/* $NetBSD: zdump.c,v 1.60.2.1 2023/07/24 17:15:59 martin Exp $ */ /* Dump time zone data in a textual format. */ /* ** This file is in the public domain, so clarified as of ** 2009-05-17 by Arthur David Olson. */ #include #ifndef lint __RCSID("$NetBSD: zdump.c,v 1.60.2.1 2023/07/24 17:15:59 martin Exp $"); #endif /* !defined lint */ #ifndef NETBSD_INSPIRED # define NETBSD_INSPIRED 1 #endif #include #include "private.h" #include #ifndef HAVE_SNPRINTF # define HAVE_SNPRINTF (199901 <= __STDC_VERSION__) #endif #ifndef HAVE_LOCALTIME_R # define HAVE_LOCALTIME_R 1 #endif #ifndef HAVE_LOCALTIME_RZ # ifdef TM_ZONE # define HAVE_LOCALTIME_RZ (NETBSD_INSPIRED && USE_LTZ) # else # define HAVE_LOCALTIME_RZ 0 # endif #endif #ifndef HAVE_TZSET # define HAVE_TZSET 1 #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 */ #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 }; #if HAVE_GETTEXT # include /* for setlocale */ #endif /* HAVE_GETTEXT */ #if ! HAVE_LOCALTIME_RZ # undef timezone_t # define timezone_t char ** #endif #if !HAVE_POSIX_DECLS extern int getopt(int argc, char * const argv[], const char * options); extern char * optarg; extern int optind; #endif /* The minimum and maximum finite time values. */ enum { atime_shift = CHAR_BIT * sizeof(time_t) - 2 }; static time_t absolute_min_time = ((time_t) -1 < 0 ? (- ((time_t) ~ (time_t) 0 < 0) - (((time_t) 1 << atime_shift) - 1 + ((time_t) 1 << atime_shift))) : 0); static time_t absolute_max_time = ((time_t) -1 < 0 ? (((time_t) 1 << atime_shift) - 1 + ((time_t) 1 << atime_shift)) : -1); static size_t longest; static char const *progname; static bool warned; static bool errout; static char const *abbr(struct tm const *); ATTRIBUTE_REPRODUCIBLE static intmax_t delta(struct tm *, struct tm *); static void dumptime(struct tm const *); static time_t hunt(timezone_t, time_t, time_t, bool); static void show(timezone_t, char *, time_t, bool); static void showextrema(timezone_t, char *, time_t, struct tm *, time_t); static void showtrans(char const *, struct tm const *, time_t, char const *, char const *); static const char *tformat(void); ATTRIBUTE_REPRODUCIBLE static time_t yeartot(intmax_t); /* Is C an ASCII digit? */ static bool is_digit(char c) { return '0' <= c && c <= '9'; } /* Is A an alphabetic character in the C locale? */ static bool is_alpha(char a) { switch (a) { default: return false; case 'A': case 'B': case 'C': case 'D': case 'E': case 'F': case 'G': case 'H': case 'I': case 'J': case 'K': case 'L': case 'M': case 'N': case 'O': case 'P': case 'Q': case 'R': case 'S': case 'T': case 'U': case 'V': case 'W': case 'X': case 'Y': case 'Z': case 'a': case 'b': case 'c': case 'd': case 'e': case 'f': case 'g': case 'h': case 'i': case 'j': case 'k': case 'l': case 'm': case 'n': case 'o': case 'p': case 'q': case 'r': case 's': case 't': case 'u': case 'v': case 'w': case 'x': case 'y': case 'z': return true; } } ATTRIBUTE_NORETURN static void size_overflow(void) { fprintf(stderr, _("%s: size overflow\n"), progname); exit(EXIT_FAILURE); } /* Return A + B, exiting if the result would overflow either ptrdiff_t or size_t. */ ATTRIBUTE_REPRODUCIBLE static ptrdiff_t sumsize(size_t a, size_t b) { #ifdef ckd_add ptrdiff_t sum; if (!ckd_add(&sum, a, b) && sum <= (ptrdiff_t)min(PTRDIFF_MAX, SIZE_MAX)) return sum; #else ptrdiff_t sum_max = (ptrdiff_t)min(PTRDIFF_MAX, SIZE_MAX); if (a <= sum_max && b <= sum_max - a) return a + b; #endif size_overflow(); } /* Return a pointer to a newly allocated buffer of size SIZE, exiting on failure. SIZE should be nonzero. */ ATTRIBUTE_MALLOC static void * xmalloc(size_t size) { void *p = malloc(size); if (!p) { fprintf(stderr, _("%s: Memory exhausted\n"), progname); exit(EXIT_FAILURE); } return p; } #if ! HAVE_TZSET # undef tzset # define tzset zdump_tzset static void tzset(void) { } #endif /* Assume gmtime_r works if localtime_r does. A replacement localtime_r is defined below if needed. */ #if ! HAVE_LOCALTIME_R # undef gmtime_r # define gmtime_r zdump_gmtime_r static struct tm * gmtime_r(time_t *tp, struct tm *tmp) { struct tm *r = gmtime(tp); if (r) { *tmp = *r; r = tmp; } return r; } #endif /* Platforms with TM_ZONE don't need tzname, so they can use the faster localtime_rz or localtime_r if available. */ #if defined TM_ZONE && HAVE_LOCALTIME_RZ # define USE_LOCALTIME_RZ true #else # define USE_LOCALTIME_RZ false #endif #if ! USE_LOCALTIME_RZ # if !defined TM_ZONE || ! HAVE_LOCALTIME_R || ! HAVE_TZSET # undef localtime_r # define localtime_r zdump_localtime_r static struct tm * localtime_r(time_t *tp, struct tm *tmp) { struct tm *r = localtime(tp); if (r) { *tmp = *r; r = tmp; } return r; } # endif # undef localtime_rz # define localtime_rz zdump_localtime_rz static struct tm * localtime_rz(timezone_t rz, time_t *tp, struct tm *tmp) { return localtime_r(tp, tmp); } # ifdef TYPECHECK # undef mktime_z # define mktime_z zdump_mktime_z static time_t mktime_z(timezone_t tz, struct tm *tmp) { return mktime(tmp); } # endif # undef tzalloc # undef tzfree # define tzalloc zdump_tzalloc # define tzfree zdump_tzfree static timezone_t tzalloc(char const *val) { # if HAVE_SETENV if (setenv("TZ", val, 1) != 0) { perror("setenv"); exit(EXIT_FAILURE); } tzset(); return &optarg; /* Any valid non-null char ** will do. */ # else enum { TZeqlen = 3 }; static char const TZeq[TZeqlen] = "TZ="; static ptrdiff_t fakeenv0size; void *freeable = NULL; char **env = fakeenv, **initial_environ; size_t valsize = strlen(val) + 1; if (fakeenv0size < valsize) { char **e = environ, **to; ptrdiff_t initial_nenvptrs = 1; /* Counting the trailing NULL pointer. */ while (*e++) { # ifdef ckd_add if (ckd_add(&initial_nenvptrs, initial_envptrs, 1) || SIZE_MAX < initial_envptrs) size_overflow(); # else if (initial_nenvptrs == (ptrdiff_t)(min(PTRDIFF_MAX, SIZE_MAX) / sizeof *environ)) size_overflow(); initial_nenvptrs++; # endif + } fakeenv0size = sumsize(valsize, valsize); fakeenv0size = max(fakeenv0size, 64); freeable = env; fakeenv = env = xmalloc(sumsize(sumsize(sizeof *environ, initial_nenvptrs * sizeof *environ), sumsize(TZeqlen, fakeenv0size))); to = env + 1; for (e = environ; (*to = *e); e++) to += strncmp(*e, TZeq, TZeqlen) != 0; env[0] = memcpy(to + 1, TZeq, TZeqlen); } memcpy(env[0] + TZeqlen, val, valsize); initial_environ = environ; environ = env; tzset(); free(freeable); return initial_environ; # endif } static void tzfree(timezone_t initial_environ) { # if !HAVE_SETENV environ = initial_environ; tzset(); # endif } #endif /* ! USE_LOCALTIME_RZ */ /* A UT time zone, and its initializer. */ static timezone_t gmtz; static void gmtzinit(void) { if (USE_LOCALTIME_RZ) { /* Try "GMT" first to find out whether this is one of the rare platforms where time_t counts