cmd/zdump/zdump.c

/*
 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * zdump 7.24
 * Taken from elsie.nci.nih.gov to replace the existing Solaris zdump,
 * which was based on an earlier version of the elsie code.
 *
 * For zdump 7.24, the following changes were made to the elsie code:
 *   locale/textdomain/messages to match existing Solaris style.
 *   Solaris verbose mode is documented to display the current time first.
 *   cstyle cleaned code.
 *   removed old locale/textdomain code.
 */

static char elsieid[] = "@(#)zdump.c    7.74";

/*
 * 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 */
#include "locale.h" /* for setlocale, textdomain */
#include "libintl.h"
#include <ctype.h>
#include "tzfile.h" /* for defines */
#include <limits.h>

#ifndef ZDUMP_LO_YEAR
#define ZDUMP_LO_YEAR   (-500)
#endif /* !defined ZDUMP_LO_YEAR */

#ifndef ZDUMP_HI_YEAR
#define ZDUMP_HI_YEAR   2500
#endif /* !defined ZDUMP_HI_YEAR */

#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 isleap_sum
/*
 * See tzfile.h for details on isleap_sum.
 */
#define isleap_sum(a, b)    isleap((a) % 400 + (b) % 400)
#endif /* !defined isleap_sum */

#ifndef SECSPERDAY
#define SECSPERDAY  ((long)SECSPERHOUR * HOURSPERDAY)
#endif
#define SECSPERNYEAR    (SECSPERDAY * DAYSPERNYEAR)
#define SECSPERLYEAR    (SECSPERNYEAR + SECSPERDAY)

#ifndef GNUC_or_lint
#ifdef lint
#define GNUC_or_lint
#else /* !defined 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)
#else /* !defined GNUC_or_lint */
#define INITIALIZE(x)
#endif /* !defined GNUC_or_lint */
#endif /* !defined INITIALIZE */

static time_t   absolute_min_time;
static time_t   absolute_max_time;
static size_t   longest;
static char *progname;
static int  warned;

static char *abbr(struct tm *);
static void abbrok(const char *, const char *);
static long delta(struct tm *, struct tm *);
static void dumptime(const struct tm *);
static time_t   hunt(char *, time_t, time_t);
static void setabsolutes(void);
static void show(char *, time_t, int);
static void usage(void);
static const char   *tformat(void);
static time_t   yeartot(long y);

#ifndef TYPECHECK
#define my_localtime    localtime
#else /* !defined TYPECHECK */
static struct tm *
my_localtime(tp)
time_t *tp;
{
    register struct tm *tmp;

    tmp = localtime(tp);
    if (tp != NULL && tmp != NULL) {
        struct tm   tm;
        register time_t t;

        tm = *tmp;
        t = mktime(&tm);
        if (t - *tp >= 1 || *tp - t >= 1) {
            (void) fflush(stdout);
            (void) fprintf(stderr, "\n%s: ", progname);
            (void) fprintf(stderr, tformat(), *tp);
            (void) fprintf(stderr, " ->");
            (void) fprintf(stderr, " year=%d", tmp->tm_year);
            (void) fprintf(stderr, " mon=%d", tmp->tm_mon);
            (void) fprintf(stderr, " mday=%d", tmp->tm_mday);
            (void) fprintf(stderr, " hour=%d", tmp->tm_hour);
            (void) fprintf(stderr, " min=%d", tmp->tm_min);
            (void) fprintf(stderr, " sec=%d", tmp->tm_sec);
            (void) fprintf(stderr, " isdst=%d", tmp->tm_isdst);
            (void) fprintf(stderr, " -> ");
            (void) fprintf(stderr, tformat(), t);
            (void) fprintf(stderr, "\n");
        }
    }
    return (tmp);
}
#endif /* !defined TYPECHECK */

static void
abbrok(const char * const abbrp, const char * const zone)
{
    register const char *cp;
    int error = 0;

    if (warned)
        return;
    cp = abbrp;
    while (isalpha(*cp) || isdigit(*cp) || *cp == '-' || *cp == '+')
        ++cp;
    (void) fflush(stdout);
    if (cp - abbrp < 3) {
        (void) fprintf(stderr, gettext("%s: warning: zone \"%s\" "
            "abbreviation \"%s\" has fewer than 3 alphabetics\n"),
            progname, zone, abbrp);
        error = 1;
    } else if (cp - abbrp > 6) {
        (void) fprintf(stderr, gettext("%s: warning: zone \"%s\" "
            "abbreviation \"%s\" has more than 6 characters\n"),
            progname, zone, abbrp);
        error = 1;
    } else if (*cp != '\0') {
        (void) fprintf(stderr, gettext("%s: warning: zone \"%s\" "
            "abbreviation \"%s\" has characters other than "
            "alphanumerics\n"), progname, zone, abbrp);
        error = 1;
    }
    if (error)
        warned = TRUE;
}

