cal.c 9.8 KB

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  1. /* vi: set sw=4 ts=4: */
  2. /*
  3. * Calendar implementation for busybox
  4. *
  5. * See original copyright at the end of this file
  6. *
  7. * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  8. */
  9. /* BB_AUDIT SUSv3 compliant with -j and -y extensions (from util-linux). */
  10. /* BB_AUDIT BUG: The output of 'cal -j 1752' is incorrect. The upstream
  11. * BB_AUDIT BUG: version in util-linux seems to be broken as well. */
  12. /* http://www.opengroup.org/onlinepubs/007904975/utilities/cal.html */
  13. /* Mar 16, 2003 Manuel Novoa III (mjn3@codepoet.org)
  14. *
  15. * Major size reduction... over 50% (>1.5k) on i386.
  16. */
  17. #include "libbb.h"
  18. #include "unicode.h"
  19. /* We often use "unsigned" intead of "int", it's easier to div on most CPUs */
  20. #define THURSDAY 4 /* for reformation */
  21. #define SATURDAY 6 /* 1 Jan 1 was a Saturday */
  22. #define FIRST_MISSING_DAY 639787 /* 3 Sep 1752 */
  23. #define NUMBER_MISSING_DAYS 11 /* 11 day correction */
  24. #define MAXDAYS 42 /* max slots in a month array */
  25. #define SPACE -1 /* used in day array */
  26. static const unsigned char days_in_month[] ALIGN1 = {
  27. 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
  28. };
  29. static const unsigned char sep1752[] ALIGN1 = {
  30. 1, 2, 14, 15, 16,
  31. 17, 18, 19, 20, 21, 22, 23,
  32. 24, 25, 26, 27, 28, 29, 30
  33. };
  34. /* Set to 0 or 1 in main */
  35. #define julian ((unsigned)option_mask32)
  36. /* leap year -- account for Gregorian reformation in 1752 */
  37. static int leap_year(unsigned yr)
  38. {
  39. if (yr <= 1752)
  40. return !(yr % 4);
  41. return (!(yr % 4) && (yr % 100)) || !(yr % 400);
  42. }
  43. /* number of centuries since 1700, not inclusive */
  44. #define centuries_since_1700(yr) \
  45. ((yr) > 1700 ? (yr) / 100 - 17 : 0)
  46. /* number of centuries since 1700 whose modulo of 400 is 0 */
  47. #define quad_centuries_since_1700(yr) \
  48. ((yr) > 1600 ? ((yr) - 1600) / 400 : 0)
  49. /* number of leap years between year 1 and this year, not inclusive */
  50. #define leap_years_since_year_1(yr) \
  51. ((yr) / 4 - centuries_since_1700(yr) + quad_centuries_since_1700(yr))
  52. static void center(char *, unsigned, unsigned);
  53. static void day_array(unsigned, unsigned, unsigned *);
  54. static void trim_trailing_spaces_and_print(char *);
  55. static void blank_string(char *buf, size_t buflen);
  56. static char *build_row(char *p, unsigned *dp);
  57. #define DAY_LEN 3 /* 3 spaces per day */
  58. #define J_DAY_LEN (DAY_LEN + 1)
  59. #define WEEK_LEN 20 /* 7 * 3 - one space at the end */
  60. #define J_WEEK_LEN (WEEK_LEN + 7)
  61. #define HEAD_SEP 2 /* spaces between day headings */
  62. int cal_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  63. int cal_main(int argc UNUSED_PARAM, char **argv)
  64. {
  65. struct tm zero_tm;
  66. time_t now;
  67. unsigned month, year, flags, i;
  68. char *month_names[12];
  69. /* normal heading: */
  70. /* "Su Mo Tu We Th Fr Sa" */
  71. /* -j heading: */
  72. /* " Su Mo Tu We Th Fr Sa" */
  73. char day_headings[ENABLE_UNICODE_SUPPORT ? 28 * 6 : 28];
  74. IF_UNICODE_SUPPORT(char *hp = day_headings;)
  75. char buf[40];
  76. init_unicode();
  77. flags = getopt32(argv, "jy");
  78. /* This sets julian = flags & 1: */
  79. option_mask32 &= 1;
  80. month = 0;
  81. argv += optind;
  82. if (!argv[0]) {
