diff options
Diffstat (limited to 'tz/zdump.c')
| -rw-r--r-- | tz/zdump.c | 230 |
1 files changed, 152 insertions, 78 deletions
@@ -42,10 +42,6 @@ #define ZDUMP_HI_YEAR 2500 #endif /* !defined ZDUMP_HI_YEAR */ -#ifndef MAX_STRING_LENGTH -#define MAX_STRING_LENGTH 1024 -#endif /* !defined MAX_STRING_LENGTH */ - #define SECSPERNYEAR (SECSPERDAY * DAYSPERNYEAR) #define SECSPERLYEAR (SECSPERNYEAR + SECSPERDAY) #define SECSPER400YEARS (SECSPERNYEAR * (intmax_t) (300 + 3) \ @@ -77,7 +73,7 @@ extern int optind; #endif /* The minimum and maximum finite time values. */ -enum { atime_shift = CHAR_BIT * sizeof (time_t) - 2 }; +enum { atime_shift = CHAR_BIT * sizeof(time_t) - 2 }; static time_t const absolute_min_time = ((time_t) -1 < 0 ? (- ((time_t) ~ (time_t) 0 < 0) @@ -95,15 +91,20 @@ static bool errout; static char const *abbr(struct tm const *); static intmax_t delta(struct tm *, struct tm *) ATTRIBUTE_PURE; static void dumptime(struct tm const *); -static time_t hunt(timezone_t, char *, time_t, time_t); +static time_t hunt(timezone_t, char *, 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); static time_t yeartot(intmax_t) ATTRIBUTE_PURE; -/* Unlike <ctype.h>'s isdigit, this also works if c < 0 | c > UCHAR_MAX. */ -#define is_digit(c) ((unsigned)(c) - '0' <= 9) +/* 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 @@ -143,7 +144,7 @@ xmalloc(size_t size) { void *p = malloc(size); if (!p) { - perror(progname); + fprintf(stderr, _("%s: Memory exhausted\n"), progname); exit(EXIT_FAILURE); } return p; @@ -263,11 +264,23 @@ static void gmtzinit(void) { if (USE_LOCALTIME_RZ) { - static char const utc[] = "UTC0"; - gmtz = tzalloc(utc); + /* 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 "Link Etc/GMT GMT" line in the "etcetera" file. If "GMT" + fails, fall back on "GMT0" which might be similar due to the + "Link Etc/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) { - perror(utc); - exit(EXIT_FAILURE); + static char const gmt0[] = "GMT0"; + gmtz = tzalloc(gmt0); + if (!gmtz) { + perror(gmt0); + exit(EXIT_FAILURE); + } } } } @@ -484,8 +497,8 @@ main(int argc, char *argv[]) if (cuttimes != loend && !*loend) { hi = lo; if (hi < cuthitime) { - if (hi < absolute_min_time) - hi = absolute_min_time; + if (hi < absolute_min_time + 1) + hi = absolute_min_time + 1; cuthitime = hi; } } else if (cuttimes != loend && *loend == ',' @@ -497,8 +510,8 @@ main(int argc, char *argv[]) cutlotime = lo; } if (hi < cuthitime) { - if (hi < absolute_min_time) - hi = absolute_min_time; + if (hi < absolute_min_time + 1) + hi = absolute_min_time + 1; cuthitime = hi; } } else { @@ -510,9 +523,12 @@ main(int argc, char *argv[]) } } gmtzinit(); - INITIALIZE (now); - if (! (iflag | vflag | Vflag)) + 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]); @@ -530,7 +546,7 @@ main(int argc, char *argv[]) perror(argv[i]); return EXIT_FAILURE; } - if (! (iflag | vflag | Vflag)) { + if (now) { show(tz, argv[i], now, false); tzfree(tz); continue; @@ -539,12 +555,15 @@ main(int argc, char *argv[]) t = absolute_min_time; if (! (iflag | Vflag)) { show(tz, argv[i], t, true); - t += SECSPERDAY; - 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 < cutlotime) - t = cutlotime; - INITIALIZE (ab); + if (t + 1 < cutlotime) + t = cutlotime - 1; tm_ok = my_localtime_rz(tz, &t, &tm) != NULL; if (tm_ok) { ab = saveabbr(&abbrev, &abbrevsize, &tm); @@ -552,19 +571,20 @@ main(int argc, char *argv[]) showtrans("\nTZ=%f", &tm, t, ab, argv[i]); showtrans("-\t-\t%Q", &tm, t, ab, argv[i]); } - } - while (t < cuthitime) { + } else + ab = NULL; + while (t < cuthitime - 1) { time_t newt = ((t < absolute_max_time - SECSPERDAY / 2 - && t + SECSPERDAY / 2 < cuthitime) + && t + SECSPERDAY / 2 < cuthitime - 1) ? t + SECSPERDAY / 2 - : cuthitime); + : cuthitime - 1); struct tm *newtmp = localtime_rz(tz, &newt, &newtm); bool newtm_ok = newtmp != NULL; if (tm_ok != newtm_ok - || (tm_ok && (delta(&newtm, &tm) != newt - t - || newtm.tm_isdst != tm.tm_isdst - || strcmp(abbr(&newtm), ab) != 0))) { - newt = hunt(tz, argv[i], t, newt); + || (ab && (delta(&newtm, &tm) != newt - t + || newtm.tm_isdst != tm.tm_isdst + || strcmp(abbr(&newtm), ab) != 0))) { + newt = hunt(tz, argv[i], t, newt, false); newtmp = localtime_rz(tz, &newt, &newtm); newtm_ok = newtmp != NULL; if (iflag) @@ -583,11 +603,15 @@ main(int argc, char *argv[]) } } if (! (iflag | Vflag)) { - t = absolute_max_time; - t -= SECSPERDAY; - show(tz, argv[i], t, true); - t += SECSPERDAY; - show(tz, argv[i], t, true); + 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); } @@ -640,36 +664,46 @@ yeartot(intmax_t y) return t; } +/* Search for a discontinuity in timezone TZ with name NAME, 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, char *name, time_t lot, time_t hit) +hunt(timezone_t tz, char *name, time_t lot, time_t hit, bool only_ok) { static char * loab; static size_t loabsize; - char const * ab; - time_t t; 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; - if (lotm_ok) - ab = saveabbr(&loab, &loabsize, &lotm); for ( ; ; ) { - time_t diff = hit - lot; - if (diff < 2) + /* 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; - t = lot; - t += diff / 2; - if (t <= lot) - ++t; - else if (t >= hit) - --t; tm_ok = my_localtime_rz(tz, &t, &tm) != NULL; - if (lotm_ok & tm_ok - ? (delta(&tm, &lotm) == t - lot - && tm.tm_isdst == lotm.tm_isdst - && strcmp(abbr(&tm), ab) == 0) - : lotm_ok == tm_ok) { + 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; @@ -685,11 +719,11 @@ hunt(timezone_t tz, char *name, time_t lot, time_t hit) static intmax_t delta_nonneg(struct tm *newp, struct tm *oldp) { - register intmax_t result; - register int tmy; - - result = 0; - for (tmy = oldp->tm_year; tmy < newp->tm_year; ++tmy) + 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; @@ -787,6 +821,51 @@ show(timezone_t tz, char *zone, time_t t, bool v) 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, zone, 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 @@ -1047,21 +1126,21 @@ static const char * tformat(void) { if (0 > (time_t) -1) { /* signed */ - if (sizeof (time_t) == sizeof (intmax_t)) + if (sizeof(time_t) == sizeof(intmax_t)) return "%"PRIdMAX; - if (sizeof (time_t) > sizeof (long)) + if (sizeof(time_t) > sizeof(long)) return "%lld"; - if (sizeof (time_t) > sizeof (int)) + if (sizeof(time_t) > sizeof(int)) return "%ld"; return "%d"; } #ifdef PRIuMAX - if (sizeof (time_t) == sizeof (uintmax_t)) + if (sizeof(time_t) == sizeof(uintmax_t)) return "%"PRIuMAX; #endif - if (sizeof (time_t) > sizeof (unsigned long)) + if (sizeof(time_t) > sizeof(unsigned long)) return "%llu"; - if (sizeof (time_t) > sizeof (unsigned int)) + if (sizeof(time_t) > sizeof(unsigned int)) return "%lu"; return "%u"; } @@ -1076,8 +1155,6 @@ dumptime(register const struct tm *timeptr) "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; @@ -1090,16 +1167,13 @@ dumptime(register const struct tm *timeptr) ** 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]; printf("%s %s%3d %.2d:%.2d:%.2d ", - wn, mn, + ((0 <= timeptr->tm_wday + && timeptr->tm_wday < sizeof wday_name / sizeof wday_name[0]) + ? wday_name[timeptr->tm_wday] : "???"), + ((0 <= timeptr->tm_mon + && timeptr->tm_mon < sizeof mon_name / sizeof mon_name[0]) + ? mon_name[timeptr->tm_mon] : "???"), timeptr->tm_mday, timeptr->tm_hour, timeptr->tm_min, timeptr->tm_sec); #define DIVISOR 10 |