1 /* vi: set sw=4 ts=4: */
3 * Calendar implementation for busybox
5 * See original copyright at the end of this file
7 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
10 /* BB_AUDIT SUSv3 compliant with -j and -y extensions (from util-linux). */
11 /* BB_AUDIT BUG: The output of 'cal -j 1752' is incorrect. The upstream
12 * BB_AUDIT BUG: version in util-linux seems to be broken as well. */
13 /* http://www.opengroup.org/onlinepubs/007904975/utilities/cal.html */
15 /* Mar 16, 2003 Manuel Novoa III (mjn3@codepoet.org)
17 * Major size reduction... over 50% (>1.5k) on i386.
22 /* We often use "unsigned" intead of "int", it's easier to div on most CPUs */
24 #define THURSDAY 4 /* for reformation */
25 #define SATURDAY 6 /* 1 Jan 1 was a Saturday */
27 #define FIRST_MISSING_DAY 639787 /* 3 Sep 1752 */
28 #define NUMBER_MISSING_DAYS 11 /* 11 day correction */
30 #define MAXDAYS 42 /* max slots in a month array */
31 #define SPACE -1 /* used in day array */
33 static const unsigned char days_in_month[] ALIGN1 = {
34 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
37 static const unsigned char sep1752[] ALIGN1 = {
39 17, 18, 19, 20, 21, 22, 23,
40 24, 25, 26, 27, 28, 29, 30
43 /* Set to 0 or 1 in main */
44 #define julian ((unsigned)option_mask32)
46 /* leap year -- account for Gregorian reformation in 1752 */
47 static int leap_year(unsigned yr)
51 return (!(yr % 4) && (yr % 100)) || !(yr % 400);
54 /* number of centuries since 1700, not inclusive */
55 #define centuries_since_1700(yr) \
56 ((yr) > 1700 ? (yr) / 100 - 17 : 0)
58 /* number of centuries since 1700 whose modulo of 400 is 0 */
59 #define quad_centuries_since_1700(yr) \
60 ((yr) > 1600 ? ((yr) - 1600) / 400 : 0)
62 /* number of leap years between year 1 and this year, not inclusive */
63 #define leap_years_since_year_1(yr) \
64 ((yr) / 4 - centuries_since_1700(yr) + quad_centuries_since_1700(yr))
66 static void center(char *, unsigned, unsigned);
67 static void day_array(unsigned, unsigned, unsigned *);
68 static void trim_trailing_spaces_and_print(char *);
70 static void blank_string(char *buf, size_t buflen);
71 static char *build_row(char *p, unsigned *dp);
73 #define DAY_LEN 3 /* 3 spaces per day */
74 #define J_DAY_LEN (DAY_LEN + 1)
75 #define WEEK_LEN 20 /* 7 * 3 - one space at the end */
76 #define J_WEEK_LEN (WEEK_LEN + 7)
77 #define HEAD_SEP 2 /* spaces between day headings */
79 int cal_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
80 int cal_main(int argc UNUSED_PARAM, char **argv)
84 unsigned month, year, flags, i;
85 char *month_names[12];
86 char day_headings[28]; /* 28 for julian, 21 for nonjulian */
89 flags = getopt32(argv, "jy");
90 /* This sets julian = flags & 1: */
99 ptm = localtime(&now);
100 year = ptm->tm_year + 1900;
101 if (!(flags & 2)) { /* no -y */
102 month = ptm->tm_mon + 1;
109 month = xatou_range(*argv++, 1, 12);
111 year = xatou_range(*argv, 1, 9999);
114 blank_string(day_headings, sizeof(day_headings) - 7 + 7*julian);
119 /* full month name according to locale */
120 strftime(buf, sizeof(buf), "%B", &zero_tm);
121 month_names[i] = xstrdup(buf);
127 //testcase with doublewidth Japanese chars: "LANG=zh_TW.utf8 cal"
128 //perhaps use wc[s]width() to probe terminal width
129 /* abbreviated weekday name according to locale */
130 strftime(buf, sizeof(buf), "%a", &zero_tm);
131 strncpy(day_headings + i * (3+julian) + julian, buf, 2);
136 unsigned row, len, days[MAXDAYS];
140 day_array(month, year, dp);
141 len = sprintf(lineout, "%s %d", month_names[month - 1], year);
142 printf("%*s%s\n%s\n",
143 ((7*julian + WEEK_LEN) - len) / 2, "",
144 lineout, day_headings);
145 for (row = 0; row < 6; row++) {
146 build_row(lineout, dp)[0] = '\0';
148 trim_trailing_spaces_and_print(lineout);
151 unsigned row, which_cal, week_len, days[12][MAXDAYS];
155 sprintf(lineout, "%u", year);
157 (WEEK_LEN * 3 + HEAD_SEP * 2)
158 + julian * (J_WEEK_LEN * 2 + HEAD_SEP
159 - (WEEK_LEN * 3 + HEAD_SEP * 2)),
161 puts("\n"); /* two \n's */
162 for (i = 0; i < 12; i++) {
163 day_array(i + 1, year, days[i]);
