ccan/ccan/daemon-with-notify/_info

#include <stdio.h>
#include <string.h>
#include "config.h"

/**
 * daemon-with-notify - turn a process into a daemon with parent exiting when
 *                      child has decided that it has started correctly.
 *
 * Daemons should detach themselves thoroughly from the process which launched
 * them, and not prevent any filesystems from being unmounted.  daemonize()
 * helps with the process.
 *
 * Daemon-with-notify is different in that the child can send a SIGUSR1 to
 * the parent to indicate it has started (e.g. after memory allocation and
 * other things that may fail) so that the parent can return a success or
 * failing exit code and init scripts can pick this up easily.
 *
 * Example:
 *	#include <ccan/daemon-with-notify/daemon-with-notify.h>
 *	#include <ccan/str/str.h>
 *	#include <err.h>
 *	#include <unistd.h>
 *	#include <stdlib.h>
 *	
 *	static void usage(const char *name)
 *	{
 *		errx(1, "Usage: %s [--daemonize]\n", name);
 *	}
 *	
 *	// Wait for a minute, possibly as a daemon.
 *	int main(int argc, char *argv[])
 *	{
 *		if (argc != 1) {
 *			if (argc == 2 && streq(argv[1], "--daemonize")) {
 *				if (!daemonize(1, 1, 1))
 *					err(1, "Failed to become daemon");
 *			} else
 *				usage(argv[1]);
 *		}
 *		sleep(10); /* do some init here */
 *		daemon_is_ready();
 *		sleep(20); /* will be done in child, detached from parent */
 *		exit(0);
 *	}
 *
 * License: BSD-MIT
 */
int main(int argc, char *argv[])
{
	if (argc != 2)
		return 1;

	if (strcmp(argv[1], "depends") == 0) {
		return 0;
	}

	if (strcmp(argv[1], "libs") == 0) {
		return 0;
	}

	return 1;
}