amiga-tz/zic.c

#

#include "stdio.h"

#ifdef OBJECTID
static char	sccsid[] = "%W%";
#endif

#include "tzfile.h"
#include "ctype.h"

#ifndef alloc_t
#define alloc_t	unsigned
#endif

#ifndef MAL
#define MAL	0
#endif

#ifndef BUFSIZ
#define BUFSIZ	1024
#endif

#ifndef TRUE
#define TRUE	1
#define FALSE	0
#endif

extern char *	calloc();
extern char *	strchr();
extern char *	malloc();
extern char *	optarg;
extern int	optind;
extern FILE *	popen();
extern char *	realloc();
extern char *	scheck();
extern char *	sprintf();
extern char *	strcat();
extern char *	strcpy();

static int	errors;
static char *	progname;
static char *	filename;
static char **	getfields();
static int	linenum;
static long	rpytime();
static long	tadd();

#define	SECS_PER_MIN	60
#define MINS_PER_HOUR	60
#define HOURS_PER_DAY	24
#define DAYS_PER_YEAR	365	/* Except in leap years */
#define	SECS_PER_HOUR	(SECS_PER_MIN * MINS_PER_HOUR)
#define SECS_PER_DAY	(SECS_PER_HOUR * HOURS_PER_DAY)
#define SECS_PER_YEAR	(SECS_PER_DAY * DAYS_PER_YEAR)

#define EPOCH_YEAR	1970
#define EPOCH_WDAY	TM_THURSDAY

/*
** Values a la localtime(3)
*/

#define TM_JANUARY	0
#define TM_FEBRUARY	1
#define TM_MARCH	2
#define TM_APRIL	3
#define TM_MAY		4
#define TM_JUNE		5
#define TM_JULY		6
#define TM_AUGUST	7
#define TM_SEPTEMBER	8
#define TM_OCTOBER	9
#define TM_NOVEMBER	10
#define TM_DECEMBER	11

#define TM_SUNDAY	0
#define TM_MONDAY	1
#define TM_TUESDAY	2
#define TM_WEDNESDAY	3
#define TM_THURSDAY	4
#define TM_FRIDAY	5
#define TM_SATURDAY	6

/*
** Line codes.
*/

#define LC_RULE		0
#define LC_ZONE		1
#define LC_LINK		2

/*
** Which fields are which on a Zone line.
*/

#define ZF_NAME		1
#define ZF_GMTOFF	2
#define ZF_RULE		3
#define ZF_FORMAT	4
#define ZONE_FIELDS	5

/*
** Which files are which on a Rule line.
*/

#define	RF_NAME		1
#define RF_LOYEAR	2
#define RF_HIYEAR	3
#define RF_COMMAND	4
#define RF_MONTH	5
#define RF_DAY		6
#define RF_TOD		7
#define RF_STDOFF	8
#define RF_ABBRVAR	9
#define RULE_FIELDS	10

/*
** Which fields are which on a Link line.
*/

#define LF_FROM		1
#define LF_TO		2
#define LINK_FIELDS	3

struct rule {
	char *	r_filename;
	int	r_linenum;
	char *	r_name;

	int	r_loyear;	/* for example, 1986 */
	int	r_hiyear;	/* for example, 1986 */
	char *	r_yrtype;

	int	r_month;	/* 0..11 */

	int	r_dycode;	/* see below */
	int	r_dayofmonth;
	int	r_wday;

	long	r_tod;		/* time from midnight */
	long	r_stdoff;	/* offset from standard time */
	char *	r_abbrvar;	/* variable part of time zone abbreviation */

	int	r_type;	/* used when creating output files */
};

