static char elsieid[] = "@(#)zdump.c 7.31"; /* ** This code has been made independent of the rest of the time ** conversion package to increase confidence in the verification it provides. ** You can use this code to help in verifying other implementations. */ #include "stdio.h" /* for stdout, stderr, perror */ #include "string.h" /* for strcpy */ #include "sys/types.h" /* for time_t */ #include "time.h" /* for struct tm */ #include "stdlib.h" /* for exit, malloc, atoi */ #ifndef MAX_STRING_LENGTH #define MAX_STRING_LENGTH 1024 #endif /* !defined MAX_STRING_LENGTH */ #ifndef TRUE #define TRUE 1 #endif /* !defined TRUE */ #ifndef FALSE #define FALSE 0 #endif /* !defined FALSE */ #ifndef EXIT_SUCCESS #define EXIT_SUCCESS 0 #endif /* !defined EXIT_SUCCESS */ #ifndef EXIT_FAILURE #define EXIT_FAILURE 1 #endif /* !defined EXIT_FAILURE */ #ifndef SECSPERMIN #define SECSPERMIN 60 #endif /* !defined SECSPERMIN */ #ifndef MINSPERHOUR #define MINSPERHOUR 60 #endif /* !defined MINSPERHOUR */ #ifndef SECSPERHOUR #define SECSPERHOUR (SECSPERMIN * MINSPERHOUR) #endif /* !defined SECSPERHOUR */ #ifndef HOURSPERDAY #define HOURSPERDAY 24 #endif /* !defined HOURSPERDAY */ #ifndef EPOCH_YEAR #define EPOCH_YEAR 1970 #endif /* !defined EPOCH_YEAR */ #ifndef TM_YEAR_BASE #define TM_YEAR_BASE 1900 #endif /* !defined TM_YEAR_BASE */ #ifndef DAYSPERNYEAR #define DAYSPERNYEAR 365 #endif /* !defined DAYSPERNYEAR */ #ifndef isleap #define isleap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0) #endif /* !defined isleap */ #if HAVE_GETTEXT - 0 #include "locale.h" /* for setlocale */ #include "libintl.h" #endif /* HAVE_GETTEXT - 0 */ #ifndef GNUC_or_lint #ifdef lint #define GNUC_or_lint #endif /* defined lint */ #ifndef lint #ifdef __GNUC__ #define GNUC_or_lint #endif /* defined __GNUC__ */ #endif /* !defined lint */ #endif /* !defined GNUC_or_lint */ #ifndef INITIALIZE #ifdef GNUC_or_lint #define INITIALIZE(x) ((x) = 0) #endif /* defined GNUC_or_lint */ #ifndef GNUC_or_lint #define INITIALIZE(x) #endif /* !defined GNUC_or_lint */ #endif /* !defined INITIALIZE */ /* ** For the benefit of GNU folk... ** `_(MSGID)' uses the current locale's message library string for MSGID. ** The default is to use gettext if available, and use MSGID otherwise. */ #ifndef _ #if HAVE_GETTEXT - 0 #define _(msgid) gettext(msgid) #else /* !(HAVE_GETTEXT - 0) */ #define _(msgid) msgid #endif /* !(HAVE_GETTEXT - 0) */ #endif /* !defined _ */ #ifndef TZ_DOMAIN #define TZ_DOMAIN "tz" #endif /* !defined TZ_DOMAIN */ #ifndef P #ifdef __STDC__ #define P(x) x #endif /* defined __STDC__ */ #ifndef __STDC__ #define P(x) () #endif /* !defined __STDC__ */ #endif /* !defined P */ extern char ** environ; extern int getopt P((int argc, char * const argv[], const char * options)); extern char * optarg; extern int optind; extern char * tzname[2]; static char * abbr P((struct tm * tmp)); static long delta P((struct tm * newp, struct tm * oldp)); static time_t hunt P((char * name, time_t lot, time_t hit)); static size_t longest; static char * progname; static void show P((char * zone, time_t t, int v)); int main(argc, argv) int argc; char * argv[]; { register int i; register int c; register int vflag; register char * cutoff; register int cutyear; register long cuttime; char ** fakeenv; time_t now; time_t t; time_t newt; time_t hibit; struct tm tm; struct tm newtm; INITIALIZE(cuttime); #if HAVE_GETTEXT - 0 (void) setlocale(LC_CTYPE, ""); (void) setlocale(LC_MESSAGES, ""); #ifdef TZ_DOMAINDIR (void) bindtextdomain(TZ_DOMAIN, TZ_DOMAINDIR); #endif /* defined(TEXTDOMAINDIR) */ (void) textdomain(TZ_DOMAIN); #endif /* HAVE_GETTEXT - 0 */ progname = argv[0]; for (i = 1; i < argc; ++i) if (strcmp(argv[i], "--version") == 0) { (void) printf("%s\n", elsieid); (void) exit(EXIT_SUCCESS); } vflag = 0; cutoff = NULL; while ((c = getopt(argc, argv, "c:v")) == 'c' || c == 'v') if (c == 'v') vflag = 1; else cutoff = optarg; if ((c != EOF && c != -1) || (optind == argc - 1 && strcmp(argv[optind], "=") == 0)) { (void) fprintf(stderr, _("%s: usage is %s [ --version ] [ -v ] [ -c cutoff ] zonename ...