DAEMON

Section: Linux Programmer's Manual (3)
Updated: 1993-06-09
Index Return to Main Contents
 

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 controlling terminal and run in the background as system daemons.

Unless the argument nochdir is non-zero, daemon() changes the current working directory to the root ("/").

Unless the argument noclose is non-zero, daemon() will redirect standard input, standard 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 character device with the expected major and minor numbers. In this case errno need not be set.  

CONFORMING TO

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


 

Index

NAME
SYNOPSIS
DESCRIPTION
RETURN VALUE
SEE ALSO
NOTES
CONFORMING TO

linux.jgfs.net manual pages