NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | CONFORMING TO | NOTES | SEE ALSO | COLOPHON
DAEMON(3) Linux Programmer's Manual DAEMON(3)
daemon - run in the background
#include <unistd.h>
int daemon(int nochdir, int noclose);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
daemon(): _BSD_SOURCE || (_XOPEN_SOURCE && _XOPEN_SOURCE < 500)
The daemon() function is for programs wishing to detach themselves from the
controlling terminal and run in the background as system daemons.
If nochdir is zero, daemon() changes the process's current working directory
to the root directory ("/"); otherwise,
If noclose is zero, daemon() redirects standard input, standard output and
standard error to /dev/null; otherwise, no changes are made to these file
descriptors.
(This function forks, and if the fork(2) succeeds, the parent calls _exit(2),
so that further errors are seen by the child only.) On success daemon()
returns zero. If an error occurs, daemon() returns -1 and sets errno to any
of the errors specified for the fork(2) and setsid(2).
Not in POSIX.1-2001. A similar function appears on the BSDs. The daemon()
function first appeared in 4.4BSD.
The glibc implementation can also return -1 when /dev/null exists but is not a
character device with the expected major and minor numbers. In this case
errno need not be set.
fork(2), setsid(2)
This page is part of release 3.23 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can be found
at http://www.kernel.org/doc/man-pages/.
GNU 2009-05-02 DAEMON(3)