0a31efe016
__noreturn macro and modify the other exiting functions to use it. The __noreturn macro, unlike __dead2, must be used BEFORE the function. This is in line with the C and C++ specifications that place _Noreturn (c1x) and [[noreturn]] (C++11) in front of the functions. As with __dead2, this macro falls back to using the GCC attribute. Unfortunately, clang currently sets the same value for the C version macro in C99 and C1x modes, so these functions are hidden by default. At some point before 10.0, I need to go through the headers and clean up the C1x / C++11 visibility. Reviewed by: brooks (mentor)
133 lines
3.6 KiB
Groff
133 lines
3.6 KiB
Groff
.\" Copyright (c) 1990, 1991, 1993
|
|
.\" The Regents of the University of California. All rights reserved.
|
|
.\"
|
|
.\" This code is derived from software contributed to Berkeley by
|
|
.\" the American National Standards Committee X3, on Information
|
|
.\" Processing Systems.
|
|
.\"
|
|
.\" 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.
|
|
.\" 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.3 8.1 (Berkeley) 6/4/93
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd September 9, 2002
|
|
.Dt EXIT 3
|
|
.Os
|
|
.Sh NAME
|
|
.Nm exit , _Exit
|
|
.Nd perform normal program termination
|
|
.Sh LIBRARY
|
|
.Lb libc
|
|
.Sh SYNOPSIS
|
|
.In stdlib.h
|
|
.Ft void
|
|
.Fn exit "int status"
|
|
.Ft void
|
|
.Fn _Exit "int status"
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Fn exit
|
|
and
|
|
.Fn _Exit
|
|
functions terminate a process.
|
|
.Pp
|
|
Before termination,
|
|
.Fn exit
|
|
performs the following functions in the order listed:
|
|
.Bl -enum -offset indent
|
|
.It
|
|
Call the functions registered with the
|
|
.Xr atexit 3
|
|
function, in the reverse order of their registration.
|
|
.It
|
|
Flush all open output streams.
|
|
.It
|
|
Close all open streams.
|
|
.It
|
|
Unlink all files created with the
|
|
.Xr tmpfile 3
|
|
function.
|
|
.El
|
|
.Pp
|
|
The
|
|
.Fn _Exit
|
|
function terminates without calling the functions registered with the
|
|
.Xr atexit 3
|
|
function, and may or may not perform the other actions listed.
|
|
Both functions make the low-order eight bits of the
|
|
.Fa status
|
|
argument available to a parent process which has called a
|
|
.Xr wait 2 Ns -family
|
|
function.
|
|
.Pp
|
|
The C Standard
|
|
.Pq St -isoC-99
|
|
defines the values
|
|
.Li 0 ,
|
|
.Dv EXIT_SUCCESS ,
|
|
and
|
|
.Dv EXIT_FAILURE
|
|
as possible values of
|
|
.Fa status .
|
|
Cooperating processes may use other values;
|
|
in a program which might be called by a mail transfer agent, the
|
|
values described in
|
|
.Xr sysexits 3
|
|
may be used to provide more information to the parent process.
|
|
.Pp
|
|
Note that
|
|
.Fn exit
|
|
does nothing to prevent bottomless recursion should a function registered
|
|
using
|
|
.Xr atexit 3
|
|
itself call
|
|
.Fn exit .
|
|
Such functions must call
|
|
.Fn _Exit
|
|
instead (although this has other effects as well which may not be desired).
|
|
.Sh RETURN VALUES
|
|
The
|
|
.Fn exit
|
|
and
|
|
.Fn _Exit
|
|
functions
|
|
never return.
|
|
.Sh SEE ALSO
|
|
.Xr _exit 2 ,
|
|
.Xr wait 2 ,
|
|
.Xr atexit 3 ,
|
|
.Xr at_quick_exit 3 ,
|
|
.Xr intro 3 ,
|
|
.Xr quick_exit 3 ,
|
|
.Xr sysexits 3 ,
|
|
.Xr tmpfile 3
|
|
.Sh STANDARDS
|
|
The
|
|
.Fn exit
|
|
and
|
|
.Fn _Exit
|
|
functions conform to
|
|
.St -isoC-99 .
|