zdump.tproj/zdump.c

   1 static const char       elsieid[] = "@(#)zdump.c        7.31";
   2
   3 #ifndef lint
   4 static const char rcsid[] =
   5   "$FreeBSD: src/usr.sbin/zic/zdump.c,v 1.10 2008/02/19 07:09:19 ru Exp $";
   6 #endif /* not lint */
   7
   8 /*
   9 ** This code has been made independent of the rest of the time
  10 ** conversion package to increase confidence in the verification it provides.
  11 ** You can use this code to help in verifying other implementations.
  12 */
  13
  14 #include <err.h>
  15 #include <stdio.h>      /* for stdout, stderr */
  16 #include <stdlib.h>     /* for exit, malloc, atoi */
  17 #include <string.h>     /* for strcpy */
  18 #include <sys/types.h>  /* for time_t */
  19 #include <time.h>       /* for struct tm */
  20 #include <unistd.h>
  21 #include <limits.h>
  22
  23 #ifndef MAX_STRING_LENGTH
  24 #define MAX_STRING_LENGTH       1024
  25 #endif /* !defined MAX_STRING_LENGTH */
  26
  27 #ifndef TRUE
  28 #define TRUE            1
  29 #endif /* !defined TRUE */
  30
  31 #ifndef FALSE
  32 #define FALSE           0
  33 #endif /* !defined FALSE */
  34
  35 #ifndef EXIT_SUCCESS
  36 #define EXIT_SUCCESS    0
  37 #endif /* !defined EXIT_SUCCESS */
  38
  39 #ifndef EXIT_FAILURE
  40 #define EXIT_FAILURE    1
  41 #endif /* !defined EXIT_FAILURE */
  42
  43 #ifndef SECSPERMIN
  44 #define SECSPERMIN      60
  45 #endif /* !defined SECSPERMIN */
  46
  47 #ifndef MINSPERHOUR
  48 #define MINSPERHOUR     60
  49 #endif /* !defined MINSPERHOUR */
  50
  51 #ifndef SECSPERHOUR
  52 #define SECSPERHOUR     (SECSPERMIN * MINSPERHOUR)
  53 #endif /* !defined SECSPERHOUR */
  54
  55 #ifndef HOURSPERDAY
  56 #define HOURSPERDAY     24
  57 #endif /* !defined HOURSPERDAY */
  58
  59 #ifndef EPOCH_YEAR
  60 #define EPOCH_YEAR      1970
  61 #endif /* !defined EPOCH_YEAR */
  62
  63 #ifndef TM_YEAR_BASE
  64 #define TM_YEAR_BASE    1900
  65 #endif /* !defined TM_YEAR_BASE */
  66
  67 #ifndef DAYSPERNYEAR
  68 #define DAYSPERNYEAR    365
  69 #endif /* !defined DAYSPERNYEAR */
  70
  71 #ifndef isleap
  72 #define isleap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0)
  73 #endif /* !defined isleap */
  74
  75 #if HAVE_GETTEXT - 0
  76 #include "locale.h"     /* for setlocale */
  77 #include "libintl.h"
  78 #endif /* HAVE_GETTEXT - 0 */
  79
  80 #ifndef GNUC_or_lint
  81 #ifdef lint
  82 #define GNUC_or_lint
  83 #endif /* defined lint */
  84 #ifndef lint
  85 #ifdef __GNUC__
  86 #define GNUC_or_lint
  87 #endif /* defined __GNUC__ */
  88 #endif /* !defined lint */
  89 #endif /* !defined GNUC_or_lint */
  90
  91 #ifndef INITIALIZE
  92 #ifdef GNUC_or_lint
  93 #define INITIALIZE(x)   ((x) = 0)
  94 #endif /* defined GNUC_or_lint */
  95 #ifndef GNUC_or_lint
  96 #define INITIALIZE(x)
  97 #endif /* !defined GNUC_or_lint */
  98 #endif /* !defined INITIALIZE */
  99
 100 /*
 101 ** For the benefit of GNU folk...