leap seconds; this works due to the "Zone GMT 0 - GMT" line in the "etcetera" file. If "GMT" fails, fall back on "GMT0" which might be similar due to the "Link GMT GMT0" line in the "backward" file, and which should work on all POSIX platforms. The rest of zdump does not use the "GMT" abbreviation that comes from this setting, so it is OK to use "GMT" here rather than the more-modern "UTC" which would not work on platforms that omit the "backward" file. */ gmtz = tzalloc("GMT"); if (!gmtz) { static char const gmt0[] = "GMT0"; gmtz = tzalloc(gmt0); if (!gmtz) { err(EXIT_FAILURE, "Cannot create %s", gmt0); } } } } /* Convert *TP to UT, storing the broken-down time into *TMP. Return TMP if successful, NULL otherwise. This is like gmtime_r(TP, TMP), except typically faster if USE_LOCALTIME_RZ. */ static struct tm * my_gmtime_r(time_t *tp, struct tm *tmp) { return USE_LOCALTIME_RZ ? localtime_rz(gmtz, tp, tmp) : gmtime_r(tp, tmp); } #ifndef TYPECHECK #define my_localtime_rz localtime_rz #else /* !defined TYPECHECK */ static struct tm * my_localtime_rz(timezone_t tz, const time_t *tp, struct tm *tmp) { tmp = localtime_rz(tz, tp, tmp); if (tmp) { struct tm tm; time_t t; tm = *tmp; t = mktime_z(tz, &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"); errout = true; } } 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; while (is_alpha(*cp) || is_digit(*cp) || *cp == '-' || *cp == '+') ++cp; if (*cp) wp = _("has characters other than ASCII alphanumerics, '-' or '+'"); else if (cp - abbrp < 3) wp = _("has fewer than 3 characters"); else if (cp - abbrp > 6) wp = _("has more than 6 characters"); else return; (void) fflush(stdout); (void) fprintf(stderr, _("%s: warning: zone \"%s\" abbreviation \"%s\" %s\n"), progname, zone, abbrp, wp); warned = errout = true; } /* Return a time zone abbreviation. If the abbreviation needs to be saved, use *BUF (of size *BUFALLOC) to save it, and return the abbreviation in the possibly-reallocated *BUF. Otherwise, just return the abbreviation. Get the abbreviation from TMP. Exit on memory allocation failure. */ static char const * saveabbr(char **buf, ptrdiff_t *bufalloc, struct tm const *tmp) { char const *ab = abbr(tmp); if (HAVE_LOCALTIME_RZ) return ab; else { size_t ablen = strlen(ab); if (*bufalloc <= (ptrdiff_t)ablen) { free(*buf); /* Make the new buffer at least twice as long as the old, to avoid O(N**2) behavior on repeated calls. */ *bufalloc = sumsize(*bufalloc, ablen + 1); *buf = xmalloc(*bufalloc); } return strcpy(*buf, ab); } } static void close_file(FILE *stream) { char const *e = (ferror(stream) ? _("I/O error") : fclose(stream) != 0 ? strerror(errno) : NULL); if (e) { errx(EXIT_FAILURE, "%s", e); } } __dead static void usage(FILE *const stream, const int status) { (void) fprintf(stream, _("%s: usage: %s OPTIONS TIMEZONE ...\n" "Options include:\n" " -c [L,]U Start at year L (default -500), end before year U (default 2500)\n" " -t [L,]U Start at time L, end before time U (in seconds since 1970)\n" " -i List transitions briefly (format is experimental)\n" \ " -v List transitions verbosely\n" " -V List transitions a bit less verbosely\n" " --help Output this help\n" " --version Output version info\n" "\n" "Report bugs to %s.