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Date:	2016-12-06	Branches:	0	159	0.0 %


/*	$OpenBSD: cal.c,v 1.30 2015/10/09 01:37:06 deraadt Exp $	*/
/*	$NetBSD: cal.c,v 1.6 1995/03/26 03:10:24 glass Exp $	*/

/*
 * Copyright (c) 1989, 1993, 1994
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Kim Letkeman.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/types.h>

#include <ctype.h>
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#define	THURSDAY		4		/* for reformation */
#define	SATURDAY		6		/* 1 Jan 1 was a Saturday */

#define	FIRST_MISSING_DAY	639799		/* 3 Sep 1752 */
#define	NUMBER_MISSING_DAYS	11		/* 11 day correction */

#define	MAXDAYS			42		/* max slots in a month array */
#define	SPACE			-1		/* used in day array */

static const int days_in_month[2][13] = {
	{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
	{0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
};

const int sep1752s[MAXDAYS] = {
	SPACE,	SPACE,	1,	2,	14,	15,	16,
	17,	18,	19,	20,	21,	22,	23,
	24,	25,	26,	27,	28,	29,	30,
	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
}, sep1752m[MAXDAYS] = {
	SPACE,	1,	2,	14,	15,	16,	17,
	18,	19,	20,	21,	22,	23,	24,
	25,	26,	27,	28,	29,	30,	SPACE,
	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
}, sep1752js[MAXDAYS] = {
	SPACE,	SPACE,	245,	246,	258,	259,	260,
	261,	262,	263,	264,	265,	266,	267,
	268,	269,	270,	271,	272,	273,	274,
	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
}, sep1752jm[MAXDAYS] = {
	SPACE,	245,	246,	258,	259,	260,	261,
	262,	263,	264,	265,	266,	267,	268,
	269,	270,	271,	272,	273,	274,	SPACE,
	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
}, empty[MAXDAYS] = {
	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
};

const char *month_names[12] = {
	"January", "February", "March", "April", "May", "June",
	"July", "August", "September", "October", "November", "December",
};

#define	DAY_HEADINGS_S	"Su Mo Tu We Th Fr Sa"
#define	DAY_HEADINGS_M	"Mo Tu We Th Fr Sa Su"
#define	DAY_HEADINGS_JS	" Su  Mo  Tu  We  Th  Fr  Sa"
#define	DAY_HEADINGS_JM	" Mo  Tu  We  Th  Fr  Sa  Su"

const int	*sep1752 = NULL;
const char	*day_headings = NULL;

/* leap year -- account for gregorian reformation in 1752 */
#define	leap_year(yr) \
	((yr) <= 1752 ? !((yr) % 4) : \
	(!((yr) % 4) && ((yr) % 100)) || !((yr) % 400))

/* number of centuries since 1700, not inclusive */
#define	centuries_since_1700(yr) \
	((yr) > 1700 ? (yr) / 100 - 17 : 0)

/* number of centuries since 1700 whose modulo of 400 is 0 */
#define	quad_centuries_since_1700(yr) \
	((yr) > 1600 ? ((yr) - 1600) / 400 : 0)

/* number of leap years between year 1 and this year, not inclusive */
#define	leap_years_since_year_1(yr) \
	((yr) / 4 - centuries_since_1700(yr) + quad_centuries_since_1700(yr))

int julian;
int mflag = 0;
int wflag = 0;

void	ascii_day(char *, int);
void	center(const char *, int, int);
void	day_array(int, int, int *);
int	day_in_week(int, int, int);
int	day_in_year(int, int, int);
int	week(int, int, int);
int	isoweek(int, int, int);
void	j_yearly(int);
void	monthly(int, int);
void	trim_trailing_spaces(char *);
void	usage(void);
void	yearly(int);
int	parsemonth(const char *);

int
main(int argc, char *argv[])
{
	struct tm *local_time;
	time_t now;
	int ch, month, year, yflag;
	const char *errstr;

	if (pledge("stdio wpath cpath rpath", NULL) == -1)
		err(1, "pledge");

	yflag = year = 0;
	while ((ch = getopt(argc, argv, "jmwy")) != -1)
		switch(ch) {
		case 'j':
			julian = 1;
			break;
		case 'm':
			mflag = 1;
			break;
		case 'w':
			wflag = 1;
			break;
		case 'y':
			yflag = 1;
			break;
		case '?':
		default:
			usage();
		}
	argc -= optind;
	argv += optind;

	if (julian && wflag)
		usage();