  83. struct tm *ptm;
  84. time(&now);
  85. ptm = localtime(&now);
  86. year = ptm->tm_year + 1900;
  87. if (!(flags & 2)) { /* no -y */
  88. month = ptm->tm_mon + 1;
  89. }
  90. } else {
  91. if (argv[1]) {
  92. if (argv[2]) {
  93. bb_show_usage();
  94. }
  95. if (!(flags & 2)) { /* no -y */
  96. month = xatou_range(*argv, 1, 12);
  97. }
  98. argv++;
  99. }
  100. year = xatou_range(*argv, 1, 9999);
  101. }
  102. blank_string(day_headings, sizeof(day_headings) - 7 + 7*julian);
  103. i = 0;
  104. do {
  105. zero_tm.tm_mon = i;
  106. /* full month name according to locale */
  107. strftime(buf, sizeof(buf), "%B", &zero_tm);
  108. month_names[i] = xstrdup(buf);
  109. if (i < 7) {
  110. zero_tm.tm_wday = i;
  111. /* abbreviated weekday name according to locale */
  112. strftime(buf, sizeof(buf), "%a", &zero_tm);
  113. #if ENABLE_UNICODE_SUPPORT
  114. if (julian)
  115. *hp++ = ' ';
  116. {
  117. char *two_wchars = unicode_conv_to_printable_fixedwidth(NULL, buf, 2);
  118. strcpy(hp, two_wchars);
  119. free(two_wchars);
  120. }
  121. hp += strlen(hp);
  122. *hp++ = ' ';
  123. #else
  124. strncpy(day_headings + i * (3+julian) + julian, buf, 2);
  125. #endif
  126. }
  127. } while (++i < 12);
  128. IF_UNICODE_SUPPORT(hp[-1] = '\0';)
  129. if (month) {
  130. unsigned row, len, days[MAXDAYS];
  131. unsigned *dp = days;
  132. char lineout[30];
  133. day_array(month, year, dp);
  134. len = sprintf(lineout, "%s %d", month_names[month - 1], year);
  135. printf("%*s%s\n%s\n",
  136. ((7*julian + WEEK_LEN) - len) / 2, "",
  137. lineout, day_headings);
  138. for (row = 0; row < 6; row++) {
  139. build_row(lineout, dp)[0] = '\0';
  140. dp += 7;
  141. trim_trailing_spaces_and_print(lineout);
  142. }
  143. } else {
  144. unsigned row, which_cal, week_len, days[12][MAXDAYS];
  145. unsigned *dp;
  146. char lineout[80];
  147. sprintf(lineout, "%u", year);
  148. center(lineout,
  149. (WEEK_LEN * 3 + HEAD_SEP * 2)
  150. + julian * (J_WEEK_LEN * 2 + HEAD_SEP
  151. - (WEEK_LEN * 3 + HEAD_SEP * 2)),
  152. 0);
  153. puts("\n"); /* two \n's */
  154. for (i = 0; i < 12; i++) {
  155. day_array(i + 1, year, days[i]);
  156. }
  157. blank_string(lineout, sizeof(lineout));
  158. week_len = WEEK_LEN + julian * (J_WEEK_LEN - WEEK_LEN);
  159. for (month = 0; month < 12; month += 3-julian) {
  160. center(month_names[month], week_len, HEAD_SEP);
  161. if (!julian) {
  162. center(month_names[month + 1], week_len, HEAD_SEP);
  163. }
  164. center(month_names[month + 2 - julian], week_len, 0);
  165. printf("\n%s%*s%s", day_headings, HEAD_SEP, "", day_headings);
  166. if (!julian) {
  167. printf("%*s%s", HEAD_SEP, "", day_headings);
  168. }
  169. bb_putchar('\n');
  170. for (row = 0; row < (6*7); row += 7) {
  171. for (which_cal = 0; which_cal < 3-julian; which_cal++) {
  172. dp = days[month + which_cal] + row;
  173. build_row(lineout + which_cal * (week_len + 2), dp);
  174. }
  175. /* blank_string took care of nul termination. */
  176. trim_trailing_spaces_and_print(lineout);
  177. }
  178. }
  179. }
  180. fflush_stdout_and_exit(EXIT_SUCCESS);
  181. }
  182. /*
  183. * day_array --
  184. * Fill in an array of 42 integers with a calendar. Assume for a moment
  185. * that you took the (maximum) 6 rows in a calendar and stretched them
  186. * out end to end. You would have 42 numbers or spaces. This routine
  187. * builds that array for any month from Jan. 1 through Dec. 9999.