 102 ** `_(MSGID)' uses the current locale's message library string for MSGID.
 103 ** The default is to use gettext if available, and use MSGID otherwise.
 104 */
 105
 106 #ifndef _
 107 #if HAVE_GETTEXT - 0
 108 #define _(msgid) gettext(msgid)
 109 #else /* !(HAVE_GETTEXT - 0) */
 110 #define _(msgid) msgid
 111 #endif /* !(HAVE_GETTEXT - 0) */
 112 #endif /* !defined _ */
 113
 114 #ifndef TZ_DOMAIN
 115 #define TZ_DOMAIN "tz"
 116 #endif /* !defined TZ_DOMAIN */
 117
 118 #ifndef P
 119 #ifdef __STDC__
 120 #define P(x)    x
 121 #endif /* defined __STDC__ */
 122 #ifndef __STDC__
 123 #define P(x)    ()
 124 #endif /* !defined __STDC__ */
 125 #endif /* !defined P */
 126
 127 extern char **  environ;
 128 extern char *   tzname[2];
 129
 130 static char *   abbr P((struct tm * tmp));
 131 static long     delta P((struct tm * newp, struct tm * oldp));
 132 static time_t   hunt P((char * name, time_t lot, time_t hit));
 133 static size_t   longest;
 134 static void     show P((char * zone, time_t t, int v));
 135 static void     usage(void);
 136
 137 int
 138 main(argc, argv)
 139 int     argc;
 140 char *  argv[];
 141 {
 142         register int            i;
 143         register int            c;
 144         register int            vflag;
 145         register char *         cutoff;
 146         register int            cutyear;
 147         register long           cuttime;
 148         char **                 fakeenv;
 149         time_t                  now;
 150         time_t                  t;
 151         time_t                  newt;
 152 #ifndef __APPLE__
 153 // <rdar://problem/6013740>
 154 // The approach of walking through every day from the minimum
 155 // possible time_t value to the maximum possible time_t value
 156 // falls apart with 64-bit time_t (takes too long to iterate,
 157 // and causes gmtime(3) and localtime(3) to return EOVERFLOW
 158 // which this code does not anticipate).  Limiting the time_t
 159 // range to [INT_MIN:INT_MAX] even on LP64.
 160         time_t                  hibit;
 161 #endif
 162         struct tm               tm;
 163         struct tm               newtm;
 164
 165         INITIALIZE(cuttime);
 166 #if HAVE_GETTEXT - 0
 167         (void) setlocale(LC_MESSAGES, "");
 168 #ifdef TZ_DOMAINDIR
 169         (void) bindtextdomain(TZ_DOMAIN, TZ_DOMAINDIR);
 170 #endif /* defined(TEXTDOMAINDIR) */
 171         (void) textdomain(TZ_DOMAIN);
 172 #endif /* HAVE_GETTEXT - 0 */
 173         for (i = 1; i < argc; ++i)
 174                 if (strcmp(argv[i], "--version") == 0) {
 175                         errx(EXIT_SUCCESS, "%s", elsieid);
 176                 }
 177         vflag = 0;
 178         cutoff = NULL;
 179         while ((c = getopt(argc, argv, "c:v")) == 'c' || c == 'v')
 180                 if (c == 'v')
 181                         vflag = 1;
 182                 else    cutoff = optarg;
 183         if ((c != -1) ||
 184                 (optind == argc - 1 && strcmp(argv[optind], "=") == 0)) {
 185                         usage();
 186         }
 187         if (cutoff != NULL) {
 188                 int     y;
 189
 190                 cutyear = atoi(cutoff);
 191                 cuttime = 0;
 192                 for (y = EPOCH_YEAR; y < cutyear; ++y)
 193                         cuttime += DAYSPERNYEAR + isleap(y);
 194                 cuttime *= SECSPERHOUR * HOURSPERDAY;
 195         }
 196         (void) time(&now);
 197         longest = 0;