	day_headings = DAY_HEADINGS_S;
	sep1752 = sep1752s;
	if (mflag && julian) {
		sep1752 = sep1752jm;
		day_headings = DAY_HEADINGS_JM;
	} else if (mflag) {
		sep1752 = sep1752m;
		day_headings = DAY_HEADINGS_M;
	} else if (julian) {
		sep1752 = sep1752js;
		day_headings = DAY_HEADINGS_JS;
	}

	month = 0;
	switch(argc) {
	case 2:
		month = parsemonth(*argv++);
		if (!month)
			errx(1, "Unable to parse month");
		/* FALLTHROUGH */
	case 1:
		if (argc == 1 && !isdigit((unsigned char)*argv[0])) {
			month = parsemonth(*argv);
			if (!month)
				errx(1, "illegal year value: use 1-9999");
			(void)time(&now);
			local_time = localtime(&now);
			year = local_time->tm_year + 1900;
		} else {
			year = strtonum(*argv, 1, 9999, &errstr);
			if (errstr)
				errx(1, "illegal year value: use 1-9999");
		}
		break;
	case 0:
		(void)time(&now);
		local_time = localtime(&now);
		year = local_time->tm_year + 1900;
		if (!yflag)
			month = local_time->tm_mon + 1;
		break;
	default:
		usage();
	}

	if (month)
		monthly(month, year);
	else if (julian)
		j_yearly(year);
	else
		yearly(year);
	exit(0);
}

#define	DAY_LEN		3		/* 3 spaces per day */
#define	J_DAY_LEN	4		/* 4 spaces per day */
#define	WEEK_LEN	20		/* 7 * 3 - one space at the end */
#define WEEKNUMBER_LEN	5		/* 5 spaces per week number */
#define	J_WEEK_LEN	27		/* 7 * 4 - one space at the end */
#define	HEAD_SEP	2		/* spaces between day headings */
#define	J_HEAD_SEP	2

int
week(int day, int month, int year)
{
	int	yearday;
	int	firstweekday;
	int	weekday;
	int	firstday;
	int	firstsunday;
	int	shift;

	if (mflag)
		return isoweek(day, month, year);

	yearday = day_in_year(day, month, year);
	firstweekday = day_in_week(1, 1, year) + 1;
	weekday = day_in_week(day, month, year) + 1;
	firstday = day_in_year(1, 1, year);
	firstsunday = firstday + (8 - firstweekday);

	shift = 1;
	if (yearday < firstsunday)
		return (1);
	if (firstweekday > THURSDAY - 1)
		shift = 2;
	return ((((yearday + 1) - (weekday - 1)) / 7) + shift);
}

int
isoweek(int day, int month, int year)
{
	/* http://www.tondering.dk/claus/cal/node8.html */
	int a, b, c, s, e, f, g, d, n;

	a = month <= 2 ? year - 1 : year;
	b = a/4 - a/100 + a/400;
	c = (a-1)/4 - (a-1)/100 + (a-1)/400;
	s = b - c;
	if (month <= 2) {
		e = 0;
		f = day - 1 + 31 * (month-1);
	} else {
		e = s + 1;
		f = day + ((153 * (month-3) + 2) / 5) + 58 + s;
	}
	g = (a + b) % 7;
	d = (f + g - e) % 7;
	n = f + 3 - d;

	if (n < 0)
		return 53 - (g - s) / 5;
	else if (n > 364 + s)
		return 1;
	else
		return n/7 + 1;
}

void
monthly(int month, int year)
{
	int col, row, len, days[MAXDAYS], firstday;
	char *p, lineout[30];

	day_array(month, year, days);
	(void)snprintf(lineout, sizeof(lineout), "%s %d",
	    month_names[month - 1], year);
	len = strlen(lineout);
	(void)printf("%*s%s\n%s\n",
	    ((julian ? J_WEEK_LEN : WEEK_LEN) - len) / 2, "",
	    lineout, day_headings);
	for (row = 0; row < 6; row++) {
		firstday = SPACE;
		for (col = 0, p = lineout; col < 7; col++,
		    p += julian ? J_DAY_LEN : DAY_LEN) {
			if (firstday == SPACE && days[row * 7 + col] != SPACE)
				firstday = days[row * 7 + col];
			ascii_day(p, days[row * 7 + col]);
		}
		*p = '\0';
		trim_trailing_spaces(lineout);
		(void)printf("%-20s", lineout);
		if (wflag && firstday != SPACE)
			printf(" [%2d]", week(firstday, month, year));
		printf("\n");
	}
}

void
j_yearly(int year)
{
	int col, *dp, i, month, row, which_cal;
	int days[12][MAXDAYS];
	char *p, lineout[80];

