1DAEMON(3)                  Linux Programmer's Manual                 DAEMON(3)
2
3
4

NAME

6       daemon - run in the background
7

SYNOPSIS

9       #include <unistd.h>
10
11       int daemon(int nochdir, int noclose);
12
13   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
14
15       daemon(): _BSD_SOURCE || (_XOPEN_SOURCE && _XOPEN_SOURCE < 500)
16

DESCRIPTION

18       The daemon() function is for programs wishing to detach themselves from
19       the controlling terminal and run in the background as system daemons.
20
21       If nochdir is zero, daemon()  changes  the  process's  current  working
22       directory to the root directory ("/"); otherwise,
23
24       If  noclose is zero, daemon() redirects standard input, standard output
25       and standard error to /dev/null; otherwise,  no  changes  are  made  to
26       these file descriptors.
27

RETURN VALUE

29       (This  function  forks,  and  if the fork(2) succeeds, the parent calls
30       _exit(2), so that further errors are seen by the child only.)  On  suc‐
31       cess  daemon()  returns  zero.  If an error occurs, daemon() returns -1
32       and sets errno to any of the errors specified for the fork(2) and  set‐
33       sid(2).
34

CONFORMING TO

36       Not in POSIX.1-2001.  A similar function appears on the BSDs.  The dae‐
37       mon() function first appeared in 4.4BSD.
38

NOTES

40       The glibc implementation can also return -1 when /dev/null  exists  but
41       is  not  a  character device with the expected major and minor numbers.
42       In this case errno need not be set.
43

SEE ALSO

45       fork(2), setsid(2)
46

COLOPHON

48       This page is part of release 3.22 of the Linux  man-pages  project.   A
49       description  of  the project, and information about reporting bugs, can
50       be found at http://www.kernel.org/doc/man-pages/.
51
52
53
54GNU                               2009-05-02                         DAEMON(3)
Impressum