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 daemons.

       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 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).

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

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