clock_t
times(
struct tms *tp
)
The
times()
function returns the value of time in clock ticks since 0 hours, 0
minutes, 0 seconds, January 1, 1970, Coordinated Universal Time (UTC).
The number of clock ticks per second may be determined by calling
sysconf(3)
with the
_SC_CLK_TCK
request.
It is generally (but not always) between 60 and 1024.
Note that at the common rate of 100 ticks per second on many NetBSD ports, and with a 32-bit unsigned clock_t, this value first wrapped in 1971.
The
times()
call also fills in the structure pointed to by
tp
with time-accounting information.
The
tms
structure is defined as follows:
typedef struct {
clock_t tms_utime;
clock_t tms_stime;
clock_t tms_cutime;
clock_t tms_cstime;
}
The elements of this structure are defined as follows:
tms_utime
tms_stime
tms_cutime
tms_utime
s
and
tms_cutime
s
of the child processes.
tms_cstime
tms_stime
s
and
tms_cstime
s
of the child processes.
All times are measured in clock ticks, as defined above. Note that at 100 ticks per second, and with a 32-bit unsigned clock_t, the values wrap after 497 days.
The times of a terminated child process are included in the
tms_cutime
and
tms_cstime
elements of the parent when one of the
wait(2)
functions returns the process ID of the terminated child to the parent.
If an error occurs,
times()
returns the value
((clock_t)-1),
and sets
errno
to indicate the error.
)
function
may fail and set the global variable
errno
for any of the errors specified for the library
routines
getrusage(2)
and
gettimeofday(2).
)
function conforms to
ISO/IEC 9945-1:1990 (``POSIX.1'') .