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 #define THURSDAY 4 /* for reformation */
23 #define SATURDAY 6 /* 1 Jan 1 was a Saturday */
25 #define FIRST_MISSING_DAY 639787 /* 3 Sep 1752 */
26 #define NUMBER_MISSING_DAYS 11 /* 11 day correction */
28 #define MAXDAYS 42 /* max slots in a month array */
29 #define SPACE -1 /* used in day array */
31 static const char days_in_month[] = {
32 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
35 static const char sep1752[] = {
37 17, 18, 19, 20, 21, 22, 23,
38 24, 25, 26, 27, 28, 29, 30
43 /* leap year -- account for Gregorian reformation in 1752 */
44 #define leap_year(yr) \
45 ((yr) <= 1752 ? !((yr) % 4) : \
46 (!((yr) % 4) && ((yr) % 100)) || !((yr) % 400))
48 static int is_leap_year(int year)
50 return leap_year(year);
53 #define leap_year(yr) is_leap_year(yr)
55 /* number of centuries since 1700, not inclusive */
56 #define centuries_since_1700(yr) \
57 ((yr) > 1700 ? (yr) / 100 - 17 : 0)
59 /* number of centuries since 1700 whose modulo of 400 is 0 */
60 #define quad_centuries_since_1700(yr) \
61 ((yr) > 1600 ? ((yr) - 1600) / 400 : 0)
63 /* number of leap years between year 1 and this year, not inclusive */
64 #define leap_years_since_year_1(yr) \
65 ((yr) / 4 - centuries_since_1700(yr) + quad_centuries_since_1700(yr))
67 static void center (char *, int, int);
68 static void day_array (int, int, int *);
69 static void trim_trailing_spaces_and_print (char *);
71 static void blank_string(char *buf, size_t buflen);
72 static char *build_row(char *p, int *dp);
74 #define DAY_LEN 3 /* 3 spaces per day */
75 #define J_DAY_LEN (DAY_LEN + 1)
76 #define WEEK_LEN 20 /* 7 * 3 - one space at the end */
77 #define J_WEEK_LEN (WEEK_LEN + 7)
78 #define HEAD_SEP 2 /* spaces between day headings */
80 int cal_main(int argc, char **argv)
82 struct tm *local_time;
85 int month, year, flags, i;
86 char *month_names[12];
87 char day_headings[28]; /* 28 for julian, 21 for nonjulian */
90 flags = getopt32(argc, argv, "jy");
98 if ((argc -= optind) > 2) {
104 local_time = localtime(&now);
105 year = local_time->tm_year + 1900;
107 month = local_time->tm_mon + 1;
111 month = xatoul_range(*argv++, 1, 12);
113 year = xatoul_range(*argv, 1, 9999);
116 blank_string(day_headings, sizeof(day_headings) - 7 + 7*julian);
121 strftime(buf, sizeof(buf), "%B", &zero_tm);
122 month_names[i] = xstrdup(buf);
126 strftime(buf, sizeof(buf), "%a", &zero_tm);
127 strncpy(day_headings + i * (3+julian) + julian, buf, 2);
132 int row, len, days[MAXDAYS];
136 day_array(month, year, dp);
137 len = sprintf(lineout, "%s %d", month_names[month - 1], year);
138 printf("%*s%s\n%s\n",
139 ((7*julian + WEEK_LEN) - len) / 2, "",
140 lineout, day_headings);
141 for (row = 0; row < 6; row++) {
142 build_row(lineout, dp)[0] = '\0';
144 trim_trailing_spaces_and_print(lineout);
147 int row, which_cal, week_len, days[12][MAXDAYS];
151 sprintf(lineout, "%d", year);
153 (WEEK_LEN * 3 + HEAD_SEP * 2)
154 + julian * (J_WEEK_LEN * 2 + HEAD_SEP
155 - (WEEK_LEN * 3 + HEAD_SEP * 2)),
157 puts("\n"); /* two \n's */
158 for (i = 0; i < 12; i++) {
159 day_array(i + 1, year, days[i]);
161 blank_string(lineout, sizeof(lineout));
162 week_len = WEEK_LEN + julian * (J_WEEK_LEN - WEEK_LEN);
163 for (month = 0; month < 12; month += 3-julian) {
164 center(month_names[month], week_len, HEAD_SEP);
166 center(month_names[month + 1], week_len, HEAD_SEP);
168 center(month_names[month + 2 - julian], week_len, 0);
169 printf("\n%s%*s%s", day_headings, HEAD_SEP, "", day_headings);
171 printf("%*s%s", HEAD_SEP, "", day_headings);
174 for (row = 0; row < (6*7); row += 7) {
