scripts daemonize themselves

darcs-hash:20080904184031-84dde-eba2061f3aa898d0c791ffeb70837f759778c567.gz

lib/daemon.php

@@ -0,0 +1,117 @@
+<?php
+/*
+ * Laconica - a distributed open-source microblogging tool
+ * Copyright (C) 2008, Controlez-Vous, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+if (!defined('LACONICA')) { exit(1); }
+
+class Daemon {
+
+	function name() {
+		return NULL;
+	}
+	
+	function background() {
+		$pid = pcntl_fork();
+		if ($pid < 0) { # error
+			return false;
+		} else if ($pid > 0) { # parent
+			common_log(LOG_INFO, "Successfully forked.");
+			exit(0);
+		} else { # child
+			return true;
+		}
+	}
+
+	function alreadyRunning() {
+
+		$pidfilename = $this->pidFilename();
+
+		if (!$pidfilename) {
+			return false;
+		}
+		
+		if (!file_exists($pidfilename)) {
+			return false;
+		}
+		$contents = file_get_contents($pidfilename);
+		if (posix_kill(trim($contents),0)) {
+			return true;
+		} else {
+			return false;
+		}
+	}
+	
+	function writePidFile() {
+		$pidfilename = $this->pidFilename();
+		
+		if (!$pidfilename) {
+			return false;
+		}
+		
+		file_put_contents($pidfilename, posix_getpid());
+	}
+
+	function clearPidFile() {
+		$pidfilename = $this->pidFilename();
+		unlink($pidfilename);
+	}
+	
+	function pidFilename() {
+		$piddir = common_config('daemon', 'piddir');
+		if (!$piddir) {
+			return NULL;
+		}
+		$name = $this->name();
+		if (!$name) {
+			return NULL;
+		}
+		return $piddir . '/' . $name;
+	}
+
+	function changeUser() {
+
+		if (common_config('daemon', 'user')) {
+			$user_info = posix_getpwnam(common_config('daemon', 'user'));
+			common_log(LOG_INFO, "Setting user to " . common_config('daemon', 'user'));
+			posix_setuid($user_info['uid']);
+		}
+		
+		if (common_config('daemon', 'group')) {
+			$group_info = posix_getgrnam(common_config('daemon', 'group'));
+			common_log(LOG_INFO, "Setting group to " . common_config('daemon', 'group'));
+			posix_setgid($group_info['gid']);
+		}
+	}
+	
+	function runOnce() {
+		if ($this->alreadyRunning()) {
+			common_log(LOG_INFO, $this->name() . ' already running. Exiting.');
+			exit(0);
+		}
+		if ($this->background()) {
+			$this->writePidFile();
+			$this->changeUser();
+			$this->run();
+			$this->clearPidFile();
+		}
+	}
+	
+	function run() {
+		return true;
+	}
+}