.\" 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.\" manual page may be incorrect or out-of-date.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 Fri Jul 23 21:26:27 1993 by Rik Faith (faith@cs.unc.edu)
.\" Modified 21 Aug 1994 by Michael Chastain (mec@shell.portal.com):
.\"   Fixed necessary '#include' lines.
.\" Modified 15 Apr 1995 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 14 Jan 1997 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.
.\"
.\" 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
.\"
.\"WORD:	timezone		ॾ
.\"WORD:	daylight savings times	ƻ(daylight savings times)
.\"WORD:	macro			ޥ
.\"WORD:	null			NULL
.\"WORD:	superuser		ѡ桼
.\"
.TH GETTIMEOFDAY 2 1997-12-10 "Linux 2.0.32" "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
ϻ֤ȥॾ (timezone) ޤꤹ롣
.I tv
 /usr/include/sys/time.h Ƥ
.B timeval 
¤ΤǤ:
.sp
.nf
struct timeval {
.in +8
long	tv_sec;		/* seconds */
long	tv_usec;	/* microseconds */
.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; /* minutes W of Greenwich */
int    tz_dsttime;     /* type of dst correction */
.in -8
};
.fi
.PP
timezone ¤ΤλѤѻ (obsolete) 줿
.I tz_dsttime
եɤ Linux ǤϻѤʤ
libc  glibc ˤäƥݡȤ뤳ȤϤʤ
ͥΥΥեɤ¸ߤΤƥХǤ롣
äƤʹߤεҤϡŪʵҤ˲᤮ʤ

.I tz_dsttime
եɤ (ʲͿ褦) ܥǼƤ롣
ϰǯΤǤIJƻ (Daylight Savings Time) »ܤ뤫򼨤Ƥ롣
(: ͤǯ֤ DST »ܤ뤳ȤؼƤ櫓ǤϤʤ
르ꥺ򤷤Ƥ롣)
ƻ (daylight savings times) ϰʲΤ褦:
.PP
.ta 14
\fB DST_NONE\fP /* not on dst */
.br
\fB DST_USA\fP  /* USA style dst */
.br
\fB DST_AUST\fP /* Australian style dst */
.br
\fB DST_WET\fP  /* Western European dst */
.br
\fB DST_MET\fP  /* Middle European dst */
.br
\fB DST_EET\fP  /* Eastern European dst */
.br
\fB DST_CAN\fP  /* Canada */
.br
\fB DST_GB\fP   /* Great Britain and Eire */
.br
\fB DST_RUM\fP  /* Rumania */
.br
\fB DST_TUR\fP  /* Turkey */
.br
\fB DST_AUSTALT\fP      /* Australian style with shift in 1986 */
.PP
󡢤ɤδ֤˲ƻ֤»ܤ뤫ˤñʥ르ꥺ¸ߤ
񤴤Ȥ˰ۤäƤ롣
ºݤˤδ֤ͽΤǤʤŪʷǤ롣
ǤΥࡦɽˡ줿
Linux ˤơ
.B settimeofday

.I tz_dsttime
եɤ 0 ˤɬפ롣
.PP
Linux ˤäΡ֥åΥ (warp clock)פ
.B settimeofday
ƥࡦ˴Ϣ¸ߤ롣
 (֡ȸ) ǽΥ
.I tz
 NULL Ǥʤ
.I tv
 NULL 
.I tz_minuteswest
եɤ 0 Ǥʤˤ롣
Τ褦ʾ硢CMOS å (local time) ǤȤߤʤ
UTC ƥ֤뤿ˡλ֤ä롣
λͤȤȤϤ餯ɤͤǤϤʤ
.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
ޤ
.I tz
Τɤ餫 NULL ʤСб빽¤Τꤵʤ֤ʤ
.PP
ѡ桼Τߤ
.B settimeofday 
ѤǤ롣
.SH ֤
.B gettimeofday

.B settimeofday
 0 ֤Ԥ \-1 ֤
(ξ
.I errno
Ŭڤꤵ)
.SH 顼
.TP
.B EPERM
.B settimeofday
ѡ桼ʳƤӽФ줿
.TP
.B EINVAL
ॾ (ޤ¾β) Ǥ롣
.TP
.B EFAULT
.I tv

.I tz
Τɤ餫ǽʥɥ쥹֤γؤƤ롣
.SH 
(glibc2.2.2) 
.B settimeofday
Υץȥפ
.BR timercmp ,
.BR timerisset ,
.BR timerclear ,
.BR timeradd ,
.BR timersub

.B _BSD_SOURCE
 (Ū⤷ϰۤ) ƤˤΤѲǽȤʤ롣
_POSIX_SOURCE Ƥ䥳ѥ -ansi ե饰
ꤷˤ _BSD_SOURCE ʤ
.SH 
SVr4, BSD 4.3
.SH Ϣ
.BR date (1),
.BR adjtimex (2),
.BR time (2),
.BR ctime (3),
.BR ftime (3)