NetBSD/lib/libc/time/zdump.c
christos 33d9f9e08d Welcome to tzcode 2013e:
Changes affecting API

    The 'zic' command now outputs a dummy transition when far-future
    data can't be summarized using a TZ string, and uses a 402-year
    window rather than a 400-year window.  For the current data, this
    affects only the Asia/Tehran file.  It does not affect any of the
    time stamps that this file represents, so zdump outputs the same
    information as before.  (Thanks to Andrew Main (Zefram).)

    The 'date' command has a new '-r' option, which lets you specify
    the integer time to display, a la FreeBSD.

    The 'tzselect' command has two new options '-c' and '-n', which lets you
    select a zone based on latitude and longitude.

    The 'zic' command's '-v' option now warns about constructs that
    require the new version-3 binary file format.  (Thanks to Arthur
    David Olson for the suggestion.)

    Support for floating-point time_t has been removed.
    It was always dicey, and POSIX no longer requires it.
    (Thanks to Eric Blake for suggesting to the POSIX committee to
    remove it, and thanks to Alan Barrett, Clive D.W. Feather, Andy
    Heninger, Arthur David Olson, and Alois Treindl, for reporting
    bugs and elucidating some of the corners of the old floating-point
    implementation.)

    The signatures of 'offtime', 'timeoff', and 'gtime' have been
    changed back to the old practice of using 'long' to represent UT
    offsets.  This had been inadvertently and mistakenly changed to
    'int_fast32_t'.  (Thanks to Christos Zoulos.)

    The code avoids undefined behavior on integer overflow in some
    more places, including gmtime, localtime, mktime and zdump.

  Changes affecting the zdump utility

    zdump now outputs "UT" when referring to Universal Time, not "UTC".
    "UTC" does not make sense for time stamps that predate the introduction
    of UTC, whereas "UT", a more-generic term, does.  (Thanks to Steve Allen
    for clarifying UT vs UTC.)

  Data changes affecting behavior of tzselect and similar programs

    Country code BQ is now called the more-common name "Caribbean Netherlands"
    rather than the more-official "Bonaire, St Eustatius & Saba".

    Remove from zone.tab the names America/Montreal, America/Shiprock,
    and Antarctica/South_Pole, as they are equivalent to existing
    same-country-code zones for post-1970 time stamps.  The data for
    these names are unchanged, so the names continue to work as before.

  Changes affecting code internals

    zic -c now runs way faster on 64-bit hosts when given large numbers.

    zic now uses vfprintf to avoid allocating and freeing some memory.

    tzselect now computes the list of continents from the data,
    rather than have it hard-coded.

    Minor changes pacify GCC 4.7.3 and GCC 4.8.1.

  Changes affecting the build procedure

    The 'leapseconds' file is now generated automatically from a
    new file 'leap-seconds.list', which is a copy of
    <ftp://time.nist.gov/pub/leap-seconds.list>.
    A new source file 'leapseconds.awk' implements this.
    The goal is simplification of the future maintenance of 'leapseconds'.

    When building the 'posix' or 'right' subdirectories, if the
    subdirectory would be a copy of the default subdirectory, it is
    now made a symbolic link if that is supported.  This saves about
    2 MB of file system space.

    The links America/Shiprock and Antarctica/South_Pole have been
    moved to the 'backward' file.  This affects only nondefault builds
    that omit 'backward'.

  Changes affecting documentation and commentary

    Changes to the 'tzfile' man page

      It now mentions that the binary file format may be extended in
      future versions by appending data.

      It now refers to the 'zdump' and 'zic' man pages.

    Changes to the 'zic' man page

      It lists conditions that elicit a warning with '-v'.

      It says that the behavior is unspecified when duplicate names
      are given, or if the source of one link is the target of another.

      Its examples are updated to match the latest data.

      The definition of white space has been clarified slightly.
      (Thanks to Michael Deckers.)

    Changes to the 'Theory' file

      There is a new section about the accuracy of the tz database,
      describing the many ways that errors can creep in, and
      explaining why so many of the pre-1970 time stamps are wrong or
      misleading (thanks to Steve Allen, Lester Caine, and Garrett
      Wollman for discussions that contributed to this).

