1994-05-27 05:00:24 +00:00
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.\" Copyright (c) 1990, 1991, 1993
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.\" The Regents of the University of California. All rights reserved.
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.\"
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.\" This code is derived from software contributed to Berkeley by
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.\" the American National Standards Committee X3, on Information
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.\" Processing Systems.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\" 4. Neither the name of the University nor the names of its contributors
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.\" may be used to endorse or promote products derived from this software
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.\" without specific prior written permission.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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.\"
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.\" @(#)clock.3 8.1 (Berkeley) 6/4/93
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1999-08-28 00:22:10 +00:00
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.\" $FreeBSD$
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1994-05-27 05:00:24 +00:00
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.\"
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.Dd June 4, 1993
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.Dt CLOCK 3
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.Os
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.Sh NAME
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.Nm clock
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.Nd determine processor time used
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2000-04-21 09:42:15 +00:00
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.Sh LIBRARY
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.Lb libc
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1994-05-27 05:00:24 +00:00
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.Sh SYNOPSIS
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2001-10-01 16:09:29 +00:00
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.In time.h
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1994-05-27 05:00:24 +00:00
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.Ft clock_t
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.Fn clock void
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.Sh DESCRIPTION
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The
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.Fn clock
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function
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determines the amount of processor time used since the invocation of the
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calling process, measured in
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2001-11-05 21:30:43 +00:00
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.Dv CLOCKS_PER_SEC Ns s
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1995-02-03 22:09:56 +00:00
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of a second.
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1994-05-27 05:00:24 +00:00
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.Sh RETURN VALUES
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The
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.Fn clock
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function returns the amount of time used unless an error occurs, in which
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case the return value is \-1.
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.Sh SEE ALSO
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1996-04-05 08:53:38 +00:00
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.Xr getrusage 2 ,
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.Xr clocks 7
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1994-05-27 05:00:24 +00:00
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.Sh STANDARDS
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The
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.Fn clock
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function conforms to
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2001-02-26 13:23:47 +00:00
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.St -isoC .
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2001-11-05 21:30:43 +00:00
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However,
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2001-11-20 13:43:58 +00:00
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.St -susv2
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2001-11-05 21:30:43 +00:00
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requires
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.Dv CLOCKS_PER_SEC
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to be defined as one million.
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.Fx
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does not conform to this requirement;
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changing the value would introduce binary incompatibility
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and one million is still inadequate on modern processors.
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