.\" 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.
.\"
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.\" modification, are permitted provided that the following conditions
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.\"    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.
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.\"     @(#)clock.3     8.1 (Berkeley) 6/4/93
.\" %FreeBSD: src/lib/libc/gen/clock.3,v 1.6.2.3 2001/12/14 18:33:50 ru Exp %
.\"
.\" $FreeBSD$
.Dd June 4, 1993
.Dt CLOCK 3
.Os
.Sh 名称
.Nm clock
.Nd 使用されたプロセッサ時間を計測する
.Sh ライブラリ
.Lb libc
.Sh 書式
.In time.h
.Ft clock_t
.Fn clock void
.Sh 解説
.Fn clock
関数は、呼び出し元プロセスの、起動時からのプロセッサ使用時間を計算します。
これは 1 秒の
.Dv CLOCKS_PER_SEC
分の 1 を単位として計測されます。
.Sh 戻り値
.Fn clock
関数は使用された時間量を返します。
エラーが生じた場合の戻り値は \-1 です。
.Sh 関連項目
.Xr getrusage 2 ,
.Xr clocks 7
.Sh 規格
.Fn clock
関数は
.St -isoC
に適合しています。