	(void)snprintf(lineout, sizeof(lineout), "%d", year);
	center(lineout, J_WEEK_LEN * 2 + J_HEAD_SEP, 0);
	(void)printf("\n\n");
	for (i = 0; i < 12; i++)
		day_array(i + 1, year, days[i]);
	(void)memset(lineout, ' ', sizeof(lineout) - 1);
	lineout[sizeof(lineout) - 1] = '\0';
	for (month = 0; month < 12; month += 2) {
		center(month_names[month], J_WEEK_LEN, J_HEAD_SEP);
		center(month_names[month + 1], J_WEEK_LEN, 0);
		(void)printf("\n%s%*s%s\n", day_headings,
		    J_HEAD_SEP, "", day_headings);

		for (row = 0; row < 6; row++) {
			for (which_cal = 0; which_cal < 2; which_cal++) {
				p = lineout + which_cal * (J_WEEK_LEN + 2);
				dp = &days[month + which_cal][row * 7];
				for (col = 0; col < 7; col++, p += J_DAY_LEN)
					ascii_day(p, *dp++);
			}
			*p = '\0';
			trim_trailing_spaces(lineout);
			(void)printf("%s\n", lineout);
		}
	}
	(void)printf("\n");
}

void
yearly(int year)
{
	int col, *dp, i, month, row, which_cal, week_len, wn, firstday;
	int days[12][MAXDAYS];
	char *p, lineout[81];

	week_len = WEEK_LEN;
	if (wflag)
		week_len += WEEKNUMBER_LEN;
	(void)snprintf(lineout, sizeof(lineout), "%d", year);
	center(lineout, week_len * 3 + HEAD_SEP * 2, 0);
	(void)printf("\n\n");
	for (i = 0; i < 12; i++)
		day_array(i + 1, year, days[i]);
	(void)memset(lineout, ' ', sizeof(lineout) - 1);
	lineout[sizeof(lineout) - 1] = '\0';
	for (month = 0; month < 12; month += 3) {
		center(month_names[month], week_len, HEAD_SEP);
		center(month_names[month + 1], week_len, HEAD_SEP);
		center(month_names[month + 2], week_len, 0);
		(void)printf("\n%s%*s%s%*s%s\n", day_headings,
		    HEAD_SEP + (wflag ? WEEKNUMBER_LEN : 0), "", day_headings,
		    HEAD_SEP + (wflag ? WEEKNUMBER_LEN : 0), "", day_headings);

		for (row = 0; row < 6; row++) {
			for (which_cal = 0; which_cal < 3; which_cal++) {
				p = lineout + which_cal * (week_len + 2);

				dp = &days[month + which_cal][row * 7];
				firstday = SPACE;
				for (col = 0; col < 7; col++, p += DAY_LEN) {
					if (firstday == SPACE && *dp != SPACE)
						firstday = *dp;
					ascii_day(p, *dp++);
				}
				if (wflag && firstday != SPACE) {
					wn = week(firstday,
					    month + which_cal + 1, year);
					(void)snprintf(p, 5, "[%2d]", wn);
					p += strlen(p);
					*p = ' ';
				} else
					memset(p, ' ', 4);
			}
			*p = '\0';
			trim_trailing_spaces(lineout);
			(void)printf("%s\n", lineout);
		}
	}
	(void)printf("\n");
}

/*
 * day_array --
 *	Fill in an array of 42 integers with a calendar.  Assume for a moment
 *	that you took the (maximum) 6 rows in a calendar and stretched them
 *	out end to end.  You would have 42 numbers or spaces.  This routine
 *	builds that array for any month from Jan. 1 through Dec. 9999.
 */
void
day_array(int month, int year, int *days)
{
	int day, dw, dm;

	if (month == 9 && year == 1752) {
		memmove(days, sep1752, MAXDAYS * sizeof(int));
		return;
	}
	memmove(days, empty, MAXDAYS * sizeof(int));
	dm = days_in_month[leap_year(year)][month];
	dw = day_in_week(mflag?0:1, month, year);
	day = julian ? day_in_year(1, month, year) : 1;
	while (dm--)
		days[dw++] = day++;
}

