d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

The rest of tzcode94g from Arthur David Olson.

Browse Source 
Obtained From: Arthur David Olson, ftp://elsie.nci.nih.gov/pub/tzcode94g.tar.gz
This commit is contained in:
Garrett Wollman 1994-09-13 03:39:01 +00:00
parent 233ca9a9cf
commit 48d96b1761
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/vendor/tzcode/dist/; revision=2708
9 changed files with 4180 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

56
lib/libc/stdtime/asctime.c Normal file
View File

@ -0,0 +1,56 @@
#ifndef lint
#ifndef NOID
static char elsieid[] = "@(#)asctime.c 7.5";
#endif /* !defined NOID */
#endif /* !defined lint */
/*LINTLIBRARY*/
#include "private.h"
#include "tzfile.h"
/*
** A la X3J11, with core dump avoidance.
*/
char *
asctime(timeptr)
register const struct tm * timeptr;
{
static const char wday_name[][3] = {
"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
};
static const char mon_name[][3] = {
"Jan", "Feb", "Mar", "Apr", "May", "Jun",
"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
};
/*
** Big enough for something such as
** ??? ???-2147483648 -2147483648:-2147483648:-2147483648 -2147483648\n
** (two three-character abbreviations, five strings denoting integers,
** three explicit spaces, two explicit colons, a newline,
** and a trailing ASCII nul).
*/
static char result[3 * 2 + 5 * INT_STRLEN_MAXIMUM(int) +
3 + 2 + 1 + 1];
register const char * wn;
register const char * mn;
if (timeptr->tm_wday < 0 || timeptr->tm_wday >= DAYSPERWEEK)
wn = "???";
else wn = wday_name[timeptr->tm_wday];
if (timeptr->tm_mon < 0 || timeptr->tm_mon >= MONSPERYEAR)
mn = "???";
else mn = mon_name[timeptr->tm_mon];
/*
** The X3J11-suggested format is
** "%.3s %.3s%3d %02.2d:%02.2d:%02.2d %d\n"
** Since the .2 in 02.2d is ignored, we drop it.
*/
(void) sprintf(result, "%.3s %.3s%3d %02d:%02d:%02d %d\n",
wn, mn,
timeptr->tm_mday, timeptr->tm_hour,
timeptr->tm_min, timeptr->tm_sec,
TM_YEAR_BASE + timeptr->tm_year);
return result;
}

74
lib/libc/stdtime/difftime.c Normal file
View File

@ -0,0 +1,74 @@
#ifndef lint
#ifndef NOID
static char elsieid[] = "@(#)difftime.c 7.4";
#endif /* !defined NOID */
#endif /* !defined lint */
/*LINTLIBRARY*/
#include "private.h"
/*
** Algorithm courtesy Paul Eggert (eggert@twinsun.com).
*/
#ifdef HAVE_LONG_DOUBLE
#define long_double long double
#endif /* defined HAVE_LONG_DOUBLE */
#ifndef HAVE_LONG_DOUBLE
#define long_double double
#endif /* !defined HAVE_LONG_DOUBLE */
double
difftime(time1, time0)
const time_t time1;
const time_t time0;
{
time_t delta;
time_t hibit;
if (sizeof(time_t) < sizeof(double))
return (double) time1 - (double) time0;
if (sizeof(time_t) < sizeof(long_double))
return (long_double) time1 - (long_double) time0;
if (time1 < time0)
return -difftime(time0, time1);
/*
** As much as possible, avoid loss of precision
** by computing the difference before converting to double.
*/
delta = time1 - time0;
if (delta >= 0)
return delta;
/*
** Repair delta overflow.
*/
hibit = 1;
while ((hibit <<= 1) > 0)
continue;
/*
** The following expression rounds twice, which means
** the result may not be the closest to the true answer.
** For example, suppose time_t is 64-bit signed int,
** long_double is IEEE 754 double with default rounding,
** time1 = 9223372036854775807 and time0 = -1536.
** Then the true difference is 9223372036854777343,
** which rounds to 9223372036854777856
** with a total error of 513.
** But delta overflows to -9223372036854774273,
** which rounds to -9223372036854774784, and correcting
** this by subtracting 2 * (long_double) hibit
** (i.e. by adding 2**64 = 18446744073709551616)
** yields 9223372036854776832, which
** rounds to 9223372036854775808
** with a total error of 1535 instead.
** This problem occurs only with very large differences.
** It's too painful to fix this portably.
** We are not alone in this problem;
** many C compilers round twice when converting
** large unsigned types to small floating types,
** so if time_t is unsigned the "return delta" above
** has the same double-rounding problem.
*/
return delta - 2 * (long_double) hibit;
}

