Browse Source Download (without any required ccan dependencies)

Module:

daemon_with_notify

Summary:

daemonize a process, can wait for child to signal readiness

Author:

Stewart Smith <stewart@flamingspork.com>

Description:

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 (3 clause)