[apple/xnu.git] / bsd / man / man2 / _exit.2

.\"	$NetBSD: _exit.2,v 1.6 1995/02/27 12:31:34 cgd Exp $
.\"
.\" Copyright (c) 1980, 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by the University of
.\"	California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"     @(#)_exit.2	8.1 (Berkeley) 6/4/93
.\"
.Dd June 4, 1993
.Dt EXIT 2
.Os BSD 4
.Sh NAME
.Nm _exit
.Nd terminate the calling process
.Sh SYNOPSIS
.Fd #include <unistd.h>
.Ft void
.Fn _exit "int status"
.Sh DESCRIPTION
The
.Fn _exit
function
terminates a process with the following consequences:
.Bl -bullet
.It
All of the descriptors open in the calling process are closed.
This may entail delays, for example, waiting for output to drain;
a process in this state may not be killed, as it is already dying.
.It
If the parent process of the calling process has an outstanding
.Xr wait
call
or catches the
.Dv SIGCHLD
signal,
it is notified of the calling process's termination and
the
.Em status
is set as defined by
.Xr wait 2 .
.It
The parent process-ID of all of the calling process's existing child
processes are set to 1; the initialization process
(see the DEFINITIONS section of
.Xr intro 2 )
inherits each of these processes.
.It
If the termination of the process causes any process group
to become orphaned (usually because the parents of all members
of the group have now exited; see
.Dq orphaned process group
in
.Xr intro 2 ) ,
and if any member of the orphaned group is stopped,
the
.Dv SIGHUP
signal and the
.Dv SIGCONT
signal are sent to all members of the newly-orphaned process group.
.It
If the process is a controlling process (see
.Xr intro 2 ) ,
the
.Dv SIGHUP
signal is sent to the foreground process group of the controlling terminal,
and all current access to the controlling terminal is revoked.
.El
.Pp
Most C programs call the library routine
.Xr exit 3 ,
which flushes buffers, closes streams, unlinks temporary files, etc.,
before
calling
.Fn _exit .
.Sh RETURN VALUE
.Fn _exit
can never return.
.Sh SEE ALSO
.Xr fork 2 ,
.Xr sigaction 2 ,
.Xr wait 2 ,
.Xr exit 3
.Sh STANDARDS
The
.Nm _exit
function is defined by
.St -p1003.1-88 .
Commit	Line	Data
9bccf70c A	1	.\" $NetBSD: _exit.2,v 1.6 1995/02/27 12:31:34 cgd Exp $
	2	.\"
	3	.\" Copyright (c) 1980, 1993
	4	.\" The Regents of the University of California. All rights reserved.
	5	.\"
	6	.\" Redistribution and use in source and binary forms, with or without
	7	.\" modification, are permitted provided that the following conditions
	8	.\" are met:
	9	.\" 1. Redistributions of source code must retain the above copyright
	10	.\" notice, this list of conditions and the following disclaimer.
	11	.\" 2. Redistributions in binary form must reproduce the above copyright
	12	.\" notice, this list of conditions and the following disclaimer in the
	13	.\" documentation and/or other materials provided with the distribution.
	14	.\" 3. All advertising materials mentioning features or use of this software
	15	.\" must display the following acknowledgement:
	16	.\" This product includes software developed by the University of
	17	.\" California, Berkeley and its contributors.
	18	.\" 4. Neither the name of the University nor the names of its contributors
	19	.\" may be used to endorse or promote products derived from this software
	20	.\" without specific prior written permission.
	21	.\"
	22	.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	23	.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	24	.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	25	.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	26	.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	27	.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	28	.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	29	.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	30	.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	31	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	32	.\" SUCH DAMAGE.
	33	.\"
	34	.\" @(#)_exit.2 8.1 (Berkeley) 6/4/93
	35	.\"
	36	.Dd June 4, 1993
	37	.Dt EXIT 2
	38	.Os BSD 4
	39	.Sh NAME
	40	.Nm _exit
	41	.Nd terminate the calling process
	42	.Sh SYNOPSIS
	43	.Fd #include <unistd.h>
	44	.Ft void
	45	.Fn _exit "int status"
	46	.Sh DESCRIPTION
	47	The
	48	.Fn _exit
	49	function
	50	terminates a process with the following consequences:
	51	.Bl -bullet
	52	.It
	53	All of the descriptors open in the calling process are closed.
	54	This may entail delays, for example, waiting for output to drain;
	55	a process in this state may not be killed, as it is already dying.
	56	.It
	57	If the parent process of the calling process has an outstanding
	58	.Xr wait
	59	call
	60	or catches the
	61	.Dv SIGCHLD
	62	signal,
	63	it is notified of the calling process's termination and
	64	the
65	.Em status
66	is set as defined by
67	.Xr wait 2 .
68	.It
69	The parent process-ID of all of the calling process's existing child
70	processes are set to 1; the initialization process
71	(see the DEFINITIONS section of
72	.Xr intro 2 )
73	inherits each of these processes.
74	.It
75	If the termination of the process causes any process group
76	to become orphaned (usually because the parents of all members
77	of the group have now exited; see
78	.Dq orphaned process group
79	in
80	.Xr intro 2 ) ,
81	and if any member of the orphaned group is stopped,
82	the
83	.Dv SIGHUP
84	signal and the
85	.Dv SIGCONT
86	signal are sent to all members of the newly-orphaned process group.
87	.It
88	If the process is a controlling process (see
89	.Xr intro 2 ) ,
90	the
91	.Dv SIGHUP
92	signal is sent to the foreground process group of the controlling terminal,
93	and all current access to the controlling terminal is revoked.
94	.El
95	.Pp
96	Most C programs call the library routine
97	.Xr exit 3 ,
98	which flushes buffers, closes streams, unlinks temporary files, etc.,
99	before
100	calling
101	.Fn _exit .
102	.Sh RETURN VALUE
103	.Fn _exit
104	can never return.
105	.Sh SEE ALSO
106	.Xr fork 2 ,
107	.Xr sigaction 2 ,
108	.Xr wait 2 ,
109	.Xr exit 3
110	.Sh STANDARDS
111	The
112	.Nm _exit
113	function is defined by
114	.St -p1003.1-88 .