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times(3)
NAME
  times - Gets process and child process times

LIBRARY
  Standard C Library (libc.so, libc.a)

SYNOPSIS
  #include <sys/times.h>

  clock_t times(
	  struct tms *buffer);

  Programs that are being developed for conformance to the AT&T System V
  Interface Definition must specify two #include statements, as follows:

  #include <sys/types.h>
  #include <sys/times.h>

STANDARDS
  Interfaces documented on this reference page conform to industry standards
  as follows:

  times():  XPG4, XPG4-UNIX

  Refer to the standards(5) reference page for more information about
  industry standards and associated tags.

PARAMETERS
  buffer    Points to type tms structure space where system time information
	    is stored.

DESCRIPTION
  The times() function fills the type tms structure space pointed to by the
  buffer parameter with time-accounting information.  All time values
  reported by this function are in hardware-dependent clock ticks.

  The times of a terminated child process are included in the tms_cutime and
  tms_cstime elements of the parent process when a wait function returns the
  process ID of that terminated child.

  The tms structure, which  is defined in the sys/times.h header file,
  contains the following members:

  clock_t  tms_utime
	    User time. The CPU time charged while executing user instructions
	    of the calling process.

  clock_t  tms_stime
	    System time. The CPU time charged during system execution on
	    behalf of the calling process.

  clock_t  tms_cutime
	    User time, children. The sum of the tms_utime and the tms_cutime
	    times of the child processes.

  clock_t  tms_cstime
	    System time, children. The sum of the tms_stime and the
	    tms_cstime times of the child processes.

  When a child process does not wait for its children, its child-process
  times are not included in its times.

  This information comes from the calling process and each of its terminated
  child processes for which a wait function has been executed.

RETURN VALUES
  Upon successful completion, the times() function returns the elapsed real
  time since an arbitrary reference time in the past (for example, system
  start-up time). The reference time does not change from one invocation of
  times() within the process to another.  The elapsed times are in units of
  1/CLK_TCK seconds, where CLK_TCK is processor dependent. For application
  portability, the value of CLK_TCK should be queried using the sysconf()
  function (see sysconf(3)).

  The return value may overflow the possible range of type clock_t values.
  When the times() function fails, a value of (clock_t)-1 is returned.

RELATED INFORMATION
  Commands: cc(1)

  Functions: exec(2), fork(2), getrusage(2), profil(2), stime(3), sysconf(3),
  time(3), wait(2)

  Standards: standards(5)

Index for Section 3

Alphabetical listing for T

Top of page