int
main(argc, argv)
int argc;
char    *argv[];
{
    register int        i;
    register int        c;
    register int        vflag;
    register char       *cutarg;
    register long       cutloyear = ZDUMP_LO_YEAR;
    register long       cuthiyear = ZDUMP_HI_YEAR;
    register time_t     cutlotime;
    register time_t     cuthitime;
    time_t          now;
    time_t          t;
    time_t          newt;
    struct tm       tm;
    struct tm       newtm;
    register struct tm  *tmp;
    register struct tm  *newtmp;

    INITIALIZE(cutlotime);
    INITIALIZE(cuthitime);

    (void) setlocale(LC_ALL, "");
#if !defined(TEXT_DOMAIN)       /* Should be defined by cc -D */
#define TEXT_DOMAIN "SYS_TEST"  /* Use this only if it weren't */
#endif
    (void) textdomain(TEXT_DOMAIN);

    progname = argv[0];
    for (i = 1; i < argc; ++i)
        if (strcmp(argv[i], "--version") == 0) {
            (void) printf("%s\n", elsieid);
            exit(EXIT_SUCCESS);
        }
    vflag = 0;
    cutarg = NULL;
    while ((c = getopt(argc, argv, "c:v")) == 'c' || c == 'v')
        if (c == 'v')
            vflag = 1;
        else    cutarg = optarg;
    if (c != EOF ||
        (optind == argc - 1 && strcmp(argv[optind], "=") == 0)) {
            usage();
            /* NOTREACHED */
    }
    if (vflag) {
        if (cutarg != NULL) {
            long    lo;
            long    hi;
            char    dummy;

            if (sscanf(cutarg, "%ld%c", &hi, &dummy) == 1) {
                cuthiyear = hi;
            } else if (sscanf(cutarg, "%ld,%ld%c",
                &lo, &hi, &dummy) == 2) {
                    cutloyear = lo;
                    cuthiyear = hi;
            } else {
(void) fprintf(stderr, gettext("%s: wild -c argument %s\n"),
                    progname, cutarg);
                exit(EXIT_FAILURE);
            }
        }
        setabsolutes();
        cutlotime = yeartot(cutloyear);
        cuthitime = yeartot(cuthiyear);
    }
    (void) time(&now);
    longest = 0;
    for (i = optind; i < argc; ++i)
        if (strlen(argv[i]) > longest)
            longest = strlen(argv[i]);

    for (i = optind; i < argc; ++i) {
        static char buf[MAX_STRING_LENGTH];
        static char *tzp = NULL;

        (void) unsetenv("TZ");
        if (tzp != NULL)
            free(tzp);
        if ((tzp = malloc(3 + strlen(argv[i]) + 1)) == NULL) {
            perror(progname);
            exit(EXIT_FAILURE);
        }
        (void) strcpy(tzp, "TZ=");
        (void) strcat(tzp, argv[i]);
        if (putenv(tzp) != 0) {
            perror(progname);
            exit(EXIT_FAILURE);
        }
        if (!vflag) {
            show(argv[i], now, FALSE);
            continue;
        }