1530
lib/libc/stdtime/localtime.c Normal file
View File

File diff suppressed because it is too large Load Diff

1530
lib/libc/stdtime/localtime.c.ORIG Normal file
View File

File diff suppressed because it is too large Load Diff

185
lib/libc/stdtime/private.h Normal file
View File

@ -0,0 +1,185 @@
#ifndef PRIVATE_H
#define PRIVATE_H
/*
** This header is for use ONLY with the time conversion code.
** There is no guarantee that it will remain unchanged,
** or that it will remain at all.
** Do NOT copy it to any system include directory.
** Thank you!
*/
/*
** ID
*/
#ifndef lint
#ifndef NOID
static char privatehid[] = "@(#)private.h 7.5";
#endif /* !defined NOID */
#endif /* !defined lint */
/*
** const
*/
#ifndef const
#ifndef __STDC__
#define const
#endif /* !defined __STDC__ */
#endif /* !defined const */
/*
** void
*/
#ifndef void
#ifndef __STDC__
#ifndef vax
#ifndef sun
#define void char
#endif /* !defined sun */
#endif /* !defined vax */
#endif /* !defined __STDC__ */
#endif /* !defined void */
/*
** P((args))
*/
#ifndef P
#ifdef __STDC__
#define P(x) x
#endif /* defined __STDC__ */
#ifndef __STDC__
#define ASTERISK *
#define P(x) ( /ASTERISK x ASTERISK/ )
#endif /* !defined __STDC__ */
#endif /* !defined P */
/*
** genericptr_t
*/
#ifdef __STDC__
typedef void * genericptr_t;
#endif /* defined __STDC__ */
#ifndef __STDC__
typedef char * genericptr_t;
#endif /* !defined __STDC__ */
#include "sys/types.h" /* for time_t */
#include "stdio.h"
#include "ctype.h"
#include "errno.h"
#include "string.h"
#include "limits.h" /* for CHAR_BIT */
#ifndef _TIME_
#include "time.h"
#endif /* !defined _TIME_ */
#ifndef remove
extern int unlink P((const char * filename));
#define remove unlink
#endif /* !defined remove */
#ifndef FILENAME_MAX
#ifndef MAXPATHLEN
#ifdef unix
#include "sys/param.h"
#endif /* defined unix */
#endif /* !defined MAXPATHLEN */
#ifdef MAXPATHLEN
#define FILENAME_MAX MAXPATHLEN
#endif /* defined MAXPATHLEN */
#ifndef MAXPATHLEN
#define FILENAME_MAX 1024 /* Pure guesswork */
#endif /* !defined MAXPATHLEN */
#endif /* !defined FILENAME_MAX */
#ifndef EXIT_SUCCESS
#define EXIT_SUCCESS 0
#endif /* !defined EXIT_SUCCESS */
#ifndef EXIT_FAILURE
#define EXIT_FAILURE 1
#endif /* !defined EXIT_FAILURE */
#ifdef __STDC__
#define alloc_size_t size_t
#define qsort_size_t size_t
#define fwrite_size_t size_t
#endif /* defined __STDC__ */
#ifndef __STDC__
#ifndef alloc_size_t
#define alloc_size_t unsigned
#endif /* !defined alloc_size_t */
#ifndef qsort_size_t
#ifdef USG
#define qsort_size_t unsigned
#endif /* defined USG */
#ifndef USG
#define qsort_size_t int
#endif /* !defined USG */
#endif /* !defined qsort_size_t */
#ifndef fwrite_size_t
#define fwrite_size_t int
#endif /* !defined fwrite_size_t */
#ifndef USG
extern char * sprintf P((char * buf, const char * format, ...));
#endif /* !defined USG */
#endif /* !defined __STDC__ */
/*
** Ensure that these are declared--redundantly declaring them shouldn't hurt.
*/
extern char * getenv P((const char * name));
extern genericptr_t malloc P((alloc_size_t size));
extern genericptr_t calloc P((alloc_size_t nelem, alloc_size_t elsize));
extern genericptr_t realloc P((genericptr_t oldptr, alloc_size_t newsize));
#ifdef USG
extern void exit P((int s));
extern void qsort P((genericptr_t base, qsort_size_t nelem,
qsort_size_t elsize, int (*comp)()));
extern void perror P((const char * string));
extern void free P((char * buf));
#endif /* defined USG */
#ifndef TRUE
#define TRUE 1
#endif /* !defined TRUE */
#ifndef FALSE
#define FALSE 0
#endif /* !defined FALSE */
#ifndef INT_STRLEN_MAXIMUM
/*
** 302 / 1000 is log10(2.0) rounded up.
** Subtract one for the sign bit;
** add one for integer division truncation;
** add one more for a minus sign.
*/
#define INT_STRLEN_MAXIMUM(type) \
((sizeof(type) * CHAR_BIT - 1) * 302 / 1000 + 2)
#endif /* !defined INT_STRLEN_MAXIMUM */
/*
** UNIX is a registered trademark of AT&T.
** VAX is a trademark of Digital Equipment Corporation.
*/
#endif /* !defined PRIVATE_H */