/*
**	r_dycode		r_dayofmonth	r_wday
*/
#define DC_DOM		0	/* 1..31 */	/* unused */
#define DC_DOWGEQ	1	/* 1..31 */	/* 0..6 (Sun..Sat) */
#define DC_DOWLEQ	2	/* 1..31 */	/* 0..6 (Sun..Sat) */

static struct rule *	rules;
static int		nrules;	/* number of rules */

struct zone {
	char *		z_filename;
	int		z_linenum;

	char *		z_name;
	long		z_gmtoff;
	char *		z_rule;
	char *		z_format;

	struct rule *	z_rules;
	int		z_nrules;
};

static struct zone *	zones;
static int		nzones;	/* number of zones */

struct link {
	char *		l_filename;
	int		l_linenum;
	char *		l_from;
	char *		l_to;
};

static struct link *	links;
static int		nlinks;

struct lookup {
	char *	l_word;
	int	l_value;
};

static struct lookup *	byword();

static struct lookup	line_codes[] = {
	"Rule",		LC_RULE,
	"Zone",		LC_ZONE,
	"Link",		LC_LINK,
	NULL,		0
};

static struct lookup	mon_names[] = {
	"January",	TM_JANUARY,
	"February",	TM_FEBRUARY,
	"March",	TM_MARCH,
	"April",	TM_APRIL,
	"May",		TM_MAY,
	"June",		TM_JUNE,
	"July",		TM_JULY,
	"August",	TM_AUGUST,
	"September",	TM_SEPTEMBER,
	"October",	TM_OCTOBER,
	"November",	TM_NOVEMBER,
	"December",	TM_DECEMBER,
	NULL,		0
};

static struct lookup	wday_names[] = {
	"Sunday",	TM_SUNDAY,
	"Monday",	TM_MONDAY,
	"Tuesday",	TM_TUESDAY,
	"Wednesday",	TM_WEDNESDAY,
	"Thursday",	TM_THURSDAY,
	"Friday",	TM_FRIDAY,
	"Saturday",	TM_SATURDAY,
	NULL,		0
};

static struct lookup	lasts[] = {
	"last-Sunday",		TM_SUNDAY,
	"last-Monday",		TM_MONDAY,
	"last-Tuesday",		TM_TUESDAY,
	"last-Wednesday",	TM_WEDNESDAY,
	"last-Thursday",	TM_THURSDAY,
	"last-Friday",		TM_FRIDAY,
	"last-Saturday",	TM_SATURDAY,
	NULL,			0
};

static int	mon_lengths[] = {	/* ". . .knuckles are 31. . ." */
	31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
};

/*
** Exits.
*/

static
tameexit()
{
	exit(0);
}

static
wild2exit(part1, part2)
char *	part1;
char *	part2;
{
	register char *	between;

	if (part1 == NULL)
		part1 = "";
	if (part2 == NULL)
		part2 = "";
	between = (*part1 == '\0' || *part2 == '\0') ? "" : " ";
	(void) fprintf(stderr, "%s: wild %s%s%s\n",
		progname, part1, between, part2);
	for ( ; ; )
		exit(1);
}

static
wildexit(string)
char *	string;
{
	wild2exit(string, (char *) NULL);
}

static
wildrexit(string)
char *	string;
{
	wild2exit("result from", string);
}

/*
** Memory allocation.
*/

static char *
emalloc(size)
{
	register char *	cp;

	if ((cp = malloc((alloc_t) size)) == NULL || cp == MAL)
		wildrexit("malloc");
	return cp;
}

static char *
erealloc(ptr, size)
char *		ptr;
{
	register char *	cp;

	if ((cp = realloc(ptr, (alloc_t) size)) == NULL)
		wildrexit("realloc");
	return cp;
}

static char *
eallocpy(old)
char *	old;
{
	register char *	new;

	if (old == NULL)
		old = "";
	new = emalloc(strlen(old) + 1);
	(void) strcpy(new, old);
	return new;
}

static
usage()
{
	(void) fprintf(stderr,
		"%s: usage is %s [ -d directory ] filename ... \n",
			progname, progname);
	exit(1);
}

static char *	directory = TZDIR;

main(argc, argv)
int	argc;
char *	argv[];
{
	register int	i;
	register int	c;

	progname = argv[0];
	while ((c = getopt(argc, argv, "d:")) != EOF)
		if (c != 'd')
			usage();
		else	directory = optarg;
	if (optind == argc - 1 && strcmp(argv[optind], "=") == 0)
		usage();	/* usage message by request */
	if (optind == argc)
		tameexit();	/* for "tzcomp `command-that-names-no-files`" */
	zones = (struct zone *) emalloc(0);
	rules = (struct rule *) emalloc(0);
	links = (struct link *) emalloc(0);
	for (i = optind; i < argc; ++i)
		infile(argv[i]);
	if (errors)
		wildexit("input data");
	associate();
	for (i = 0; i < nzones; ++i)
		outzone(&zones[i]);
	/*
	** We'll take the easy way out on this last part.
	*/
	if (chdir(directory) != 0)
		wild2exit("result from chdir to", directory);
	for (i = 0; i < nlinks; ++i) {
		(void) unlink(links[i].l_to);
		if (link(links[i].l_from, links[i].l_to) != 0)
			wild2exit("result creating", links[i].l_to);
	}
	tameexit();
}

