times(3) [netbsd man page]

TIMES(3)						   BSD Library Functions Manual 						  TIMES(3)

NAME

     times -- process times

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <sys/times.h>

     clock_t
     times(struct tms *tp);

DESCRIPTION

     This interface is obsoleted by getrusage(2) and gettimeofday(2).

     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	 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_utime s and tms_cutime s of the child processes.

     tms_cstime  The sum of the tms_stimes and tms_cstimes 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) func-
     tions 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.

ERRORS

     The times() function may fail and set the global variable errno for any of the errors specified for the library routines getrusage(2) and
     gettimeofday(2).

SEE ALSO

     time(1), getrusage(2), gettimeofday(2), wait(2), sysconf(3)

STANDARDS

     The times() function conforms to ISO/IEC 9945-1:1990 (``POSIX.1'').

BSD
								   June 4, 1993 							       BSD

TIMES(2)						     Linux Programmer's Manual							  TIMES(2)

NAME

       times - get process times

SYNOPSIS

       #include <sys/times.h>

       clock_t times(struct tms *buf);

DESCRIPTION

       The times() function stores the current process times in the struct tms that buf points to.  The struct tms is as defined in <sys/times.h>:

       struct tms {
	      clock_t tms_utime;  /* user time */
	      clock_t tms_stime;  /* system time */
	      clock_t tms_cutime; /* user time of children */
	      clock_t tms_cstime; /* system time of children */
       };

       The  tms_utime  field contains the CPU time spent executing instructions of the calling process.  The tms_stime field contains the CPU time
       spent in the system while executing tasks on behalf of the calling process.  The tms_cutime field contains the sum  of  the  tms_utime  and
       tms_cutime values for all waited-for terminated children.  The tms_cstime field contains the sum of the tms_stime and tms_cstime values for
       all waited-for terminated children.

       Times for terminated children (and their descendants) is added in at the moment wait(2) or waitpid(2) returns their process ID. In particu-
       lar, times of grandchildren that the children did not wait for are never seen.

       All times reported are in clock ticks.

RETURN VALUE

       The  function  times  returns the number of clock ticks that have elapsed since an arbitrary point in the past. For Linux this point is the
       moment the system was booted.  This return value may overflow the possible range of type clock_t.  On error, (clock_t) -1 is returned,  and
       errno is set appropriately.

NOTES

       The number of clock ticks per second can be obtained using
	      sysconf(_SC_CLK_TCK);
       In POSIX-1996 the symbol CLK_TCK (defined in <time.h>) is mentioned as obsolescent. It is obsolete now.

       On  Linux,  if  the  disposition  of  SIGCHLD  is  set  to  SIG_IGN then the times of terminated children are automatically included in the
       tms_cstime and tms_cutime fields, although POSIX 1003.1-2001 says that this should only happen if the calling process wait()s on its  chil-
       dren.

       Note that clock(3) returns values of type clock_t that are not measured in clock ticks but in CLOCKS_PER_SEC.

CONFORMING TO

       SVr4, SVID, POSIX, X/OPEN, BSD 4.3

HISTORICAL NOTES

       SVr1-3  returns	long and the struct members are of type time_t although they store clock ticks, not seconds since the epoch.  V7 used long
       for the struct members, because it had no type time_t yet.

       On older systems the number of clock ticks per second is given by the variable HZ.

SEE ALSO

       time(1), getrusage(2), wait(2), clock(3), sysconf(3)

Linux								    2002-06-14								  TIMES(2)