393
lib/libc/stdtime/strftime.c Normal file
View File

@ -0,0 +1,393 @@
#ifndef lint
#ifndef NOID
static char elsieid[] = "@(#)strftime.c 7.19";
/*
** Based on the UCB version with the ID appearing below.
** This is ANSIish only when time is treated identically in all locales and
** when "multibyte character == plain character".
*/
#endif /* !defined NOID */
#endif /* !defined lint */
#include "private.h"
/*
* Copyright (c) 1989 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley. The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#ifndef LIBC_SCCS
#ifndef lint
static const char sccsid[] = "@(#)strftime.c 5.4 (Berkeley) 3/14/89";
#endif /* !defined lint */
#endif /* !defined LIBC_SCCS */
#include "tzfile.h"
static const char afmt[][4] = {
"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
};
static const char Afmt[][10] = {
"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday",
"Saturday"
};
static const char bfmt[][4] = {
"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep",
"Oct", "Nov", "Dec"
};
static const char Bfmt[][10] = {
"January", "February", "March", "April", "May", "June", "July",
"August", "September", "October", "November", "December"
};
static char *_add P((const char *, char *, const char *));
static char *_conv P((int, const char *, char *, const char *));
static char *_fmt P((const char *, const struct tm *, char *, const char *));
size_t strftime P((char *, size_t, const char *, const struct tm *));
extern char *tzname[];
size_t
strftime(s, maxsize, format, t)
char *s;
size_t maxsize;
const char *format;
const struct tm *t;
{
char *p;
p = _fmt(format, t, s, s + maxsize);
if (p == s + maxsize)
return 0;
*p = '\0';
return p - s;
}
static char *
_fmt(format, t, pt, ptlim)
const char *format;
const struct tm *t;
char *pt;
const char *ptlim;
{
for (; *format; ++format) {
if (*format == '%') {
label:
switch(*++format) {
case '\0':
--format;
break;
case 'A':
pt = _add((t->tm_wday < 0 || t->tm_wday > 6) ?
"?" : Afmt[t->tm_wday], pt, ptlim);
continue;
case 'a':
pt = _add((t->tm_wday < 0 || t->tm_wday > 6) ?
"?" : afmt[t->tm_wday], pt, ptlim);
continue;
case 'B':
pt = _add((t->tm_mon < 0 || t->tm_mon > 11) ?
"?" : Bfmt[t->tm_mon], pt, ptlim);
continue;
case 'b':
case 'h':
pt = _add((t->tm_mon < 0 || t->tm_mon > 11) ?
"?" : bfmt[t->tm_mon], pt, ptlim);
continue;
case 'c':
pt = _fmt("%D %X", t, pt, ptlim);
continue;
case 'C':
/*
** %C used to do a...
** _fmt("%a %b %e %X %Y", t);
** ...whereas now POSIX 1003.2 calls for
** something completely different.
** (ado, 5/24/93)
*/
pt = _conv((t->tm_year + TM_YEAR_BASE) / 100,
"%02d", pt, ptlim);
continue;
case 'D':
pt = _fmt("%m/%d/%y", t, pt, ptlim);
continue;
case 'x':
/*
