zdump.tproj/zdump.c

   1 static const char       elsieid[] = "@(#)zdump.c        7.31";
   2
   3 #ifndef lint
   4 #include <sys/cdefs.h>
   5 __unused static const char rcsid[] =
   6   "$FreeBSD: src/usr.sbin/zic/zdump.c,v 1.10 2008/02/19 07:09:19 ru Exp $";
   7 #endif /* not lint */
   8
   9 /*
  10 ** This code has been made independent of the rest of the time
  11 ** conversion package to increase confidence in the verification it provides.
  12 ** You can use this code to help in verifying other implementations.
  13 */
  14
  15 #include <err.h>
  16 #include <stdio.h>      /* for stdout, stderr */
  17 #include <stdlib.h>     /* for exit, malloc, atoi */
  18 #include <string.h>     /* for strcpy */
  19 #include <sys/types.h>  /* for time_t */
  20 #include <time.h>       /* for struct tm */
  21 #include <unistd.h>
  22 #include <limits.h>
  23
  24 #ifndef MAX_STRING_LENGTH
  25 #define MAX_STRING_LENGTH       1024
  26 #endif /* !defined MAX_STRING_LENGTH */
  27
  28 #ifndef TRUE
  29 #define TRUE            1
  30 #endif /* !defined TRUE */
  31
  32 #ifndef FALSE
  33 #define FALSE           0
  34 #endif /* !defined FALSE */
  35
  36 #ifndef EXIT_SUCCESS
  37 #define EXIT_SUCCESS    0
  38 #endif /* !defined EXIT_SUCCESS */
  39
  40 #ifndef EXIT_FAILURE
  41 #define EXIT_FAILURE    1
  42 #endif /* !defined EXIT_FAILURE */
  43
  44 #ifndef SECSPERMIN
  45 #define SECSPERMIN      60
  46 #endif /* !defined SECSPERMIN */
  47
  48 #ifndef MINSPERHOUR
  49 #define MINSPERHOUR     60
  50 #endif /* !defined MINSPERHOUR */
  51
  52 #ifndef SECSPERHOUR
  53 #define SECSPERHOUR     (SECSPERMIN * MINSPERHOUR)
  54 #endif /* !defined SECSPERHOUR */
  55
  56 #ifndef HOURSPERDAY
  57 #define HOURSPERDAY     24
  58 #endif /* !defined HOURSPERDAY */
  59
  60 #ifndef EPOCH_YEAR
  61 #define EPOCH_YEAR      1970
  62 #endif /* !defined EPOCH_YEAR */
  63
  64 #ifndef TM_YEAR_BASE
  65 #define TM_YEAR_BASE    1900
  66 #endif /* !defined TM_YEAR_BASE */
  67
  68 #ifndef DAYSPERNYEAR
  69 #define DAYSPERNYEAR    365
  70 #endif /* !defined DAYSPERNYEAR */
  71
  72 #ifndef isleap
  73 #define isleap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0)
  74 #endif /* !defined isleap */
  75
  76 #if HAVE_GETTEXT - 0
  77 #include "locale.h"     /* for setlocale */
  78 #include "libintl.h"
  79 #endif /* HAVE_GETTEXT - 0 */
  80
  81 #ifndef GNUC_or_lint
  82 #ifdef lint
  83 #define GNUC_or_lint
  84 #endif /* defined lint */
  85 #ifndef lint
  86 #ifdef __GNUC__
  87 #define GNUC_or_lint
  88 #endif /* defined __GNUC__ */
  89 #endif /* !defined lint */
  90 #endif /* !defined GNUC_or_lint */
  91
  92 #ifndef INITIALIZE
  93 #ifdef GNUC_or_lint
  94 #define INITIALIZE(x)   ((x) = 0)
  95 #endif /* defined GNUC_or_lint */
  96 #ifndef GNUC_or_lint
  97 #define INITIALIZE(x)
  98 #endif /* !defined GNUC_or_lint */
  99 #endif /* !defined INITIALIZE */
 100
 101 /*
 102 ** For the benefit of GNU folk...
 103 ** `_(MSGID)' uses the current locale's message library string for MSGID.
 104 ** The default is to use gettext if available, and use MSGID otherwise.