\n"), progname, progname, REPORT_BUGS_TO); if (status == EXIT_SUCCESS) close_file(stream); exit(status); } int main(int argc, char *argv[]) { /* These are static so that they're initially zero. */ static char * abbrev; static ptrdiff_t abbrevsize; int i; bool vflag; bool Vflag; char * cutarg; char * cuttimes; time_t cutlotime; time_t cuthitime; time_t now; bool iflag = false; 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] ? argv[0] : "zdump"; for (i = 1; i < argc; ++i) if (strcmp(argv[i], "--version") == 0) { (void) printf("zdump %s%s\n", PKGVERSION, TZVERSION); return EXIT_SUCCESS; } else if (strcmp(argv[i], "--help") == 0) { usage(stdout, EXIT_SUCCESS); } vflag = Vflag = false; cutarg = cuttimes = NULL; for (;;) switch (getopt(argc, argv, "c:it:vV")) { case 'c': cutarg = optarg; break; case 't': cuttimes = optarg; break; case 'i': iflag = true; break; case 'v': vflag = true; break; case 'V': Vflag = true; break; case -1: if (! (optind == argc - 1 && strcmp(argv[optind], "=") == 0)) goto arg_processing_done; ATTRIBUTE_FALLTHROUGH; default: usage(stderr, EXIT_FAILURE); } arg_processing_done:; if (iflag | vflag | Vflag) { intmax_t lo; intmax_t hi; char *loend, *hiend; intmax_t cutloyear = ZDUMP_LO_YEAR; 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 { fprintf(stderr, _("%s: wild -c argument %s\n"), progname, cutarg); return 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 + 1) hi = absolute_min_time + 1; 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 + 1) hi = absolute_min_time + 1; cuthitime = hi; } } else { (void) fprintf(stderr, _("%s: wild -t argument %s\n"), progname, cuttimes); return EXIT_FAILURE; } } } gmtzinit(); if (iflag | vflag | Vflag) now = 0; else { now = time(NULL); now |= !now; } longest = 0; for (i = optind; i < argc; i++) { size_t arglen = strlen(argv[i]); if (longest < arglen) longest = min(arglen, INT_MAX); } for (i = optind; i < argc; ++i) { timezone_t tz = tzalloc(argv[i]); char const *ab; time_t t; struct tm tm, newtm; bool tm_ok; if (!tz) { errx(EXIT_FAILURE, "%s", argv[i]); } if (now) { show(tz, argv[i], now, false); tzfree(tz); continue; } warned = false; t = absolute_min_time; if (! (iflag | Vflag)) { show(tz, argv[i], t, true); if (my_localtime_rz(tz, &t, &tm) == NULL && t < cutlotime) { time_t newt = cutlotime; if (my_localtime_rz(tz, &newt, &newtm) != NULL) showextrema(tz, argv[i], t, NULL, newt); } } if (t + 1 < cutlotime) t = cutlotime - 1; tm_ok = my_localtime_rz(tz, &t, &tm) != NULL; if (tm_ok) { ab = saveabbr(&abbrev, &abbrevsize, &tm); if (iflag) { showtrans("\nTZ=%f", &tm, t, ab, argv[i]); showtrans("-\t-\t%Q", &tm, t, ab, argv[i]); } } else ab = NULL; while (t < cuthitime - 1) { time_t newt = ((t < absolute_max_time - SECSPERDAY / 2 && t + SECSPERDAY / 2 < cuthitime - 1) ? t + SECSPERDAY / 2 : cuthitime - 1); struct tm *newtmp = localtime_rz(tz, &newt, &newtm); bool newtm_ok = newtmp != NULL; if (tm_ok != newtm_ok || (ab && (delta(&newtm, &tm) != newt - t || newtm.tm_isdst != tm.tm_isdst || strcmp(abbr(&newtm), ab) != 0))) { newt = hunt(tz, t, newt, false); newtmp = localtime_rz(tz, &newt, &newtm); newtm_ok = newtmp != NULL; if (iflag) showtrans("%Y-%m-%d\t%L\t%Q", newtmp, newt, newtm_ok ? abbr(&newtm) : NULL, argv[i]); else { show(tz, argv[i], newt - 1, true); show(tz, argv[i], newt, true); } } t = newt; tm_ok = newtm_ok; if (newtm_ok) { ab = saveabbr(&abbrev, &abbrevsize, &newtm); tm = newtm; } } if (! (iflag | Vflag)) { time_t newt = absolute_max_time; t = cuthitime; if (t < newt) { struct