Manual Pages  — TIMES

The times() function returns the value of time in CLK_TCK's of a second since the system startup time. The current value of CLK_TCK, the frequency of the statistics clock in ticks per second, may be obtained through the sysconf(3) interface.

It also fills in the structure pointed to by tp with time-accounting information.

The tms structure is defined as follows:

struct tms {
        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
	The CPU time charged for the execution of user instructions.
tms_stime
	The CPU time charged for execution by the system on behalf of the process.
tms_cutime
	The sum of the tms_utimes and tms_cutimes of the child processes.
tms_cstime
	The sum of the tms_stime, Ns, s and tms_cstime, Ns, s of the child processes.

All times are in CLK_TCK's of a second.

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.