zdump.c revision 1.5
1 /* $NetBSD: zdump.c,v 1.5 1997/06/18 01:13:00 jtc Exp $ */ 2 3 #ifndef lint 4 #ifndef NOID 5 static char elsieid[] = "@(#)zdump.c 7.26"; 6 #endif /* !defined NOID */ 7 #endif /* !defined 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 "stdio.h" /* for stdout, stderr, perror */ 16 #include "string.h" /* for strcpy */ 17 #include "sys/types.h" /* for time_t */ 18 #include "time.h" /* for struct tm */ 19 #include "stdlib.h" /* for exit, malloc, atoi */ 20 21 #ifndef MAX_STRING_LENGTH 22 #define MAX_STRING_LENGTH 1024 23 #endif /* !defined MAX_STRING_LENGTH */ 24 25 #ifndef TRUE 26 #define TRUE 1 27 #endif /* !defined TRUE */ 28 29 #ifndef FALSE 30 #define FALSE 0 31 #endif /* !defined FALSE */ 32 33 #ifndef EXIT_SUCCESS 34 #define EXIT_SUCCESS 0 35 #endif /* !defined EXIT_SUCCESS */ 36 37 #ifndef EXIT_FAILURE 38 #define EXIT_FAILURE 1 39 #endif /* !defined EXIT_FAILURE */ 40 41 #ifndef SECSPERMIN 42 #define SECSPERMIN 60 43 #endif /* !defined SECSPERMIN */ 44 45 #ifndef MINSPERHOUR 46 #define MINSPERHOUR 60 47 #endif /* !defined MINSPERHOUR */ 48 49 #ifndef SECSPERHOUR 50 #define SECSPERHOUR (SECSPERMIN * MINSPERHOUR) 51 #endif /* !defined SECSPERHOUR */ 52 53 #ifndef HOURSPERDAY 54 #define HOURSPERDAY 24 55 #endif /* !defined HOURSPERDAY */ 56 57 #ifndef EPOCH_YEAR 58 #define EPOCH_YEAR 1970 59 #endif /* !defined EPOCH_YEAR */ 60 61 #ifndef TM_YEAR_BASE 62 #define TM_YEAR_BASE 1900 63 #endif /* !defined TM_YEAR_BASE */ 64 65 #ifndef DAYSPERNYEAR 66 #define DAYSPERNYEAR 365 67 #endif /* !defined DAYSPERNYEAR */ 68 69 #ifndef isleap 70 #define isleap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0) 71 #endif /* !defined isleap */ 72 73 #if HAVE_GETTEXT - 0 74 #include "locale.h" /* for setlocale */ 75 #include "libintl.h" 76 #endif /* HAVE_GETTEXT - 0 */ 77 78 #ifndef GNUC_or_lint 79 #ifdef lint 80 #define GNUC_or_lint 81 #endif /* defined lint */ 82 #ifndef lint 83 #ifdef __GNUC__ 84 #define GNUC_or_lint 85 #endif /* defined __GNUC__ */ 86 #endif /* !defined lint */ 87 #endif /* !defined GNUC_or_lint */ 88 89 #ifndef INITIALIZE 90 #ifdef GNUC_or_lint 91 #define INITIALIZE(x) ((x) = 0) 92 #endif /* defined GNUC_or_lint */ 93 #ifndef GNUC_or_lint 94 #define INITIALIZE(x) 95 #endif /* !defined GNUC_or_lint */ 96 #endif /* !defined INITIALIZE */ 97 98 /* 99 ** For the benefit of GNU folk... 100 ** `_(MSGID)' uses the current locale's message library string for MSGID. 101 ** The default is to use gettext if available, and use MSGID otherwise. 102 */ 103 104 #ifndef _ 105 #if HAVE_GETTEXT - 0 106 #define _(msgid) gettext(msgid) 107 #else /* !(HAVE_GETTEXT - 0) */ 108 #define _(msgid) msgid 109 #endif /* !