centos man page for daemon

DAEMON(3)						     Linux Programmer's Manual							 DAEMON(3)

NAME
       daemon - run in the background

SYNOPSIS
       #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)

DESCRIPTION
       The  daemon()  function is for programs wishing to detach themselves from the controlling terminal and run in the background as system dae-
       mons.

       If nochdir is zero, daemon() changes the calling process's current working directory to the root directory ("/");  otherwise,  the  current
       working directory is left unchanged.

       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.

RETURN VALUE
       (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  suc-
       cess daemon() returns zero.  If an error occurs, daemon() returns -1 and sets errno to any of the errors specified for the fork(2) and set-
       sid(2).

CONFORMING TO
       Not in POSIX.1-2001.  A similar function appears on the BSDs.  The daemon() function first appeared in 4.4BSD.

NOTES
       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.

SEE ALSO
       fork(2), setsid(2)

COLOPHON
       This  page is part of release 3.53 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
								    2009-12-05								 DAEMON(3)