tm *tmp = my_localtime_rz(tz, &t, &tm); if (tmp != NULL && my_localtime_rz(tz, &newt, &newtm) == NULL) showextrema(tz, argv[i], t, tmp, newt); } show(tz, argv[i], absolute_max_time, true); } tzfree(tz); } close_file(stdout); if (errout && (ferror(stderr) || fclose(stderr) != 0)) return EXIT_FAILURE; return EXIT_SUCCESS; } static time_t yeartot(intmax_t 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; } /* Search for a discontinuity in timezone TZ, in the timestamps ranging from LOT through HIT. LOT and HIT disagree about some aspect of timezone. If ONLY_OK, search only for definedness changes, i.e., localtime succeeds on one side of the transition but fails on the other side. Return the timestamp just before the transition from LOT's settings. */ static time_t hunt(timezone_t tz, time_t lot, time_t hit, bool only_ok) { static char * loab; static ptrdiff_t loabsize; struct tm lotm; struct tm tm; /* Convert LOT into a broken-down time here, even though our caller already did that. On platforms without TM_ZONE, tzname may have been altered since our caller broke down LOT, and tzname needs to be changed back. */ bool lotm_ok = my_localtime_rz(tz, &lot, &lotm) != NULL; bool tm_ok; char const *ab = lotm_ok ? saveabbr(&loab, &loabsize, &lotm) : NULL; for ( ; ; ) { /* T = average of LOT and HIT, rounding down. Avoid overflow, even on oddball C89 platforms where / rounds down and TIME_T_MIN == -TIME_T_MAX so lot / 2 + hit / 2 might overflow. */ time_t t = (lot / 2 - ((lot % 2 + hit % 2) < 0) + ((lot % 2 + hit % 2) == 2) + hit / 2); if (t == lot) break; tm_ok = my_localtime_rz(tz, &t, &tm) != NULL; if (lotm_ok == tm_ok && (only_ok || (ab && tm.tm_isdst == lotm.tm_isdst && delta(&tm, &lotm) == t - lot && strcmp(abbr(&tm), ab) == 0))) { lot = t; if (tm_ok) lotm = tm; } else hit = t; } return hit; } /* ** Thanks to Paul Eggert for logic used in delta_nonneg. */ static intmax_t delta_nonneg(struct tm *newp, struct tm *oldp) { intmax_t oldy = oldp->tm_year; int cycles = (newp->tm_year - oldy) / YEARSPERREPEAT; intmax_t sec = SECSPERREPEAT, result = cycles * sec; int tmy = oldp->tm_year + cycles * YEARSPERREPEAT; for ( ; 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 intmax_t delta(struct tm *newp, struct tm *oldp) { return (newp->tm_year < oldp->tm_year ? -delta_nonneg(oldp, newp) : delta_nonneg(newp, oldp)); } #ifndef TM_GMTOFF /* Return A->tm_yday, adjusted to compare it fairly to B->tm_yday. Assume A and B differ by at most one year. */ static int adjusted_yday(struct tm const *a, struct tm const *b) { int yday = a->tm_yday; if (b->tm_year < a->tm_year) yday += 365 + isleap_sum(b->tm_year, TM_YEAR_BASE); return yday; } #endif /* If A is the broken-down local time and B the broken-down UT for the same instant, return A's UT offset in seconds, where positive offsets are east of Greenwich. On failure, return LONG_MIN. If T is nonnull, *T is the timestamp that corresponds to A; call my_gmtime_r and use its result instead of B. Otherwise, B is the possibly nonnull result of an earlier call to my_gmtime_r. */ static long gmtoff(struct tm const *a, ATTRIBUTE_MAYBE_UNUSED time_t *t, ATTRIBUTE_MAYBE_UNUSED struct tm const *b) { #ifdef TM_GMTOFF return a->TM_GMTOFF; #else struct tm tm; if (t) b = my_gmtime_r(t, &tm); if (! b) return LONG_MIN; else { int ayday = adjusted_yday(a, b); int byday = adjusted_yday(b, a); int