(HAVE_GETTEXT - 0) */ 110 #endif /* !defined _ */ 111 112 #ifndef TZ_DOMAIN 113 #define TZ_DOMAIN "tz" 114 #endif /* !defined TZ_DOMAIN */ 115 116 #ifndef P 117 #ifdef __STDC__ 118 #define P(x) x 119 #endif /* defined __STDC__ */ 120 #ifndef __STDC__ 121 #define P(x) () 122 #endif /* !defined __STDC__ */ 123 #endif /* !defined P */ 124 125 extern char ** environ; 126 extern int getopt P((int argc, char * const argv[], 127 const char * options)); 128 extern char * optarg; 129 extern int optind; 130 extern char * tzname[2]; 131 132 static char * abbr P((struct tm * tmp)); 133 static long delta P((struct tm * newp, struct tm * oldp)); 134 static time_t hunt P((char * name, time_t lot, time_t hit)); 135 static size_t longest; 136 static char * progname; 137 static void show P((char * zone, time_t t, int v)); 138 139 int 140 main(argc, argv) 141 int argc; 142 char * argv[]; 143 { 144 register int i; 145 register int c; 146 register int vflag; 147 register char * cutoff; 148 register int cutyear; 149 register long cuttime; 150 char ** fakeenv; 151 time_t now; 152 time_t t; 153 time_t newt; 154 time_t hibit; 155 struct tm tm; 156 struct tm newtm; 157 158 INITIALIZE(cuttime); 159 #if HAVE_GETTEXT - 0 160 (void) setlocale(LC_MESSAGES, ""); 161 #ifdef TZ_DOMAINDIR 162 (void) bindtextdomain(TZ_DOMAIN, TZ_DOMAINDIR); 163 #endif /* defined(TEXTDOMAINDIR) */ 164 (void) textdomain(TZ_DOMAIN); 165 #endif /* HAVE_GETTEXT - 0 */ 166 progname = argv[0]; 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 (void) fprintf(stderr, 176 _("%s: usage is %s [ -v ] [ -c cutoff ] zonename ...\n"), 177 argv[0], argv[0]); 178 (void) exit(EXIT_FAILURE); 179 } 180 if (cutoff != NULL) { 181 int y; 182 183 cutyear = atoi(cutoff); 184 cuttime = 0; 185 for (y = EPOCH_YEAR; y < cutyear; ++y) 186 cuttime += DAYSPERNYEAR + isleap(y); 187 cuttime *= SECSPERHOUR * HOURSPERDAY; 188 } 189 (void) time(&now); 190 longest = 0; 191 for (i = optind; i < argc; ++i) 192 if (strlen(argv[i]) > longest) 193 longest = strlen(argv[i]); 194 for (hibit = 1; (hibit << 1) != 0; hibit <<= 1) 195 continue; 196 { 197 register int from; 198 register int to; 199 200 for (i = 0; environ[i] != NULL; ++i) 201 continue; 202 fakeenv = (char **) malloc((size_t) ((i + 2) * 203 sizeof *fakeenv)); 204 if (fakeenv == NULL || 205 (fakeenv[0] = (char *) malloc(longest + 4)) == NULL) { 206 (void) perror(progname); 207 (void) exit(EXIT_FAILURE); 208 } 209 to = 0; 210 (void)strcpy(fakeenv[to++], "TZ="); /* XXX strcpy is safe */ 211 for (from = 0; environ[from] != NULL; ++from) 212 if (strncmp(environ[from], "TZ=", 3) != 0) 213 fakeenv[to++] = environ[from]; 214 fakeenv[to] = NULL; 215 environ = fakeenv; 216 } 217 for (i = optind; i < argc; ++i) { 218 static char buf[MAX_STRING_LENGTH]; 219 220 (void) strcpy(&fakeenv[0][3], argv[i]); /* XXX strcpy is safe */ 221 if (!vflag) { 222 show(argv[i], now, FALSE); 223 continue; 224 } 225 /* 226 ** Get lowest value of t. 227 */ 228 t = hibit; 229 if (t > 0) /* time_t is unsigned */ 230 t = 0; 231 show(argv[i], t, TRUE); 232 t += SECSPERHOUR * HOURSPERDAY; 233 show(argv[i], t, TRUE); 234 tm = *localtime(&t); 235 (void) strncpy(buf, abbr(&tm), (sizeof buf) - 1); 236 for ( ; ; ) { 237 if (cutoff != NULL && t >= cuttime) 238 break; 239 newt = t + SECSPERHOUR * 12; 240 if (cutoff != NULL && newt >= cuttime) 241 break; 242 if (newt <= t) 243 break; 244 newtm = *localtime(&newt); 245 if (delta(&newtm, &tm) != (newt - t) || 