xref: /netbsd-src/lib/libc/sys/_exit.2 (revision 5e4c038a45edbc7d63b7c2daa76e29f88b64a4e3)
1.\"	$NetBSD: _exit.2,v 1.13 2002/02/08 01:28:15 ross 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
39.Sh NAME
40.Nm _exit
41.Nd terminate the calling process
42.Sh LIBRARY
43.Lb libc
44.Sh SYNOPSIS
45.Fd #include \*[Lt]unistd.h\*[Gt]
46.Ft void
47.Fn _exit "int status"
48.Sh DESCRIPTION
49The
50.Fn _exit
51function terminates a process with the following consequences:
52.Bl -bullet
53.It
54All of the descriptors open in the calling process are closed.
55This may entail delays, for example, waiting for output to drain;
56a process in this state may not be killed, as it is already dying.
57.It
58If the parent process of the calling process has an outstanding
59.Xr wait 2
60call
61or catches the
62.Dv SIGCHLD
63signal,
64it is notified of the calling process's termination and
65the
66.Em status
67is set as defined by
68.Xr wait 2 .
69.It
70The parent process-ID of all of the calling process's existing child
71processes are set to 1; the initialization process
72(see the DEFINITIONS section of
73.Xr intro 2 )
74inherits each of these processes.
75.It
76If the termination of the process causes any process group
77to become orphaned (usually because the parents of all members
78of the group have now exited; see
79.Dq orphaned process group
80in
81.Xr intro 2 ) ,
82and if any member of the orphaned group is stopped,
83the
84.Dv SIGHUP
85signal and the
86.Dv SIGCONT
87signal are sent to all members of the newly-orphaned process group.
88.It
89If the process is a controlling process (see
90.Xr intro 2 ) ,
91the
92.Dv SIGHUP
93signal is sent to the foreground process group of the controlling terminal,
94and all current access to the controlling terminal is revoked.
95.El
96.Pp
97Most C programs call the library routine
98.Xr exit 3 ,
99which flushes buffers, closes streams, unlinks temporary files, etc.,
100before
101calling
102.Fn _exit .
103.Sh RETURN VALUES
104.Fn _exit
105can never return.
106.Sh SEE ALSO
107.Xr fork 2 ,
108.Xr sigaction 2 ,
109.Xr wait 2 ,
110.Xr exit 3
111.Sh STANDARDS
112The
113.Fn _exit
114function conforms to
115.St -p1003.1-90 .
116