NAME
clock —
determine processor time
used
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include
<time.h>
clock_t
clock(void);
DESCRIPTION
The
clock()
function determines the amount of processor time used since the invocation
of the calling process, measured in CLOCKS_PER_SECs
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.
SEE ALSO
STANDARDS
The clock() function conforms to
ISO/IEC 9899:1990 (“ISO C90”).
However, Version 2 of the Single UNIX Specification
(“SUSv2”) requires
CLOCKS_PER_SEC 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.