usr.sbin/zic/zdump.c

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