      The 'Theory' file describes LMT better (this follows a
      suggestion by Guy Harris).

      It refers to the 2013 edition of POSIX rather than the 2004 edition.

      It's mentioned that excluding 'backward' should not affect the
      other data, and it suggests at least one zone.tab name per
      inhabited country (thanks to Stephen Colebourne).

      Some longstanding restrictions on names are documented, e.g.,
      'America/New_York' precludes 'America/New_York/Bronx'.

      It gives more reasons for the 1970 cutoff.

      It now mentions which time_t variants are supported, such as
      signed integer time_t.  (Thanks to Paul Goyette for reporting
      typos in an experimental version of this change.)

      (Thanks to Philip Newton for correcting typos in these changes.)

    Documentation and commentary is more careful to distinguish UT in
    general from UTC in particular.  (Thanks to Steve Allen.)

    Add a better source for the Zurich 1894 transition.
    (Thanks to Pierre-Yves Berger.)

    Update shapefile citations in tz-link.htm.  (Thanks to Guy Harris.)
2013-09-20 19:06:54 +00:00

754 lines
18 KiB
C

/* $NetBSD: zdump.c,v 1.31 2013/09/20 19:06:54 christos Exp $ */
/*
** This file is in the public domain, so clarified as of
** 2009-05-17 by Arthur David Olson.
*/
#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: zdump.c,v 1.31 2013/09/20 19:06:54 christos Exp $");
#endif /* !defined lint */
#include "version.h"
/*
** This code has been made independent of the rest of the time
** conversion package to increase confidence in the verification it provides.
** You can use this code to help in verifying other implementations.
**
** However, include private.h when debugging, so that it overrides
** time_t consistently with the rest of the package.
*/
#include "private.h"
#include "stdio.h" /* for stdout, stderr */
#include "string.h" /* for strcpy */
#include "sys/types.h" /* for time_t */
#include "time.h" /* for struct tm */
#include "stdlib.h" /* for exit, malloc, atoi */
#include <err.h>
#include "ctype.h" /* for isalpha et al. */
#ifndef isascii
#define isascii(x) 1
#endif /* !defined isascii */
/*
** Substitutes for pre-C99 compilers.
** Much of this section of code is stolen from private.h.
*/
#ifndef HAVE_STDINT_H
# define HAVE_STDINT_H \
(199901 <= __STDC_VERSION__ || 2 < (__GLIBC__ + (0 < __GLIBC_MINOR__)))
#endif
#if HAVE_STDINT_H
# include "stdint.h"
#endif
#ifndef HAVE_INTTYPES_H
# define HAVE_INTTYPES_H HAVE_STDINT_H
#endif
#if HAVE_INTTYPES_H
# include <inttypes.h>
#endif
#ifndef INT_FAST32_MAX
# if INT_MAX >> 31 == 0
typedef long int_fast32_t;
# else
typedef int int_fast32_t;
# endif
#endif
#ifndef INTMAX_MAX
# if defined LLONG_MAX || defined __LONG_LONG_MAX__
typedef long long intmax_t;
# define PRIdMAX "lld"
# ifdef LLONG_MAX
# define INTMAX_MAX LLONG_MAX
# else
# define INTMAX_MAX __LONG_LONG_MAX__
# endif
# else
typedef long intmax_t;
# define PRIdMAX "ld"
# define INTMAX_MAX LONG_MAX
# endif
#endif
#ifndef SCNdMAX
