tor-browser

zdump.c (25923B)

---

/*
** This file is in the public domain, so clarified as of
** 2009-05-17 by Arthur David Olson.
*/

#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.
*/

#ifdef time_tz
# include "private.h"
#endif

#include <stdbool.h>

#include "stdio.h"	/* for stdout, stderr, perror */
#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 "limits.h"	/* for CHAR_BIT, LLONG_MAX */
#include "ctype.h"	/* for isalpha et al. */

/* Enable extensions and modifications for ICU. */
#define ICU

#ifdef ICU
#include "tzdir.h"
#include "dirent.h"
#include "sys/stat.h"
#endif

#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 strtoimax strtoll
#  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 strtoimax strtol
#  define PRIdMAX "ld"
#  define INTMAX_MAX LONG_MAX
# endif
#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 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 */

#if 2 < __GNUC__ || (__GNUC__ == 2 && 96 <= __GNUC_MINOR__)
# define ATTRIBUTE_PURE __attribute__ ((__pure__))
#else
# define ATTRIBUTE_PURE /* empty */
#endif

/*
** 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;
extern char *	tzname[2];

/* The minimum and maximum finite time values.  */
static time_t const absolute_min_time =
 ((time_t) -1 < 0
  ? (time_t) -1 << (CHAR_BIT * sizeof (time_t) - 1)
  : 0);
static time_t const 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 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(intmax_t y) ATTRIBUTE_PURE;
#ifdef ICU
typedef struct listentry {
char *		name;
struct listentry *	next;
} listentry;

static time_t	huntICU(char * name, time_t lot, time_t	hit, FILE *fp);
static void	dumptimeICU(FILE * fp, time_t t);
static void	showICU(FILE * fp, char * zone, time_t t1, time_t t2);
static int	getall(struct listentry ** namelist);
static void getzones(char * basedir, char * subdir, struct listentry ** last, int * count);
#endif

#ifndef TYPECHECK
#define my_localtime	localtime
#else /* !defined TYPECHECK */
static struct tm *
my_localtime(time_t *tp)
{
register struct tm *	tmp;

tmp = localtime(tp);
if (tp != NULL && tmp != NULL) {
	struct tm	tm;
	register 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)
{
register const char *	cp;
register 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;
}

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[])
{
register int		i;
register int		vflag;
register int		Vflag;
register char *		cutarg;
register char *		cuttimes;
register time_t		cutlotime;
register time_t		cuthitime;
register char **	fakeenv;
time_t			now;
time_t			t;
time_t			newt;
struct tm		tm;
struct tm		newtm;
register struct tm *	tmp;
register struct tm *	newtmp;
#ifdef ICU
int		nextopt;
char *	dirarg;
int		aflag;
int		iflag;
listentry *	namelist = NULL;
FILE *	fp = stdout;
#endif

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;
#ifdef ICU
aflag = 0;
iflag = 0;
dirarg = NULL;
for (;;)
	switch(getopt(argc, argv, "ac:d:it:vV")) {
	case 'a': aflag = 1; break;
	case 'c': cutarg = optarg; break;
	case 'd': dirarg = optarg; break;
	case 'i': iflag = 1; 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:
		(void) fprintf(stderr,
			_("%s: usage is %s [ --version ] [ -a ] [ -v ] [ -V ] [ -i ] [ -c [loyear,]hiyear ] [ -t [lotime,]hitime] ][ -d dir ] [ zonename ... ]\n"),
			progname, progname);
		exit(EXIT_FAILURE);
	}
#else
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);
  }
#endif
arg_processing_done:;

#ifdef ICU
if (dirarg != NULL) {
	DIR *	dp;
	/* create the output directory */
	mkdir(dirarg, 0777);
	if ((dp = opendir(dirarg)) == NULL) {
		fprintf(stderr, "cannot create the target directory");
		exit(EXIT_FAILURE);
	}
	closedir(dp);
}
#endif

if (vflag | Vflag) {
	intmax_t	lo;
	intmax_t	hi;
	char *loend, *hiend;
	register intmax_t cutloyear = ZDUMP_LO_YEAR;
	register intmax_t cuthiyear = ZDUMP_HI_YEAR;
	if (cutarg != NULL) {
		lo = strtoimax(cutarg, &loend, 10);
		if (cutarg != loend && !*loend) {
			hi = lo;
			cuthiyear = hi;
		} else if (cutarg != loend && *loend == ','
			   && (hi = strtoimax(loend + 1, &hiend, 10),
			       loend + 1 != hiend && !*hiend)) {
			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) {
		lo = strtoimax(cuttimes, &loend, 10);
		if (cuttimes != loend && !*loend) {
			hi = lo;
			if (hi < cuthitime) {
				if (hi < absolute_min_time)
					hi = absolute_min_time;
				cuthitime = hi;
			}
		} else if (cuttimes != loend && *loend == ','
			   && (hi = strtoimax(loend + 1, &hiend, 10),
			       loend + 1 != hiend && !*hiend)) {
			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);
		}
	}
}