165 blank_string(lineout, sizeof(lineout));
166 week_len = WEEK_LEN + julian * (J_WEEK_LEN - WEEK_LEN);
167 for (month = 0; month < 12; month += 3-julian) {
168 center(month_names[month], week_len, HEAD_SEP);
170 center(month_names[month + 1], week_len, HEAD_SEP);
172 center(month_names[month + 2 - julian], week_len, 0);
173 printf("\n%s%*s%s", day_headings, HEAD_SEP, "", day_headings);
175 printf("%*s%s", HEAD_SEP, "", day_headings);
178 for (row = 0; row < (6*7); row += 7) {
179 for (which_cal = 0; which_cal < 3-julian; which_cal++) {
180 dp = days[month + which_cal] + row;
181 build_row(lineout + which_cal * (week_len + 2), dp);
183 /* blank_string took care of nul termination. */
184 trim_trailing_spaces_and_print(lineout);
189 fflush_stdout_and_exit(EXIT_SUCCESS);
194 * Fill in an array of 42 integers with a calendar. Assume for a moment
195 * that you took the (maximum) 6 rows in a calendar and stretched them
196 * out end to end. You would have 42 numbers or spaces. This routine
197 * builds that array for any month from Jan. 1 through Dec. 9999.
199 static void day_array(unsigned month, unsigned year, unsigned *days)
203 unsigned day, dw, dm;
205 memset(days, SPACE, MAXDAYS * sizeof(int));
207 if ((month == 9) && (year == 1752)) {
208 /* Assumes the Gregorian reformation eliminates
209 * 3 Sep. 1752 through 13 Sep. 1752.
211 unsigned j_offset = julian * 244;
215 days[oday+2] = sep1752[oday] + j_offset;
216 } while (++oday < sizeof(sep1752));
222 * return the 1 based day number within the year
225 if ((month > 2) && leap_year(year)) {
231 day += days_in_month[--i];
235 * return the 0 based day number for any date from 1 Jan. 1 to
236 * 31 Dec. 9999. Assumes the Gregorian reformation eliminates
237 * 3 Sep. 1752 through 13 Sep. 1752. Returns Thursday for all
240 temp = (long)(year - 1) * 365 + leap_years_since_year_1(year - 1) + day;
241 if (temp < FIRST_MISSING_DAY) {
242 dw = ((temp - 1 + SATURDAY) % 7);
244 dw = (((temp - 1 + SATURDAY) - NUMBER_MISSING_DAYS) % 7);
251 dm = days_in_month[month];
252 if ((month == 2) && leap_year(year)) {
261 static void trim_trailing_spaces_and_print(char *s)
279 static void center(char *str, unsigned len, unsigned separate)
281 unsigned n = strlen(str);
283 printf("%*s%*s", (len/2) + n, str, (len/2) + (len % 2) + separate, "");
286 static void blank_string(char *buf, size_t buflen)
288 memset(buf, ' ', buflen);
289 buf[buflen-1] = '\0';
292 static char *build_row(char *p, unsigned *dp)
294 unsigned col, val, day;
296 memset(p, ' ', (julian + DAY_LEN) * 7);
306 p[-1] = (day / 100) + '0';
314 *++p = day % 10 + '0';
317 p += DAY_LEN + julian;
325 * Copyright (c) 1989, 1993, 1994
326 * The Regents of the University of California. All rights reserved.
328 * This code is derived from software contributed to Berkeley by
331 * Redistribution and use in source and binary forms, with or without
332 * modification, are permitted provided that the following conditions
334 * 1. Redistributions of source code must retain the above copyright
335 * notice, this list of conditions and the following disclaimer.
336 * 2. Redistributions in binary form must reproduce the above copyright
337 * notice, this list of conditions and the following disclaimer in the
338 * documentation and/or other materials provided with the distribution.
339 * 3. Neither the name of the University nor the names of its contributors
340 * may be used to endorse or promote products derived from this software
341 * without specific prior written permission.
343 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
344 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
345 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
346 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
347 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
348 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
349 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
350 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
351 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
352 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF