.\" Hey Emacs! This file is -*- nroff -*- source.
.\"
.\" Copyright (c) 1992 Drew Eckhardt (drew@cs.colorado.edu), March 28, 1992
.\"
.\" 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.\" manual page may be incorrect or out-of-date.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.
.\"
.\" Modified by Michael Haardt (michael@moria.de)
.\" Modified 1993-07-23 by Rik Faith (faith@cs.unc.edu)
.\" Modified 1994-08-21 by Michael Chastain (mec@shell.portal.com):
.\"   Fixed necessary '#include' lines.
.\" Modified 1995-04-15 by Michael Chastain (mec@shell.portal.com):
.\"   Added reference to adjtimex.
.\" Removed some nonsense lines pointed out by Urs Thuermann,
.\"   (urs@isnogud.escape.de), aeb, 950722.
.\" Modified 1997-01-14 by Austin Donnelly (and1000@debian.org):
.\"   Added return values section, and bit on EFAULT
.\" Added clarification on timezone, aeb, 971210.
.\" Removed "#include <unistd.h>", aeb, 010316.
.\" Modified, 2004-05-27 by Michael Kerrisk <mtk-manpages@gmx.net>
.\"   Added notes on capability requirement.
.\"
.\" Japanese Version Copyright (c) 1998 HANATAKA Shinya
.\"         all rights reserved.
.\" Translated Mon May 11 22:23:09 JST 1998
.\"         by HANATAKA Shinya <hanataka@abyss.rim.or.jp>
.\" Updated & Modified Sat Jun  2 17:20:23 JST 2001
.\"         by Yuichi SATO <ysato@h4.dion.ne.jp>
.\" Updated & Modified Sun Dec 23 00:42:12 JST 2001 by Yuichi SATO
.\" Updated & Modified Sat Sep  6 16:51:14 JST 2003
.\"         by Yuichi SATO <ysato444@yahoo.co.jp>
.\" Updated & Modified Thu Dec 30 13:52:26 JST 2004 by Yuichi SATO
.\"
.\"WORD:	timezone		ॾ
.\"WORD:	daylight savings times	ƻ(daylight savings times)
.\"WORD:	macro			ޥ
.\"WORD:	null			NULL
.\"WORD:	superuser		ѡ桼
.\"
.TH GETTIMEOFDAY 2 2004-05-27 "Linux 2.6.6" "Linux Programmer's Manual"
.SH ̾
gettimeofday, settimeofday \- /ꤹ
.SH 
.B #include <sys/time.h>
.sp
.BI "int gettimeofday(struct timeval *" tv ", struct timezone *" tz );
.br
.BI "int settimeofday(const struct timeval *" tv
.BI ", const struct timezone *" tz );
.SH 
ؿ
.B gettimeofday

.B settimeofday
ϻȥॾ (timezone) ޤꤹ롣
.I tv
 <sys/time.h> Ƥ
.B timeval 
¤ΤǤ:
.sp
.nf
struct timeval {
.in +8
time_t		tv_sec;		/*  */
suseconds_t	tv_usec;	/* ޥ */
.in -8
};
.fi
.sp
ˤ굪 (the Epoch:
.BR time (2)
򻲾) äȥޥäǤ롣
.I tz

.B timezone 
¤ΤǤ:
.sp
.nf
struct timezone {
.in +8
int    tz_minuteswest; /* ˥åɸȤκ (ʬñ) */
int    tz_dsttime;     /* ƻĴη */
.in -8
};
.fi
.PP
timezone ¤ΤȤΤϻ٤ (obsolete) Ǥ롣
.I tz_dsttime
եɤ Linux ǤϰڻȤƤʤä
libc  glibc Ǥ⥵ݡȤƤʤä
줫⥵ݡȤ뤳ȤϤʤ
ͥΥʳǡΥեɤ¸ߤΤƥХǤ롣
äƤʹߤεҤϡỤ̄˴ŤΤǤ롣