#if defined(sun)
        /*
         * We show the current time first, probably because we froze
         * the behavior of zdump some time ago and then it got
         * changed.
         */
        show(argv[i], now, TRUE);
#endif
        warned = FALSE;
        t = absolute_min_time;
        show(argv[i], t, TRUE);
        t += SECSPERHOUR * HOURSPERDAY;
        show(argv[i], t, TRUE);
        if (t < cutlotime)
            t = cutlotime;
        tmp = my_localtime(&t);
        if (tmp != NULL) {
            tm = *tmp;
            (void) strncpy(buf, abbr(&tm), sizeof (buf) - 1);
        }
        for (;;) {
            if (t >= cuthitime)
                break;
            /* check if newt will overrun maximum time_t value */
            if (t > LONG_MAX - (SECSPERHOUR * 12))
                break;
            newt = t + SECSPERHOUR * 12;
            if (newt >= cuthitime)
                break;
            newtmp = localtime(&newt);
            if (newtmp != NULL)
                newtm = *newtmp;
            if ((tmp == NULL || newtmp == NULL) ? (tmp != newtmp) :
                (delta(&newtm, &tm) != (newt - t) ||
                newtm.tm_isdst != tm.tm_isdst ||
                strcmp(abbr(&newtm), buf) != 0)) {
                    newt = hunt(argv[i], t, newt);
                    newtmp = localtime(&newt);
                    if (newtmp != NULL) {
                        newtm = *newtmp;
                        (void) strncpy(buf,
                            abbr(&newtm),
                            sizeof (buf) - 1);
                    }
            }
            t = newt;
            tm = newtm;
            tmp = newtmp;
        }
        t = absolute_max_time;
#if defined(sun)
        show(argv[i], t, TRUE);
        t -= SECSPERHOUR * HOURSPERDAY;
        show(argv[i], t, TRUE);
#else /* !defined(sun) */
        t -= SECSPERHOUR * HOURSPERDAY;
        show(argv[i], t, TRUE);
        t += SECSPERHOUR * HOURSPERDAY;
        show(argv[i], t, TRUE);
#endif /* !defined(sun) */
    }
    if (fflush(stdout) || ferror(stdout)) {
        (void) fprintf(stderr, "%s: ", progname);
        (void) perror(gettext("Error writing standard output"));
        exit(EXIT_FAILURE);
    }
    return (EXIT_SUCCESS);
}

static void
setabsolutes()
{
#if defined(sun)
    absolute_min_time = LONG_MIN;
    absolute_max_time = LONG_MAX;
#else
    if (0.5 == (time_t)0.5) {
        /*
         * time_t is floating.
         */
        if (sizeof (time_t) == sizeof (float)) {
            absolute_min_time = (time_t)-FLT_MAX;
            absolute_max_time = (time_t)FLT_MAX;
        } else if (sizeof (time_t) == sizeof (double)) {
            absolute_min_time = (time_t)-DBL_MAX;
            absolute_max_time = (time_t)DBL_MAX;
        } else {
            (void) fprintf(stderr, gettext("%s: use of -v on "
                "system with floating time_t other than float "
                "or double\n"), progname);
            exit(EXIT_FAILURE);
        }
    } else
    /*CONSTANTCONDITION*/
    if (0 > (time_t)-1) {
        /*
         * time_t is signed.
         */
        register time_t hibit;

        for (hibit = 1; (hibit * 2) != 0; hibit *= 2)
            continue;
        absolute_min_time = hibit;
        absolute_max_time = -(hibit + 1);
    } else {
        /*
         * time_t is unsigned.
         */
        absolute_min_time = 0;
        absolute_max_time = absolute_min_time - 1;
    }
#endif
}

static time_t
yeartot(y)
const long  y;
{
    register long   myy;
    register long   seconds;
    register time_t t;

    myy = EPOCH_YEAR;
    t = 0;
    while (myy != y) {
        if (myy < y) {
            seconds = isleap(myy) ? SECSPERLYEAR : SECSPERNYEAR;
            ++myy;
            if (t > absolute_max_time - seconds) {
                t = absolute_max_time;
                break;
            }
            t += seconds;
        } else {
            --myy;
            seconds = isleap(myy) ? SECSPERLYEAR : SECSPERNYEAR;
            if (t < absolute_min_time + seconds) {
                t = absolute_min_time;
                break;
            }
            t -= seconds;
        }
    }
    return (t);
}

static time_t
hunt(name, lot, hit)
char    *name;
time_t  lot;
time_t  hit;
{
    time_t          t;
    long            diff;
    struct tm       lotm;
    register struct tm  *lotmp;
    struct tm       tm;
    register struct tm  *tmp;
    char            loab[MAX_STRING_LENGTH];

    lotmp = my_localtime(&lot);
    if (lotmp != NULL) {
        lotm = *lotmp;
        (void) strncpy(loab, abbr(&lotm), sizeof (loab) - 1);
    }
    for (;;) {
        diff = (long)(hit - lot);
        if (diff < 2)
            break;
        t = lot;
        t += diff / 2;
        if (t <= lot)
            ++t;
        else if (t >= hit)
            --t;
        tmp = my_localtime(&t);
        if (tmp != NULL)
            tm = *tmp;
        if ((lotmp == NULL || tmp == NULL) ? (lotmp == tmp) :
            (delta(&tm, &lotm) == (t - lot) &&
            tm.tm_isdst == lotm.tm_isdst &&
            strcmp(abbr(&tm), loab) == 0)) {
                lot = t;
                lotm = tm;
                lotmp = tmp;
        } else  hit = t;
    }
    show(name, lot, TRUE);
    show(name, hit, TRUE);
    return (hit);
}

