usr.sbin/zic/zdump.c

   1 #ifndef lint
   2 #ifndef NOID
   3 static char     elsieid[] = "@(#)zdump.c        7.28";
   4 #endif /* !defined NOID */
   5 #endif /* !defined lint */
   6
   7 /*
   8  * @(#)zdump.c  7.28
   9  * $FreeBSD: src/usr.sbin/zic/zdump.c,v 1.7 1999/08/28 01:21:19 peter Exp $
  10  * $DragonFly: src/usr.sbin/zic/zdump.c,v 1.2 2003/06/17 04:30:05 dillon Exp $
  11  */
  12 /*
  13 ** This code has been made independent of the rest of the time
  14 ** conversion package to increase confidence in the verification it provides.
  15 ** You can use this code to help in verifying other implementations.
  16 */
  17
  18 #include <err.h>
  19 #include <stdio.h>      /* for stdout, stderr */
  20 #include <stdlib.h>     /* for exit, malloc, atoi */
  21 #include <string.h>     /* for strcpy */
  22 #include <sys/types.h>  /* for time_t */
  23 #include <time.h>       /* for struct tm */
  24 #include <unistd.h>
  25
  26 #ifndef MAX_STRING_LENGTH
  27 #define MAX_STRING_LENGTH       1024
  28 #endif /* !defined MAX_STRING_LENGTH */
  29
  30 #ifndef TRUE
  31 #define TRUE            1
  32 #endif /* !defined TRUE */
  33
  34 #ifndef FALSE
  35 #define FALSE           0
  36 #endif /* !defined FALSE */
  37
  38 #ifndef EXIT_SUCCESS
  39 #define EXIT_SUCCESS    0
  40 #endif /* !defined EXIT_SUCCESS */
  41
  42 #ifndef EXIT_FAILURE
  43 #define EXIT_FAILURE    1
  44 #endif /* !defined EXIT_FAILURE */
  45
  46 #ifndef SECSPERMIN
  47 #define SECSPERMIN      60
  48 #endif /* !defined SECSPERMIN */
  49
  50 #ifndef MINSPERHOUR
  51 #define MINSPERHOUR     60
  52 #endif /* !defined MINSPERHOUR */
  53
  54 #ifndef SECSPERHOUR
  55 #define SECSPERHOUR     (SECSPERMIN * MINSPERHOUR)
  56 #endif /* !defined SECSPERHOUR */
  57
  58 #ifndef HOURSPERDAY
  59 #define HOURSPERDAY     24
  60 #endif /* !defined HOURSPERDAY */
  61
  62 #ifndef EPOCH_YEAR
  63 #define EPOCH_YEAR      1970
  64 #endif /* !defined EPOCH_YEAR */
  65
  66 #ifndef TM_YEAR_BASE
  67 #define TM_YEAR_BASE    1900
  68 #endif /* !defined TM_YEAR_BASE */
  69
  70 #ifndef DAYSPERNYEAR
  71 #define DAYSPERNYEAR    365
  72 #endif /* !defined DAYSPERNYEAR */
  73
  74 #ifndef isleap
  75 #define isleap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0)
  76 #endif /* !defined isleap */
  77
  78 #if HAVE_GETTEXT - 0
  79 #include "locale.h"     /* for setlocale */
  80 #include "libintl.h"
  81 #endif /* HAVE_GETTEXT - 0 */
  82
  83 #ifndef GNUC_or_lint
  84 #ifdef lint
  85 #define GNUC_or_lint
  86 #endif /* defined lint */
  87 #ifndef lint
  88 #ifdef __GNUC__
  89 #define GNUC_or_lint
  90 #endif /* defined __GNUC__ */
  91 #endif /* !defined lint */
  92 #endif /* !defined GNUC_or_lint */
  93
  94 #ifndef INITIALIZE
  95 #ifdef GNUC_or_lint
  96 #define INITIALIZE(x)   ((x) = 0)
  97 #endif /* defined GNUC_or_lint */
  98 #ifndef GNUC_or_lint
  99 #define INITIALIZE(x)
 100 #endif /* !defined GNUC_or_lint */
 101 #endif /* !defined INITIALIZE */
 102
 103 /*
 104 ** For the benefit of GNU folk...
 105 ** `_(MSGID)' uses the current locale's message library string for MSGID.
 106 ** The default is to use gettext if available, and use MSGID otherwise.