# define SCNdMAX PRIdMAX
#endif
#ifndef ZDUMP_LO_YEAR
#define ZDUMP_LO_YEAR (-500)
#endif /* !defined ZDUMP_LO_YEAR */
#ifndef ZDUMP_HI_YEAR
#define ZDUMP_HI_YEAR 2500
#endif /* !defined ZDUMP_HI_YEAR */
#ifndef MAX_STRING_LENGTH
#define MAX_STRING_LENGTH 1024
#endif /* !defined MAX_STRING_LENGTH */
#ifndef TRUE
#define TRUE 1
#endif /* !defined TRUE */
#ifndef FALSE
#define FALSE 0
#endif /* !defined FALSE */
#ifndef EXIT_SUCCESS
#define EXIT_SUCCESS 0
#endif /* !defined EXIT_SUCCESS */
#ifndef EXIT_FAILURE
#define EXIT_FAILURE 1
#endif /* !defined EXIT_FAILURE */
#ifndef SECSPERMIN
#define SECSPERMIN 60
#endif /* !defined SECSPERMIN */
#ifndef MINSPERHOUR
#define MINSPERHOUR 60
#endif /* !defined MINSPERHOUR */
#ifndef SECSPERHOUR
#define SECSPERHOUR (SECSPERMIN * MINSPERHOUR)
#endif /* !defined SECSPERHOUR */
#ifndef HOURSPERDAY
#define HOURSPERDAY 24
#endif /* !defined HOURSPERDAY */
#ifndef EPOCH_YEAR
#define EPOCH_YEAR 1970
#endif /* !defined EPOCH_YEAR */
#ifndef TM_YEAR_BASE
#define TM_YEAR_BASE 1900
#endif /* !defined TM_YEAR_BASE */
#ifndef DAYSPERNYEAR
#define DAYSPERNYEAR 365
#endif /* !defined DAYSPERNYEAR */
#ifndef isleap
#define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0))
#endif /* !defined isleap */
#ifndef isleap_sum
/*
** See tzfile.h for details on isleap_sum.
*/
#define isleap_sum(a, b) isleap((a) % 400 + (b) % 400)
#endif /* !defined isleap_sum */
#define SECSPERDAY ((int_fast32_t) SECSPERHOUR * HOURSPERDAY)
#define SECSPERNYEAR (SECSPERDAY * DAYSPERNYEAR)
#define SECSPERLYEAR (SECSPERNYEAR + SECSPERDAY)
#define SECSPER400YEARS (SECSPERNYEAR * (intmax_t) (300 + 3) \
+ SECSPERLYEAR * (intmax_t) (100 - 3))
/*
** True if SECSPER400YEARS is known to be representable as an
** intmax_t. It's OK that SECSPER400YEARS_FITS can in theory be false
** even if SECSPER400YEARS is representable, because when that happens
** the code merely runs a bit more slowly, and this slowness doesn't
** occur on any practical platform.
*/
enum { SECSPER400YEARS_FITS = SECSPERLYEAR <= INTMAX_MAX / 400 };
#ifndef HAVE_GETTEXT
#define HAVE_GETTEXT 0
#endif
#if HAVE_GETTEXT
#include "locale.h" /* for setlocale */
#include "libintl.h"
#endif /* HAVE_GETTEXT */
#ifndef GNUC_or_lint
#ifdef lint
#define GNUC_or_lint
#else /* !defined lint */
#ifdef __GNUC__
#define GNUC_or_lint
#endif /* defined __GNUC__ */
#endif /* !defined lint */
#endif /* !defined GNUC_or_lint */
#ifndef ATTRIBUTE_PURE
#if 2 < __GNUC__ || (__GNUC__ == 2 && 96 <= __GNUC_MINOR__)
# define ATTRIBUTE_PURE __attribute__ ((ATTRIBUTE_PURE__))
#else
# define ATTRIBUTE_PURE /* empty */
#endif
#endif
#ifndef INITIALIZE
#ifdef GNUC_or_lint
#define INITIALIZE(x) ((x) = 0)
#else /* !defined GNUC_or_lint */
#define INITIALIZE(x)
#endif /* !defined GNUC_or_lint */
#endif /* !defined INITIALIZE */
/*
** For the benefit of GNU folk...
** `_(MSGID)' uses the current locale's message library string for MSGID.
** The default is to use gettext if available, and use MSGID otherwise.
*/
#ifndef _
#if HAVE_GETTEXT