246 newtm.tm_isdst != tm.tm_isdst || 247 strcmp(abbr(&newtm), buf) != 0) { 248 newt = hunt(argv[i], t, newt); 249 newtm = *localtime(&newt); 250 (void) strncpy(buf, abbr(&newtm), 251 (sizeof buf) - 1); 252 } 253 t = newt; 254 tm = newtm; 255 } 256 /* 257 ** Get highest value of t. 258 */ 259 t = ~((time_t) 0); 260 if (t < 0) /* time_t is signed */ 261 t &= ~hibit; 262 t -= SECSPERHOUR * HOURSPERDAY; 263 show(argv[i], t, TRUE); 264 t += SECSPERHOUR * HOURSPERDAY; 265 show(argv[i], t, TRUE); 266 } 267 if (fflush(stdout) || ferror(stdout)) { 268 (void) fprintf(stderr, _("%s: Error writing standard output "), 269 argv[0]); 270 (void) perror(_("standard output")); 271 (void) exit(EXIT_FAILURE); 272 } 273 exit(EXIT_SUCCESS); 274 275 /* gcc -Wall pacifier */ 276 for ( ; ; ) 277 continue; 278 } 279 280 static time_t 281 hunt(name, lot, hit) 282 char * name; 283 time_t lot; 284 time_t hit; 285 { 286 time_t t; 287 struct tm lotm; 288 struct tm tm; 289 static char loab[MAX_STRING_LENGTH]; 290 291 lotm = *localtime(&lot); 292 (void) strncpy(loab, abbr(&lotm), (sizeof loab) - 1); 293 while ((hit - lot) >= 2) { 294 t = lot / 2 + hit / 2; 295 if (t <= lot) 296 ++t; 297 else if (t >= hit) 298 --t; 299 tm = *localtime(&t); 300 if (delta(&tm, &lotm) == (t - lot) && 301 tm.tm_isdst == lotm.tm_isdst && 302 strcmp(abbr(&tm), loab) == 0) { 303 lot = t; 304 lotm = tm; 305 } else hit = t; 306 } 307 show(name, lot, TRUE); 308 show(name, hit, TRUE); 309 return hit; 310 } 311 312 /* 313 ** Thanks to Paul Eggert (eggert (at) twinsun.com) for logic used in delta. 314 */ 315 316 static long 317 delta(newp, oldp) 318 struct tm * newp; 319 struct tm * oldp; 320 { 321 long result; 322 int tmy; 323 324 if (newp->tm_year < oldp->tm_year) 325 return -delta(oldp, newp); 326 result = 0; 327 for (tmy = oldp->tm_year; tmy < newp->tm_year; ++tmy) 328 result += DAYSPERNYEAR + isleap(tmy + TM_YEAR_BASE); 329 result += newp->tm_yday - oldp->tm_yday; 330 result *= HOURSPERDAY; 331 result += newp->tm_hour - oldp->tm_hour; 332 result *= MINSPERHOUR; 333 result += newp->tm_min - oldp->tm_min; 334 result *= SECSPERMIN; 335 result += newp->tm_sec - oldp->tm_sec; 336 return result; 337 } 338 339 static void 340 show(zone, t, v) 341 char * zone; 342 time_t t; 343 int v; 344 { 345 struct tm * tmp; 346 347 (void) printf("%-*s ", (int) longest, zone); 348 if (v) 349 (void) printf("%.24s GMT = ", asctime(gmtime(&t))); 350 tmp = localtime(&t); 351 (void) printf("%.24s", asctime(tmp)); 352 if (*abbr(tmp) != '\0') 353 (void) printf(" %s", abbr(tmp)); 354 if (v) { 355 (void) printf(" isdst=%d", tmp->tm_isdst); 356 #ifdef TM_GMTOFF 357 (void) printf(" gmtoff=%ld", tmp->TM_GMTOFF); 358 #endif /* defined TM_GMTOFF */ 359 } 360 (void) printf("\n"); 361 } 362 363 static char * 364 abbr(tmp) 365 struct tm * tmp; 366 { 367 register char * result; 368 static char nada; 369 370 if (tmp->tm_isdst != 0 && tmp->tm_isdst != 1) 371 return &nada; 372 result = tzname[tmp->tm_isdst]; 373 return (result == NULL) ? &nada : result; 374 } 375
Indexes created Sat Sep 20 22:09:52 GMT 2025