/*
 * Thanks to Paul Eggert for logic used in delta.
 */

static long
delta(newp, oldp)
struct tm   *newp;
struct tm   *oldp;
{
    register long   result;
    register 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_sum(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;
{
    register struct tm  *tmp;

    (void) printf("%-*s  ", (int)longest, zone);
    if (v) {
        tmp = gmtime(&t);
        if (tmp == NULL) {
            (void) printf(tformat(), t);
        } else {
            dumptime(tmp);
            (void) printf(" UTC");
        }
        (void) printf(" = ");
    }
    tmp = my_localtime(&t);
    dumptime(tmp);
    if (tmp != NULL) {
        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");
    if (tmp != NULL && *abbr(tmp) != '\0')
        abbrok(abbr(tmp), zone);
}

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);
}

/*
 * The code below can fail on certain theoretical systems;
 * it works on all known real-world systems as of 2004-12-30.
 */

static const char *
tformat()
{
#if defined(sun)
    /* time_t is signed long */
    return ("%ld");
#else
    /*CONSTANTCONDITION*/
    if (0.5 == (time_t)0.5) {   /* floating */
        /*CONSTANTCONDITION*/
        if (sizeof (time_t) > sizeof (double))
            return ("%Lg");
        return ("%g");
    }
    /*CONSTANTCONDITION*/
    if (0 > (time_t)-1) {       /* signed */
        /*CONSTANTCONDITION*/
        if (sizeof (time_t) > sizeof (long))
            return ("%lld");
        /*CONSTANTCONDITION*/
        if (sizeof (time_t) > sizeof (int))
            return ("%ld");
        return ("%d");
    }
    /*CONSTANTCONDITION*/
    if (sizeof (time_t) > sizeof (unsigned long))
        return ("%llu");
    /*CONSTANTCONDITION*/
    if (sizeof (time_t) > sizeof (unsigned int))
        return ("%lu");
    return ("%u");
#endif
}

static void
dumptime(timeptr)
register const struct tm    *timeptr;
{
    static const char   wday_name[][3] = {
        "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
    };
    static const char   mon_name[][3] = {
        "Jan", "Feb", "Mar", "Apr", "May", "Jun",
        "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
    };
    register const char *wn;
    register const char *mn;
    register int        lead;
    register int        trail;

    if (timeptr == NULL) {
        (void) printf("NULL");
        return;
    }
    /*
     * The packaged versions of localtime and gmtime never put out-of-range
     * values in tm_wday or tm_mon, but since this code might be compiled
     * with other (perhaps experimental) versions, paranoia is in order.
     */
    if (timeptr->tm_wday < 0 || timeptr->tm_wday >=
        (int)(sizeof (wday_name) / sizeof (wday_name[0])))
            wn = "???";
    else        wn = wday_name[timeptr->tm_wday];
    if (timeptr->tm_mon < 0 || timeptr->tm_mon >=
        (int)(sizeof (mon_name) / sizeof (mon_name[0])))
            mn = "???";
    else        mn = mon_name[timeptr->tm_mon];
    (void) printf("%.3s %.3s%3d %.2d:%.2d:%.2d ",
        wn, mn,
        timeptr->tm_mday, timeptr->tm_hour,
        timeptr->tm_min, timeptr->tm_sec);
#define DIVISOR 10
    trail = timeptr->tm_year % DIVISOR + TM_YEAR_BASE % DIVISOR;
    lead = timeptr->tm_year / DIVISOR + TM_YEAR_BASE / DIVISOR +
        trail / DIVISOR;
    trail %= DIVISOR;
    if (trail < 0 && lead > 0) {
        trail += DIVISOR;
        --lead;
    } else if (lead < 0 && trail > 0) {
        trail -= DIVISOR;
        ++lead;
    }
    if (lead == 0)
        (void) printf("%d", trail);
    else
        (void) printf("%d%d", lead, ((trail < 0) ? -trail : trail));
}

static void
usage()
{
    (void) fprintf(stderr, gettext(
        "%s: [ --version ] [ -v ] [ -c [loyear,]hiyear ] zonename ...\n"),
        progname);
    exit(EXIT_FAILURE);
    /* NOTREACHED */
}