/*
 * day_in_year --
 *	return the 1 based day number within the year
 */
int
day_in_year(int day, int month, int year)
{
	int i, leap;

	leap = leap_year(year);
	for (i = 1; i < month; i++)
		day += days_in_month[leap][i];
	return (day);
}

/*
 * day_in_week
 *	return the 0 based day number for any date from 1 Jan. 1 to
 *	31 Dec. 9999.  Assumes the Gregorian reformation eliminates
 *	3 Sep. 1752 through 13 Sep. 1752.  Returns Thursday for all
 *	missing days.
 */
int
day_in_week(int day, int month, int year)
{
	long temp;

	temp = (long)(year - 1) * 365 + leap_years_since_year_1(year - 1)
	    + day_in_year(day, month, year);
	if (temp < FIRST_MISSING_DAY)
		return ((temp - 1 + SATURDAY) % 7);
	if (temp >= (FIRST_MISSING_DAY + NUMBER_MISSING_DAYS))
		return (((temp - 1 + SATURDAY) - NUMBER_MISSING_DAYS) % 7);
	return (THURSDAY);
}

void
ascii_day(char *p, int day)
{
	int display, val;
	static const char *aday[] = {
		"",
		" 1", " 2", " 3", " 4", " 5", " 6", " 7",
		" 8", " 9", "10", "11", "12", "13", "14",
		"15", "16", "17", "18", "19", "20", "21",
		"22", "23", "24", "25", "26", "27", "28",
		"29", "30", "31",
	};

	if (day == SPACE) {
		memset(p, ' ', julian ? J_DAY_LEN : DAY_LEN);
		return;
	}
	if (julian) {
		val = day / 100;
		if (val) {
			day %= 100;
			*p++ = val + '0';
			display = 1;
		} else {
			*p++ = ' ';
			display = 0;
		}
		val = day / 10;
		if (val || display)
			*p++ = val + '0';
		else
			*p++ = ' ';
		*p++ = day % 10 + '0';
	} else {
		*p++ = aday[day][0];
		*p++ = aday[day][1];
	}
	*p = ' ';
}

void
trim_trailing_spaces(char *s)
{
	char *p;

	for (p = s; *p; ++p)
		continue;
	while (p > s && isspace((unsigned char)*--p))
		continue;
	if (p > s)
		++p;
	*p = '\0';
}

void
center(const char *str, int len, int separate)
{

	len -= strlen(str);
	(void)printf("%*s%s%*s", len / 2, "", str,
	    len / 2 + len % 2 + separate, "");
}

void
usage(void)
{

	(void)fprintf(stderr, "usage: cal [-jmwy] [month] [year]\n");
	exit(1);
}

int
parsemonth(const char *s)
{
	struct tm tm;
	char *cp;
	int v;

	v = (int)strtol(s, &cp, 10);
	if (*cp != '\0') {		/* s wasn't purely numeric */
		v = 0;
		if ((cp = strptime(s, "%b", &tm)) != NULL && *cp == '\0')
			v = tm.tm_mon + 1;
	}
	if (v <= 0 || v > 12)
		errx(1, "invalid month: use 1-12 or a name");
	return (v);
}


Generated by: GCOVR (Version 3.3)