 107 */
 108
 109 #ifndef _
 110 #if HAVE_GETTEXT - 0
 111 #define _(msgid) gettext(msgid)
 112 #else /* !(HAVE_GETTEXT - 0) */
 113 #define _(msgid) msgid
 114 #endif /* !(HAVE_GETTEXT - 0) */
 115 #endif /* !defined _ */
 116
 117 #ifndef TZ_DOMAIN
 118 #define TZ_DOMAIN "tz"
 119 #endif /* !defined TZ_DOMAIN */
 120
 121 #ifndef P
 122 #ifdef __STDC__
 123 #define P(x)    x
 124 #endif /* defined __STDC__ */
 125 #ifndef __STDC__
 126 #define P(x)    ()
 127 #endif /* !defined __STDC__ */
 128 #endif /* !defined P */
 129
 130 extern char **  environ;
 131 extern char *   tzname[2];
 132
 133 static char *   abbr P((struct tm * tmp));
 134 static long     delta P((struct tm * newp, struct tm * oldp));
 135 static time_t   hunt P((char * name, time_t lot, time_t hit));
 136 static size_t   longest;
 137 static char *   progname;
 138 static void     show P((char * zone, time_t t, int v));
 139 static void     usage(void);
 140
 141 int
 142 main(argc, argv)
 143 int     argc;
 144 char *  argv[];
 145 {
 146         register int            i;
 147         register int            c;
 148         register int            vflag;
 149         register char *         cutoff;
 150         register int            cutyear;
 151         register long           cuttime;
 152         char **                 fakeenv;
 153         time_t                  now;
 154         time_t                  t;
 155         time_t                  newt;
 156         time_t                  hibit;
 157         struct tm               tm;
 158         struct tm               newtm;
 159
 160         INITIALIZE(cuttime);
 161 #if HAVE_GETTEXT - 0
 162         (void) setlocale(LC_MESSAGES, "");
 163 #ifdef TZ_DOMAINDIR
 164         (void) bindtextdomain(TZ_DOMAIN, TZ_DOMAINDIR);
 165 #endif /* defined(TEXTDOMAINDIR) */
 166         (void) textdomain(TZ_DOMAIN);
 167 #endif /* HAVE_GETTEXT - 0 */
 168         vflag = 0;
 169         cutoff = NULL;
 170         while ((c = getopt(argc, argv, "c:v")) == 'c' || c == 'v')
 171                 if (c == 'v')
 172                         vflag = 1;
 173                 else    cutoff = optarg;
 174         if ((c != EOF && c != -1) ||
 175                 (optind == argc - 1 && strcmp(argv[optind], "=") == 0)) {
 176                         usage();
 177         }
 178         if (cutoff != NULL) {
 179                 int     y;
 180
 181                 cutyear = atoi(cutoff);
 182                 cuttime = 0;
 183                 for (y = EPOCH_YEAR; y < cutyear; ++y)
 184                         cuttime += DAYSPERNYEAR + isleap(y);
 185                 cuttime *= SECSPERHOUR * HOURSPERDAY;
 186         }
 187         (void) time(&now);
 188         longest = 0;
 189         for (i = optind; i < argc; ++i)
 190                 if (strlen(argv[i]) > longest)
 191                         longest = strlen(argv[i]);
 192         for (hibit = 1; (hibit << 1) != 0; hibit <<= 1)
 193                 continue;
 194         {
 195                 register int    from;
 196                 register int    to;
 197
 198                 for (i = 0;  environ[i] != NULL;  ++i)
 199                         continue;
 200                 fakeenv = (char **) malloc((size_t) ((i + 2) *
 201                         sizeof *fakeenv));
 202                 if (fakeenv == NULL ||
 203                         (fakeenv[0] = (char *) malloc((size_t) (longest +
 204                                 4))) == NULL)
 205                                         errx(EXIT_FAILURE,
 206                                              _("malloc() failed"));
 207                 to = 0;
 208                 (void) strcpy(fakeenv[to++], "TZ=");
 209                 for (from = 0; environ[from] != NULL; ++from)
 210                         if (strncmp(environ[from], "TZ=", 3) != 0)
 211                                 fakeenv[to++] = environ[from];
 212                 fakeenv[to] = NULL;
 213                 environ = fakeenv;
 214         }
 215         for (i = optind; i < argc; ++i) {
 216                 static char     buf[MAX_STRING_LENGTH];
 217
 218                 (void) strcpy(&fakeenv[0][3], argv[i]);
 219                 if (!vflag) {
 220                         show(argv[i], now, FALSE);
 221                         continue;
 222                 }
 223                 /*
 224                 ** Get lowest value of t.
 225                 */
 226                 t = hibit;
 227                 if (t > 0)              /* time_t is unsigned */
 228                         t = 0;
 229                 show(argv[i], t, TRUE);
 230                 t += SECSPERHOUR * HOURSPERDAY;
 231                 show(argv[i], t, TRUE);
 232                 tm = *localtime(&t);
 233                 (void) strncpy(buf, abbr(&tm), (sizeof buf) - 1);
 234                 for ( ; ; ) {
 235                         if (cutoff != NULL && t >= cuttime)
 236                                 break;
 237                         newt = t + SECSPERHOUR * 12;
 238                         if (cutoff != NULL && newt >= cuttime)
 239                                 break;
 240                         if (newt <= t)
 241                                 break;
 242                         newtm = *localtime(&newt);
 243                         if (delta(&newtm, &tm) != (newt - t) ||
 244                                 newtm.tm_isdst != tm.tm_isdst ||
 245                                 strcmp(abbr(&newtm), buf) != 0) {
 246                                         newt = hunt(argv[i], t, newt);
 247                                         newtm = *localtime(&newt);
 248                                         (void) strncpy(buf, abbr(&newtm),
 249                                                 (sizeof buf) - 1);
 250                         }
 251                         t = newt;
 252                         tm = newtm;
 253                 }
 254                 /*
 255                 ** Get highest value of t.
 256                 */
 257                 t = ~((time_t) 0);
 258                 if (t < 0)              /* time_t is signed */
 259                         t &= ~hibit;
 260                 t -= SECSPERHOUR * HOURSPERDAY;
 261                 show(argv[i], t, TRUE);
 262                 t += SECSPERHOUR * HOURSPERDAY;
 263                 show(argv[i], t, TRUE);
 264         }
 265         if (fflush(stdout) || ferror(stdout))
 266                 errx(EXIT_FAILURE, _("error writing standard output"));
 267         exit(EXIT_SUCCESS);
 268
 269         /* gcc -Wall pacifier */
 270         for ( ; ; )
 271                 continue;
 272 }
 273
 274 static void
 275 usage(void)
 276 {
 277         fprintf(stderr, _("usage: zdump [-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 }