summaryrefslogtreecommitdiff
path: root/coreutils/cal.c
blob: 9368dccf92373b8be0928a57ffed1237323e790d (plain)
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
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
/*
 * Calendar implementation for busybox
 *
 * See original copyright at the end of this file
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
*/

/* BB_AUDIT SUSv3 compliant with -j and -y extensions (from util-linux). */
/* BB_AUDIT BUG: The output of 'cal -j 1752' is incorrect.  The upstream
 * BB_AUDIT BUG: version in util-linux seems to be broken as well. */
/* http://www.opengroup.org/onlinepubs/007904975/utilities/cal.html */

/* Mar 16, 2003      Manuel Novoa III   (mjn3@codepoet.org)
 *
 * Major size reduction... over 50% (>1.5k) on i386.
 */

#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>

#include "busybox.h"

#ifdef CONFIG_LOCALE_SUPPORT
#include <locale.h>
#endif

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

#define	FIRST_MISSING_DAY	639787		/* 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 char days_in_month[] = {
	0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
};

static const char sep1752[] = {
	         1,	2,	14,	15,	16,
	17,	18,	19,	20,	21,	22,	23,
	24,	25,	26,	27,	28,	29,	30
};

static int julian;

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

static int is_leap_year(int year)
{
	return leap_year(year);
}
#undef leap_year
#define leap_year(yr) is_leap_year(yr)

/* 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))

static void center __P((char *, int, int));
static void day_array __P((int, int, int *));
static void trim_trailing_spaces_and_print __P((char *));

static void blank_string(char *buf, size_t buflen);
static char *build_row(char *p, int *dp);

#define	DAY_LEN		3		/* 3 spaces per day */
#define	J_DAY_LEN	(DAY_LEN + 1)
#define	WEEK_LEN	20		/* 7 * 3 - one space at the end */
#define	J_WEEK_LEN	(WEEK_LEN + 7)
#define	HEAD_SEP	2		/* spaces between day headings */

int cal_main(int argc, char **argv)
{
	struct tm *local_time;
	struct tm zero_tm;
	time_t now;
	int month, year, flags, i;
	char *month_names[12];
	char day_headings[28];	/* 28 for julian, 21 for nonjulian */
	char buf[40];

#ifdef CONFIG_LOCALE_SUPPORT
	setlocale(LC_TIME, "");
#endif

	flags = bb_getopt_ulflags(argc, argv, "jy");

	julian = flags & 1;

	argv += optind;

	month = 0;

	if ((argc -= optind) > 2) {
		bb_show_usage();
	}

	if (!argc) {
		time(&now);
		local_time = localtime(&now);
		year = local_time->tm_year + 1900;
		if (!(flags & 2)) {
			month = local_time->tm_mon + 1;
		}
	} else {
		if (argc == 2) {
			month = bb_xgetularg10_bnd(*argv++, 1, 12);
		}
		year = bb_xgetularg10_bnd(*argv, 1, 9999);
	}

	blank_string(day_headings, sizeof(day_headings) - 7 +  7*julian);

	i = 0;
	do {
		zero_tm.tm_mon = i;
		strftime(buf, sizeof(buf), "%B", &zero_tm);
		month_names[i] = bb_xstrdup(buf);

		if (i < 7) {
			zero_tm.tm_wday = i;
			strftime(buf, sizeof(buf), "%a", &zero_tm);
			strncpy(day_headings + i * (3+julian) + julian, buf, 2);
		}
	} while (++i < 12);

	if (month) {
		int row, len, days[MAXDAYS];
		int *dp = days;
		char lineout[30];

		day_array(month, year, dp);
		len = sprintf(lineout, "%s %d", month_names[month - 1], year);
		bb_printf("%*s%s\n%s\n",
			   ((7*julian + WEEK_LEN) - len) / 2, "",
			   lineout, day_headings);
		for (row = 0; row < 6; row++) {
			build_row(lineout, dp)[0] = '\0';
			dp += 7;
			trim_trailing_spaces_and_print(lineout);
		}
	} else {
		int row, which_cal, week_len, days[12][MAXDAYS];
		int *dp;
		char lineout[80];