Line	Branch	Exec	Source
1			/* $OpenBSD: cal.c,v 1.30 2015/10/09 01:37:06 deraadt Exp $ */
2			/* $NetBSD: cal.c,v 1.6 1995/03/26 03:10:24 glass Exp $ */
3
4			/*
5			* Copyright (c) 1989, 1993, 1994
6			* The Regents of the University of California. All rights reserved.
7			*
8			* This code is derived from software contributed to Berkeley by
9			* Kim Letkeman.
10			*
11			* Redistribution and use in source and binary forms, with or without
12			* modification, are permitted provided that the following conditions
13			* are met:
14			* 1. Redistributions of source code must retain the above copyright
15			* notice, this list of conditions and the following disclaimer.
16			* 2. Redistributions in binary form must reproduce the above copyright
17			* notice, this list of conditions and the following disclaimer in the
18			* documentation and/or other materials provided with the distribution.
19			* 3. Neither the name of the University nor the names of its contributors
20			* may be used to endorse or promote products derived from this software
21			* without specific prior written permission.
22			*
23			* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24			* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25			* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26			* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27			* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28			* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29			* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30			* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31			* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32			* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33			* SUCH DAMAGE.
34			*/
35
36			#include <sys/types.h>
37
38			#include <ctype.h>
39			#include <err.h>
40			#include <stdio.h>
41			#include <stdlib.h>
42			#include <string.h>
43			#include <time.h>
44			#include <unistd.h>
45
46			#define THURSDAY 4 /* for reformation */
47			#define SATURDAY 6 /* 1 Jan 1 was a Saturday */
48
49			#define FIRST_MISSING_DAY 639799 /* 3 Sep 1752 */
50			#define NUMBER_MISSING_DAYS 11 /* 11 day correction */
51
52			#define MAXDAYS 42 /* max slots in a month array */
53			#define SPACE -1 /* used in day array */
54
55			static const int days_in_month[2][13] = {
56			{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
57			{0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
58			};
59
60			const int sep1752s[MAXDAYS] = {
61			SPACE, SPACE, 1, 2, 14, 15, 16,
62			17, 18, 19, 20, 21, 22, 23,
63			24, 25, 26, 27, 28, 29, 30,
64			SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
65			SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
66			SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
67			}, sep1752m[MAXDAYS] = {
68			SPACE, 1, 2, 14, 15, 16, 17,
69			18, 19, 20, 21, 22, 23, 24,
70			25, 26, 27, 28, 29, 30, SPACE,
71			SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
72			SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
73			SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
74			}, sep1752js[MAXDAYS] = {
75			SPACE, SPACE, 245, 246, 258, 259, 260,
76			261, 262, 263, 264, 265, 266, 267,
77			268, 269, 270, 271, 272, 273, 274,
78			SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
79			SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
80			SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
81			}, sep1752jm[MAXDAYS] = {
82			SPACE, 245, 246, 258, 259, 260, 261,
83			262, 263, 264, 265, 266, 267, 268,
84			269, 270, 271, 272, 273, 274, SPACE,
85			SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
86			SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
87			SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
88			}, empty[MAXDAYS] = {
89			SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
90			SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
91			SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
92			SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
93			SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
94			SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
95			};
96
97			const char *month_names[12] = {
98			"January", "February", "March", "April", "May", "June",
