feat(process): add process signaler service

Signed-off-by: Vitor Mattos <1079143+vitormattos@users.noreply.github.com>

Author: vitormattos

lib/Service/Process/ProcessSignaler.php

@@ -0,0 +1,70 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * SPDX-FileCopyrightText: 2026 LibreCode coop and contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\Libresign\Service\Process;
+
+use Psr\Log\LoggerInterface;
+
+class ProcessSignaler {
+	public function __construct(
+		private LoggerInterface $logger,
+	) {
+	}
+
+	public function isRunning(int $pid): bool {
+		if ($pid <= 0) {
+			return false;
+		}
+
+		if (function_exists('posix_kill')) {
+			return @posix_kill($pid, 0);
+		}
+
+		if (!function_exists('exec')) {
+			return false;
+		}
+
+		try {
+			exec(sprintf('kill -0 %d 2>/dev/null', $pid), $output, $exitCode);
+			return $exitCode === 0;
+		} catch (\Throwable $e) {
+			$this->logger->debug('Failed to probe process status', [
+				'pid' => $pid,
+				'error' => $e->getMessage(),
+			]);
+			return false;
+		}
+	}
+
+	public function stopPid(int $pid, int $signal = SIGTERM): bool {
+		if ($pid <= 0) {
+			return false;
+		}
+
+		if (function_exists('posix_kill')) {
+			return @posix_kill($pid, $signal);
+		}
+
+		if (!function_exists('exec')) {
+			return false;
+		}
+
+		try {
+			exec(sprintf('kill -%d %d 2>/dev/null', $signal, $pid), $output, $exitCode);
+			return $exitCode === 0;
+		} catch (\Throwable $e) {
+			$this->logger->debug('Failed to terminate process', [
+				'pid' => $pid,
+				'signal' => $signal,
+				'error' => $e->getMessage(),
+			]);
+			return false;
+		}
+	}
+
+}