175 for (which_cal = 0; which_cal < 3-julian; which_cal++) {
176 dp = days[month + which_cal] + row;
177 build_row(lineout + which_cal * (week_len + 2), dp);
179 /* blank_string took care of nul termination. */
180 trim_trailing_spaces_and_print(lineout);
185 fflush_stdout_and_exit(0);
190 * Fill in an array of 42 integers with a calendar. Assume for a moment
191 * that you took the (maximum) 6 rows in a calendar and stretched them
192 * out end to end. You would have 42 numbers or spaces. This routine
193 * builds that array for any month from Jan. 1 through Dec. 9999.
195 static void day_array(int month, int year, int *days)
202 memset(days, SPACE, MAXDAYS * sizeof(int));
204 if ((month == 9) && (year == 1752)) {
207 j_offset = julian * 244;
209 days[oday+2] = sep1752[oday] + j_offset;
210 } while (++oday < sizeof(sep1752));
216 * return the 1 based day number within the year
219 if ((month > 2) && leap_year(year)) {
225 day += days_in_month[--i];
229 * return the 0 based day number for any date from 1 Jan. 1 to
230 * 31 Dec. 9999. Assumes the Gregorian reformation eliminates
231 * 3 Sep. 1752 through 13 Sep. 1752. Returns Thursday for all
235 temp = (long)(year - 1) * 365 + leap_years_since_year_1(year - 1)
237 if (temp < FIRST_MISSING_DAY) {
238 dw = ((temp - 1 + SATURDAY) % 7);
239 } else if (temp >= (FIRST_MISSING_DAY + NUMBER_MISSING_DAYS)) {
240 dw = (((temp - 1 + SATURDAY) - NUMBER_MISSING_DAYS) % 7);
247 dm = days_in_month[month];
248 if ((month == 2) && leap_year(year)) {
258 static void trim_trailing_spaces_and_print(char *s)
267 if (!(isspace)(*p)) { /* We want the function... not the inline. */
276 static void center(char *str, int len, int separate)
280 printf("%*s%*s", (len/2) + n, str, (len/2) + (len % 2) + separate, "");
283 static void blank_string(char *buf, size_t buflen)
285 memset(buf, ' ', buflen);
286 buf[buflen-1] = '\0';
289 static char *build_row(char *p, int *dp)
293 memset(p, ' ', (julian + DAY_LEN) * 7);
297 if ((day = *dp++) != SPACE) {
302 p[-1] = (day / 100) + '0';
306 if ((val = day / 10) > 0) {
309 *++p = day % 10 + '0';
312 p += DAY_LEN + julian;
320 * Copyright (c) 1989, 1993, 1994
321 * The Regents of the University of California. All rights reserved.
323 * This code is derived from software contributed to Berkeley by
326 * Redistribution and use in source and binary forms, with or without
327 * modification, are permitted provided that the following conditions
329 * 1. Redistributions of source code must retain the above copyright
330 * notice, this list of conditions and the following disclaimer.
331 * 2. Redistributions in binary form must reproduce the above copyright
332 * notice, this list of conditions and the following disclaimer in the
333 * documentation and/or other materials provided with the distribution.
334 * 3. Neither the name of the University nor the names of its contributors
335 * may be used to endorse or promote products derived from this software
336 * without specific prior written permission.
338 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
339 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
340 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
341 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
342 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
343 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
344 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
345 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
346 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
347 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF