Tribblix: manual page: times.2

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.