days = ayday - byday; long hours = a->tm_hour - b->tm_hour + 24 * days; long minutes = a->tm_min - b->tm_min + 60 * hours; long seconds = a->tm_sec - b->tm_sec + 60 * minutes; return seconds; } #endif } static void show(timezone_t tz, char *zone, time_t t, bool v) { struct tm * tmp; struct tm * gmtmp; struct tm tm, gmtm; (void) printf("%-*s ", (int) longest, zone); if (v) { gmtmp = my_gmtime_r(&t, &gmtm); if (gmtmp == NULL) { printf(tformat(), t); printf(_(" (gmtime failed)")); } else { dumptime(gmtmp); (void) printf(" UT"); } (void) printf(" = "); } tmp = my_localtime_rz(tz, &t, &tm); if (tmp == NULL) { printf(tformat(), t); printf(_(" (localtime failed)")); } else { dumptime(tmp); if (*abbr(tmp) != '\0') (void) printf(" %s", abbr(tmp)); if (v) { long off = gmtoff(tmp, NULL, gmtmp); (void) printf(" isdst=%d", tmp->tm_isdst); if (off != LONG_MIN) (void) printf(" gmtoff=%ld", off); } } (void) printf("\n"); if (tmp != NULL && *abbr(tmp) != '\0') abbrok(abbr(tmp), zone); } /* Show timestamps just before and just after a transition between defined and undefined (or vice versa) in either localtime or gmtime. These transitions are for timezone TZ with name ZONE, in the range from LO (with broken-down time LOTMP if that is nonnull) through HI. LO and HI disagree on definedness. */ static void showextrema(timezone_t tz, char *zone, time_t lo, struct tm *lotmp, time_t hi) { struct tm localtm[2], gmtm[2]; time_t t, boundary = hunt(tz, lo, hi, true); bool old = false; hi = (SECSPERDAY < hi - boundary ? boundary + SECSPERDAY : hi + (hi < TIME_T_MAX)); if (SECSPERDAY < boundary - lo) { lo = boundary - SECSPERDAY; lotmp = my_localtime_rz(tz, &lo, &localtm[old]); } if (lotmp) localtm[old] = *lotmp; else localtm[old].tm_sec = -1; if (! my_gmtime_r(&lo, &gmtm[old])) gmtm[old].tm_sec = -1; /* Search sequentially for definedness transitions. Although this could be sped up by refining 'hunt' to search for either localtime or gmtime definedness transitions, it hardly seems worth the trouble. */ for (t = lo + 1; t < hi; t++) { bool new = !old; if (! my_localtime_rz(tz, &t, &localtm[new])) localtm[new].tm_sec = -1; if (! my_gmtime_r(&t, &gmtm[new])) gmtm[new].tm_sec = -1; if (((localtm[old].tm_sec < 0) != (localtm[new].tm_sec < 0)) | ((gmtm[old].tm_sec < 0) != (gmtm[new].tm_sec < 0))) { show(tz, zone, t - 1, true); show(tz, zone, t, true); } old = new; } } #if HAVE_SNPRINTF # define my_snprintf snprintf #else # include /* A substitute for snprintf that is good enough for zdump. */ ATTRIBUTE_FORMAT((printf, 3, 4)) static int my_snprintf(char *s, size_t size, char const *format, ...) { int n; va_list args; char const *arg; size_t arglen, slen; char buf[1024]; va_start(args, format); if (strcmp(format, "%s") == 0) { arg = va_arg(args, char const *); arglen = strlen(arg); } else { n = vsprintf(buf, format, args); if (n < 0) { va_end(args); return n; } arg = buf; arglen = n; } slen = arglen < size ? arglen : size - 1; memcpy(s, arg, slen); s[slen] = '\0'; n = arglen <= INT_MAX ? arglen : -1; va_end(args); return n; } #endif /* Store into BUF, of size SIZE, a formatted local time taken from *TM. Use ISO 8601 format +HH:MM:SS. Omit :SS if SS is zero, and omit :MM too if MM is also zero. Return the length of the resulting string. If the string does not fit, return the length that the string would have been if it had fit; do