#ifdef ICU
if (aflag) {
	/* get all available zones */
	char ** fakeargv;
	int i;
	int count;

	count = getall(&namelist);
	fakeargv = (char **) malloc((size_t) (argc + count) * sizeof *argv);
	/*
	if ((fakeargv = (char **) malloc((size_t) (argc + count) * sizeof *argv)) == NULL) {
		exit(EXIT_FAILURE);
	}
	*/
	for (i = 0; i < argc; i++) {
		fakeargv[i] = argv[i];
	}
	for (i = 0; i < count; i++) {
		fakeargv[i + argc] = namelist->name;
		namelist = namelist->next;
	}
	argv = fakeargv;
	argc += count;
}
#endif
(void) time(&now);
longest = 0;
for (i = optind; i < argc; ++i)
	if (strlen(argv[i]) > longest)
		longest = strlen(argv[i]);
{
	register int	from;
	register 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) {
				(void) perror(progname);
				exit(EXIT_FAILURE);
	}
	to = 0;
	(void) strcpy(fakeenv[to++], "TZ=");
	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]);
	if (! (vflag | Vflag)) {
		show(argv[i], now, false);
		continue;
	}
#ifdef ICU
	fp = NULL;
	if (iflag) {
		if (dirarg == NULL) {
			/* we want to display a zone name here */
			if (i != optind) {
				printf("\n");
			}
			printf("ZONE: %s\n", argv[i]);
		} else {
			int		zstart;
			char	path[FILENAME_MAX + 1];
			strcpy(path, dirarg);
			strcat(path, "/");
			zstart = strlen(path);
			strcat(path, argv[i]);
			/* replace '/' with '-' */
			while(path[++zstart] != 0) {
				if (path[zstart] == '/') {
					path[zstart] = '-';
				}
			}
			if ((fp = fopen(path, "w")) == NULL) {
				fprintf(stderr, "cannot create output file %s\n", path);
				exit(EXIT_FAILURE);
			}
		}
	}
#endif
	warned = false;
	t = absolute_min_time;
#ifdef ICU
	/* skip displaying info for the lowest time, which is actually not
	 * a transition when -i option is set */
	if (!iflag) {
#endif
	if (!Vflag) {
		show(argv[i], t, true);
		t += SECSPERDAY;
		show(argv[i], t, true);
	}
#ifdef ICU
	}
#endif
	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;
#ifdef ICU
		if (iflag) {
			/* We  do not want to capture transitions just for
			 * abbreviated zone name changes */
			if ((tmp == NULL || newtmp == NULL) ? (tmp != newtmp) :
				(delta(&newtm, &tm) != (newt - t) ||
				newtm.tm_isdst != tm.tm_isdst)) {
					newt = huntICU(argv[i], t, newt, fp);
					newtmp = localtime(&newt);
					if (newtmp != NULL) {
						newtm = *newtmp;
						(void) strncpy(buf,
							abbr(&newtm),
							(sizeof buf) - 1);
					}
			}
		} else {
#endif
		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);
				}
		}
#ifdef ICU
		}
#endif
		t = newt;
		tm = newtm;
		tmp = newtmp;
	}
#ifdef ICU
	if (!iflag) {
	/* skip displaying info for the highest time, which is actually not
	 * a transition when -i option is used*/
#endif
	if (!Vflag) {
		t = absolute_max_time;
		t -= SECSPERDAY;
		show(argv[i], t, true);
		t += SECSPERDAY;
		show(argv[i], t, true);
	}
#ifdef ICU
	}
	/* close file */
	if (fp != NULL) {
		fclose(fp);
	}
#endif
}
if (fflush(stdout) || ferror(stdout)) {
	(void) fprintf(stderr, "%s: ", progname);
	(void) perror(_("Error writing to standard output"));
	exit(EXIT_FAILURE);
}
#ifdef ICU
if (aflag) {
	struct listentry *	entry = namelist;
	struct listentry *	next;
	while (entry != NULL) {
		free(entry->name);
		next = entry->next;
		free(entry);
		entry = next;
	}
}
#endif
exit(EXIT_SUCCESS);
/* If exit fails to exit... */
return EXIT_FAILURE;
}

static time_t
yeartot(const intmax_t y)
{
register intmax_t	myy, seconds, years;
register 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;
register struct tm *	lotmp;
struct tm		tm;
register 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)
{
register intmax_t	result;
register 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)
{
register 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 char *
abbr(struct tm *tmp)
{
register char *	result;
static 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(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"
};
register const char *	wn;
register const char *	mn;
register int		lead;
register 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));
}