  188. */
  189. static void day_array(unsigned month, unsigned year, unsigned *days)
  190. {
  191. unsigned long temp;
  192. unsigned i;
  193. unsigned day, dw, dm;
  194. memset(days, SPACE, MAXDAYS * sizeof(int));
  195. if ((month == 9) && (year == 1752)) {
  196. /* Assumes the Gregorian reformation eliminates
  197. * 3 Sep. 1752 through 13 Sep. 1752.
  198. */
  199. unsigned j_offset = julian * 244;
  200. size_t oday = 0;
  201. do {
  202. days[oday+2] = sep1752[oday] + j_offset;
  203. } while (++oday < sizeof(sep1752));
  204. return;
  205. }
  206. /* day_in_year
  207. * return the 1 based day number within the year
  208. */
  209. day = 1;
  210. if ((month > 2) && leap_year(year)) {
  211. ++day;
  212. }
  213. i = month;
  214. while (i) {
  215. day += days_in_month[--i];
  216. }
  217. /* day_in_week
  218. * return the 0 based day number for any date from 1 Jan. 1 to
  219. * 31 Dec. 9999. Assumes the Gregorian reformation eliminates
  220. * 3 Sep. 1752 through 13 Sep. 1752. Returns Thursday for all
  221. * missing days.
  222. */
  223. temp = (long)(year - 1) * 365 + leap_years_since_year_1(year - 1) + day;
  224. if (temp < FIRST_MISSING_DAY) {
  225. dw = ((temp - 1 + SATURDAY) % 7);
  226. } else {
  227. dw = (((temp - 1 + SATURDAY) - NUMBER_MISSING_DAYS) % 7);
  228. }
  229. if (!julian) {
  230. day = 1;
  231. }
  232. dm = days_in_month[month];
  233. if ((month == 2) && leap_year(year)) {
  234. ++dm;
  235. }
  236. do {
  237. days[dw++] = day++;
  238. } while (--dm);
  239. }
  240. static void trim_trailing_spaces_and_print(char *s)
  241. {
  242. char *p = s;
  243. while (*p) {
  244. ++p;
  245. }
  246. while (p != s) {
  247. --p;
  248. if (!isspace(*p)) {
  249. p[1] = '\0';
  250. break;
  251. }
  252. }
  253. puts(s);
  254. }
  255. static void center(char *str, unsigned len, unsigned separate)
  256. {
  257. unsigned n = strlen(str);
  258. len -= n;
  259. printf("%*s%*s", (len/2) + n, str, (len/2) + (len % 2) + separate, "");
  260. }
  261. static void blank_string(char *buf, size_t buflen)
  262. {
  263. memset(buf, ' ', buflen);
  264. buf[buflen-1] = '\0';
  265. }
  266. static char *build_row(char *p, unsigned *dp)
  267. {
  268. unsigned col, val, day;
  269. memset(p, ' ', (julian + DAY_LEN) * 7);
  270. col = 0;
  271. do {
  272. day = *dp++;
  273. if (day != SPACE) {
  274. if (julian) {
  275. ++p;
  276. if (day >= 100) {
  277. *p = '0';
  278. p[-1] = (day / 100) + '0';
  279. day %= 100;
  280. }
  281. }
  282. val = day / 10;
  283. if (val > 0) {
  284. *p = val + '0';
  285. }
  286. *++p = day % 10 + '0';
  287. p += 2;
  288. } else {
  289. p += DAY_LEN + julian;
  290. }
  291. } while (++col < 7);
  292. return p;
  293. }
  294. /*
  295. * Copyright (c) 1989, 1993, 1994
  296. * The Regents of the University of California. All rights reserved.
  297. *
  298. * This code is derived from software contributed to Berkeley by
  299. * Kim Letkeman.
  300. *
  301. * Redistribution and use in source and binary forms, with or without
  302. * modification, are permitted provided that the following conditions
  303. * are met:
  304. * 1. Redistributions of source code must retain the above copyright
  305. * notice, this list of conditions and the following disclaimer.
  306. * 2. Redistributions in binary form must reproduce the above copyright
  307. * notice, this list of conditions and the following disclaimer in the
  308. * documentation and/or other materials provided with the distribution.
  309. * 3. Neither the name of the University nor the names of its contributors
  310. * may be used to endorse or promote products derived from this software
  311. * without specific prior written permission.
  312. *
  313. * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  314. * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  315. * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  316. * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  317. * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  318. * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  319. * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  320. * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  321. * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  322. * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  323. * SUCH DAMAGE.
  324. */