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man 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);
DESCRIPTION
The daemon() function is for programs wishing to detach themselves from the control-
ling terminal and run in the background as system daemons.
Unless the argument nochdir is non-zero, daemon() changes the current working direc-
tory to the root ("/").
Unless the argument noclose is non-zero, daemon() will redirect standard input, stan-
dard output and standard error to /dev/null.
RETURN VALUE
(This function forks, and if the fork() succeeds, the parent does _exit(0), so that
further errors are seen by the child only.) On success zero will be returned. If an
error occurs, daemon() returns -1 and sets the global variable errno to any of the
errors specified for the library functions fork(2) and setsid(2).
SEE ALSO
fork(2), setsid(2)
NOTES
The glibc implementation can also return -1 when /dev/null exists but is not a charac-
ter device with the expected major and minor numbers. In this case errno need not be
set.
HISTORY
The daemon() function first appeared in 4.4BSD.
BSD MANPAGE 1993-06-09 DAEMON(3) |
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