		sprintf(lineout, "%d", year);
		center(lineout,
			   (WEEK_LEN * 3 + HEAD_SEP * 2)
			   + julian * (J_WEEK_LEN * 2 + HEAD_SEP
						   - (WEEK_LEN * 3 + HEAD_SEP * 2)),
			   0);
		puts("\n");		/* two \n's */
		for (i = 0; i < 12; i++) {
			day_array(i + 1, year, days[i]);
		}
		blank_string(lineout, sizeof(lineout));
		week_len = WEEK_LEN + julian * (J_WEEK_LEN - WEEK_LEN);
		for (month = 0; month < 12; month += 3-julian) {
			center(month_names[month], week_len, HEAD_SEP);
			if (!julian) {
				center(month_names[month + 1], week_len, HEAD_SEP);
			}
			center(month_names[month + 2 - julian], week_len, 0);
			bb_printf("\n%s%*s%s", day_headings, HEAD_SEP, "", day_headings);
			if (!julian) {
				bb_printf("%*s%s", HEAD_SEP, "", day_headings);
			}
			putchar('\n');
			for (row = 0; row < (6*7); row += 7) {
				for (which_cal = 0; which_cal < 3-julian; which_cal++) {
					dp = days[month + which_cal] + row;
					build_row(lineout + which_cal * (week_len + 2), dp);
				}
				/* blank_string took care of nul termination. */
				trim_trailing_spaces_and_print(lineout);
			}
		}
	}

	bb_fflush_stdout_and_exit(0);
}

/*
 * 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.
 */
static void day_array(int month, int year, int *days)
{
	long temp;
	int i;
	int j_offset;
	int day, dw, dm;

	memset(days, SPACE, MAXDAYS * sizeof(int));

	if ((month == 9) && (year == 1752)) {
		j_offset = julian * 244;
		i = 0;
		do {
			days[i+2] = sep1752[i] + j_offset;
		} while (++i < sizeof(sep1752));

		return;
	}

	/* day_in_year
	 *	return the 1 based day number within the year
	 */
	day = 1;
	if ((month > 2) && leap_year(year)) {
		++day;
	}

	i = month;
	while (i) {
		day += days_in_month[--i];
	}

	/* 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.
	 */
	dw = THURSDAY;
	temp = (long)(year - 1) * 365 + leap_years_since_year_1(year - 1)
		+ day;
	if (temp < FIRST_MISSING_DAY) {
		dw = ((temp - 1 + SATURDAY) % 7);
	} else if (temp >= (FIRST_MISSING_DAY + NUMBER_MISSING_DAYS)) {
		dw = (((temp - 1 + SATURDAY) - NUMBER_MISSING_DAYS) % 7);
	}

	if (!julian) {
		day = 1;
	}

	dm = days_in_month[month];
	if ((month == 2) && leap_year(year)) {
		++dm;
	}

	while (dm) {
		days[dw++] = day++;
		--dm;
	}
}

static void trim_trailing_spaces_and_print(char *s)
{
	char *p = s;

	while (*p) {
		++p;
	}
	while (p > s) {
		--p;
		if (!(isspace)(*p)) {	/* We want the function... not the inline. */
			p[1] = '\0';
			break;
		}
	}

	puts(s);
}

static void center(char *str, int len, int separate)
{
	int n = strlen(str);
	len -= n;
	bb_printf("%*s%*s", (len/2) + n, str, (len/2) + (len % 2) + separate, "");
}

static void blank_string(char *buf, size_t buflen)
{
	memset(buf, ' ', buflen);
	buf[buflen-1] = '\0';
}

static char *build_row(char *p, int *dp)
{
	int col, val, day;

	memset(p, ' ', (julian + DAY_LEN) * 7);

	col = 0;
	do {
		if ((day = *dp++) != SPACE) {
			if (julian) {
				++p;
				if (day >= 100) {
					*p = '0';
					p[-1] = (day / 100) + '0';
					day %= 100;
				}
			}
			if ((val = day / 10) > 0) {
				*p = val + '0';
			}
			*++p = day % 10 + '0';
			p += 2;
		} else {
			p += DAY_LEN + julian;
		}
	} while (++col < 7);

	return p;
}

/*
 * 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.
 */