99			"July", "August", "September", "October", "November", "December",
100			};
101
102			#define DAY_HEADINGS_S "Su Mo Tu We Th Fr Sa"
103			#define DAY_HEADINGS_M "Mo Tu We Th Fr Sa Su"
104			#define DAY_HEADINGS_JS " Su Mo Tu We Th Fr Sa"
105			#define DAY_HEADINGS_JM " Mo Tu We Th Fr Sa Su"
106
107			const int *sep1752 = NULL;
108			const char *day_headings = NULL;
109
110			/* leap year -- account for gregorian reformation in 1752 */
111			#define leap_year(yr) \
112			((yr) <= 1752 ? !((yr) % 4) : \
113			(!((yr) % 4) && ((yr) % 100)) \|\| !((yr) % 400))
114
115			/* number of centuries since 1700, not inclusive */
116			#define centuries_since_1700(yr) \
117			((yr) > 1700 ? (yr) / 100 - 17 : 0)
118
119			/* number of centuries since 1700 whose modulo of 400 is 0 */
120			#define quad_centuries_since_1700(yr) \
121			((yr) > 1600 ? ((yr) - 1600) / 400 : 0)
122
123			/* number of leap years between year 1 and this year, not inclusive */
124			#define leap_years_since_year_1(yr) \
125			((yr) / 4 - centuries_since_1700(yr) + quad_centuries_since_1700(yr))
126
127			int julian;
128			int mflag = 0;
129			int wflag = 0;
130
131			void ascii_day(char *, int);
132			void center(const char *, int, int);
133			void day_array(int, int, int *);
134			int day_in_week(int, int, int);
135			int day_in_year(int, int, int);
136			int week(int, int, int);
137			int isoweek(int, int, int);
138			void j_yearly(int);
139			void monthly(int, int);
140			void trim_trailing_spaces(char *);
141			void usage(void);
142			void yearly(int);
143			int parsemonth(const char *);
144
145			int
146			main(int argc, char *argv[])
147			{
148			struct tm *local_time;
149			time_t now;
150			int ch, month, year, yflag;
151			const char *errstr;
152
153			if (pledge("stdio wpath cpath rpath", NULL) == -1)
154			err(1, "pledge");
155
156			yflag = year = 0;
157			while ((ch = getopt(argc, argv, "jmwy")) != -1)
158			switch(ch) {
159			case 'j':
160			julian = 1;
161			break;
162			case 'm':
163			mflag = 1;
164			break;
165			case 'w':
166			wflag = 1;
167			break;
168			case 'y':
169			yflag = 1;
170			break;
171			case '?':
172			default:
173			usage();
174			}
175			argc -= optind;
176			argv += optind;
177
178			if (julian && wflag)
179			usage();
180
181			day_headings = DAY_HEADINGS_S;
182			sep1752 = sep1752s;
183			if (mflag && julian) {
184			sep1752 = sep1752jm;
185			day_headings = DAY_HEADINGS_JM;
186			} else if (mflag) {
187			sep1752 = sep1752m;
188			day_headings = DAY_HEADINGS_M;
189			} else if (julian) {
190			sep1752 = sep1752js;
191			day_headings = DAY_HEADINGS_JS;
192			}
193
194			month = 0;
195			switch(argc) {
196			case 2:
197			month = parsemonth(*argv++);
198			if (!month)
199			errx(1, "Unable to parse month");
200			/* FALLTHROUGH */
201			case 1:
202			if (argc == 1 && !isdigit((unsigned char)*argv[0])) {
203			month = parsemonth(*argv);
204			if (!month)
205			errx(1, "illegal year value: use 1-9999");
206			(void)time(&now);
207			local_time = localtime(&now);
208			year = local_time->tm_year + 1900;
209			} else {
210			year = strtonum(*argv, 1, 9999, &errstr);
211			if (errstr)
212			errx(1, "illegal year value: use 1-9999");
213			}
214			break;
215			case 0:
216			(void)time(&now);
217			local_time = localtime(&now);
218			year = local_time->tm_year + 1900;
219			if (!yflag)
220			month = local_time->tm_mon + 1;
221			break;
222			default:
223			usage();
224			}
225
226			if (month)
227			monthly(month, year);
228			else if (julian)
229			j_yearly(year);
230			else
231			yearly(year);
232			exit(0);
233			}
234
235			#define DAY_LEN 3 /* 3 spaces per day */
236			#define J_DAY_LEN 4 /* 4 spaces per day */
237			#define WEEK_LEN 20 /* 7 * 3 - one space at the end */
238			#define WEEKNUMBER_LEN 5 /* 5 spaces per week number */
239			#define J_WEEK_LEN 27 /* 7 * 4 - one space at the end */
240			#define HEAD_SEP 2 /* spaces between day headings */
241			#define J_HEAD_SEP 2
242
243			int
244			week(int day, int month, int year)
245			{
246			int yearday;
247			int firstweekday;
248			int weekday;
249			int firstday;
250			int firstsunday;
251			int shift;
252
253			if (mflag)
254			return isoweek(day, month, year);
255
256			yearday = day_in_year(day, month, year);