#define _(msgid) gettext(msgid)
#else /* !HAVE_GETTEXT */
#define _(msgid) msgid
#endif /* !HAVE_GETTEXT */
#endif /* !defined _ */
#ifndef TZ_DOMAIN
#define TZ_DOMAIN "tz"
#endif /* !defined TZ_DOMAIN */
extern char ** environ;
extern int getopt(int argc, char * const argv[],
const char * options);
extern char * optarg;
extern int optind;
/* The minimum and maximum finite time values. */
static time_t absolute_min_time =
((time_t) -1 < 0
? (time_t) -1 << (CHAR_BIT * sizeof (time_t) - 1)
: 0);
static time_t absolute_max_time =
((time_t) -1 < 0
? - (~ 0 < 0) - ((time_t) -1 << (CHAR_BIT * sizeof (time_t) - 1))
: -1);
static size_t longest;
static char * progname;
static int warned;
static const char * abbr(struct tm * tmp);
static void abbrok(const char * abbrp, const char * zone);
static intmax_t delta(struct tm * newp, struct tm * oldp) ATTRIBUTE_PURE;
static void dumptime(const struct tm * tmp);
static time_t hunt(char * name, time_t lot, time_t hit);
static void show(char * zone, time_t t, int v);
static const char * tformat(void);
static time_t yeartot(long y) ATTRIBUTE_PURE;
#ifndef TYPECHECK
#define my_localtime localtime
#else /* !defined TYPECHECK */
static struct tm *
my_localtime(time_t *tp)
{
struct tm *tmp;
tmp = localtime(tp);
if (tp != NULL && tmp != NULL) {
struct tm tm;
time_t t;
tm = *tmp;
t = mktime(&tm);
if (t != *tp) {
(void) fflush(stdout);
(void) fprintf(stderr, "\n%s: ", progname);
(void) fprintf(stderr, tformat(), *tp);
(void) fprintf(stderr, " ->");
(void) fprintf(stderr, " year=%d", tmp->tm_year);
(void) fprintf(stderr, " mon=%d", tmp->tm_mon);
(void) fprintf(stderr, " mday=%d", tmp->tm_mday);
(void) fprintf(stderr, " hour=%d", tmp->tm_hour);
(void) fprintf(stderr, " min=%d", tmp->tm_min);
(void) fprintf(stderr, " sec=%d", tmp->tm_sec);
(void) fprintf(stderr, " isdst=%d", tmp->tm_isdst);
(void) fprintf(stderr, " -> ");
(void) fprintf(stderr, tformat(), t);
(void) fprintf(stderr, "\n");
}
}
return tmp;
}
#endif /* !defined TYPECHECK */
static void
abbrok(const char *const abbrp, const char *const zone)
{
const char *cp;
const char *wp;
if (warned)
return;
cp = abbrp;
wp = NULL;
while (isascii((unsigned char) *cp) && isalpha((unsigned char) *cp))
++cp;
if (cp - abbrp == 0)
wp = _("lacks alphabetic at start");
else if (cp - abbrp < 3)
wp = _("has fewer than 3 alphabetics");
else if (cp - abbrp > 6)
wp = _("has more than 6 alphabetics");
if (wp == NULL && (*cp == '+' || *cp == '-')) {
++cp;
if (isascii((unsigned char) *cp) &&
isdigit((unsigned char) *cp))
if (*cp++ == '1' && *cp >= '0' && *cp <= '4')
++cp;
if (*cp != '\0')
wp = _("differs from POSIX standard");
}
if (wp == NULL)
return;
(void) fflush(stdout);
(void) fprintf(stderr,
_("%s: warning: zone \"%s\" abbreviation \"%s\" %s\n"),
progname, zone, abbrp, wp);
warned = TRUE;
}
__dead static void
usage(FILE *const stream, const int status)
{
(void) fprintf(stream,
_("%s: usage: %s [--version] [--help] [-{vV}] [-{ct} [lo,]hi] zonename ...\n"
"\n"
"Report bugs to %s.\n"),
progname, progname, REPORT_BUGS_TO);
