times(2)

times -- get process and child process times

Synopsis

   #include <sys/types.h>
   #include <sys/times.h>
   
   clock_t times(struct tms buffer);

Description

times fills the tms structure pointed to by buffer with time-accounting information. The tms structure is defined in sys/times.h and includes the following fields:

   clock_t    tms_utime;
   clock_t    tms_stime;
   clock_t    tms_cutime;
   clock_t    tms_cstime;

This information comes from the calling process and each of its terminated child processes for which it has executed a wait routine. All times are reported in clock ticks. The clock ticks at a system-dependent rate. The specific value of this rate for an implementation is defined, in ticks per second, by the variable CLK_TCK, found in the include file limits.h.

tms_utime is the CPU time used while executing instructions in the user space of the calling process.

tms_stime is the CPU time used by the system on behalf of the calling process.

tms_cutime is the sum of the tms_utime and the tms_cutime of the child processes.

tms_cstime is the sum of the tms_stime and the tms_cstime of the child processes.

Return values

On success, times returns the elapsed real time in clock ticks from an arbitrary point in the past (for example, system start-up time). This point does not change from one invocation of times to another. On failure, times returns -1 and sets errno to identify the error.

Errors

In the following conditions, times fails and sets errno to:

EFAULT: buffer points to an invalid address.

References

exec(2), fork(2), time(1), time(2), timex(1) wait(2), waitid(2), waitpid(2)

Notices

Considerations for threads programming

Statistics are gathered at the process level and represent the combined usage of all contained threads.