xref: /freebsd/lib/libc/gen/clock.3 (revision dc36d6f9bb1753f3808552f3afd30eda9a7b206a)
158f0484fSRodney W. Grimes.\" Copyright (c) 1990, 1991, 1993
258f0484fSRodney W. Grimes.\"	The Regents of the University of California.  All rights reserved.
358f0484fSRodney W. Grimes.\"
458f0484fSRodney W. Grimes.\" This code is derived from software contributed to Berkeley by
558f0484fSRodney W. Grimes.\" the American National Standards Committee X3, on Information
658f0484fSRodney W. Grimes.\" Processing Systems.
758f0484fSRodney W. Grimes.\"
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958f0484fSRodney W. Grimes.\" modification, are permitted provided that the following conditions
1058f0484fSRodney W. Grimes.\" are met:
1158f0484fSRodney W. Grimes.\" 1. Redistributions of source code must retain the above copyright
1258f0484fSRodney W. Grimes.\"    notice, this list of conditions and the following disclaimer.
1358f0484fSRodney W. Grimes.\" 2. Redistributions in binary form must reproduce the above copyright
1458f0484fSRodney W. Grimes.\"    notice, this list of conditions and the following disclaimer in the
1558f0484fSRodney W. Grimes.\"    documentation and/or other materials provided with the distribution.
16*fbbd9655SWarner Losh.\" 3. Neither the name of the University nor the names of its contributors
1758f0484fSRodney W. Grimes.\"    may be used to endorse or promote products derived from this software
1858f0484fSRodney W. Grimes.\"    without specific prior written permission.
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2058f0484fSRodney W. Grimes.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
2158f0484fSRodney W. Grimes.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
2258f0484fSRodney W. Grimes.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
2358f0484fSRodney W. Grimes.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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3258f0484fSRodney W. Grimes.Dd June 4, 1993
3358f0484fSRodney W. Grimes.Dt CLOCK 3
3458f0484fSRodney W. Grimes.Os
3558f0484fSRodney W. Grimes.Sh NAME
3658f0484fSRodney W. Grimes.Nm clock
3758f0484fSRodney W. Grimes.Nd determine processor time used
3825bb73e0SAlexey Zelkin.Sh LIBRARY
3925bb73e0SAlexey Zelkin.Lb libc
4058f0484fSRodney W. Grimes.Sh SYNOPSIS
4132eef9aeSRuslan Ermilov.In time.h
4258f0484fSRodney W. Grimes.Ft clock_t
4358f0484fSRodney W. Grimes.Fn clock void
4458f0484fSRodney W. Grimes.Sh DESCRIPTION
4558f0484fSRodney W. GrimesThe
4658f0484fSRodney W. Grimes.Fn clock
4758f0484fSRodney W. Grimesfunction
4858f0484fSRodney W. Grimesdetermines the amount of processor time used since the invocation of the
4958f0484fSRodney W. Grimescalling process, measured in
507e1b8179SDavid Malone.Dv CLOCKS_PER_SEC Ns s
51711fbb0aSBruce Evansof a second.
5258f0484fSRodney W. Grimes.Sh RETURN VALUES
5358f0484fSRodney W. GrimesThe
5458f0484fSRodney W. Grimes.Fn clock
5558f0484fSRodney W. Grimesfunction returns the amount of time used unless an error occurs, in which
5658f0484fSRodney W. Grimescase the return value is \-1.
5758f0484fSRodney W. Grimes.Sh SEE ALSO
589cb8a105SJoerg Wunsch.Xr getrusage 2 ,
599cb8a105SJoerg Wunsch.Xr clocks 7
6058f0484fSRodney W. Grimes.Sh STANDARDS
6158f0484fSRodney W. GrimesThe
6258f0484fSRodney W. Grimes.Fn clock
6358f0484fSRodney W. Grimesfunction conforms to
64588a200cSRuslan Ermilov.St -isoC .
657e1b8179SDavid MaloneHowever,
667e1b8179SDavid Malone.St -susv2
677e1b8179SDavid Malonerequires
687e1b8179SDavid Malone.Dv CLOCKS_PER_SEC
697e1b8179SDavid Maloneto be defined as one million.
707e1b8179SDavid Malone.Fx
717e1b8179SDavid Malonedoes not conform to this requirement;
727e1b8179SDavid Malonechanging the value would introduce binary incompatibility
737e1b8179SDavid Maloneand one million is still inadequate on modern processors.
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