#include <ctype.h>
#include <inttypes.h>
#include <limits.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <time.h>
#define ZDUMP_LO_YEAR (-500)
#define ZDUMP_HI_YEAR 2500
#define MAX_STRING_LENGTH 1024
#define TRUE 1
#define FALSE 0
#define SECSPERMIN 60
#define MINSPERHOUR 60
#define SECSPERHOUR (SECSPERMIN * MINSPERHOUR)
#define HOURSPERDAY 24
#define EPOCH_YEAR 1970
#define TM_YEAR_BASE 1900
#define DAYSPERNYEAR 365
#define SECSPERDAY (SECSPERHOUR * HOURSPERDAY)
#define SECSPERNYEAR (SECSPERDAY * DAYSPERNYEAR)
#define SECSPERLYEAR (SECSPERNYEAR + SECSPERDAY)
#define SECSPER400YEARS (SECSPERNYEAR * (intmax_t) (300 + 3) \
+ SECSPERLYEAR * (intmax_t) (100 - 3))
enum { SECSPER400YEARS_FITS = SECSPERLYEAR <= INTMAX_MAX / 400 };
#define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0))
#ifndef isleap_sum
#define isleap_sum(a, b) isleap((a) % 400 + (b) % 400)
#endif
extern char **environ;
extern char *tzname[2];
extern char *__progname;
static const time_t absolute_min_time = LLONG_MIN;
static const time_t absolute_max_time = LLONG_MAX;
static size_t longest;
static int warned;
static char *abbr(struct tm *tmp);
static void abbrok(const char *abbrp, const char *zone);
static __pure intmax_t delta(struct tm *newp, struct tm *oldp);
static void dumptime(const struct tm *tmp);
static time_t hunt(char *name, time_t lot, time_t hit);
static void show(char *zone, time_t t, int v);
static __pure time_t yeartot(intmax_t y);
static __dead void usage(void);
static void
abbrok(const char * const abbrp, const char * const zone)
{
const char *cp;
char *wp;
if (warned)
return;
cp = abbrp;
wp = NULL;
while (isascii((unsigned char)*cp) &&
(isalnum((unsigned char)*cp) || *cp == '-' || *cp == '+'))
++cp;
if (cp - abbrp < 3)
wp = "has fewer than 3 characters";
else if (cp - abbrp > 6)
wp = "has more than 6 characters";
else if (*cp)
wp = "has characters other than ASCII alphanumerics, '-' or '+'";
else
return;
fflush(stdout);
fprintf(stderr, "%s: warning: zone \"%s\" abbreviation \"%s\" %s\n",
__progname, zone, abbrp, wp);
warned = TRUE;
}
static void
usage(void)
{
fprintf(stderr, "usage: %s [-Vv] [-c [loyear,]hiyear] "
"[-t [lotime,]hitime] zonename ...\n", __progname);
exit(EXIT_FAILURE);
}
int
main(int argc, char *argv[])
{
int ch, i, Vflag = 0, vflag = 0;
char *cutarg = NULL;
char *cuttimes = NULL;
time_t cutlotime = absolute_min_time;
time_t cuthitime = absolute_max_time;
time_t now, t, newt;
struct tm tm, newtm, *tmp, *newtmp;
char **fakeenv;
if (pledge("stdio rpath", NULL) == -1) {
perror("pledge");
exit(1);
}
while ((ch = getopt(argc, argv, "c:t:Vv")) != -1) {
switch (ch) {
case 'c':
cutarg = optarg;
break;
case 't':
cuttimes = optarg;
break;
case 'V':
Vflag = 1;
break;
case 'v':
vflag = 1;
break;
default:
usage();
}
}
argc -= optind;
argv += optind;
if (argc == 1 && strcmp(argv[0], "=") == 0)
usage();
if (vflag || Vflag) {
char dummy;
intmax_t cutloyear = ZDUMP_LO_YEAR;
intmax_t cuthiyear = ZDUMP_HI_YEAR;
intmax_t lo, hi;
if (cutarg != NULL) {
if (sscanf(cutarg, "%"SCNdMAX"%c", &hi, &dummy) == 1) {
cuthiyear = hi;
} else if (sscanf(cutarg, "%"SCNdMAX",%"SCNdMAX"%c",
&lo, &hi, &dummy) == 2) {
cutloyear = lo;
cuthiyear = hi;
} else {
fprintf(stderr, "%s: wild -c argument %s\n",
__progname, cutarg);
exit(EXIT_FAILURE);
}
}
if (cutarg != NULL || cuttimes == NULL) {
cutlotime = yeartot(cutloyear);
cuthitime = yeartot(cuthiyear);
}
if (cuttimes != NULL) {
if (sscanf(cuttimes, "%"SCNdMAX"%c", &hi, &dummy) == 1) {
cutlotime = yeartot(cutloyear);
if (hi < cuthitime) {
if (hi < absolute_min_time)
hi = absolute_min_time;
cuthitime = hi;
}
} else if (sscanf(cuttimes, "%"SCNdMAX",%"SCNdMAX"%c",
&lo, &hi, &dummy) == 2) {
if (cutlotime < lo) {
if (absolute_max_time < lo)
lo = absolute_max_time;
cutlotime = lo;
}
if (hi < cuthitime) {
if (hi < absolute_min_time)
hi = absolute_min_time;
cuthitime = hi;
}
} else {
(void) fprintf(stderr,
"%s: wild -t argument %s\n",
