
+
+    public static function setUpBeforeClass(): void
+    {
+        $phpBin = new PhpExecutableFinder();
+        self::$phpBin = getenv('SYMFONY_PROCESS_PHP_TEST_BINARY') ?: ('phpdbg' === \PHP_SAPI ? 'php' : $phpBin->find());
+    }
+
+    /**
+     * @dataProvider subprocessProvider
+     */
+    public function testSubprocess(string $processClass, string $memoryLimit, string $expectedMemoryLimit)
+    {
+        $process = new Process([self::$phpBin,
+            '-d',
+            'memory_limit='.$memoryLimit,
+            __DIR__.'/OutputMemoryLimitProcess.php',
+            '-e', self::$phpBin,
+            '-p', $processClass,
+        ]);
+
+        $process->mustRun();
+        $this->assertEquals($expectedMemoryLimit, trim($process->getOutput()));
+    }
+
+    public static function subprocessProvider(): \Generator
+    {
+        yield 'Process does ignore dynamic memory_limit' => [
+            'Process',
+            self::getRandomMemoryLimit(),
+            self::getCurrentMemoryLimit(),
+        ];
+
+        yield 'PhpSubprocess does not ignore dynamic memory_limit' => [
+            'PhpSubprocess',
+            self::getRandomMemoryLimit(),
+            self::getRandomMemoryLimit(),
+        ];
+    }
+
+    private static function getCurrentMemoryLimit(): string
+    {
+        return trim(\ini_get('memory_limit'));
+    }
+
+    private static function getRandomMemoryLimit(): string
+    {
+        $memoryLimit = 123; // Take something that's really unlikely to be configured on a user system.
+
+        while (($formatted = $memoryLimit.'M') === self::getCurrentMemoryLimit()) {
+            ++$memoryLimit;
+        }
+
+        return $formatted;
+    }
+}