Added helper to find the PHP binary

Author: asgrim

composer.json

@@ -34,6 +34,7 @@
         "illuminate/container": "^10.47",
         "psr/http-message": "^2.0",
         "symfony/console": "^6.4",
+        "symfony/process": "^6.4",
         "webmozart/assert": "^1.11"
     },
     "require-dev": {

composer.lock

@@ -0,0 +1,44 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Php\Pie\TargetPhp;
+
+use Symfony\Component\Process\PhpExecutableFinder;
+use Symfony\Component\Process\Process;
+use Webmozart\Assert\Assert;
+
+/** @internal This is not public API for PIE, so should not be depended upon unless you accept the risk of BC breaks */
+final class PhpBinaryPath
+{
+    /** @param non-empty-string $phpBinaryPath */
+    private function __construct(readonly string $phpBinaryPath)
+    {
+    }
+
+    public function version(): string
+    {
+        $phpVersion = trim((new Process([$this->phpBinaryPath, '-r', 'echo phpversion();']))
+            ->mustRun()
+            ->getOutput());
+        Assert::stringNotEmpty($phpVersion, 'Could not determine PHP version');
+        return $phpVersion;
+    }
+
+    public static function fromPhpConfigExecutable(string $phpConfig): self
+    {
+        // @todo filter input/sanitize output
+        $phpExecutable = trim((new Process([$phpConfig, '--php-binary']))
+            ->mustRun()
+            ->getOutput());
+        Assert::stringNotEmpty($phpExecutable, 'Could not find path to PHP executable.');
+        return new self($phpExecutable);
+    }
+
+    public static function fromCurrentProcess(): self
+    {
+        $phpExecutable = trim((new PhpExecutableFinder())->find());
+        Assert::stringNotEmpty($phpExecutable, 'Could not find path to PHP executable.');
+        return new self($phpExecutable);
+    }
+}

src/TargetPhp/PhpBinaryPath.php

@@ -0,0 +1,18 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Php\PieUnitTest\TargetPhp;
+
+use Php\Pie\TargetPhp\PhpBinaryPath;
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\TestCase;
+
+#[CoversClass(PhpBinaryPath::class)]
+final class PhpBinaryPathTest extends TestCase
+{
+    public function testVersionFromCurrentProcess(): void
+    {
+        self::assertSame(PHP_VERSION, PhpBinaryPath::fromCurrentProcess()->version());
+    }
+}