\n"), argv[0], argv[0]); (void) exit(EXIT_FAILURE); } if (cutoff != NULL) { int y; cutyear = atoi(cutoff); cuttime = 0; for (y = EPOCH_YEAR; y < cutyear; ++y) cuttime += DAYSPERNYEAR + isleap(y); cuttime *= SECSPERHOUR * HOURSPERDAY; } (void) time(&now); longest = 0; for (i = optind; i < argc; ++i) if (strlen(argv[i]) > longest) longest = strlen(argv[i]); for (hibit = 1; (hibit << 1) != 0; hibit <<= 1) continue; { register int from; register int to; for (i = 0; environ[i] != NULL; ++i) continue; fakeenv = (char **) malloc((size_t) ((i + 2) * sizeof *fakeenv)); if (fakeenv == NULL || (fakeenv[0] = (char *) malloc(longest + 4)) == NULL) { (void) perror(progname); (void) exit(EXIT_FAILURE); } to = 0; (void) strcpy(fakeenv[to++], "TZ="); for (from = 0; environ[from] != NULL; ++from) if (strncmp(environ[from], "TZ=", 3) != 0) fakeenv[to++] = environ[from]; fakeenv[to] = NULL; environ = fakeenv; } for (i = optind; i < argc; ++i) { static char buf[MAX_STRING_LENGTH]; (void) strcpy(&fakeenv[0][3], argv[i]); if (!vflag) { show(argv[i], now, FALSE); continue; } /* ** Get lowest value of t. */ t = hibit; if (t > 0) /* time_t is unsigned */ t = 0; show(argv[i], t, TRUE); t += SECSPERHOUR * HOURSPERDAY; show(argv[i], t, TRUE); tm = *localtime(&t); (void) strncpy(buf, abbr(&tm), (sizeof buf) - 1); for ( ; ; ) { if (cutoff != NULL && t >= cuttime) break; newt = t + SECSPERHOUR * 12; if (cutoff != NULL && newt >= cuttime) break; if (newt <= t) break; newtm = *localtime(&newt); if (delta(&newtm, &tm) != (newt - t) || newtm.tm_isdst != tm.tm_isdst || strcmp(abbr(&newtm), buf) != 0) { newt = hunt(argv[i], t, newt); newtm = *localtime(&newt); (void) strncpy(buf, abbr(&newtm), (sizeof buf) - 1); } t = newt; tm = newtm; } /* ** Get highest value of t. */ t = ~((time_t) 0); if (t < 0) /* time_t is signed */ t &= ~hibit; t -= SECSPERHOUR * HOURSPERDAY; show(argv[i], t, TRUE); t += SECSPERHOUR * HOURSPERDAY; show(argv[i], t, TRUE); } if (fflush(stdout) || ferror(stdout)) { (void) fprintf(stderr, "%s: ", argv[0]); (void) perror(_("Error writing standard output")); (void) exit(EXIT_FAILURE); } exit(EXIT_SUCCESS); /* gcc -Wall pacifier */ for ( ; ; ) continue; } static time_t hunt(name, lot, hit) char * name; time_t lot; time_t hit; { time_t t; struct tm lotm; struct tm tm; static char loab[MAX_STRING_LENGTH]; lotm = *localtime(&lot); (void) strncpy(loab, abbr(&lotm), (sizeof loab) - 1); while ((hit - lot) >= 2) { t = lot / 2 + hit / 2; if (t <= lot) ++t; else if (t >= hit) --t; tm = *localtime(&t); if (delta(&tm, &lotm) == (t - lot) && tm.tm_isdst == lotm.tm_isdst && strcmp(abbr(&tm), loab) == 0) { lot = t; lotm = tm; } else hit = t; } show(name, lot, TRUE); show(name, hit, TRUE); return hit; } /* ** Thanks to Paul Eggert (eggert@twinsun.com) for logic used in delta. */ static long delta(newp, oldp) struct tm * newp; struct tm * oldp; { long result; int tmy; if (newp->tm_year < oldp->tm_year) return -delta(oldp, newp); result = 0; for (tmy = oldp->tm_year; tmy < newp->tm_year; ++tmy) result += DAYSPERNYEAR + isleap(tmy + TM_YEAR_BASE); result += newp->tm_yday - oldp->tm_yday; result *= HOURSPERDAY; result += newp->tm_hour - oldp->tm_hour; result *= MINSPERHOUR; result += newp->tm_min - oldp->tm_min; result *= SECSPERMIN; result += newp->tm_sec - oldp->tm_sec; return result; } static void show(zone, t, v) char * zone; time_t t; int v; { struct tm * tmp; (void) printf("%-*s ", (int) longest, zone); if (v) (void) printf("%.24s UTC = ", asctime(gmtime(&t))); tmp = localtime(&t); (void) printf("%.24s", asctime(tmp)); if (*abbr(tmp) != '\0') (void) printf(" %s", abbr(tmp)); if (v) { (void) printf(" isdst=%d", tmp->tm_isdst); #ifdef TM_GMTOFF (void) printf(" gmtoff=%ld", tmp->TM_GMTOFF); #endif /* defined TM_GMTOFF */ } (void) printf("\n"); } static char * abbr(tmp) struct tm * tmp; { register char * result; static char nada; if (tmp->tm_isdst != 0 && tmp->tm_isdst != 1) return &nada; result = tzname[tmp->tm_isdst]; return (result == NULL) ? &nada : result; }