not overrun the output buffer. */ static int format_local_time(char *buf, ptrdiff_t size, struct tm const *tm) { int ss = tm->tm_sec, mm = tm->tm_min, hh = tm->tm_hour; return (ss ? my_snprintf(buf, size, "%02d:%02d:%02d", hh, mm, ss) : mm ? my_snprintf(buf, size, "%02d:%02d", hh, mm) : my_snprintf(buf, size, "%02d", hh)); } /* Store into BUF, of size SIZE, a formatted UT offset for the localtime *TM corresponding to time T. Use ISO 8601 format +HHMMSS, or -HHMMSS for timestamps west of Greenwich; use the format -00 for unknown UT offsets. If the hour needs more than two digits to represent, extend the length of HH as needed. Otherwise, omit SS if SS is zero, and omit MM too if MM is also zero. Return the length of the resulting string, or -1 if the result is not representable as a string. If the string does not fit, return the length that the string would have been if it had fit; do not overrun the output buffer. */ static int format_utc_offset(char *buf, ptrdiff_t size, struct tm const *tm, time_t t) { long off = gmtoff(tm, &t, NULL); char sign = ((off < 0 || (off == 0 && (*abbr(tm) == '-' || strcmp(abbr(tm), "zzz") == 0))) ? '-' : '+'); long hh; int mm, ss; if (off < 0) { if (off == LONG_MIN) return -1; off = -off; } ss = off % 60; mm = off / 60 % 60; hh = off / 60 / 60; return (ss || 100 <= hh ? my_snprintf(buf, size, "%c%02ld%02d%02d", sign, hh, mm, ss) : mm ? my_snprintf(buf, size, "%c%02ld%02d", sign, hh, mm) : my_snprintf(buf, size, "%c%02ld", sign, hh)); } /* Store into BUF (of size SIZE) a quoted string representation of P. If the representation's length is less than SIZE, return the length; the representation is not null terminated. Otherwise return SIZE, to indicate that BUF is too small. */ static ptrdiff_t format_quoted_string(char *buf, ptrdiff_t size, char const *p) { char *b = buf; ptrdiff_t s = size; if (!s) return size; *b++ = '"', s--; for (;;) { char c = *p++; if (s <= 1) return size; switch (c) { default: *b++ = c, s--; continue; case '\0': *b++ = '"', s--; return size - s; case '"': case '\\': break; case ' ': c = 's'; break; case '\f': c = 'f'; break; case '\n': c = 'n'; break; case '\r': c = 'r'; break; case '\t': c = 't'; break; case '\v': c = 'v'; break; } *b++ = '\\', *b++ = c, s -= 2; } } /* Store into BUF (of size SIZE) a timestamp formatted by TIME_FMT. TM is the broken-down time, T the seconds count, AB the time zone abbreviation, and ZONE_NAME the zone name. Return true if successful, false if the output would require more than SIZE bytes. TIME_FMT uses the same format that strftime uses, with these additions: %f zone name %L local time as per format_local_time %Q like "U\t%Z\tD" where U is the UT offset as for format_utc_offset and D is the isdst flag; except omit D if it is zero, omit %Z if it equals U, quote and escape %Z if it contains nonalphabetics, and omit any trailing tabs. */ static bool istrftime(char *buf, ptrdiff_t size, char const *time_fmt, struct tm const *tm, time_t t, char const *ab, char const *zone_name) { char *b = buf; ptrdiff_t s = size; char const *f = time_fmt, *p; for (p = f; ; p++) if (*p == '%' && p[1] == '%') p++; else if (!