#ifdef ICU
static time_t
huntICU(char *name, time_t lot, time_t hit, FILE * fp)
{
time_t			t;
long			diff;
struct tm		lotm;
register struct tm *	lotmp;
struct tm		tm;
register 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 ( ; ; ) {
	diff = (long) (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;
	/* We  do not want to capture transitions just for
	 * abbreviated zone name changes */
	if ((lotmp == NULL || tmp == NULL) ? (lotmp == tmp) :
		(delta(&tm, &lotm) == (t - lot) &&
		tm.tm_isdst == lotm.tm_isdst)) {
			lot = t;
			lotm = tm;
			lotmp = tmp;
	} else	hit = t;
}
showICU(fp, name, lot, hit);
return hit;
}

static void showICU(FILE * fp, char *zone, time_t t1, time_t t2)
{
if (fp == NULL) {
	fp = stdout;
}
dumptimeICU(fp, t1);
fprintf(fp, " > ");
dumptimeICU(fp, t2);
fprintf(fp, "\n");
}

static void dumptimeICU(FILE * fp, time_t t)
{
static const char	wday_name[][3] = {
	"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
};
struct tm gmt;
struct tm loc;
register int		lead;
register int		trail;
long	offset;
long	hour, min, sec;

loc = *my_localtime(&t);

trail = loc.tm_year % DIVISOR + TM_YEAR_BASE % DIVISOR;
lead = loc.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;
}

fprintf(fp, "%04d-%02d-%02d", lead * DIVISOR + trail, loc.tm_mon + 1, loc.tm_mday);
fprintf(fp, " %.3s ", wday_name[loc.tm_wday]);
fprintf(fp, "%02d:%02d:%02d", loc.tm_hour, loc.tm_min, loc.tm_sec);

gmt = *gmtime(&t);
offset = delta(&loc, &gmt);
if (offset < 0) {
	offset = -offset;
	fprintf(fp, "-");
} else {
	fprintf(fp, "+");
}

sec = offset % 60;
offset = (offset - sec) / 60;
min = offset % 60;
hour = offset / 60;

fprintf(fp, "%02ld", hour);
fprintf(fp, "%02ld", min);
fprintf(fp, "%02ld", sec);
fprintf(fp, "[DST=%d]", loc.tm_isdst);
}

static int getall(struct listentry ** namelist) {
int count = 0;
struct listentry dummyentry;
struct listentry *	last = &dummyentry;

getzones(TZDIR, NULL, &last, &count);
if (count > 0) {
	*namelist = dummyentry.next;
}

return count;
}

static void getzones(char * basedir, char * relpath, struct listentry ** last, int * count) {
char	path[FILENAME_MAX + 1];
struct	dirent *	dir;
DIR *	dp;

strcpy(path, basedir);
if (relpath != NULL) {
	strcat(path, "/");
	strcat(path, relpath);
}

if ((dp = opendir(path)) == NULL) {
	/* file */
	if (strstr(relpath, ".tab") == NULL && strcmp(relpath, "Etc/Unknown") != 0) {
		char *		pzonename;
		listentry *	pentry;

		if ((pzonename = malloc(strlen(relpath) + 1)) == NULL) {
			exit(EXIT_FAILURE);
		}
		strcpy(pzonename, relpath);
	
		if ((pentry = malloc(sizeof(listentry))) == NULL) {
			exit(EXIT_FAILURE);
		}

		pentry->name = pzonename;
		pentry->next = NULL;
		(*last)->next = pentry;
		*last = pentry;
		(*count)++;
	}
} else {
	/* directory */
	while ((dir = readdir(dp)) != NULL) {
		char	subpath[FILENAME_MAX + 1];

		if (strcmp(dir->d_name, ".") == 0
			|| strcmp(dir->d_name, "..") == 0) {
			continue;
		}
		if (relpath != NULL) {
			strcpy(subpath, relpath);
			strcat(subpath, "/");
			strcat(subpath, dir->d_name);
		} else {
			strcpy(subpath, dir->d_name);
		}
		getzones(basedir, subpath, last, count);
	}
	closedir(dp);
}
}
#endif