'\" te .\" Copyright 1989 AT&T Copyright (c) 2002, Sun Microsystems, Inc. All Rights Reserved .\" The contents of this file are subject to the terms of the Common Development and Distribution License (the "License"). You may not use this file except in compliance with the License. .\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing. See the License for the specific language governing permissions and limitations under the License. .\" When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner] .TH CLOCK 3C "Jul 24, 2002" .SH NAME clock \- report CPU time used .SH SYNOPSIS .LP .nf #include \fBclock_t\fR \fBclock\fR(\fBvoid\fR); .fi .SH DESCRIPTION .sp .LP The \fBclock()\fR function returns the amount of CPU time (in microseconds) used since the first call to \fBclock()\fR in the calling process. The time reported is the sum of the user and system times of the calling process and its terminated child processes for which it has executed the \fBwait\fR(3C) function, the \fBpclose\fR(3C) function, or the \fBsystem\fR(3C) function. .SH RETURN VALUES .sp .LP Dividing the value returned by \fBclock()\fR by the constant \fBCLOCKS_PER_SEC\fR, defined in the <\fBtime.h\fR> header, will give the time in seconds. If the process time used is not available or cannot be represented, clock returns the value \fB(clock_t) \(mi1\fR. .SH USAGE .sp .LP The value returned by \fBclock()\fR is defined in microseconds for compatibility with systems that have CPU clocks with much higher resolution. Because of this, the value returned will wrap around after accumulating only 2147 seconds of CPU time (about 36 minutes). .SH ATTRIBUTES .sp .LP See \fBattributes\fR(5) for descriptions of the following attributes: .sp .sp .TS box; c | c l | l . ATTRIBUTE TYPE ATTRIBUTE VALUE _ Interface Stability Standard _ MT-Level MT-Safe .TE .SH SEE ALSO .sp .LP \fBtimes\fR(2), \fBpopen\fR(3C), \fBsystem\fR(3C), \fBwait\fR(3C), \fBattributes\fR(5), \fBstandards\fR(5)