__progname, cuttimes);
exit(EXIT_FAILURE);
}
}
}
time(&now);
longest = 0;
for (i = 0; i < argc; ++i)
if (strlen(argv[i]) > longest)
longest = strlen(argv[i]);
{
int from, to;
for (i = 0; environ[i] != NULL; ++i)
continue;
fakeenv = reallocarray(NULL, i + 2, sizeof *fakeenv);
if (fakeenv == NULL ||
(fakeenv[0] = malloc(longest + 4)) == NULL) {
perror(__progname);
exit(EXIT_FAILURE);
}
to = 0;
strlcpy(fakeenv[to++], "TZ=", longest + 4);
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 = 0; i < argc; ++i) {
char buf[MAX_STRING_LENGTH];
strlcpy(&fakeenv[0][3], argv[i], longest + 1);
if (!(vflag | Vflag)) {
show(argv[i], now, FALSE);
continue;
}
warned = FALSE;
t = absolute_min_time;
if (!Vflag) {
show(argv[i], t, TRUE);
t += SECSPERDAY;
show(argv[i], t, TRUE);
}
if (t < cutlotime)
t = cutlotime;
tmp = localtime(&t);
if (tmp != NULL) {
tm = *tmp;
strlcpy(buf, abbr(&tm), sizeof buf);
}
for ( ; ; ) {
newt = (t < absolute_max_time - SECSPERDAY / 2
? t + SECSPERDAY / 2
: absolute_max_time);
if (cuthitime <= newt)
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;
strlcpy(buf, abbr(&newtm), sizeof buf);
}
}
t = newt;
tm = newtm;
tmp = newtmp;
}
if (!Vflag) {
t = absolute_max_time;
t -= SECSPERDAY;
show(argv[i], t, TRUE);
t += SECSPERDAY;
show(argv[i], t, TRUE);
}
}
if (fflush(stdout) || ferror(stdout)) {
fprintf(stderr, "%s: ", __progname);
perror("Error writing to standard output");
exit(EXIT_FAILURE);
}
return 0;
}
static time_t
yeartot(const intmax_t y)
{
intmax_t seconds, years, myy = EPOCH_YEAR;
time_t t = 0;
while (myy < y) {
if (SECSPER400YEARS_FITS && 400 <= y - myy) {
intmax_t diff400 = (y - myy) / 400;
if (INTMAX_MAX / SECSPER400YEARS < diff400)
return absolute_max_time;
seconds = diff400 * SECSPER400YEARS;
years = diff400 * 400;
} else {
seconds = isleap(myy) ? SECSPERLYEAR : SECSPERNYEAR;
years = 1;
}
myy += years;
if (t > absolute_max_time - seconds)
return absolute_max_time;
t += seconds;
}
while (y < myy) {
if (SECSPER400YEARS_FITS && y + 400 <= myy && myy < 0) {
intmax_t diff400 = (myy - y) / 400;
if (INTMAX_MAX / SECSPER400YEARS < diff400)
return absolute_min_time;
seconds = diff400 * SECSPER400YEARS;
years = diff400 * 400;
} else {
seconds = isleap(myy - 1) ? SECSPERLYEAR : SECSPERNYEAR;
years = 1;
}
myy -= years;
if (t < absolute_min_time + seconds)
return absolute_min_time;
t -= seconds;
}
return t;
}
static time_t
hunt(char *name, time_t lot, time_t hit)
{
time_t t;
struct tm lotm, *lotmp;
struct tm tm, *tmp;
char loab[MAX_STRING_LENGTH];
lotmp = localtime(&lot);
if (lotmp != NULL) {
lotm = *lotmp;
strlcpy(loab, abbr(&lotm), sizeof loab);
}
for ( ; ; ) {
time_t diff = hit - lot;
if (diff < 2)
break;
t = lot;
t += diff / 2;
if (t <= lot)
++t;
else if (t >= hit)
--t;
tmp = 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;
}
static intmax_t
delta(struct tm *newp, struct tm *oldp)
{
intmax_t 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_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(char *zone, time_t t, int v)
{
struct tm *tmp;
printf("%-*s ", (int) longest, zone);
if (v) {
tmp = gmtime(&t);
if (tmp == NULL) {
printf("%lld", t);
} else {
dumptime(tmp);
printf(" UT");
}
printf(" = ");
}
tmp = localtime(&t);
dumptime(tmp);
if (tmp != NULL) {
if (*abbr(tmp) != '\0')
printf(" %s", abbr(tmp));
if (v) {
printf(" isdst=%d", tmp->tm_isdst);
#ifdef TM_GMTOFF
printf(" gmtoff=%ld", tmp->TM_GMTOFF);
#endif
}
}
printf("\n");
if (tmp != NULL && *abbr(tmp) != '\0')
abbrok(abbr(tmp), zone);
}
static char *
abbr(struct tm *tmp)
{
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;
}
static void
dumptime(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"
};
const char *wn, *mn;
int lead, trail;
if (timeptr == NULL) {
printf("NULL");
return;
}
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];
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)
printf("%d", trail);
else
printf("%d%d", lead, ((trail < 0) ? -trail : trail));
}