** Version 3.0 of strftime from Arnold Robbins
** (arnold@skeeve.atl.ga.us) does the
** equivalent of...
** _fmt("%a %b %e %Y");
** ...for %x; since the X3J11 C language
** standard calls for "date, using locale's
** date format," anything goes. Using just
** numbers (as here) makes Quakers happier.
** Word from Paul Eggert (eggert@twinsun.com)
** is that %Y-%m-%d is the ISO standard date
** format, specified in ISO 2014 and later
** ISO 8601:1988, with a summary available in
** pub/doc/ISO/english/ISO8601.ps.Z on
** ftp.uni-erlangen.de.
** (ado, 5/30/93)
*/
pt = _fmt("%m/%d/%y", t, pt, ptlim);
continue;
case 'd':
pt = _conv(t->tm_mday, "%02d", pt, ptlim);
continue;
case 'E':
case 'O':
/*
** POSIX locale extensions, a la
** Arnold Robbins' strftime version 3.0.
** The sequences
** %Ec %EC %Ex %Ey %EY
** %Od %oe %OH %OI %Om %OM
** %OS %Ou %OU %OV %Ow %OW %Oy
** are supposed to provide alternate
** representations.
** (ado, 5/24/93)
*/
goto label;
case 'e':
pt = _conv(t->tm_mday, "%2d", pt, ptlim);
continue;
case 'H':
pt = _conv(t->tm_hour, "%02d", pt, ptlim);
continue;
case 'I':
pt = _conv((t->tm_hour % 12) ?
(t->tm_hour % 12) : 12,
"%02d", pt, ptlim);
continue;
case 'j':
pt = _conv(t->tm_yday + 1, "%03d", pt, ptlim);
continue;
case 'k':
/*
** This used to be...
** _conv(t->tm_hour % 12 ?
** t->tm_hour % 12 : 12, 2, ' ');
** ...and has been changed to the below to
** match SunOS 4.1.1 and Arnold Robbins'
** strftime version 3.0. That is, "%k" and
** "%l" have been swapped.
** (ado, 5/24/93)
*/
pt = _conv(t->tm_hour, "%2d", pt, ptlim);
continue;
#ifdef KITCHEN_SINK
case 'K':
/*
** After all this time, still unclaimed!
*/
pt = _add("kitchen sink", pt, ptlim);
continue;
#endif /* defined KITCHEN_SINK */
case 'l':
/*
** This used to be...
** _conv(t->tm_hour, 2, ' ');
** ...and has been changed to the below to
** match SunOS 4.1.1 and Arnold Robbin's
** strftime version 3.0. That is, "%k" and
** "%l" have been swapped.
** (ado, 5/24/93)
*/
pt = _conv((t->tm_hour % 12) ?
(t->tm_hour % 12) : 12,
"%2d", pt, ptlim);
continue;
case 'M':
pt = _conv(t->tm_min, "%02d", pt, ptlim);
continue;
case 'm':
pt = _conv(t->tm_mon + 1, "%02d", pt, ptlim);
continue;
case 'n':
pt = _add("\n", pt, ptlim);
continue;
case 'p':
pt = _add(t->tm_hour >= 12 ? "PM" : "AM",
pt, ptlim);
continue;
case 'R':
pt = _fmt("%H:%M", t, pt, ptlim);
continue;
case 'r':
pt = _fmt("%I:%M:%S %p", t, pt, ptlim);
continue;
case 'S':
pt = _conv(t->tm_sec, "%02d", pt, ptlim);
continue;
case 'T':
case 'X':
pt = _fmt("%H:%M:%S", t, pt, ptlim);
continue;
case 't':
pt = _add("\t", pt, ptlim);
continue;
case 'U':
pt = _conv((t->tm_yday + 7 - t->tm_wday) / 7,
"%02d", pt, ptlim);
continue;
case 'u':
/*
** From Arnold Robbins' strftime version 3.0:
** "ISO 8601: Weekday as a decimal number
** [1 (Monday) - 7]"
** (ado, 5/24/93)
*/
