diff options
Diffstat (limited to 'time/zdump.c')
| -rw-r--r-- | time/zdump.c | 331 |
1 files changed, 331 insertions, 0 deletions
diff --git a/time/zdump.c b/time/zdump.c new file mode 100644 index 0000000..d35df33 --- /dev/null +++ b/time/zdump.c @@ -0,0 +1,331 @@ +#ifndef lint +#ifndef NOID +static char elsieid[] = "@(#)zdump.c 7.12"; +#endif /* !defined NOID */ +#endif /* !defined lint */ + +/* +** 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 */ +#include "string.h" /* for strcpy */ +#include "sys/types.h" /* for time_t */ +#include "time.h" /* for struct tm */ + +#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 */ + +#ifndef GNUC_or_lint +#ifdef lint +#define GNUC_or_lint +#endif /* defined lint */ +#ifdef __GNUC__ +#define GNUC_or_lint +#endif /* defined __GNUC__ */ +#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 */ + +extern char ** environ; +extern int getopt(); +extern char * optarg; +extern int optind; +extern time_t time(); +extern char * tzname[2]; + +#ifdef USG +extern void exit(); +extern void perror(); +#endif /* defined USG */ + +static char * abbr(); +static long delta(); +static time_t hunt(); +static int longest; +static char * progname; +static void show(); + +int +main(argc, argv) +int argc; +char * argv[]; +{ + register int i, c; + register int vflag; + register char * cutoff; + register int cutyear; + register long cuttime; + char ** fakeenv; + time_t now; + time_t t, newt; + time_t hibit; + struct tm tm, newtm; + + INITIALIZE(cuttime); + progname = argv[0]; + 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 || + (optind == argc - 1 && strcmp(argv[optind], "=") == 0)) { + (void) fprintf(stderr, +"%s: usage is %s [ -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, to; + + for (i = 0; environ[i] != NULL; ++i) + continue; + fakeenv = (char **) malloc((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]); + show(argv[i], now, FALSE); + if (!vflag) + 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: Error writing standard output ", + argv[0]); + (void) perror("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; +} + +extern struct tm * localtime(); + +static void +show(zone, t, v) +char * zone; +time_t t; +int v; +{ + struct tm * tmp; + + (void) printf("%-*s ", longest, zone); + if (v) + (void) printf("%.24s GMT = ", 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; +} |