 198         for (i = optind; i < argc; ++i)
 199                 if (strlen(argv[i]) > longest)
 200                         longest = strlen(argv[i]);
 201 #ifndef __APPLE__
 202         for (hibit = 1; (hibit << 1) != 0; hibit <<= 1)
 203                 continue;
 204 #endif
 205         {
 206                 register int    from;
 207                 register int    to;
 208
 209                 for (i = 0;  environ[i] != NULL;  ++i)
 210                         continue;
 211                 fakeenv = (char **) malloc((size_t) ((i + 2) *
 212                         sizeof *fakeenv));
 213                 if (fakeenv == NULL ||
 214                         (fakeenv[0] = (char *) malloc((size_t) (longest +
 215                                 4))) == NULL)
 216                                         errx(EXIT_FAILURE,
 217                                              _("malloc() failed"));
 218                 to = 0;
 219                 (void) strcpy(fakeenv[to++], "TZ=");
 220                 for (from = 0; environ[from] != NULL; ++from)
 221                         if (strncmp(environ[from], "TZ=", 3) != 0)
 222                                 fakeenv[to++] = environ[from];
 223                 fakeenv[to] = NULL;
 224                 environ = fakeenv;
 225         }
 226         for (i = optind; i < argc; ++i) {
 227                 static char     buf[MAX_STRING_LENGTH];
 228
 229                 (void) strcpy(&fakeenv[0][3], argv[i]);
 230                 if (!vflag) {
 231                         show(argv[i], now, FALSE);
 232                         continue;
 233                 }
 234                 /*
 235                 ** Get lowest value of t.
 236                 */
 237 #ifdef __APPLE__
 238                 t = INT_MIN;
 239 #else
 240                 t = hibit;
 241                 if (t > 0)              /* time_t is unsigned */
 242                         t = 0;
 243 #endif
 244                 show(argv[i], t, TRUE);
 245                 t += SECSPERHOUR * HOURSPERDAY;
 246                 show(argv[i], t, TRUE);
 247                 tm = *localtime(&t);
 248                 (void) strncpy(buf, abbr(&tm), (sizeof buf) - 1);
 249                 for ( ; ; ) {
 250                         if (cutoff != NULL && t >= cuttime)
 251                                 break;
 252                         newt = t + SECSPERHOUR * 12;
 253                         if (cutoff != NULL && newt >= cuttime)
 254                                 break;
 255 #ifdef __APPLE__
 256                         if (newt > INT_MAX)
 257                                 break;
 258 #else
 259                         if (newt <= t)
 260                                 break;
 261 #endif
 262                         newtm = *localtime(&newt);
 263                         if (delta(&newtm, &tm) != (newt - t) ||
 264                                 newtm.tm_isdst != tm.tm_isdst ||
 265                                 strcmp(abbr(&newtm), buf) != 0) {
 266                                         newt = hunt(argv[i], t, newt);
 267                                         newtm = *localtime(&newt);
 268                                         (void) strncpy(buf, abbr(&newtm),
 269                                                 (sizeof buf) - 1);
 270                         }
 271                         t = newt;
 272                         tm = newtm;
 273                 }
 274                 /*
 275                 ** Get highest value of t.