pt = _conv((t->tm_wday == 0) ? 7 : t->tm_wday,
"%d", pt, ptlim);
continue;
case 'V':
/*
** From Arnold Robbins' strftime version 3.0:
** "the week number of the year (the first
** Monday as the first day of week 1) as a
** decimal number (01-53). The method for
** determining the week number is as specified
** by ISO 8601 (to wit: if the week containing
** January 1 has four or more days in the new
** year, then it is week 1, otherwise it is
** week 53 of the previous year and the next
** week is week 1)."
** (ado, 5/24/93)
*/
/*
** XXX--If January 1 falls on a Friday,
** January 1-3 are part of week 53 of the
** previous year. By analogy, if January
** 1 falls on a Thursday, are December 29-31
** of the PREVIOUS year part of week 1???
** (ado 5/24/93)
**
** You are understood not to expect this.
*/
{
int i;
i = (t->tm_yday + 10 - (t->tm_wday ?
(t->tm_wday - 1) : 6)) / 7;
if (i == 0) {
/*
** What day of the week does
** January 1 fall on?
*/
i = t->tm_wday -
(t->tm_yday - 1);
/*
** Fri Jan 1: 53
** Sun Jan 1: 52
** Sat Jan 1: 53 if previous
** year a leap
** year, else 52
*/
if (i == TM_FRIDAY)
i = 53;
else if (i == TM_SUNDAY)
i = 52;
else i = isleap(t->tm_year +
TM_YEAR_BASE) ?
53 : 52;
#ifdef XPG4_1994_04_09
/*
** As of 4/9/94, though,
** XPG4 calls for 53
** unconditionally.
*/
i = 53;
#endif /* defined XPG4_1994_04_09 */
}
pt = _conv(i, "%02d", pt, ptlim);
}
continue;
case 'v':
/*
** From Arnold Robbins' strftime version 3.0:
** "date as dd-bbb-YYYY"
** (ado, 5/24/93)
*/
pt = _fmt("%e-%b-%Y", t, pt, ptlim);
continue;
case 'W':
pt = _conv((t->tm_yday + 7 -
(t->tm_wday ?
(t->tm_wday - 1) : 6)) / 7,
"%02d", pt, ptlim);
continue;
case 'w':
pt = _conv(t->tm_wday, "%d", pt, ptlim);
continue;
case 'y':
pt = _conv((t->tm_year + TM_YEAR_BASE) % 100,
"%02d", pt, ptlim);
continue;
case 'Y':
pt = _conv(t->tm_year + TM_YEAR_BASE, "%04d",
pt, ptlim);
continue;
case 'Z':
#ifdef TM_ZONE
if (t->TM_ZONE)
pt = _add(t->TM_ZONE, pt, ptlim);
else
#endif /* defined TM_ZONE */
if (t->tm_isdst == 0 || t->tm_isdst == 1) {
pt = _add(tzname[t->tm_isdst],
pt, ptlim);
} else pt = _add("?", pt, ptlim);
continue;
case '%':
/*
* X311J/88-090 (4.12.3.5): if conversion char is
* undefined, behavior is undefined. Print out the
* character itself as printf(3) also does.
*/
default:
break;
}
}
if (pt == ptlim)
break;
*pt++ = *format;
}
return pt;
}
static char *
_conv(n, format, pt, ptlim)
int n;
const char *format;
char *pt;
const char *ptlim;
{
char buf[INT_STRLEN_MAXIMUM(int) + 1];
(void) sprintf(buf, format, n);
return _add(buf, pt, ptlim);
}
static char *
_add(str, pt, ptlim)
const char *str;
char *pt;
const char *ptlim;
{
while (pt < ptlim && (*pt = *str++) != '\0')
++pt;
return pt;
}

119
lib/libc/stdtime/time2posix.3 Normal file
View File

@ -0,0 +1,119 @@
.TH TIME2POSIX 3
.SH NAME
time2posix, posix2time \- convert seconds since the Epoch
.SH SYNOPSIS
.nf
.B #include <sys/types.h>
.B #include <time.h>
.PP
.B time_t time2posix(t)
.B time_t t
.PP
.B time_t posix2time(t)
.B time_t t
.PP
.B cc ... -lz
.fi
.SH DESCRIPTION
IEEE Standard 1003.1
(POSIX)
legislates that a time_t value of
536457599 shall correspond to "Wed Dec 31 23:59:59 GMT 1986."
This effectively implies that POSIX time_t's cannot include leap
seconds and,
therefore,
that the system time must be adjusted as each leap occurs.
.PP
If the time package is configured with leap-second support
enabled,
however,
no such adjustment is needed and
time_t values continue to increase over leap events
(as a true `seconds since...' value).
This means that these values will differ from those required by POSIX
by the net number of leap seconds inserted since the Epoch.
.PP
Typically this is not a problem as the type time_t is intended
to be
(mostly)
opaque\(emtime_t values should only be obtained-from and
passed-to functions such as
.IR time(2) ,
.IR localtime(3) ,
.IR mktime(3) ,
and
.IR difftime(3) .
However,
POSIX gives an arithmetic
expression for directly computing a time_t value from a given date/time,
and the same relationship is assumed by some
(usually older)
applications.
Any programs creating/dissecting time_t's
using such a relationship will typically not handle intervals
over leap seconds correctly.
.PP
The
.I time2posix
and
.I posix2time
functions are provided to address this time_t mismatch by converting
between local time_t values and their POSIX equivalents.
This is done by accounting for the number of time-base changes that
would have taken place on a POSIX system as leap seconds were inserted
or deleted.
These converted values can then be used in lieu of correcting the older
applications,
or when communicating with POSIX-compliant systems.
.PP
.I Time2posix
is single-valued.
That is,
every local time_t
corresponds to a single POSIX time_t.
.I Posix2time
is less well-behaved:
for a positive leap second hit the result is not unique,
and for a negative leap second hit the corresponding
POSIX time_t doesn't exist so an adjacent value is returned.
Both of these are good indicators of the inferiority of the
POSIX representation.
.PP
The following table summarizes the relationship between a time
T and it's conversion to,
and back from,
the POSIX representation over the leap second inserted at the end of June,
1993.
.nf
.ta \w'93/06/30 'u +\w'23:59:59 'u +\w'A+0 'u +\w'X=time2posix(T) 'u
DATE TIME T X=time2posix(T) posix2time(X)
93/06/30 23:59:59 A+0 B+0 A+0
93/06/30 23:59:60 A+1 B+1 A+1 or A+2
93/07/01 00:00:00 A+2 B+1 A+1 or A+2
93/07/01 00:00:01 A+3 B+2 A+3
A leap second deletion would look like...
DATE TIME T X=time2posix(T) posix2time(X)
??/06/30 23:59:58 A+0 B+0 A+0
??/07/01 00:00:00 A+1 B+2 A+1
??/07/01 00:00:01 A+2 B+3 A+2
.sp
.ce
[Note: posix2time(B+1) => A+0 or A+1]
.fi
.PP
If leap-second support is not enabled,
local time_t's and
POSIX time_t's are equivalent,
and both
.I time2posix
and
.I posix2time
degenerate to the identity function.
.SH SEE ALSO
difftime(3),
localtime(3),
mktime(3),
time(2)
.\" @(#)time2posix.3 7.3