 105 */
 106
 107 #ifndef _
 108 #if HAVE_GETTEXT - 0
 109 #define _(msgid) gettext(msgid)
 110 #else /* !(HAVE_GETTEXT - 0) */
 111 #define _(msgid) msgid
 112 #endif /* !(HAVE_GETTEXT - 0) */
 113 #endif /* !defined _ */
 114
 115 #ifndef TZ_DOMAIN
 116 #define TZ_DOMAIN "tz"
 117 #endif /* !defined TZ_DOMAIN */
 118
 119 #ifndef P
 120 #ifdef __STDC__
 121 #define P(x)    x
 122 #endif /* defined __STDC__ */
 123 #ifndef __STDC__
 124 #define P(x)    ()
 125 #endif /* !defined __STDC__ */
 126 #endif /* !defined P */
 127
 128 extern char **  environ;
 129 extern char *   tzname[2];
 130
 131 static char *   abbr P((struct tm * tmp));
 132 static long     delta P((struct tm * newp, struct tm * oldp));
 133 static time_t   hunt P((char * name, time_t lot, time_t hit));
 134 static size_t   longest;
 135 static void     show P((char * zone, time_t t, int v));
 136 static void     usage(void);
 137
 138 int
 139 main(int argc, char *argv[])
 140 {
 141         int                     i;
 142         int                     c;
 143         int                     vflag;
 144         char *                  cutoff;
 145         int                     cutyear;
 146         long                    cuttime;
 147         char **                 fakeenv;
 148         time_t                  now;
 149         time_t                  t;
 150         time_t                  newt;
 151 #ifndef __APPLE__
 152 // <rdar://problem/6013740>
 153 // The approach of walking through every day from the minimum
 154 // possible time_t value to the maximum possible time_t value
 155 // falls apart with 64-bit time_t (takes too long to iterate,
 156 // and causes gmtime(3) and localtime(3) to return EOVERFLOW
 157 // which this code does not anticipate).  Limiting the time_t
 158 // range to [INT_MIN:INT_MAX] even on LP64.
 159         time_t                  hibit;
 160 #endif
 161         struct tm               tm;
 162         struct tm               newtm;
 163
 164         INITIALIZE(cuttime);
 165 #if HAVE_GETTEXT - 0
 166         (void) setlocale(LC_MESSAGES, "");
 167 #ifdef TZ_DOMAINDIR
 168         (void) bindtextdomain(TZ_DOMAIN, TZ_DOMAINDIR);
 169 #endif /* defined(TEXTDOMAINDIR) */
 170         (void) textdomain(TZ_DOMAIN);
 171 #endif /* HAVE_GETTEXT - 0 */
 172         for (i = 1; i < argc; ++i)
 173                 if (strcmp(argv[i], "--version") == 0) {
 174                         errx(EXIT_SUCCESS, "%s", elsieid);
 175                 }
 176         vflag = 0;
 177         cutoff = NULL;
 178         while ((c = getopt(argc, argv, "c:v")) == 'c' || c == 'v')
 179                 if (c == 'v')
 180                         vflag = 1;
 181                 else    cutoff = optarg;
 182         if ((c != -1) ||
 183                 (optind == argc - 1 && strcmp(argv[optind], "=") == 0)) {
 184                         usage();
 185         }
 186         if (cutoff != NULL) {
 187                 int     y;
 188
 189                 cutyear = atoi(cutoff);
 190                 cuttime = 0;
 191                 for (y = EPOCH_YEAR; y < cutyear; ++y)
 192                         cuttime += DAYSPERNYEAR + isleap(y);
 193                 cuttime *= SECSPERHOUR * HOURSPERDAY;
 194         }
 195         (void) time(&now);
 196         longest = 0;
 197         for (i = optind; i < argc; ++i)
 198                 if (strlen(argv[i]) > longest)
 199                         longest = strlen(argv[i]);
 200 #ifndef __APPLE__
 201         for (hibit = 1; (hibit << 1) != 0; hibit <<= 1)
 202                 continue;
 203 #endif
 204         {
 205                 int     from;
 206                 int     to;
 207
 208                 for (i = 0;  environ[i] != NULL;  ++i)
 209                         continue;
 210                 fakeenv = (char **) malloc((size_t) ((i + 2) *
 211                         sizeof *fakeenv));
 212                 if (fakeenv == NULL ||
 213                         (fakeenv[0] = (char *) malloc((size_t) (longest +
 214                                 4))) == NULL)
 215                                         errx(EXIT_FAILURE,
 216                                              _("malloc() failed"));
 217                 to = 0;
 218                 (void) strcpy(fakeenv[to++], "TZ=");
 219                 for (from = 0; environ[from] != NULL; ++from)
 220                         if (strncmp(environ[from], "TZ=", 3) != 0)
 221                                 fakeenv[to++] = environ[from];
 222                 fakeenv[to] = NULL;
 223                 environ = fakeenv;
 224         }
 225         for (i = optind; i < argc; ++i) {
 226                 static char     buf[MAX_STRING_LENGTH];
 227
 228                 (void) strcpy(&fakeenv[0][3], argv[i]);
 229                 if (!vflag) {
 230                         show(argv[i], now, FALSE);
 231                         continue;
 232                 }
 233                 /*
 234                 ** Get lowest value of t.