/*
** Associate sets of rules with zones.
*/

/*
** Sort by rule name, and by magnitude of standard time offset for rules of
** the same name.  The second sort gets standard time entries to the start
** of the dsinfo table (and we want a standard time entry at the start of
** the table, since the first entry gets used for times not covered by the
** rules).
*/

static
rcomp(cp1, cp2)
char *	cp1;
char *	cp2;
{
	register struct rule *	rp1;
	register struct rule *	rp2;
	register int		diff;

	rp1 = (struct rule *) cp1;
	rp2 = (struct rule *) cp2;
	if ((diff = strcmp(rp1->r_name, rp2->r_name)) != 0)
		return diff;
	return abs(rp1->r_stdoff) - abs(rp2->r_stdoff);
}

static
associate()
{
	register struct zone *	zp;
	register struct rule *	rp;
	register int		base, out;
	register int		i;

	if (nrules != 0)
		(void) qsort((char *) rules, nrules, sizeof *rules, rcomp);
	base = 0;
	for (i = 0; i < nzones; ++i) {
		zp = &zones[i];
		zp->z_rules = NULL;
		zp->z_nrules = 0;
	}
	while (base < nrules) {
		rp = &rules[base];
		for (out = base + 1; out < nrules; ++out)
			if (strcmp(rp->r_name, rules[out].r_name) != 0)
				break;
		for (i = 0; i < nzones; ++i) {
			zp = &zones[i];
			if (strcmp(zp->z_rule, rp->r_name) != 0)
				continue;
			zp->z_rules = rp;
			zp->z_nrules = out - base;
		}
		base = out;
	}
	for (i = 0; i < nzones; ++i) {
		zp = &zones[i];
		if (*zp->z_rule != '\0' && zp->z_nrules == 0) {
			filename = zp->z_filename;
			linenum = zp->z_linenum;
			error("unruly zone");
		}
	}
	if (errors)
		wildexit("unruly zone(s)");
}

static
error(string)
char *	string;
{
	(void) fprintf(stderr, "%s: file \"%s\", line %d: wild %s\n",
		progname, filename, linenum, string);
	++errors;
}

static
infile(name)
char *	name;
{
	register FILE *			fp;
	register char **		fields;
	register char *			cp;
	register struct lookup *	lp;
	register int			nfields;
	char				buf[BUFSIZ];

	if (strcmp(name, "-") == 0) {
		name = "standard input";
		fp = stdin;
	} else if ((fp = fopen(name, "r")) == NULL)
		wild2exit("result opening", name);
	filename = eallocpy(name);
	for (linenum = 1; ; ++linenum) {
		if (fgets(buf, sizeof buf, fp) != buf)
			break;
		cp = strchr(buf, '\n');
		if (cp == NULL) {
			error("long line");
			wildexit("input data");
		}
		*cp = '\0';
		/*
		** Zap trailing comments.
		*/
		if ((cp = strchr(buf, '#')) != NULL)
			*cp = '\0';
		if ((fields = getfields(buf)) == NULL)
			wildrexit("getfields");
		nfields = 0;
		while (fields[nfields] != NULL) {
			if (ciequal(fields[nfields], "-"))
				fields[nfields] = "";
			++nfields;
		}
		if (nfields > 0)	/* non-blank line */
			if ((lp = byword(fields[0], line_codes)) == NULL)
				error("input line of unknown type");
			else switch (lp->l_value) {
				case LC_RULE:
					inrule(fields, nfields);
					break;
				case LC_ZONE:
					inzone(fields, nfields);
					break;
				case LC_LINK:
					inlink(fields, nfields);
					break;
				default:	/* "cannot happen" */
					wildrexit("lookup");
			}
		free((char *) fields);
	}
	if (ferror(fp))
		wild2exit("result reading", filename);
	if (fp != stdin && fclose(fp))
		wild2exit("result closing", filename);
}

/*
** Convert a string of one of the forms
**	h	-h 	hh:mm	-hh:mm	hh:mm:ss	-hh:mm:ss
** into a number of seconds. 
** Return -1 on errors.
*/

static long
getoff(string)
char *		string;
{
	int	hh, mm, ss, sign;

	if (*string == '-') {
		sign = -1;
		++string;
	} else	sign = 1;
	if (sscanf(string, scheck(string, "%d"), &hh) == 1)
		mm = ss = 0;
	else if (sscanf(string, scheck(string, "%d:%d"), &hh, &mm) == 2)
		ss = 0;
	else if (sscanf(string, scheck(string, "%d:%d:%d"), &hh, &mm, &ss) != 3)
		return -1;
	if (hh < 0 || hh >= HOURS_PER_DAY ||
		mm < 0 || mm >= MINS_PER_HOUR ||
		ss < 0 || ss >= SECS_PER_MIN)
			return -1;
	return (long) sign * (((hh * MINS_PER_HOUR) + mm) * SECS_PER_MIN + ss);
}

static
inrule(fields, nfields)
char **	fields;
{
	register struct lookup *	lp;
	register char *			cp;
	struct rule			r;

	if (nfields != RULE_FIELDS) {
		error("number of fields on Rule line");
		return;
	}
	r.r_filename = filename;
	r.r_linenum = linenum;
	if ((lp = byword(fields[RF_MONTH], mon_names)) == NULL) {
		error("month name");
		return;
	} else r.r_month = lp->l_value;
	if ((r.r_tod = getoff(fields[RF_TOD])) < 0) {
		error("time of day");
		return;
	}
	if ((r.r_stdoff = getoff(fields[RF_STDOFF])) == -1) {
		error("Standard Time offset");
		return;
	}
	/*
	** Year work.
	*/
	cp = fields[RF_LOYEAR];
	if (sscanf(cp, scheck(cp, "%d"), &r.r_loyear) != 1 || r.r_loyear <= 0) {
		error("low year");
		return;
	}
	cp = fields[RF_HIYEAR];
	if (*cp == '\0' || ciequal(cp, "only"))
		r.r_hiyear = r.r_loyear;
	else if (sscanf(cp, scheck(cp, "%d"), &r.r_hiyear) != 1 ||
		r.r_hiyear <= 0) {
			error("high year");
			return;
	}
	if (r.r_loyear > r.r_hiyear) {
		error("low year (greater than high year)");
		return;
	}
	if (*fields[RF_COMMAND] == '\0')
		r.r_yrtype = NULL;
	else {
		if (r.r_loyear == r.r_hiyear) {
			error("typed single year");
			return;
		}
		r.r_yrtype = eallocpy(fields[RF_COMMAND]);
	}
	/*
	** Day work.
	** Accept things like:
	**	1
	**	last-Sunday
	**	Sun<=20
	**	Sun>=7
	*/
	cp = fields[RF_DAY];
	if ((lp = byword(cp, lasts)) != NULL) {
		r.r_dycode = DC_DOWLEQ;
		r.r_wday = lp->l_value;
		r.r_dayofmonth = mon_lengths[r.r_month];
		if (r.r_month == TM_FEBRUARY)
			++r.r_dayofmonth;
	} else {
		if ((cp = strchr(fields[RF_DAY], '<')) != 0)
			r.r_dycode = DC_DOWLEQ;
		else if ((cp = strchr(fields[RF_DAY], '>')) != 0)
			r.r_dycode = DC_DOWGEQ;
		else {
			cp = fields[RF_DAY];
			r.r_dycode = DC_DOM;
		}
		if (r.r_dycode != DC_DOM) {
			*cp++ = 0;
			if (*cp++ != '=') {
				error("day of month");
				return;
			}
			if ((lp = byword(fields[RF_DAY], wday_names)) == NULL) {
				error("weekday name");
				return;
			}
			r.r_wday = lp->l_value;
		}
		if (sscanf(cp, scheck(cp, "%d"), &r.r_dayofmonth) != 1 ||
			r.r_dayofmonth <= 0 ||
			(r.r_dayofmonth > mon_lengths[r.r_month] &&
			r.r_month != TM_FEBRUARY && r.r_dayofmonth != 29)) {
				error("day of month");
				return;
		}
	}
	if (*fields[RF_NAME] == '\0') {
		error("nameless rule");
		return;
	}
	r.r_name = eallocpy(fields[RF_NAME]);
	r.r_abbrvar = eallocpy(fields[RF_ABBRVAR]);
	rules = (struct rule *) erealloc((char *) rules,
		(nrules + 1) * sizeof *rules);
	rules[nrules++] = r;
}