257			firstweekday = day_in_week(1, 1, year) + 1;
258			weekday = day_in_week(day, month, year) + 1;
259			firstday = day_in_year(1, 1, year);
260			firstsunday = firstday + (8 - firstweekday);
261
262			shift = 1;
263			if (yearday < firstsunday)
264			return (1);
265			if (firstweekday > THURSDAY - 1)
266			shift = 2;
267			return ((((yearday + 1) - (weekday - 1)) / 7) + shift);
268			}
269
270			int
271			isoweek(int day, int month, int year)
272			{
273			/* http://www.tondering.dk/claus/cal/node8.html */
274			int a, b, c, s, e, f, g, d, n;
275
276			a = month <= 2 ? year - 1 : year;
277			b = a/4 - a/100 + a/400;
278			c = (a-1)/4 - (a-1)/100 + (a-1)/400;
279			s = b - c;
280			if (month <= 2) {
281			e = 0;
282			f = day - 1 + 31 * (month-1);
283			} else {
284			e = s + 1;
285			f = day + ((153 * (month-3) + 2) / 5) + 58 + s;
286			}
287			g = (a + b) % 7;
288			d = (f + g - e) % 7;
289			n = f + 3 - d;
290
291			if (n < 0)
292			return 53 - (g - s) / 5;
293			else if (n > 364 + s)
294			return 1;
295			else
296			return n/7 + 1;
297			}
298
299			void
300			monthly(int month, int year)
301			{
302			int col, row, len, days[MAXDAYS], firstday;
303			char *p, lineout[30];
304
305			day_array(month, year, days);
306			(void)snprintf(lineout, sizeof(lineout), "%s %d",
307			month_names[month - 1], year);
308			len = strlen(lineout);
309			(void)printf("%*s%s\n%s\n",
310			((julian ? J_WEEK_LEN : WEEK_LEN) - len) / 2, "",
311			lineout, day_headings);
312			for (row = 0; row < 6; row++) {
313			firstday = SPACE;
314			for (col = 0, p = lineout; col < 7; col++,
315			p += julian ? J_DAY_LEN : DAY_LEN) {
316			if (firstday == SPACE && days[row * 7 + col] != SPACE)
317			firstday = days[row * 7 + col];
318			ascii_day(p, days[row * 7 + col]);
319			}
320			*p = '\0';
321			trim_trailing_spaces(lineout);
322			(void)printf("%-20s", lineout);
323			if (wflag && firstday != SPACE)
324			printf(" [%2d]", week(firstday, month, year));
325			printf("\n");
326			}
327			}
328
329			void
330			j_yearly(int year)
331			{
332			int col, *dp, i, month, row, which_cal;
333			int days[12][MAXDAYS];
334			char *p, lineout[80];
335
336			(void)snprintf(lineout, sizeof(lineout), "%d", year);
337			center(lineout, J_WEEK_LEN * 2 + J_HEAD_SEP, 0);
338			(void)printf("\n\n");
339			for (i = 0; i < 12; i++)
340			day_array(i + 1, year, days[i]);
341			(void)memset(lineout, ' ', sizeof(lineout) - 1);
342			lineout[sizeof(lineout) - 1] = '\0';
343			for (month = 0; month < 12; month += 2) {
344			center(month_names[month], J_WEEK_LEN, J_HEAD_SEP);
345			center(month_names[month + 1], J_WEEK_LEN, 0);
346			(void)printf("\n%s%*s%s\n", day_headings,
347			J_HEAD_SEP, "", day_headings);
348
349			for (row = 0; row < 6; row++) {
350			for (which_cal = 0; which_cal < 2; which_cal++) {
351			p = lineout + which_cal * (J_WEEK_LEN + 2);
352			dp = &days[month + which_cal][row * 7];
353			for (col = 0; col < 7; col++, p += J_DAY_LEN)
354			ascii_day(p, *dp++);
355			}
356			*p = '\0';
357			trim_trailing_spaces(lineout);
358			(void)printf("%s\n", lineout);
359			}
360			}
361			(void)printf("\n");
362			}
363
364			void
365			yearly(int year)
366			{
367			int col, *dp, i, month, row, which_cal, week_len, wn, firstday;
368			int days[12][MAXDAYS];
369			char *p, lineout[81];
370
371			week_len = WEEK_LEN;
372			if (wflag)
373			week_len += WEEKNUMBER_LEN;
374			(void)snprintf(lineout, sizeof(lineout), "%d", year);
375			center(lineout, week_len * 3 + HEAD_SEP * 2, 0);
376			(void)printf("\n\n");
377			for (i = 0; i < 12; i++)
378			day_array(i + 1, year, days[i]);
379			(void)memset(lineout, ' ', sizeof(lineout) - 1);
380			lineout[sizeof(lineout) - 1] = '\0';
381			for (month = 0; month < 12; month += 3) {
382			center(month_names[month], week_len, HEAD_SEP);
383			center(month_names[month + 1], week_len, HEAD_SEP);
384			center(month_names[month + 2], week_len, 0);
385			(void)printf("\n%s%s%s%s%s\n", day_headings,
386			HEAD_SEP + (wflag ? WEEKNUMBER_LEN : 0), "", day_headings,
387			HEAD_SEP + (wflag ? WEEKNUMBER_LEN : 0), "", day_headings);
388
389			for (row = 0; row < 6; row++) {
390			for (which_cal = 0; which_cal < 3; which_cal++) {
391			p = lineout + which_cal * (week_len + 2);
392
393			dp = &days[month + which_cal][row * 7];