123
lib/libc/stdtime/tzfile.5 Normal file
View File

@ -0,0 +1,123 @@
.TH TZFILE 5
.SH NAME
tzfile \- time zone information
.SH SYNOPSIS
.B
#include <tzfile.h>
.SH DESCRIPTION
The time zone information files used by
.IR tzset (3)
begin with bytes reserved for future use,
followed by four four-byte values of type
.BR long ,
written in a ``standard'' byte order
(the high-order byte of the value is written first).
These values are,
in order:
.TP
.I tzh_ttisstdcnt
The number of standard/wall indicators stored in the file.
.TP
.I tzh_leapcnt
The number of leap seconds for which data is stored in the file.
.TP
.I tzh_timecnt
The number of "transition times" for which data is stored
in the file.
.TP
.I tzh_typecnt
The number of "local time types" for which data is stored
in the file (must not be zero).
.TP
.I tzh_charcnt
The number of characters of "time zone abbreviation strings"
stored in the file.
.PP
The above header is followed by
.I tzh_timecnt
four-byte values of type
.BR long ,
sorted in ascending order.
These values are written in ``standard'' byte order.
Each is used as a transition time (as returned by
.IR time (2))
at which the rules for computing local time change.
Next come
.I tzh_timecnt
one-byte values of type
.BR "unsigned char" ;
each one tells which of the different types of ``local time'' types
described in the file is associated with the same-indexed transition time.
These values serve as indices into an array of
.I ttinfo
structures that appears next in the file;
these structures are defined as follows:
.in +.5i
.sp
.nf
.ta .5i +\w'unsigned int\0\0'u
struct ttinfo {
long tt_gmtoff;
int tt_isdst;
unsigned int tt_abbrind;
};
.in -.5i
.fi
.sp
Each structure is written as a four-byte value for
.I tt_gmtoff
of type
.BR long ,
in a standard byte order, followed by a one-byte value for
.I tt_isdst
and a one-byte value for
.IR tt_abbrind .
In each structure,
.I tt_gmtoff
gives the number of seconds to be added to GMT,
.I tt_isdst
tells whether
.I tm_isdst
should be set by
.I localtime (3)
and
.I tt_abbrind
serves as an index into the array of time zone abbreviation characters
that follow the
.I ttinfo
structure(s) in the file.
.PP
Then there are
.I tzh_leapcnt
pairs of four-byte values, written in standard byte order;
the first value of each pair gives the time
(as returned by
.IR time(2))
at which a leap second occurs;
the second gives the
.I total
number of leap seconds to be applied after the given time.
The pairs of values are sorted in ascending order by time.
.PP
Finally there are
.I tzh_ttisstdcnt
standard/wall indicators, each stored as a one-byte value;
they tell whether the transition times associated with local time types
were specified as standard time or wall clock time,
and are used when a time zone file is used in handling POSIX-style
time zone environment variables.
.PP
.I Localtime
uses the first standard-time
.I ttinfo
structure in the file
(or simply the first
.I ttinfo
structure in the absence of a standard-time structure)
if either
.I tzh_timecnt
is zero or the time argument is less than the first transition time recorded
in the file.
.SH SEE ALSO
newctime(3)
.\" @(#)tzfile.5 7.2

