xref: /freebsd-14.2/lib/libc/sys/_exit.2 (revision 9b50d902)
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32.\"     @(#)_exit.2	8.1 (Berkeley) 6/4/93
33.\"
34.Dd June 4, 1993
35.Dt EXIT 2
36.Os BSD 4
37.Sh NAME
38.Nm _exit
39.Nd terminate the calling process
40.Sh SYNOPSIS
41.Fd #include <unistd.h>
42.Ft void
43.Fn _exit "int status"
44.Sh DESCRIPTION
45The
46.Fn _exit
47function
48terminates a process with the following consequences:
49.Bl -bullet
50.It
51All of the descriptors open in the calling process are closed.
52This may entail delays, for example, waiting for output to drain;
53a process in this state may not be killed, as it is already dying.
54.It
55If the parent process of the calling process has an outstanding
56.Xr wait
57call
58or catches the
59.Dv SIGCHLD
60signal,
61it is notified of the calling process's termination and
62the
63.Em status
64is set as defined by
65.Xr wait 2 .
66.It
67The parent process-ID of all of the calling process's existing child
68processes are set to 1; the initialization process
69(see the DEFINITIONS section of
70.Xr intro 2 )
71inherits each of these processes.
72.It
73If the termination of the process causes any process group
74to become orphaned (usually because the parents of all members
75of the group have now exited; see
76.Dq orphaned process group
77in
78.Xr intro 2 ) ,
79and if any member of the orphaned group is stopped,
80the
81.Dv SIGHUP
82signal and the
83.Dv SIGCONT
84signal are sent to all members of the newly-orphaned process group.
85.It
86If the process is a controlling process (see
87.Xr intro 2 ) ,
88the
89.Dv SIGHUP
90signal is sent to the foreground process group of the controlling terminal,
91and all current access to the controlling terminal is revoked.
92.El
93.Pp
94Most C programs call the library routine
95.Xr exit 3 ,
96which flushes buffers, closes streams, unlinks temporary files, etc.,
97before
98calling
99.Fn _exit .
100.Sh RETURN VALUE
101.Fn _exit
102can never return.
103.Sh SEE ALSO
104.Xr fork 2 ,
105.Xr sigvec 2 ,
106.Xr wait 2 ,
107.Xr exit 3
108.Sh STANDARDS
109The
110.Nm _exit
111function is defined by
112.St -p1003.1-88 .
113