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 1.4 2004/12/18 22:48:15 swildner 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 extern char **  environ;
 122 extern char *   tzname[2];
 123
 124 static char     *abbr(struct tm *tmp);
 125 static long      delta(struct tm *newp, struct tm *oldp);
 126 static time_t    hunt(char *name, time_t lot, time_t hit);
 127 static size_t    longest;
 128 static char     *progname;
 129 static void      show(char *zone, time_t t, int v);
 130 static void      usage(void);
 131
 132 int
 133 main(int argc, char *argv[])
 134 {
 135         int i;
 136         int c;
 137         int vflag;
 138         char *cutoff;
 139         int cutyear;
 140         long cuttime;
 141         char **fakeenv;
 142         time_t now;
 143         time_t t;
 144         time_t newt;
 145         time_t hibit;
 146         struct tm tm;
 147         struct tm newtm;
 148
 149         INITIALIZE(cuttime);
 150 #if HAVE_GETTEXT - 0
 151         setlocale(LC_MESSAGES, "");
 152 #ifdef TZ_DOMAINDIR
 153         bindtextdomain(TZ_DOMAIN, TZ_DOMAINDIR);
 154 #endif /* defined(TEXTDOMAINDIR) */
 155         textdomain(TZ_DOMAIN);
 156 #endif /* HAVE_GETTEXT - 0 */
 157         vflag = 0;
 158         cutoff = NULL;
 159         while ((c = getopt(argc, argv, "c:v")) == 'c' || c == 'v')
 160                 if (c == 'v')
 161                         vflag = 1;
 162                 else    cutoff = optarg;
 163         if ((c != EOF && c != -1) ||
 164                 (optind == argc - 1 && strcmp(argv[optind], "=") == 0)) {
 165                         usage();
 166         }
 167         if (cutoff != NULL) {
 168                 int     y;
 169
 170                 cutyear = atoi(cutoff);
 171                 cuttime = 0;
 172                 for (y = EPOCH_YEAR; y < cutyear; ++y)
 173                         cuttime += DAYSPERNYEAR + isleap(y);
 174                 cuttime *= SECSPERHOUR * HOURSPERDAY;
 175         }
 176         time(&now);
 177         longest = 0;
 178         for (i = optind; i < argc; ++i)
 179                 if (strlen(argv[i]) > longest)
 180                         longest = strlen(argv[i]);
 181         for (hibit = 1; (hibit << 1) != 0; hibit <<= 1)
 182                 continue;
 183         {
 184                 int from;
 185                 int to;
 186
 187                 for (i = 0;  environ[i] != NULL;  ++i)
 188                         continue;
 189                 fakeenv = (char **) malloc((size_t) ((i + 2) *
 190                         sizeof *fakeenv));
 191                 if (fakeenv == NULL ||
 192                         (fakeenv[0] = (char *) malloc((size_t) (longest +
 193                                 4))) == NULL)
 194                                         errx(EXIT_FAILURE,
 195                                              _("malloc() failed"));
 196                 to = 0;
 197                 strcpy(fakeenv[to++], "TZ=");
 198                 for (from = 0; environ[from] != NULL; ++from)
 199                         if (strncmp(environ[from], "TZ=", 3) != 0)
 200                                 fakeenv[to++] = environ[from];
 201                 fakeenv[to] = NULL;
 202                 environ = fakeenv;
 203         }
 204         for (i = optind; i < argc; ++i) {
 205                 static char     buf[MAX_STRING_LENGTH];
 206
 207                 strcpy(&fakeenv[0][3], argv[i]);
 208                 if (!vflag) {
 209                         show(argv[i], now, FALSE);
 210                         continue;
 211                 }
 212                 /*
 213                 ** Get lowest value of t.
 214                 */
 215                 t = hibit;
 216                 if (t > 0)              /* time_t is unsigned */
 217                         t = 0;
 218                 show(argv[i], t, TRUE);
 219                 t += SECSPERHOUR * HOURSPERDAY;
 220                 show(argv[i], t, TRUE);
 221                 tm = *localtime(&t);
 222                 strncpy(buf, abbr(&tm), (sizeof buf) - 1);
 223                 for ( ; ; ) {
 224                         if (cutoff != NULL && t >= cuttime)
 225                                 break;
 226                         newt = t + SECSPERHOUR * 12;
 227                         if (cutoff != NULL && newt >= cuttime)
 228                                 break;
 229                         if (newt <= t)
 230                                 break;
 231                         newtm = *localtime(&newt);
 232                         if (delta(&newtm, &tm) != (newt - t) ||
 233                                 newtm.tm_isdst != tm.tm_isdst ||
 234                                 strcmp(abbr(&newtm), buf) != 0) {
 235                                         newt = hunt(argv[i], t, newt);
 236                                         newtm = *localtime(&newt);
 237                                         strncpy(buf, abbr(&newtm),
 238                                                 (sizeof buf) - 1);
 239                         }
 240                         t = newt;
 241                         tm = newtm;
 242                 }
 243                 /*
 244                 ** Get highest value of t.
