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+/*
+ daemonize.h - definition of functions for daemonising an application
+
+ Copyright (C) 2014 Arthur de Jong
+
+ This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ This library 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
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with this library; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ 02110-1301 USA
+*/
+
+#ifndef NSLCD__DAEMONINZE_H
+#define NSLCD__DAEMONINZE_H 1
+
+/*
+ To properly run as a daemon an application should:
+
+ - close all open file descriptors (see daemonize_closefds() for that)
+ - (re)set proper signal handlers and signal mask
+ - sanitise the environment
+ - fork() / setsid() / fork() to detach from terminal, become process
+ leader and run in the background (see daemonize_demon() for that)
+ - reconnect stdin/stdout/stderr to /dev/null (see
+ daemonize_redirect_stdio() for that)
+ - set the umask to a reasonable value
+ - chdir(/) to avoid locking any mounts
+ - drop privileges as appropriate
+ - chroot() if appropriate
+ - create and lock a pidfile
+ - exit the starting process if initialisation is complete (see
+ daemonize_ready() for that)
+*/
+
+/* This closes all open file descriptors, except stdin, stdout and stderr. */
+void daemonize_closefds(void);
+
+/* Redirect stdio, stdin and stderr to /dev/null. */
+void daemonize_redirect_stdio(void);
+
+/* Detach from the controlling terminal and run in the background. This
+ function does:
+ - double fork and exit first child
+ - in the first child call setsid() to detach from any terminal and
+ create an independent session
+ - keep the parent process waiting until a call to daemonize_ready() is
+ done by the deamon process
+ This function returns either an error which indicates that the
+ daemonizing failed for some reason (usually sets errno), or returns
+ without error indicating that the process has been daemonized. */
+int daemonize_daemon(void);
+
+/* Signal that the original parent may exit because the service has been
+ initialised. The status indicates the exit code of the original process and
+ message, if not NULL or an empty string, is printed to stderr. */
+void daemonize_ready(int status, const char *message);
+
+#endif /* not NSLCD__DAEMONINZE_H */