.\" 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
.\" Chris Torek and 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.
.\" 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.
.\"
.\" @(#)atexit.3 8.1 (Berkeley) 6/4/93
.\" %FreeBSD: src/lib/libc/stdlib/atexit.3,v 1.3.2.3 2001/03/06 16:46:02 ru Exp %
.\"
.\" $FreeBSD$
.Dd June 4, 1993
.Dt ATEXIT 3
.Os
.Sh 名称
.Nm atexit
.Nd 終了時に呼び出される関数を登録する
.Sh ライブラリ
.Lb libc
.Sh 書式
.Fd #include <stdlib.h>
.Ft int
.Fn atexit "void (*function)(void)"
.Sh 解説
.Fn atexit
関数は、
.Xr exit 3
によるものであろうが、プログラムの
.Em main
関数からの戻りによるものであろうが
プログラム終了時に、与えられた
.Ar function
が呼び出されるよう登録します。
登録された関数は、逆の順序で呼び出されます。
引数は渡されません。
少なくとも 32 個の関数が常に登録でき、
十分なメモリが割り当てられる限り、それを超える関数も登録できます。
.Sh 戻り値
.\"X .Rv -std atexit
.Fn atexit
関数は、処理が成功すると値 0 を返します。
そうでない場合は -1 が返され、エラーを示すためにグローバル変数
.Fa errno
が設定されます。
.Sh エラー
.Bl -tag -width Er
.It Bq Er ENOMEM
関数をリストに追加するメモリが利用できませんでした。
関数の既存のリストは無修正です。
.El
.Sh 関連項目
.Xr exit 3
.Sh 規格
.Fn atexit
関数は
.St -isoC
に適合しています。
