+++ /dev/null
-.\" Copyright (c) 1992 Drew Eckhardt (drew@cs.colorado.edu), March 28, 1992
-.\"
-.\" %%%LICENSE_START(VERBATIM)
-.\" Permission is granted to make and distribute verbatim copies of this
-.\" manual provided the copyright notice and this permission notice are
-.\" preserved on all copies.
-.\"
-.\" Permission is granted to copy and distribute modified versions of this
-.\" manual under the conditions for verbatim copying, provided that the
-.\" entire resulting derived work is distributed under the terms of a
-.\" permission notice identical to this one.
-.\"
-.\" Since the Linux kernel and libraries are constantly changing, this
-.\" manual page may be incorrect or out-of-date. The author(s) assume no
-.\" responsibility for errors or omissions, or for damages resulting from
-.\" the use of the information contained herein. The author(s) may not
-.\" have taken the same level of care in the production of this manual,
-.\" which is licensed free of charge, as they might when working
-.\" professionally.
-.\"
-.\" Formatted or processed versions of this manual, if unaccompanied by
-.\" the source, must acknowledge the copyright and authors of this work.
-.\" %%%LICENSE_END
-.\"
-.\" Modified by Michael Haardt (michael@moria.de)
-.\" Modified Sat Jul 24 14:29:17 1993 by Rik Faith (faith@cs.unc.edu)
-.\" Modified 961203 and 001211 and 010326 by aeb@cwi.nl
-.\" Modified 001213 by Michael Haardt (michael@moria.de)
-.\" Modified 13 Jun 02, Michael Kerrisk <mtk.manpages@gmail.com>
-.\" Added note on nonstandard behavior when SIGCHLD is ignored.
-.\" Modified 2004-11-16, mtk, Noted that the nonconformance when
-.\" SIGCHLD is being ignored is fixed in 2.6.9; other minor changes
-.\" Modified 2004-12-08, mtk, in 2.6 times() return value changed
-.\" 2005-04-13, mtk
-.\" Added notes on nonstandard behavior: Linux allows 'buf' to
-.\" be NULL, but POSIX.1 doesn't specify this and it's nonportable.
-.\"
-.TH TIMES 2 2012-10-22 "Linux" "Linux Programmer's Manual"
-.SH NAME
-times \- get process times
-.SH SYNOPSIS
-.B #include <sys/times.h>
-.sp
-.BI "clock_t times(struct tms *" buf );
-.SH DESCRIPTION
-.BR times ()
-stores the current process times in the
-.I "struct tms"
-that
-.I buf
-points to.
-The
-.I struct tms
-is as defined in
-.IR <sys/times.h> :
-.sp
-.in +4n
-.nf
-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 */
-};
-.fi
-.in
-.LP
-The
-.I tms_utime
-field contains the CPU time spent executing instructions
-of the calling process.
-The
-.I tms_stime
-field contains the CPU time spent in the system while
-executing tasks on behalf of the calling process.
-The
-.I tms_cutime
-field contains the sum of the
-.I tms_utime
-and
-.I tms_cutime
-values for all waited-for terminated children.
-The
-.I tms_cstime
-field contains the sum of the
-.I tms_stime
-and
-.I tms_cstime
-values for all waited-for terminated children.
-.LP
-Times for terminated children (and their descendants)
-are added in at the moment
-.BR wait (2)
-or
-.BR waitpid (2)
-returns their process ID.
-In particular, times of grandchildren
-that the children did not wait for are never seen.
-.LP
-All times reported are in clock ticks.
-.SH RETURN VALUE
-.BR times ()
-returns the number of clock ticks that have elapsed since
-an arbitrary point in the past.
-The return value may overflow the possible range of type
-.IR clock_t .
-On error, \fI(clock_t)\ \-1\fP is returned, and
-.I errno
-is set appropriately.
-.SH ERRORS
-.TP
-.B EFAULT
-.I tms
-points outside the process's address space.
-.SH CONFORMING TO
-SVr4, 4.3BSD, POSIX.1-2001.
-.SH NOTES
-The number of clock ticks per second can be obtained using:
-.in +4n
-
-sysconf(_SC_CLK_TCK);
-.in
-.PP
-In POSIX.1-1996 the symbol \fBCLK_TCK\fP (defined in
-.IR <time.h> )
-is mentioned as obsolescent.
-It is obsolete now.
-.PP
-In Linux kernel versions before 2.6.9,
-if the disposition of
-.B SIGCHLD
-is set to
-.BR SIG_IGN ,
-then the times of terminated children
-are automatically included in the
-.I tms_cstime
-and
-.I tms_cutime
-fields, although POSIX.1-2001 says that this should happen
-only if the calling process
-.BR wait (2)s
-on its children.
-This nonconformance is rectified in Linux 2.6.9 and later.
-.\" See the description of times() in XSH, which says:
-.\" The times of a terminated child process are included... when wait()
-.\" or waitpid() returns the process ID of this terminated child.
-
-On Linux, the
-.I buf
-argument can be specified as NULL, with the result that
-.BR times ()
-just returns a function result.
-However, POSIX does not specify this behavior, and most
-other UNIX implementations require a non-NULL value for
-.IR buf .
-.LP
-Note that
-.BR clock (3)
-also returns a value of type
-.IR clock_t ,
-but this value is measured in units of
-.BR CLOCKS_PER_SEC ,
-not the clock ticks used by
-.BR times ().
-
-On Linux, the "arbitrary point in the past" from which the return value of
-.BR times ()
-is measured has varied across kernel versions.
-On Linux 2.4 and earlier this point is the moment the system was booted.
-Since Linux 2.6, this point is \fI(2^32/HZ) \- 300\fP
-(i.e., about 429 million) seconds before system boot time.
-This variability across kernel versions (and across UNIX implementations),
-combined with the fact that the returned value may overflow the range of
-.IR clock_t ,
-means that a portable application would be wise to avoid using this value.
-To measure changes in elapsed time, use
-.BR clock_gettime (2)
-instead.
-.\" .PP
-.\" On older systems the number of clock ticks per second is given
-.\" by the variable HZ.
-.SS Historical
-SVr1-3 returns
-.I long
-and the struct members are of type
-.I time_t
-although they store clock ticks, not seconds since the Epoch.
-V7 used
-.I long
-for the struct members, because it had no type
-.I time_t
-yet.
-.SH BUGS
-A limitation of the Linux system call conventions on some architectures
-(notably i386) means that on Linux 2.6 there is a small time window
-(41 seconds) soon after boot when
-.BR times ()
-can return \-1, falsely indicating that an error occurred.
-The same problem can occur when the return value wraps past
-the maximum value that can be stored in
-.BR clock_t .
-.\" The problem is that a syscall return of -4095 to -1
-.\" is interpreted by glibc as an error, and the wrapper converts
-.\" the return value to -1.
-.\" http://marc.info/?l=linux-kernel&m=119447727031225&w=2
-.\" "compat_sys_times() bogus until jiffies >= 0"
-.\" November 2007
-.SH SEE ALSO
-.BR time (1),
-.BR getrusage (2),
-.BR wait (2),
-.BR clock (3),
-.BR sysconf (3),
-.BR time (7)
-.SH COLOPHON
-This page is part of release 3.79 of the Linux
-.I man-pages
-project.
-A description of the project,
-information about reporting bugs,
-and the latest version of this page,
-can be found at
-\%http://www.kernel.org/doc/man\-pages/.
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