.I tz_dsttime
եɤˤ (ʲͿ褦) ܥǼ롣
ϰǯΤǤIJƻ (Daylight Savings Time) »ܤ뤫򼨤Ƥ롣
(: ͤǯ֤̤Ǥ롣
ƻ֤»Ǥ뤳Ȥ򼨤櫓ǤϤʤ
르ꥺ򤷤ƤǤ롣)
ƻ֤ϰʲΤ褦:
.PP
.ta 14
\fB DST_NONE\fP /* ƻ֤ѤƤʤ */
.br
\fB DST_USA\fP  /* ꥫ罰񼰲ƻ */
.br
\fB DST_AUST\fP /* ȥꥢƻ */
.br
\fB DST_WET\fP  /* 衼åѼƻ */
.br
\fB DST_MET\fP  /* 衼åѼƻ */
.br
\fB DST_EET\fP  /* 衼åѼƻ */
.br
\fB DST_CAN\fP  /* ʥ */
.br
\fB DST_GB\fP   /* 졼ȥ֥ƥ󤪤ӥ */
.br
\fB DST_RUM\fP  /* 롼ޥ˥ */
.br
\fB DST_TUR\fP  /* ȥ륳 */
.br
\fB DST_AUSTALT\fP      /* 1986ǯ˰ܹԤ줿ȥꥢ */
.PP
ΤȤʤ顢ƻ֤ɤδ֤˼»ܤ뤫
񤴤Ȥδñʥ르ꥺƳȤǤʤȤȽ
ºݡƻ֤δ֤ͽ¬ԲǽŪǷޤ롣
ΤᤳˡǥࡦɽȤǰ줿
Linux ˤ
.B settimeofday
ƤӽФȤϡ
.I tz_dsttime
եɤ 0 ˤ٤Ǥ롣
.PP
Linux Ǥϡ
.B settimeofday
ƥࡦ˴ϢơäΡ֥åΥ (warp clock)פ¸ߤ롣
 (֡ȸ) ǽθƤӽФ
.I tz
 NULL Ǥʤ
.I tv
 NULL 
.I tz_minuteswest
եɤ 0 Ǥʤ˵롣
Τ褦ʾ硢
.B settimeofday
 CMOS å (local time) Ǥꡢ
UTC ƥ֤뤿ˤϡ
.I tz_minuteswest
ʬäʤƤϤʤʤȤߤʤƤޤ
ʤεȤȤɤͤǤϤʤ
.PP
timeval ¤Τ뤿˰ʲΥޥ (macro) Ƥ :
.br
.nf
#define	timerisset(tvp)\\
.ti +8
((tvp)->tv_sec || (tvp)->tv_usec)
#define	timercmp(tvp, uvp, cmp)\\
.in +8
((tvp)->tv_sec cmp (uvp)->tv_sec ||\\
(tvp)->tv_sec == (uvp)->tv_sec &&\\
(tvp)->tv_usec cmp (uvp)->tv_usec)
.ti -8
#define        timerclear(tvp)\\
.ti +8
((tvp)->tv_sec = (tvp)->tv_usec = 0)
.fi
.PP
.I tv

.I tz
 NULL Ǥ硢б빽¤Τꤵ줺֤뤳Ȥʤ
.PP
ѡ桼Τߤ
.B settimeofday 
ѤǤ롣
.SH ֤
.B gettimeofday

.B settimeofday
 0 ֤Ԥ \-1 ֤
(ξ
.I errno
Ŭڤꤵ)
.SH 顼
.TP
.B EFAULT
.I tv

.I tz
λؤΰΤɤ餫ǽʥɥ쥹֤ˤʤ
.TP
.B EINVAL
ॾ (ޤ¾β) Ǥ롣
.TP
.B EPERM
ƤӽФץ
.B settimeofday
ƤӽФνʬøʤ
Linux Ǥ
.B CAP_SYS_TIME
ѥӥƥ (capability) ɬפǤ롣
.SH 
.B settimeofday
Υץȥפ
.BR timercmp ,
.BR timerisset ,
.BR timerclear ,
.BR timeradd ,
.BR timersub
 (glibc2.2.2 )
.B _BSD_SOURCE
 (Ū⤷ϰۤ) ƤˤΤѲǽȤʤ롣
_POSIX_SOURCE Ƥ䥳ѥ -ansi ե饰
ꤷˤ _BSD_SOURCE ʤ
.LP
ΤϹ¤ timeval Υեɤ long Ǥä
.SH 
SVr4, BSD 4.3 ˽򤹤롣
POSIX 1003.1-2001  gettimeofday() ˤĤƤϵҤƤ뤬
settimeofday() ˤĤƤϵҤƤʤ
.SH Ϣ
.BR date (1),
.BR adjtimex (2),
.BR time (2),
.BR ctime (3),
.BR ftime (3),
.BR capabilities (7)