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diff --git a/man-pages-posix-2003/man3p/clock.3p b/man-pages-posix-2003/man3p/clock.3p new file mode 100644 index 0000000..7eb35da --- /dev/null +++ b/man-pages-posix-2003/man3p/clock.3p @@ -0,0 +1,76 @@ +.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved +.TH "CLOCK" 3P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual" +.\" clock +.SH PROLOG +This manual page is part of the POSIX Programmer's Manual. +The Linux implementation of this interface may differ (consult +the corresponding Linux manual page for details of Linux behavior), +or the interface may not be implemented on Linux. +.SH NAME +clock \- report CPU time used +.SH SYNOPSIS +.LP +\fB#include <time.h> +.br +.sp +clock_t clock(void); +.br +\fP +.SH DESCRIPTION +.LP +The \fIclock\fP() function shall return the implementation's best +approximation to the processor time used by the process since +the beginning of an implementation-defined era related only to the +process invocation. +.SH RETURN VALUE +.LP +To determine the time in seconds, the value returned by \fIclock\fP() +should be divided by the value of the macro +CLOCKS_PER_SEC. CLOCKS_PER_SEC is defined to be one million in +\fI<time.h>\fP. If the processor time used is not available or its +value cannot be +represented, the function shall return the value ( \fBclock_t\fP)-1. +.SH ERRORS +.LP +No errors are defined. +.LP +\fIThe following sections are informative.\fP +.SH EXAMPLES +.LP +None. +.SH APPLICATION USAGE +.LP +In order to measure the time spent in a program, \fIclock\fP() should +be called at the start of the program and its return +value subtracted from the value returned by subsequent calls. The +value returned by \fIclock\fP() is defined for compatibility +across systems that have clocks with different resolutions. The resolution +on any particular system need not be to microsecond +accuracy. +.LP +The value returned by \fIclock\fP() may wrap around on some implementations. +For example, on a machine with 32-bit values for +\fBclock_t\fP, it wraps after 2147 seconds or 36 minutes. +.SH RATIONALE +.LP +None. +.SH FUTURE DIRECTIONS +.LP +None. +.SH SEE ALSO +.LP +\fIasctime\fP(), \fIctime\fP(), \fIdifftime\fP(), \fIgmtime\fP(), +\fIlocaltime\fP(), +\fImktime\fP(), \fIstrftime\fP(), \fIstrptime\fP(), \fItime\fP(), +\fIutime\fP(), the Base +Definitions volume of IEEE\ Std\ 1003.1-2001, \fI<time.h>\fP +.SH COPYRIGHT +Portions of this text are reprinted and reproduced in electronic form +from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology +-- Portable Operating System Interface (POSIX), The Open Group Base +Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of +Electrical and Electronics Engineers, Inc and The Open Group. In the +event of any discrepancy between this version and the original IEEE and +The Open Group Standard, the original IEEE and The Open Group Standard +is the referee document. The original Standard can be obtained online at +http://www.opengroup.org/unix/online.html . |