170
lib/libc/stdtime/tzfile.h Normal file
View File

@ -0,0 +1,170 @@
#ifndef TZFILE_H
#define TZFILE_H
/*
** This header is for use ONLY with the time conversion code.
** There is no guarantee that it will remain unchanged,
** or that it will remain at all.
** Do NOT copy it to any system include directory.
** Thank you!
*/
/*
** ID
*/
#ifndef lint
#ifndef NOID
static char tzfilehid[] = "@(#)tzfile.h 7.4";
#endif /* !defined NOID */
#endif /* !defined lint */
/*
** Information about time zone files.
*/
#ifndef TZDIR
#define TZDIR "/usr/local/etc/zoneinfo" /* Time zone object file directory */
#endif /* !defined TZDIR */
#ifndef TZDEFAULT
#define TZDEFAULT "localtime"
#endif /* !defined TZDEFAULT */
#ifndef TZDEFRULES
#define TZDEFRULES "posixrules"
#endif /* !defined TZDEFRULES */
/*
** Each file begins with. . .
*/
struct tzhead {
char tzh_reserved[24]; /* reserved for future use */
char tzh_ttisstdcnt[4]; /* coded number of trans. time flags */
char tzh_leapcnt[4]; /* coded number of leap seconds */
char tzh_timecnt[4]; /* coded number of transition times */
char tzh_typecnt[4]; /* coded number of local time types */
char tzh_charcnt[4]; /* coded number of abbr. chars */
};
/*
** . . .followed by. . .
**
** tzh_timecnt (char [4])s coded transition times a la time(2)
** tzh_timecnt (unsigned char)s types of local time starting at above
** tzh_typecnt repetitions of
** one (char [4]) coded GMT offset in seconds
** one (unsigned char) used to set tm_isdst
** one (unsigned char) that's an abbreviation list index
** tzh_charcnt (char)s '\0'-terminated zone abbreviations
** tzh_leapcnt repetitions of
** one (char [4]) coded leap second transition times
** one (char [4]) total correction after above
** tzh_ttisstdcnt (char)s indexed by type; if TRUE, transition
** time is standard time, if FALSE,
** transition time is wall clock time
** if absent, transition times are
** assumed to be wall clock time
*/
/*
** In the current implementation, "tzset()" refuses to deal with files that
** exceed any of the limits below.
*/
#ifndef TZ_MAX_TIMES
/*
** The TZ_MAX_TIMES value below is enough to handle a bit more than a
** year's worth of solar time (corrected daily to the nearest second) or
** 138 years of Pacific Presidential Election time
** (where there are three time zone transitions every fourth year).
*/
#define TZ_MAX_TIMES 370
#endif /* !defined TZ_MAX_TIMES */
#ifndef TZ_MAX_TYPES
#ifndef NOSOLAR
#define TZ_MAX_TYPES 256 /* Limited by what (unsigned char)'s can hold */
#endif /* !defined NOSOLAR */
#ifdef NOSOLAR
#define TZ_MAX_TYPES 10 /* Maximum number of local time types */
#endif /* !defined NOSOLAR */
#endif /* !defined TZ_MAX_TYPES */
#ifndef TZ_MAX_CHARS
#define TZ_MAX_CHARS 50 /* Maximum number of abbreviation characters */
/* (limited by what unsigned chars can hold) */
#endif /* !defined TZ_MAX_CHARS */
#ifndef TZ_MAX_LEAPS
#define TZ_MAX_LEAPS 50 /* Maximum number of leap second corrections */
#endif /* !defined TZ_MAX_LEAPS */
#define SECSPERMIN 60
#define MINSPERHOUR 60
#define HOURSPERDAY 24
#define DAYSPERWEEK 7
#define DAYSPERNYEAR 365
#define DAYSPERLYEAR 366
#define SECSPERHOUR (SECSPERMIN * MINSPERHOUR)
#define SECSPERDAY ((long) SECSPERHOUR * HOURSPERDAY)
#define MONSPERYEAR 12
#define TM_SUNDAY 0
#define TM_MONDAY 1
#define TM_TUESDAY 2
#define TM_WEDNESDAY 3
#define TM_THURSDAY 4
#define TM_FRIDAY 5
#define TM_SATURDAY 6
#define TM_JANUARY 0
#define TM_FEBRUARY 1
#define TM_MARCH 2
#define TM_APRIL 3
#define TM_MAY 4
#define TM_JUNE 5
#define TM_JULY 6
#define TM_AUGUST 7
#define TM_SEPTEMBER 8
#define TM_OCTOBER 9
#define TM_NOVEMBER 10
#define TM_DECEMBER 11
#define TM_YEAR_BASE 1900
#define EPOCH_YEAR 1970
#define EPOCH_WDAY TM_THURSDAY
/*
** Accurate only for the past couple of centuries;
** that will probably do.
*/
#define isleap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0)
#ifndef USG
/*
** Use of the underscored variants may cause problems if you move your code to
** certain System-V-based systems; for maximum portability, use the
** underscore-free variants. The underscored variants are provided for
** backward compatibility only; they may disappear from future versions of
** this file.
*/
#define SECS_PER_MIN SECSPERMIN
#define MINS_PER_HOUR MINSPERHOUR
#define HOURS_PER_DAY HOURSPERDAY
#define DAYS_PER_WEEK DAYSPERWEEK
#define DAYS_PER_NYEAR DAYSPERNYEAR
#define DAYS_PER_LYEAR DAYSPERLYEAR
#define SECS_PER_HOUR SECSPERHOUR
#define SECS_PER_DAY SECSPERDAY
#define MONS_PER_YEAR MONSPERYEAR
#endif /* !defined USG */
#endif /* !defined TZFILE_H */