static
inzone(fields, nfields)
char **	fields;
{
	register char *	cp;
	register int	i;
	struct zone	z;
	char		buf[132];

	if (nfields != ZONE_FIELDS) {
		error("number of fields on Zone line");
		return;
	}
	z.z_filename = filename;
	z.z_linenum = linenum;
	for (i = 0; i < nzones; ++i)
		if (strcmp(zones[i].z_name, fields[ZF_NAME]) == 0) {
			(void) sprintf(buf,
				"duplicate zone name %s (file \"%s\", line %d)",
				fields[ZF_NAME],
				zones[i].z_filename,
				zones[i].z_linenum);
			error(buf);
			return;
		}
	if ((z.z_gmtoff = getoff(fields[ZF_GMTOFF])) == -1) {
		error("GMT offset");
		return;
	}
	if ((cp = strchr(fields[ZF_FORMAT], '%')) != 0) {
		if (*++cp != 's' || strchr(cp, '%') != 0) {
			error("format");
			return;
		}
	}
	z.z_name = eallocpy(fields[ZF_NAME]);
	z.z_rule = eallocpy(fields[ZF_RULE]);
	z.z_format = eallocpy(fields[ZF_FORMAT]);
	zones = (struct zone *) erealloc((char *) zones,
		(nzones + 1) * sizeof *zones);
	zones[nzones++] = z;
}

static
inlink(fields, nfields)
char **	fields;
{
	struct link	l;

	if (nfields != LINK_FIELDS) {
		error("number of fields on Link line");
		return;
	}
	if (*fields[LF_FROM] == '\0') {
		error("blank FROM field on Link line");
		return;
	}
	if (*fields[LF_TO] == '\0') {
		error("blank TO field on Link line");
		return;
	}
	l.l_filename = filename;
	l.l_linenum = linenum;
	l.l_from = eallocpy(fields[LF_FROM]);
	l.l_to = eallocpy(fields[LF_TO]);
	links = (struct link *) erealloc((char *) links,
		(nlinks + 1) * sizeof *links);
	links[nlinks++] = l;
}

static
writezone(name, data)
register char *	name;
struct tzinfo *	data;
{
	register FILE *	fp;
	char		fullname[BUFSIZ];

	(void) sprintf(fullname, "%s/%s", directory, name);
	if ((fp = fopen(fullname, "w")) == NULL)
		wild2exit("result creating", fullname);
	if (fwrite((char *) data, sizeof *data, 1, fp) != 1)
		wild2exit("result writing", fullname);
	if (fclose(fp))
		wild2exit("result closing", fullname);
}

struct temp {
	long		t_time;
	struct rule *	t_rp;
};

static struct temp	temps[TZ_MAX_RULES];
static int		ntemps;

static
tcomp(cp1, cp2)
char *	cp1;
char *	cp2;
{
	register struct temp *	tp1;
	register struct temp *	tp2;
	register long		diff;

	tp1 = (struct temp *) cp1;
	tp2 = (struct temp *) cp2;
	if ((diff = tp1->t_time - tp2->t_time) > 0)
		return 1;
	else if (diff < 0)
		return -1;
	/*
	** Oops!
	*/
	if (tp1->t_rp->r_type == tp2->t_rp->r_type)
		error("duplicate rule?!");
	else	error("inconsistent rules?!");
	wildexit("input data");
	/*NOTREACHED*/
}

static
addrule(rp, y)
register struct rule *	rp;
{
	if (ntemps >= TZ_MAX_RULES) {
		filename = rp->r_filename;
		linenum = rp->r_linenum;
		error("too many transitions?!");
		wildexit("large number of transitions");
	}
	temps[ntemps].t_time = rpytime(rp, y);
	temps[ntemps].t_rp = rp;
	++ntemps;
}

