GSP
Quick Navigator

Search Site

Linux VPS
A - Starter
B - Basic
C - Preferred
D - Commercial
MPS - Dedicated
Previous VPSs
* Sign Up! *

Support
Contact Us
Online Help
Handbooks
Domain Status
Man Pages

FAQ
Virtual Servers
Pricing
Billing
Technical

Network
Facilities
Connectivity
Topology Map

Miscellaneous
Server Agreement
Year 2038
Credits
 

USA Flag

 

 

Man Pages


Manual Reference Pages  - DAEMON (3)

NAME

daemon - run in the background

CONTENTS

Library
Synopsis
Description
Return Values
Errors
See Also
History
Caveats

LIBRARY


.Lb libc

SYNOPSIS


.In stdlib.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 VALUES


.Rv -std daemon

ERRORS

The daemon function may fail and set errno for any of the errors specified for the library functions fork(2) and setsid(2).

SEE ALSO

fork(2), setsid(2), sigaction(2)

HISTORY

The daemon function first appeared in BSD 4.4 .

CAVEATS

Unless the noclose argument is non-zero, daemon will close the first three file descriptors and redirect them to /dev/null. Normally, these correspond to standard input, standard output, and standard error. However, if any of those file descriptors refer to something else, they will still be closed, resulting in incorrect behavior of the calling program. This can happen if any of standard input, standard output, or standard error have been closed before the program was run. Programs using daemon should therefore either call daemon before opening any files or sockets, or verify that any file descriptors obtained have values greater than 2.

The daemon function temporarily ignores SIGHUP while calling setsid(2) to prevent a parent session group leader’s calls to fork(2) and then _exit(2) from prematurely terminating the child process.

Search for    or go to Top of page |  Section 3 |  Main Index


June 9, 1993 DAEMON (3)

Powered by GSP Visit the GSP FreeBSD Man Page Interface.
Output converted with manServer 1.07.