file struturce changed.

src/lib/utils/daemon.cpp

@@ -0,0 +1,117 @@
+/*
+ * Copyright (C) Roland Jax 2012-2014 <ebusd@liwest.at>
+ *
+ * This file is part of ebusd.
+ *
+ * ebusd is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * ebusd 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with ebusd. If not, see http://www.gnu.org/licenses/.
+ */
+
+#include "daemon.h"
+#include <iostream>
+#include <cstring>
+#include <cstdio>
+#include <cstdlib>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+Daemon& Daemon::Instance()
+{
+	static Daemon instance;
+	return instance;
+}
+
+void Daemon::run(const char* file)
+{
+	m_status = false;
+	m_pidfile = file;
+	m_pidfd = 0;
+
+	pid_t pid;
+
+	// fork off the parent process
+	pid = fork();
+
+	if (pid < 0) {
+		std::cerr << "daemon fork() failed." << std::endl;
+		exit(EXIT_FAILURE);
+	}
+
+	// If we got a good PID, then we can exit the parent process
+	if (pid > 0) {
+		// printf("Child process created: %d\n", pid);
+		exit(EXIT_SUCCESS);
+	}
+
+	// At this point we are executing as the child process
+
+	// Set file permissions 750
+	umask(027);
+
+	// Create a new SID for the child process and
+	// detach the process from the parent (normally a shell)
+	if (setsid() < 0) {
+		std::cerr << "daemon setsid() failed." << std::endl;
+		exit(EXIT_FAILURE);
+	}
+
+	// Change the current working directory. This prevents the current
+	// directory from being locked; hence not being able to remove it.
+	if (chdir("/tmp") < 0) {  //DAEMON_WORKDIR
+		std::cerr << "daemon chdir() failed." << std::endl;
+		exit(EXIT_FAILURE);
+	}
+
+	// Close stdin, stdout and stderr
+	close(STDIN_FILENO);
+	close(STDOUT_FILENO);
+	close(STDERR_FILENO);
+
+	// write pidfile and try to lock it
+	if (pidfile_open() == false) {
+		std::cerr << "can't open pidfile: %s" << m_pidfile << std::endl;
+		exit(EXIT_FAILURE);
+	}
+
+	m_status = true;
+}
+
+bool Daemon::pidfile_open()
+{
+	char pid[10];
+
+	m_pidfd = open(m_pidfile, O_RDWR|O_CREAT, 0600);
+	if (m_pidfd < 0)
+		return false;
+
+	if (lockf(m_pidfd, F_TLOCK, 0) < 0)
+		return false;
+
+	sprintf(pid, "%d\n", getpid());
+	if (write(m_pidfd, pid, strlen(pid)) < 0)
+		return false;
+
+	return true;
+}
+
+bool Daemon::pidfile_close()
+{
+	if (close(m_pidfd) < 0)
+		return false;
+
+	if (remove(m_pidfile) < 0)
+		return false;
+
+	return true;
+}