 235                 */
 236 #ifdef __APPLE__
 237                 t = INT_MIN;
 238 #else
 239                 t = hibit;
 240                 if (t > 0)              /* time_t is unsigned */
 241                         t = 0;
 242 #endif
 243                 show(argv[i], t, TRUE);
 244                 t += SECSPERHOUR * HOURSPERDAY;
 245                 show(argv[i], t, TRUE);
 246                 tm = *localtime(&t);
 247                 (void) strncpy(buf, abbr(&tm), (sizeof buf) - 1);
 248                 for ( ; ; ) {
 249                         if (cutoff != NULL && t >= cuttime)
 250                                 break;
 251                         newt = t + SECSPERHOUR * 12;
 252                         if (cutoff != NULL && newt >= cuttime)
 253                                 break;
 254 #ifdef __APPLE__
 255                         if (newt > INT_MAX)
 256                                 break;
 257 #else
 258                         if (newt <= t)
 259                                 break;
 260 #endif
 261                         newtm = *localtime(&newt);
 262                         if (delta(&newtm, &tm) != (newt - t) ||
 263                                 newtm.tm_isdst != tm.tm_isdst ||
 264                                 strcmp(abbr(&newtm), buf) != 0) {
 265                                         newt = hunt(argv[i], t, newt);
 266                                         newtm = *localtime(&newt);
 267                                         (void) strncpy(buf, abbr(&newtm),
 268                                                 (sizeof buf) - 1);
 269                         }
 270                         t = newt;
 271                         tm = newtm;
 272                 }
 273                 /*
 274                 ** Get highest value of t.
 275                 */
 276 #ifdef __APPLE__
 277                 t = INT_MAX;
 278 #else
 279                 t = ~((time_t) 0);
 280                 if (t < 0)              /* time_t is signed */
 281                         t &= ~hibit;
 282 #endif
 283                 t -= SECSPERHOUR * HOURSPERDAY;
 284                 show(argv[i], t, TRUE);
 285                 t += SECSPERHOUR * HOURSPERDAY;
 286                 show(argv[i], t, TRUE);
 287         }
 288         if (fflush(stdout) || ferror(stdout))
 289                 errx(EXIT_FAILURE, _("error writing standard output"));
 290         exit(EXIT_SUCCESS);
 291
 292         /* gcc -Wall pacifier */
 293         for ( ; ; )
 294                 continue;
 295 }
 296
 297 static void
 298 usage(void)
 299 {
 300         fprintf(stderr,
 301 _("usage: zdump [--version] [-v] [-c cutoff] zonename ...\n"));
 302         exit(EXIT_FAILURE);
 303 }
 304
 305 static time_t
 306 hunt(char *name, time_t lot, time_t hit)
 307 {
 308         time_t          t;
 309         struct tm       lotm;
 310         struct tm       tm;
 311         static char     loab[MAX_STRING_LENGTH];
 312
 313         lotm = *localtime(&lot);
 314         (void) strncpy(loab, abbr(&lotm), (sizeof loab) - 1);
 315         while ((hit - lot) >= 2) {
 316                 t = lot / 2 + hit / 2;
 317                 if (t <= lot)
 318                         ++t;
 319                 else if (t >= hit)
 320                         --t;
 321                 tm = *localtime(&t);
 322                 if (delta(&tm, &lotm) == (t - lot) &&
 323                         tm.tm_isdst == lotm.tm_isdst &&
 324                         strcmp(abbr(&tm), loab) == 0) {
 325                                 lot = t;
 326                                 lotm = tm;
 327                 } else  hit = t;
 328         }
 329         show(name, lot, TRUE);
 330         show(name, hit, TRUE);
 331         return hit;
 332 }
 333
 334 /*
 335 ** Thanks to Paul Eggert (eggert@twinsun.com) for logic used in delta.
 336 */
 337
 338 static long
 339 delta(struct tm *newp, struct tm *oldp)
 340 {
 341         long    result;
 342         int     tmy;
 343
 344         if (newp->tm_year < oldp->tm_year)
 345                 return -delta(oldp, newp);
 346         result = 0;
 347         for (tmy = oldp->tm_year; tmy < newp->tm_year; ++tmy)
 348                 result += DAYSPERNYEAR + isleap(tmy + TM_YEAR_BASE);
 349         result += newp->tm_yday - oldp->tm_yday;
 350         result *= HOURSPERDAY;
 351         result += newp->tm_hour - oldp->tm_hour;
 352         result *= MINSPERHOUR;
 353         result += newp->tm_min - oldp->tm_min;
 354         result *= SECSPERMIN;
 355         result += newp->tm_sec - oldp->tm_sec;
 356         return result;
 357 }
 358
 359 static void
 360 show(char *zone, time_t t, int v)
 361 {
 362         struct tm *     tmp;
 363
 364         (void) printf("%-*s  ", (int) longest, zone);
 365         if (v)
 366                 (void) printf("%.24s UTC = ", asctime(gmtime(&t)));
 367         tmp = localtime(&t);
 368         (void) printf("%.24s", asctime(tmp));
 369         if (*abbr(tmp) != '\0')
 370                 (void) printf(" %s", abbr(tmp));
 371         if (v) {
 372                 (void) printf(" isdst=%d", tmp->tm_isdst);
 373 #ifdef TM_GMTOFF
 374                 (void) printf(" gmtoff=%ld", tmp->TM_GMTOFF);
 375 #endif /* defined TM_GMTOFF */
 376         }
 377         (void) printf("\n");
 378 }
 379
 380 static char *
 381 abbr(struct tm *tmp)
 382 {
 383         char *          result;
 384         static char     nada;
 385
 386         if (tmp->tm_isdst != 0 && tmp->tm_isdst != 1)
 387                 return &nada;
 388         result = tzname[tmp->tm_isdst];
 389         return (result == NULL) ? &nada : result;
 390 }