394			firstday = SPACE;
395			for (col = 0; col < 7; col++, p += DAY_LEN) {
396			if (firstday == SPACE && *dp != SPACE)
397			firstday = *dp;
398			ascii_day(p, *dp++);
399			}
400			if (wflag && firstday != SPACE) {
401			wn = week(firstday,
402			month + which_cal + 1, year);
403			(void)snprintf(p, 5, "[%2d]", wn);
404			p += strlen(p);
405			*p = ' ';
406			} else
407			memset(p, ' ', 4);
408			}
409			*p = '\0';
410			trim_trailing_spaces(lineout);
411			(void)printf("%s\n", lineout);
412			}
413			}
414			(void)printf("\n");
415			}
416
417			/*
418			* day_array --
419			* Fill in an array of 42 integers with a calendar. Assume for a moment
420			* that you took the (maximum) 6 rows in a calendar and stretched them
421			* out end to end. You would have 42 numbers or spaces. This routine
422			* builds that array for any month from Jan. 1 through Dec. 9999.
423			*/
424			void
425			day_array(int month, int year, int *days)
426			{
427			int day, dw, dm;
428
429			if (month == 9 && year == 1752) {
430			memmove(days, sep1752, MAXDAYS * sizeof(int));
431			return;
432			}
433			memmove(days, empty, MAXDAYS * sizeof(int));
434			dm = days_in_month[leap_year(year)][month];
435			dw = day_in_week(mflag?0:1, month, year);
436			day = julian ? day_in_year(1, month, year) : 1;
437			while (dm--)
438			days[dw++] = day++;
439			}
440
441			/*
442			* day_in_year --
443			* return the 1 based day number within the year
444			*/
445			int
446			day_in_year(int day, int month, int year)
447			{
448			int i, leap;
449
450			leap = leap_year(year);
451			for (i = 1; i < month; i++)
452			day += days_in_month[leap][i];
453			return (day);
454			}
455
456			/*
457			* day_in_week
458			* return the 0 based day number for any date from 1 Jan. 1 to
459			* 31 Dec. 9999. Assumes the Gregorian reformation eliminates
460			* 3 Sep. 1752 through 13 Sep. 1752. Returns Thursday for all
461			* missing days.
462			*/
463			int
464			day_in_week(int day, int month, int year)
465			{
466			long temp;
467
468			temp = (long)(year - 1) * 365 + leap_years_since_year_1(year - 1)
469			+ day_in_year(day, month, year);
470			if (temp < FIRST_MISSING_DAY)
471			return ((temp - 1 + SATURDAY) % 7);
472			if (temp >= (FIRST_MISSING_DAY + NUMBER_MISSING_DAYS))
473			return (((temp - 1 + SATURDAY) - NUMBER_MISSING_DAYS) % 7);
474			return (THURSDAY);
475			}
476
477			void
478			ascii_day(char *p, int day)
479			{
480			int display, val;
481			static const char *aday[] = {
482			"",
483			" 1", " 2", " 3", " 4", " 5", " 6", " 7",
484			" 8", " 9", "10", "11", "12", "13", "14",
485			"15", "16", "17", "18", "19", "20", "21",
486			"22", "23", "24", "25", "26", "27", "28",
487			"29", "30", "31",
488			};
489
490			if (day == SPACE) {
491			memset(p, ' ', julian ? J_DAY_LEN : DAY_LEN);
492			return;
493			}
494			if (julian) {
495			val = day / 100;
496			if (val) {
497			day %= 100;
498			*p++ = val + '0';
499			display = 1;
500			} else {
501			*p++ = ' ';
502			display = 0;
503			}
504			val = day / 10;
505			if (val \|\| display)
506			*p++ = val + '0';
507			else
508			*p++ = ' ';
509			*p++ = day % 10 + '0';
510			} else {
511			*p++ = aday[day][0];
512			*p++ = aday[day][1];
513			}
514			*p = ' ';
515			}
516
517			void
518			trim_trailing_spaces(char *s)
519			{
520			char *p;
521
522			for (p = s; *p; ++p)
523			continue;
524			while (p > s && isspace((unsigned char)*--p))
525			continue;
526			if (p > s)
527			++p;
528			*p = '\0';
529			}
530
531			void
532			center(const char *str, int len, int separate)
533			{
534
535			len -= strlen(str);
536			(void)printf("%s%s%s", len / 2, "", str,
537			len / 2 + len % 2 + separate, "");
538			}
539
540			void
541			usage(void)
542			{
543
544			(void)fprintf(stderr, "usage: cal [-jmwy] [month] [year]\n");
545			exit(1);
546			}
547
548			int
549			parsemonth(const char *s)
550			{
551			struct tm tm;
552			char *cp;
553			int v;
554
555			v = (int)strtol(s, &cp, 10);
556			if (cp != '\0') { / s wasn't purely numeric */
557			v = 0;
558			if ((cp = strptime(s, "%b", &tm)) != NULL && *cp == '\0')
559			v = tm.tm_mon + 1;
560			}
561			if (v <= 0 \|\| v > 12)
562			errx(1, "invalid month: use 1-12 or a name");
563			return (v);
564			}