static
outzone(zp)
register struct zone *	zp;
{
	register struct rule *		rp;
	register struct dsinfo *	dsp;
	register int			ndstypes;
	register int			i, j;
	register int			y;
	char				buf[BUFSIZ];
	struct tzinfo			t;
	struct dsinfo			d;
	static struct tzinfo		tzero;
	static struct dsinfo		dzero;

	filename = zp->z_filename;
	linenum = zp->z_linenum;
	t = tzero;
	if (zp->z_nrules == 0) {	/* Piece of cake! */
		t.tz_rulecnt = 0;
		t.tz_dsinfo[0].ds_gmtoff = zp->z_gmtoff;
		t.tz_dsinfo[0].ds_isdst = 0;
		(void) strcpy(t.tz_dsinfo[0].ds_abbr, zp->z_format);
		writezone(zp->z_name, &t);
		return;
	}
	t.tz_rulecnt = 0;
	/*
	** See what the different Saving Time types are.
	** Plug the indices into the rules.
	*/
	ndstypes = 0;
	for (i = 0; i < zp->z_nrules; ++i) {
		rp = &zp->z_rules[i];
		(void) sprintf(buf, zp->z_format, rp->r_abbrvar);
		if (strlen(buf) > TZ_ABBR_LEN) {
			(void) strcat(buf, " is too long as a Time Zone abbr.");
			error(buf);
			wildexit("input data");
		}
		d = dzero;
		(void) strcpy(d.ds_abbr, buf);
		d.ds_gmtoff = zp->z_gmtoff + rp->r_stdoff;
		d.ds_isdst = rp->r_stdoff != 0;
		for (j = 0; j < ndstypes; ++j) {
			dsp = &t.tz_dsinfo[j];
			if (d.ds_gmtoff == dsp->ds_gmtoff &&
				strcmp(d.ds_abbr, dsp->ds_abbr) == 0)
					break;
		}
		if (j >= ndstypes) {
			if (ndstypes >= TZ_MAX_TYPES) {
				error("large number of Saving Time types");
				wildexit("input data");
			}
			t.tz_dsinfo[ndstypes++] = d;
		}
		rp->r_type = j;
	}
	/*
	** Now. . .finally. . .generate some useable data!
	*/
	ntemps = 0;
	for (i = 0; i < zp->z_nrules; ++i) {
		rp = &zp->z_rules[i];
		if (rp->r_yrtype != NULL && *rp->r_yrtype != '\0')
			hard(rp);
		else for (y = rp->r_loyear; y <= rp->r_hiyear; ++y)
			addrule(rp, y);
	}
	t.tz_rulecnt = ntemps;
	(void) qsort((char *) temps, ntemps, sizeof *temps, tcomp);
	for (i = 0; i < ntemps; ++i) {
		t.tz_times[i] = temps[i].t_time - zp->z_gmtoff;
		t.tz_types[i] = temps[i].t_rp->r_type;
	}
	writezone(zp->z_name, &t);
	return;
}

static
hard(rp)
register struct rule *	rp;
{
	register FILE *	fp;
	register int	n;
	int		y;
	char		buf[BUFSIZ];
	char		command[BUFSIZ];

	(void) sprintf(command, "years %d %d %s",
		rp->r_loyear, rp->r_hiyear, rp->r_yrtype);
	if ((fp = popen(command, "r")) == NULL)
		wild2exit("result opening pipe to", command);
	for (n = 0; fgets(buf, sizeof buf, fp) == buf; ++n) {
		if (strchr(buf, '\n') == 0)
			wildrexit(command);
		*strchr(buf, '\n') = '\0';
		if (sscanf(buf, scheck(buf, "%d"), &y) != 1)
			wildrexit(command);
		if (y < rp->r_loyear || y > rp->r_hiyear)
			wildrexit(command);
		addrule(rp, y);
	}
	if (ferror(fp))
		wild2exit("result reading from", command);
	if (pclose(fp))
		wild2exit("result closing pipe to", command);
	if (n == 0) {
		filename = rp->r_filename;
		linenum = rp->r_linenum;
		error("no year in range matches type");
		wildexit("input data");
	}
}

