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authorRoland McGrath <roland@gnu.org>1995-02-18 01:27:10 +0000
committerRoland McGrath <roland@gnu.org>1995-02-18 01:27:10 +0000
commit28f540f45bbacd939bfd07f213bcad2bf730b1bf (patch)
tree15f07c4c43d635959c6afee96bde71fb1b3614ee /time/zdump.c
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initial import
Diffstat (limited to 'time/zdump.c')
-rw-r--r--time/zdump.c331
1 files changed, 331 insertions, 0 deletions
diff --git a/time/zdump.c b/time/zdump.c
new file mode 100644
index 0000000000..d35df33073
--- /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;
+}