Flashnux

GNU/Linux man pages

Livre :
Expressions régulières,
Syntaxe et mise en oeuvre :

ISBN : 978-2-7460-9712-4
EAN : 9782746097124
(Editions ENI)

GNU/Linux

CentOS 2.1AS

(Slurm)

clock(3)


CLOCK

CLOCK

NAME
SYNOPSIS
DESCRIPTION
RETURN VALUE
CONFORMING TO
NOTES
SEE ALSO

NAME

clock − Determine processor time

SYNOPSIS

#include <time.h>

clock_t clock(void);

DESCRIPTION

The clock() function returns an approximation of processor time used by the program.

RETURN VALUE

The value returned is the CPU time used so far as a clock_t; to get the number of seconds used, divide by CLOCKS_PER_SEC. If the processor time used is not available or its value cannot be represented, the function returns the value (clock_t)-1.

CONFORMING TO

ANSI C. POSIX requires that CLOCKS_PER_SEC equals 1000000 independent of the actual resolution.

NOTES

The C standard allows for arbitrary values at the start of the program; subtract the value returned from a call to clock() at the start of the program to get maximum portability.

Note that the time can wrap around. On a 32bit system where CLOCKS_PER_SEC equals 1000000 this function will return the same value approximately every 72 minutes.

The times() function call returns more information.

SEE ALSO

getrusage(2), times(2)



clock(3)