TIMES(2) System Calls TIMES(2)
NAME
times - get process and child process times
SYNOPSIS
#include <sys/times.h>
#include <limits.h>
clock_t times(
struct tms *buffer);
DESCRIPTION
The
times() function fills the
tms structure pointed to by
buffer with
time-accounting information. The
tms structure, defined in
<sys/times.h>,
contains the following members:
clock_t tms_utime;
clock_t tms_stime;
clock_t tms_cutime;
clock_t tms_cstime;
All times are reported in clock ticks. The specific value for a clock
tick is defined by the variable
CLK_TCK, found in the header <
limits.h>.
The times of a terminated child process are included in the
tms_cutime and
tms_cstime members of the parent when
wait(3C) or
waitpid(3C) returns
the process
ID of this terminated child. If a child process has not
waited for its children, their times will not be included in its times.
The
tms_utime member is the
CPU time used while executing instructions in
the user space of the calling process.
The
tms_stime member is the
CPU time used by the system on behalf of the
calling process.
The
tms_cutime member is the sum of the
tms_utime and the
tms_cutime of
the child processes.
The
tms_cstime member is the sum of the
tms_stime and the
tms_cstime of
the child processes.
RETURN VALUES
Upon successful completion,
times() returns the elapsed real time, in
clock ticks, since an arbitrary point in the past (for example, system
start-up time). This point does not change from one invocation of
times() within the process to another. The return value may overflow the possible
range of type
clock_t. If
times() fails,
(clock_t)-1 is returned and
errno is set to indicate the error.
ERRORS
The
times() function will fail if:
EFAULT The
buffer argument points to an illegal address.
ATTRIBUTES
See
attributes(7) for descriptions of the following attributes:
+--------------------+-------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-------------------+
|Interface Stability | Standard |
+--------------------+-------------------+
|MT-Level | Async-Signal-Safe |
+--------------------+-------------------+
SEE ALSO
time(1),
timex(1),
exec(2),
fork(2),
time(2),
waitid(2),
wait(3C),
waitpid(3C),
attributes(7),
standards(7) May 14, 1997
TIMES(2)