 245                 */
 246                 t = ~((time_t) 0);
 247                 if (t < 0)              /* time_t is signed */
 248                         t &= ~hibit;
 249                 t -= SECSPERHOUR * HOURSPERDAY;
 250                 show(argv[i], t, TRUE);
 251                 t += SECSPERHOUR * HOURSPERDAY;
 252                 show(argv[i], t, TRUE);
 253         }
 254         if (fflush(stdout) || ferror(stdout))
 255                 errx(EXIT_FAILURE, _("error writing standard output"));
 256         exit(EXIT_SUCCESS);
 257
 258         /* gcc -Wall pacifier */
 259         for ( ; ; )
 260                 continue;
 261 }
 262
 263 static void
 264 usage(void)
 265 {
 266         fprintf(stderr, _("usage: zdump [-v] [-c cutoff] zonename ...\n"));
 267         exit(EXIT_FAILURE);
 268 }
 269
 270 static time_t
 271 hunt(char *name, time_t lot, time_t hit)
 272 {
 273         time_t          t;
 274         struct tm       lotm;
 275         struct tm       tm;
 276         static char     loab[MAX_STRING_LENGTH];
 277
 278         lotm = *localtime(&lot);
 279         strncpy(loab, abbr(&lotm), (sizeof loab) - 1);
 280         while ((hit - lot) >= 2) {
 281                 t = lot / 2 + hit / 2;
 282                 if (t <= lot)
 283                         ++t;
 284                 else if (t >= hit)
 285                         --t;
 286                 tm = *localtime(&t);
 287                 if (delta(&tm, &lotm) == (t - lot) &&
 288                         tm.tm_isdst == lotm.tm_isdst &&
 289                         strcmp(abbr(&tm), loab) == 0) {
 290                                 lot = t;
 291                                 lotm = tm;
 292                 } else  hit = t;
 293         }
 294         show(name, lot, TRUE);
 295         show(name, hit, TRUE);
 296         return hit;
 297 }
 298
 299 /*
 300 ** Thanks to Paul Eggert (eggert@twinsun.com) for logic used in delta.
 301 */
 302
 303 static long
 304 delta(struct tm *newp, struct tm *oldp)
 305 {
 306         long    result;
 307         int     tmy;
 308
 309         if (newp->tm_year < oldp->tm_year)
 310                 return -delta(oldp, newp);
 311         result = 0;
 312         for (tmy = oldp->tm_year; tmy < newp->tm_year; ++tmy)
 313                 result += DAYSPERNYEAR + isleap(tmy + TM_YEAR_BASE);
 314         result += newp->tm_yday - oldp->tm_yday;
 315         result *= HOURSPERDAY;
 316         result += newp->tm_hour - oldp->tm_hour;
 317         result *= MINSPERHOUR;
 318         result += newp->tm_min - oldp->tm_min;
 319         result *= SECSPERMIN;
 320         result += newp->tm_sec - oldp->tm_sec;
 321         return result;
 322 }
 323
 324 static void
 325 show(char *zone, time_t t, int v)
 326 {
 327         struct tm *     tmp;
 328
 329         printf("%-*s  ", (int) longest, zone);
 330         if (v)
 331                 printf("%.24s UTC = ", asctime(gmtime(&t)));
 332         tmp = localtime(&t);
 333         printf("%.24s", asctime(tmp));
 334         if (*abbr(tmp) != '\0')
 335                 printf(" %s", abbr(tmp));
 336         if (v) {
 337                 printf(" isdst=%d", tmp->tm_isdst);
 338 #ifdef TM_GMTOFF
 339                 printf(" gmtoff=%ld", tmp->TM_GMTOFF);
 340 #endif /* defined TM_GMTOFF */
 341         }
 342         printf("\n");
 343 }
 344
 345 static char *
 346 abbr(struct tm *tmp)
 347 {
 348         char * result;
 349         static char nada;
 350
 351         if (tmp->tm_isdst != 0 && tmp->tm_isdst != 1)
 352                 return &nada;
 353         result = tzname[tmp->tm_isdst];
 354         return (result == NULL) ? &nada : result;
 355 }