 276                 */
 277 #ifdef __APPLE__
 278                 t = INT_MAX;
 279 #else
 280                 t = ~((time_t) 0);
 281                 if (t < 0)              /* time_t is signed */
 282                         t &= ~hibit;
 283 #endif
 284                 t -= SECSPERHOUR * HOURSPERDAY;
 285                 show(argv[i], t, TRUE);
 286                 t += SECSPERHOUR * HOURSPERDAY;
 287                 show(argv[i], t, TRUE);
 288         }
 289         if (fflush(stdout) || ferror(stdout))
 290                 errx(EXIT_FAILURE, _("error writing standard output"));
 291         exit(EXIT_SUCCESS);
 292
 293         /* gcc -Wall pacifier */
 294         for ( ; ; )
 295                 continue;
 296 }
 297
 298 static void
 299 usage(void)
 300 {
 301         fprintf(stderr,
 302 _("usage: zdump [--version] [-v] [-c cutoff] zonename ...\n"));
 303         exit(EXIT_FAILURE);
 304 }
 305
 306 static time_t
 307 hunt(name, lot, hit)
 308 char *  name;
 309 time_t  lot;
 310 time_t  hit;
 311 {
 312         time_t          t;
 313         struct tm       lotm;
 314         struct tm       tm;
 315         static char     loab[MAX_STRING_LENGTH];
 316
 317         lotm = *localtime(&lot);
 318         (void) strncpy(loab, abbr(&lotm), (sizeof loab) - 1);
 319         while ((hit - lot) >= 2) {
 320                 t = lot / 2 + hit / 2;
 321                 if (t <= lot)
 322                         ++t;
 323                 else if (t >= hit)
 324                         --t;
 325                 tm = *localtime(&t);
 326                 if (delta(&tm, &lotm) == (t - lot) &&
 327                         tm.tm_isdst == lotm.tm_isdst &&
 328                         strcmp(abbr(&tm), loab) == 0) {
 329                                 lot = t;
 330                                 lotm = tm;
 331                 } else  hit = t;
 332         }
 333         show(name, lot, TRUE);
 334         show(name, hit, TRUE);
 335         return hit;
 336 }
 337
 338 /*
 339 ** Thanks to Paul Eggert (eggert@twinsun.com) for logic used in delta.
 340 */
 341
 342 static long
 343 delta(newp, oldp)
 344 struct tm *     newp;
 345 struct tm *     oldp;
 346 {
 347         long    result;
 348         int     tmy;
 349
 350         if (newp->tm_year < oldp->tm_year)
 351                 return -delta(oldp, newp);
 352         result = 0;
 353         for (tmy = oldp->tm_year; tmy < newp->tm_year; ++tmy)
 354                 result += DAYSPERNYEAR + isleap(tmy + TM_YEAR_BASE);
 355         result += newp->tm_yday - oldp->tm_yday;
 356         result *= HOURSPERDAY;
 357         result += newp->tm_hour - oldp->tm_hour;
 358         result *= MINSPERHOUR;
 359         result += newp->tm_min - oldp->tm_min;
 360         result *= SECSPERMIN;
 361         result += newp->tm_sec - oldp->tm_sec;
 362         return result;
 363 }
 364
 365 static void
 366 show(zone, t, v)
 367 char *  zone;
 368 time_t  t;
 369 int     v;
 370 {
 371         struct tm *     tmp;
 372
 373         (void) printf("%-*s  ", (int) longest, zone);
 374         if (v)
 375                 (void) printf("%.24s UTC = ", asctime(gmtime(&t)));
 376         tmp = localtime(&t);
 377         (void) printf("%.24s", asctime(tmp));
 378         if (*abbr(tmp) != '\0')
 379                 (void) printf(" %s", abbr(tmp));
 380         if (v) {
 381                 (void) printf(" isdst=%d", tmp->tm_isdst);
 382 #ifdef TM_GMTOFF
 383                 (void) printf(" gmtoff=%ld", tmp->TM_GMTOFF);
 384 #endif /* defined TM_GMTOFF */
 385         }
 386         (void) printf("\n");
 387 }
 388
 389 static char *
 390 abbr(tmp)
 391 struct tm *     tmp;
 392 {
 393         register char * result;
 394         static char     nada;
 395
 396         if (tmp->tm_isdst != 0 && tmp->tm_isdst != 1)
 397                 return &nada;
 398         result = tzname[tmp->tm_isdst];
 399         return (result == NULL) ? &nada : result;
 400 }