exit(status);
}
int
main(int argc, char *argv[])
{
int i;
int vflag;
int Vflag;
char * cutarg;
char * cuttimes;
time_t cutlotime;
time_t cuthitime;
char ** fakeenv;
time_t now;
time_t t;
time_t newt;
struct tm tm;
struct tm newtm;
struct tm * tmp;
struct tm * newtmp;
cutlotime = absolute_min_time;
cuthitime = absolute_max_time;
#if HAVE_GETTEXT
(void) setlocale(LC_ALL, "");
#ifdef TZ_DOMAINDIR
(void) bindtextdomain(TZ_DOMAIN, TZ_DOMAINDIR);
#endif /* defined TEXTDOMAINDIR */
(void) textdomain(TZ_DOMAIN);
#endif /* HAVE_GETTEXT */
progname = argv[0];
for (i = 1; i < argc; ++i)
if (strcmp(argv[i], "--version") == 0) {
(void) printf("zdump %s%s\n", PKGVERSION, TZVERSION);
exit(EXIT_SUCCESS);
} else if (strcmp(argv[i], "--help") == 0) {
usage(stdout, EXIT_SUCCESS);
}
vflag = Vflag = 0;
cutarg = cuttimes = NULL;
for (;;)
switch (getopt(argc, argv, "c:t:vV")) {
case 'c': cutarg = optarg; break;
case 't': cuttimes = optarg; break;
case 'v': vflag = 1; break;
case 'V': Vflag = 1; break;
case -1:
if (! (optind == argc - 1 && strcmp(argv[optind], "=") == 0))
goto arg_processing_done;
/* Fall through. */
default:
usage(stderr, EXIT_FAILURE);
}
arg_processing_done:;
if (vflag | Vflag) {
intmax_t lo;
intmax_t hi;
char dummy;
intmax_t cutloyear = ZDUMP_LO_YEAR;
intmax_t cuthiyear = ZDUMP_HI_YEAR;
if (cutarg != NULL) {
if (sscanf(cutarg, "%"SCNdMAX"%c", &hi, &dummy) == 1) {
cuthiyear = hi;
} else if (sscanf(cutarg, "%"SCNdMAX",%"SCNdMAX"%c",
&lo, &hi, &dummy) == 2) {
cutloyear = lo;
cuthiyear = hi;
} else {
(void) fprintf(stderr, _("%s: wild -c argument %s\n"),
progname, cutarg);
exit(EXIT_FAILURE);
}
}
if (cutarg != NULL || cuttimes == NULL) {
cutlotime = yeartot(cutloyear);
cuthitime = yeartot(cuthiyear);
}
if (cuttimes != NULL) {
if (sscanf(cuttimes, "%"SCNdMAX"%c", &hi, &dummy) == 1) {
if (hi < cuthitime) {
if (hi < absolute_min_time)
hi = absolute_min_time;
cuthitime = hi;
}
} else if (sscanf(cuttimes, "%"SCNdMAX",%"SCNdMAX"%c",
&lo, &hi, &dummy) == 2) {
if (cutlotime < lo) {
if (absolute_max_time < lo)
lo = absolute_max_time;
cutlotime = lo;
}
if (hi < cuthitime) {
if (hi < absolute_min_time)
hi = absolute_min_time;
cuthitime = hi;
}
} else {
(void) fprintf(stderr,
_("%s: wild -t argument %s\n"),
progname, cuttimes);
exit(EXIT_FAILURE);
}
}
}
(void) time(&now);
longest = 0;
for (i = optind; i < argc; ++i)
if (strlen(argv[i]) > longest)
longest = strlen(argv[i]);
{
int from;
int to;
for (i = 0; environ[i] != NULL; ++i)
continue;
fakeenv = malloc((i + 2) * sizeof *fakeenv);
if (fakeenv == NULL ||
(fakeenv[0] = malloc(longest + 4)) == NULL) {
err(EXIT_FAILURE, "Can't allocated %zu bytes",
longest + 4);
}
to = 0;
(void)strcpy(fakeenv[to++], "TZ="); /* XXX strcpy is safe */
for (from = 0; environ[from] != NULL; ++from)
if (strncmp(environ[from], "TZ=", 3) != 0)
fakeenv[to++] = environ[from];
fakeenv[to] = NULL;
environ = fakeenv;
}
for (i = optind; i < argc; ++i) {
static char buf[MAX_STRING_LENGTH];
(void) strcpy(&fakeenv[0][3], argv[i]); /* XXX strcpy is safe */
