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| author | Alejandro Colomar <alx@kernel.org> | 2024-04-26 15:06:49 +0200 |
|---|---|---|
| committer | Alejandro Colomar <alx@kernel.org> | 2024-05-02 01:24:19 +0200 |
| commit | dcde2f70372b49ec43efc5db864c9ff585d0a2dd (patch) | |
| tree | 78b9b7425130e4a5858e4c01a524d802423879ed /man/man3/daemon.3 | |
| parent | 12aca537ce78a41bbcdaf485209691e10f8002d7 (diff) | |
| download | man-pages-dcde2f70372b49ec43efc5db864c9ff585d0a2dd.tar.gz | |
man/, share/mk/: Move man*/ to man/
This is a scripted change:
$ mkdir man/;
$ mv man* man/;
$ ln -st . man/man*;
$ find share/mk/ -type f \
| xargs grep -l '^MANDIR *:=' \
| xargs sed -i '/^MANDIR *:=/s,$,/man,';
$ find share/mk/dist/ -type f \
| xargs grep -l man \
| xargs sed -i 's,man%,man/%,g';
Link: <https://lore.kernel.org/linux-man/YxcV4h+Xn7cd6+q2@pevik/T/>
Cc: Petr Vorel <pvorel@suse.cz>
Cc: Jakub Wilk <jwilk@jwilk.net>
Cc: Stefan Puiu <stefan.puiu@gmail.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
Diffstat (limited to 'man/man3/daemon.3')
| -rw-r--r-- | man/man3/daemon.3 | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/man/man3/daemon.3 b/man/man3/daemon.3 new file mode 100644 index 0000000000..edc4e54b60 --- /dev/null +++ b/man/man3/daemon.3 @@ -0,0 +1,129 @@ +'\" t +.\" Copyright (c) 1993 +.\" The Regents of the University of California. All rights reserved. +.\" +.\" SPDX-License-Identifier: BSD-4-Clause-UC +.\" +.\" @(#)daemon.3 8.1 (Berkeley) 6/9/93 +.\" Added mentioning of glibc weirdness wrt unistd.h. 5/11/98, Al Viro +.TH daemon 3 (date) "Linux man-pages (unreleased)" +.SH NAME +daemon \- run in the background +.SH LIBRARY +Standard C library +.RI ( libc ", " \-lc ) +.SH SYNOPSIS +.nf +.B #include <unistd.h> +.P +.BI "int daemon(int " nochdir ", int " noclose ); +.fi +.P +.RS -4 +Feature Test Macro Requirements for glibc (see +.BR feature_test_macros (7)): +.RE +.P +.BR daemon (): +.nf + Since glibc 2.21: +.\" commit 266865c0e7b79d4196e2cc393693463f03c90bd8 + _DEFAULT_SOURCE + In glibc 2.19 and 2.20: + _DEFAULT_SOURCE || (_XOPEN_SOURCE && _XOPEN_SOURCE < 500) + Up to and including glibc 2.19: + _BSD_SOURCE || (_XOPEN_SOURCE && _XOPEN_SOURCE < 500) +.fi +.SH DESCRIPTION +The +.BR daemon () +function is for programs wishing to detach themselves from the +controlling terminal and run in the background as system daemons. +.P +If +.I nochdir +is zero, +.BR daemon () +changes the process's current working directory +to the root directory ("/"); +otherwise, the current working directory is left unchanged. +.P +If +.I noclose +is zero, +.BR daemon () +redirects standard input, standard output, and standard error +to +.IR /dev/null ; +otherwise, no changes are made to these file descriptors. +.SH RETURN VALUE +(This function forks, and if the +.BR fork (2) +succeeds, the parent calls +.\" not .IR in order not to underline _ +.BR _exit (2), +so that further errors are seen by the child only.) +On success +.BR daemon () +returns zero. +If an error occurs, +.BR daemon () +returns \-1 and sets +.I errno +to any of the errors specified for the +.BR fork (2) +and +.BR setsid (2). +.SH ATTRIBUTES +For an explanation of the terms used in this section, see +.BR attributes (7). +.TS +allbox; +lbx lb lb +l l l. +Interface Attribute Value +T{ +.na +.nh +.BR daemon () +T} Thread safety MT-Safe +.TE +.SH VERSIONS +A similar function appears on the BSDs. +.P +The glibc implementation can also return \-1 when +.I /dev/null +exists but is not a character device with the expected +major and minor numbers. +In this case, +.I errno +need not be set. +.SH STANDARDS +None. +.SH HISTORY +4.4BSD. +.SH BUGS +The GNU C library implementation of this function was taken from BSD, +and does not employ the double-fork technique (i.e., +.BR fork (2), +.BR setsid (2), +.BR fork (2)) +that is necessary to ensure that the resulting daemon process is +not a session leader. +Instead, the resulting daemon +.I is +a session leader. +.\" FIXME . https://sourceware.org/bugzilla/show_bug.cgi?id=19144 +.\" Tested using a program that uses daemon() and then opens an +.\" otherwise unused console device (/dev/ttyN) that does not +.\" have an associated getty process. +On systems that follow System V semantics (e.g., Linux), +this means that if the daemon opens a terminal that is not +already a controlling terminal for another session, +then that terminal will inadvertently become +the controlling terminal for the daemon. +.SH SEE ALSO +.BR fork (2), +.BR setsid (2), +.BR daemon (7), +.BR logrotate (8) |