*p || (*p == '%' && (p[1] == 'f' || p[1] == 'L' || p[1] == 'Q'))) { ptrdiff_t formatted_len; ptrdiff_t f_prefix_len = p - f; ptrdiff_t f_prefix_copy_size = sumsize(f_prefix_len, 2); char fbuf[100]; bool oversized = (ptrdiff_t)sizeof fbuf <= f_prefix_copy_size; char *f_prefix_copy = oversized ? xmalloc(f_prefix_copy_size) : fbuf; memcpy(f_prefix_copy, f, f_prefix_len); strcpy(f_prefix_copy + f_prefix_len, "X"); formatted_len = strftime(b, s, f_prefix_copy, tm); if (oversized) free(f_prefix_copy); if (formatted_len == 0) return false; formatted_len--; b += formatted_len, s -= formatted_len; if (!*p++) break; switch (*p) { case 'f': formatted_len = format_quoted_string(b, s, zone_name); break; case 'L': formatted_len = format_local_time(b, s, tm); break; case 'Q': { bool show_abbr; int offlen = format_utc_offset(b, s, tm, t); if (! (0 <= offlen && offlen < s)) return false; show_abbr = strcmp(b, ab) != 0; b += offlen, s -= offlen; if (show_abbr) { char const *abp; ptrdiff_t len; if (s <= 1) return false; *b++ = '\t', s--; for (abp = ab; is_alpha(*abp); abp++) continue; len = (!*abp && *ab ? my_snprintf(b, s, "%s", ab) : format_quoted_string(b, s, ab)); if (s <= len) return false; b += len, s -= len; } formatted_len = (tm->tm_isdst ? my_snprintf(b, s, &"\t\t%d"[show_abbr], tm->tm_isdst) : 0); } break; } if (s <= formatted_len) return false; b += formatted_len, s -= formatted_len; f = p + 1; } *b = '\0'; return true; } /* Show a time transition. */ static void showtrans(char const *time_fmt, struct tm const *tm, time_t t, char const *ab, char const *zone_name) { if (!tm) { printf(tformat(), t); putchar('\n'); } else { char stackbuf[1000]; ptrdiff_t size = sizeof stackbuf; char *buf = stackbuf; char *bufalloc = NULL; while (! istrftime(buf, size, time_fmt, tm, t, ab, zone_name)) { size = sumsize(size, size); free(bufalloc); buf = bufalloc = xmalloc(size); } puts(buf); free(bufalloc); } } static const char * abbr(struct tm const *tmp) { #ifdef TM_ZONE return tmp->TM_ZONE; #else # if HAVE_TZNAME if (0 <= tmp->tm_isdst && tzname[0 < tmp->tm_isdst]) return tzname[0 < tmp->tm_isdst]; # endif return ""; #endif } /* ** The code below can fail on certain theoretical systems; ** it works on all known real-world systems as of 2022-01-25. */ static const char * tformat(void) { #if HAVE_GENERIC /* C11-style _Generic is more likely to return the correct format when distinct types have the same size. */ char const *fmt = _Generic(+ (time_t) 0, int: "%d", long: "%ld", long long: "%lld", unsigned: "%u", unsigned long: "%lu", unsigned long long: "%llu", default: NULL); if (fmt) return fmt; fmt = _Generic((time_t) 0, intmax_t: "%"PRIdMAX, uintmax_t: "%"PRIuMAX, default: NULL); if (fmt) return fmt; #endif 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[][4] = { "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat" }; static const char mon_name[][4] = { "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" }; int lead; int trail; int DIVISOR = 10; /* ** The packaged localtime_rz and gmtime_r 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. */ printf("%s %s%3d %.2d:%.2d:%.2d ", ((0 <= timeptr->tm_wday && timeptr->tm_wday < (int) (sizeof wday_name / sizeof wday_name[0])) ? wday_name[timeptr->tm_wday] : "???"), ((0 <= timeptr->tm_mon && timeptr->tm_mon < (int) (sizeof mon_name / sizeof mon_name[0])) ? mon_name[timeptr->tm_mon] : "???"), timeptr->tm_mday, timeptr->tm_hour, timeptr->tm_min, timeptr->tm_sec); 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) printf("%d", trail); else printf("%d%d", lead, ((trail < 0) ? -trail : trail)); }