if (! (vflag | Vflag)) {
show(argv[i], now, FALSE);
continue;
}
warned = FALSE;
t = absolute_min_time;
if (!Vflag) {
show(argv[i], t, TRUE);
t += SECSPERDAY;
show(argv[i], t, TRUE);
}
if (t < cutlotime)
t = cutlotime;
tmp = my_localtime(&t);
if (tmp != NULL) {
tm = *tmp;
(void) strncpy(buf, abbr(&tm), (sizeof buf) - 1);
}
for ( ; ; ) {
newt = (t < absolute_max_time - SECSPERDAY / 2
? t + SECSPERDAY / 2
: absolute_max_time);
if (cuthitime <= newt)
break;
newtmp = localtime(&newt);
if (newtmp != NULL)
newtm = *newtmp;
if ((tmp == NULL || newtmp == NULL) ? (tmp != newtmp) :
(delta(&newtm, &tm) != (newt - t) ||
newtm.tm_isdst != tm.tm_isdst ||
strcmp(abbr(&newtm), buf) != 0)) {
newt = hunt(argv[i], t, newt);
newtmp = localtime(&newt);
if (newtmp != NULL) {
newtm = *newtmp;
(void) strncpy(buf,
abbr(&newtm),
(sizeof buf) - 1);
}
}
t = newt;
tm = newtm;
tmp = newtmp;
}
if (!Vflag) {
t = absolute_max_time;
t -= SECSPERDAY;
show(argv[i], t, TRUE);
t += SECSPERDAY;
show(argv[i], t, TRUE);
}
}
if (fflush(stdout) || ferror(stdout)) {
err(EXIT_FAILURE, _("Error writing standard output"));
}
exit(EXIT_SUCCESS);
/* If exit fails to exit... */
return EXIT_FAILURE;
}
static time_t
yeartot(const long y)
{
intmax_t myy, seconds, years;
time_t t;
myy = EPOCH_YEAR;
t = 0;
while (myy < y) {
if (SECSPER400YEARS_FITS && 400 <= y - myy) {
intmax_t diff400 = (y - myy) / 400;
if (INTMAX_MAX / SECSPER400YEARS < diff400)
return absolute_max_time;
seconds = diff400 * SECSPER400YEARS;
years = diff400 * 400;
} else {
seconds = isleap(myy) ? SECSPERLYEAR : SECSPERNYEAR;
years = 1;
}
myy += years;
if (t > absolute_max_time - seconds)
return absolute_max_time;
t += seconds;
}
while (y < myy) {
if (SECSPER400YEARS_FITS && y + 400 <= myy && myy < 0) {
intmax_t diff400 = (myy - y) / 400;
if (INTMAX_MAX / SECSPER400YEARS < diff400)
return absolute_min_time;
seconds = diff400 * SECSPER400YEARS;
years = diff400 * 400;
} else {
seconds = isleap(myy - 1) ? SECSPERLYEAR : SECSPERNYEAR;
years = 1;
}
myy -= years;
if (t < absolute_min_time + seconds)
return absolute_min_time;
t -= seconds;
}
return t;
}
static time_t
hunt(char *name, time_t lot, time_t hit)
{
time_t t;
struct tm lotm;
struct tm * lotmp;
struct tm tm;
struct tm * tmp;
char loab[MAX_STRING_LENGTH];
lotmp = my_localtime(&lot);
if (lotmp != NULL) {
lotm = *lotmp;
(void) strncpy(loab, abbr(&lotm), (sizeof loab) - 1);
}
for ( ; ; ) {
time_t diff = hit - lot;
if (diff < 2)
break;
t = lot;
t += diff / 2;
if (t <= lot)
++t;
else if (t >= hit)
--t;
tmp = my_localtime(&t);
if (tmp != NULL)
tm = *tmp;
if ((lotmp == NULL || tmp == NULL) ? (lotmp == tmp) :
(delta(&tm, &lotm) == (t - lot) &&
tm.tm_isdst == lotm.tm_isdst &&
strcmp(abbr(&tm), loab) == 0)) {
lot = t;
lotm = tm;
lotmp = tmp;
} else hit = t;
}
show(name, lot, TRUE);
show(name, hit, TRUE);
return hit;
}
/*
** Thanks to Paul Eggert for logic used in delta.
*/
static intmax_t
delta(struct tm *newp, struct tm *oldp)
{
intmax_t result;
int tmy;
if (newp->tm_year < oldp->tm_year)
return -delta(oldp, newp);
