clock

NAME

clock

INTERFACE

#include <time.h> clock_t clock ( void ) </time.h>

DESCRIPTION

The clock function determines the amount of processor time used since the invocation of the calling process, measured in <span class="Dv">CLOCKS_PER_SEC</span>s of a second.

RETURN VALUES

The clock function returns the amount of time used unless an error occurs, in which case the return value is -1.

STANDARDS

The clock function conforms to ISO/IEC 9899:1990 ('ISO C90'). However, version 2 of the Single UNIX Specification ('SUSv2') <span class="Dv">CLOCKS_PER_SEC</span> to be defined as one million. FreeBSD does not conform to this requirement; changing the value would introduce binary incompatibility and one million is still inadequate on modern processors.