xref: /netbsd-src/lib/libc/sys/_exit.2 (revision dc306354b0b29af51801a7632f1e95265a68cd81)
1.\"	$NetBSD: _exit.2,v 1.9 1998/04/28 22:28:30 fair Exp $
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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
47The
48.Fn _exit
49function terminates a process with the following consequences:
50.Bl -bullet
51.It
52All of the descriptors open in the calling process are closed.
53This may entail delays, for example, waiting for output to drain;
54a process in this state may not be killed, as it is already dying.
55.It
56If the parent process of the calling process has an outstanding
57.Xr wait 2
58call
59or catches the
60.Dv SIGCHLD
61signal,
62it is notified of the calling process's termination and
63the
64.Em status
65is set as defined by
66.Xr wait 2 .
67.It
68The parent process-ID of all of the calling process's existing child
69processes are set to 1; the initialization process
70(see the DEFINITIONS section of
71.Xr intro 2 )
72inherits each of these processes.
73.It
74If the termination of the process causes any process group
75to become orphaned (usually because the parents of all members
76of the group have now exited; see
77.Dq orphaned process group
78in
79.Xr intro 2 ) ,
80and if any member of the orphaned group is stopped,
81the
82.Dv SIGHUP
83signal and the
84.Dv SIGCONT
85signal are sent to all members of the newly-orphaned process group.
86.It
87If the process is a controlling process (see
88.Xr intro 2 ) ,
89the
90.Dv SIGHUP
91signal is sent to the foreground process group of the controlling terminal,
92and all current access to the controlling terminal is revoked.
93.El
94.Pp
95Most C programs call the library routine
96.Xr exit 3 ,
97which flushes buffers, closes streams, unlinks temporary files, etc.,
98before
99calling
100.Fn _exit .
101.Sh RETURN VALUE
102.Fn _exit
103can never return.
104.Sh SEE ALSO
105.Xr fork 2 ,
106.Xr sigaction 2 ,
107.Xr wait 2 ,
108.Xr exit 3
109.Sh STANDARDS
110The
111.Fn _exit
112function conforms to
113.St -p1003.1-90 .
114