result = 0;
for (tmy = oldp->tm_year; tmy < newp->tm_year; ++tmy)
result += DAYSPERNYEAR + isleap_sum(tmy, TM_YEAR_BASE);
result += newp->tm_yday - oldp->tm_yday;
result *= HOURSPERDAY;
result += newp->tm_hour - oldp->tm_hour;
result *= MINSPERHOUR;
result += newp->tm_min - oldp->tm_min;
result *= SECSPERMIN;
result += newp->tm_sec - oldp->tm_sec;
return result;
}
static void
show(char *zone, time_t t, int v)
{
struct tm * tmp;
(void) printf("%-*s ", (int) longest, zone);
if (v) {
tmp = gmtime(&t);
if (tmp == NULL) {
(void) printf(tformat(), t);
} else {
dumptime(tmp);
(void) printf(" UT");
}
(void) printf(" = ");
}
tmp = my_localtime(&t);
dumptime(tmp);
if (tmp != NULL) {
if (*abbr(tmp) != '\0')
(void) printf(" %s", abbr(tmp));
if (v) {
(void) printf(" isdst=%d", tmp->tm_isdst);
#ifdef TM_GMTOFF
(void) printf(" gmtoff=%ld", tmp->TM_GMTOFF);
#endif /* defined TM_GMTOFF */
}
}
(void) printf("\n");
if (tmp != NULL && *abbr(tmp) != '\0')
abbrok(abbr(tmp), zone);
}
static const char *
abbr(struct tm *tmp)
{
const char * result;
static const char nada;
if (tmp->tm_isdst != 0 && tmp->tm_isdst != 1)
return &nada;
result = tzname[tmp->tm_isdst];
return (result == NULL) ? &nada : result;
}
/*
** The code below can fail on certain theoretical systems;
** it works on all known real-world systems as of 2004-12-30.
*/
static const char *
tformat(void)
{
if (0 > (time_t) -1) { /* signed */
if (sizeof (time_t) == sizeof (intmax_t))
return "%"PRIdMAX;
if (sizeof (time_t) > sizeof (long))
return "%lld";
if (sizeof (time_t) > sizeof (int))
return "%ld";
return "%d";
}
#ifdef PRIuMAX
if (sizeof (time_t) == sizeof (uintmax_t))
return "%"PRIuMAX;
#endif
if (sizeof (time_t) > sizeof (unsigned long))
return "%llu";
if (sizeof (time_t) > sizeof (unsigned int))
return "%lu";
return "%u";
}
static void
dumptime(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"
};
const char * wn;
const char * mn;
int lead;
int trail;
if (timeptr == NULL) {
(void) printf("NULL");
return;
}
/*
** The packaged versions of localtime and gmtime never put out-of-range
** values in tm_wday or tm_mon, but since this code might be compiled
** with other (perhaps experimental) versions, paranoia is in order.
*/
if (timeptr->tm_wday < 0 || timeptr->tm_wday >=
(int) (sizeof wday_name / sizeof wday_name[0]))
wn = "???";
else wn = wday_name[timeptr->tm_wday];
if (timeptr->tm_mon < 0 || timeptr->tm_mon >=
(int) (sizeof mon_name / sizeof mon_name[0]))
mn = "???";
else mn = mon_name[timeptr->tm_mon];
(void) printf("%.3s %.3s%3d %.2d:%.2d:%.2d ",
wn, mn,
timeptr->tm_mday, timeptr->tm_hour,
timeptr->tm_min, timeptr->tm_sec);
#define DIVISOR 10
trail = timeptr->tm_year % DIVISOR + TM_YEAR_BASE % DIVISOR;
lead = timeptr->tm_year / DIVISOR + TM_YEAR_BASE / DIVISOR +
trail / DIVISOR;
trail %= DIVISOR;
if (trail < 0 && lead > 0) {
trail += DIVISOR;
--lead;
} else if (lead < 0 && trail > 0) {
trail -= DIVISOR;
++lead;
}
if (lead == 0)
(void) printf("%d", trail);
else (void) printf("%d%d", lead, ((trail < 0) ? -trail : trail));
}