static
lowerit(a)
{
	return (isascii(a) && isupper(a)) ? tolower(a) : a;
}

static
ciequal(ap, bp)		/* case-insensitive equality */
register char *	ap;
register char *	bp;
{
	while (lowerit(*ap) == lowerit(*bp++))
		if (*ap++ == '\0')
			return TRUE;
	return FALSE;
}

static
isabbr(abbr, word)
register char *		abbr;
register char *		word;
{
	if (lowerit(*abbr) != lowerit(*word))
		return FALSE;
	++word;
	while (*++abbr != '\0')
		do if (*word == '\0')
			return FALSE;
				while (lowerit(*word++) != lowerit(*abbr));
	return TRUE;
}

static struct lookup *
byword(word, table)
register char *			word;
register struct lookup *	table;
{
	register struct lookup *	foundlp;
	register struct lookup *	lp;

	if (word == NULL || table == NULL)
		return NULL;
	foundlp = NULL;
	for (lp = table; lp->l_word != NULL; ++lp)
		if (ciequal(word, lp->l_word))		/* "exact" match */
			return lp;
		else if (!isabbr(word, lp->l_word))
			continue;
		else if (foundlp == NULL)
			foundlp = lp;
		else	return NULL;		/* two inexact matches */
	return foundlp;
}

static char **
getfields(cp)
register char *	cp;
{
	register char **	array;
	register int		nsubs;

	if (cp == NULL)
		return NULL;
	array = (char **) emalloc((strlen(cp) + 1) * sizeof *array);
	nsubs = 0;
	for ( ; ; ) {
		while (isascii(*cp) && isspace(*cp))
			++cp;
		if (*cp == '\0')
			break;
		array[nsubs++] = cp;
		while (*cp != '\0' && (!isascii(*cp) || !isspace(*cp)))
			++cp;
		if (*cp == '\0')
			break;
		*cp++ = '\0';
	}
	array[nsubs] = NULL;
	return array;
}

static long
tadd(t1, t2)
long	t1;
long	t2;
{
	register long	t;

	t = t1 + t2;
	if (t1 > 0 && t2 > 0 && t <= 0 || t1 < 0 && t2 < 0 && t >= 0)
		wildexit("time overflow");
	return t;
}

static
isleap(y)
{
	return (y % 4) == 0 && ((y % 100) != 0 || (y % 400) == 0);
}

static long
rpytime(rp, wantedy)
register struct rule *	rp;
register int		wantedy;
{
	register int	i;
	register int	y;
	register int	m;
	register int	wday;
	register long	dayoff;
	register long	t;

	t = 0;
	dayoff = 0;
	m = TM_JANUARY;
	y = EPOCH_YEAR;
	while (wantedy != y) {
		if (wantedy > y) {
			i = DAYS_PER_YEAR + isleap(y);
			++y;
		} else {
			--y;
			i = -(DAYS_PER_YEAR + isleap(y));
		}
		dayoff += i;
		t = tadd(t, (long) i * SECS_PER_DAY);
	}
	while (m != rp->r_month) {
		i = mon_lengths[m];
		if (m == TM_FEBRUARY && isleap(y))
			++i;
		dayoff += i;
		t = tadd(t, (long) i * SECS_PER_DAY);
		++m;
	}
	i = rp->r_dayofmonth - 1;
	dayoff += i;
	t = tadd(t, (long) i * SECS_PER_DAY);
	if (rp->r_dycode == DC_DOWGEQ || rp->r_dycode == DC_DOWLEQ) {
		wday = EPOCH_WDAY;
		/*
		** Don't trust mod of negative numbers.
		*/
		if (dayoff >= 0)
			wday = (wday + dayoff) % 7;
		else {
			wday -= ((-dayoff) % 7);
			if (wday < 0)
				wday += 7;
		}
		while (wday != rp->r_wday) {
			if (rp->r_dycode == DC_DOWGEQ)
				i = 1;
			else	i = -1;
			dayoff += i;
			t = tadd(t, (long) i * SECS_PER_DAY);
			wday = (wday + i + 7) % 7;
		}
	}
	return tadd(t, rp->r_tod);
}