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cal.c 10 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 source tree.
  8. */
  9. /* Mar 16, 2003 Manuel Novoa III (mjn3@codepoet.org)
  10. *
  11. * Major size reduction... over 50% (>1.5k) on i386.
  12. */
  13. //config:config CAL
  14. //config: bool "cal (5.8 kb)"
  15. //config: default y
  16. //config: help
  17. //config: cal is used to display a monthly calendar.
  18. //applet:IF_CAL(APPLET_NOEXEC(cal, cal, BB_DIR_USR_BIN, BB_SUID_DROP, cal))
  19. /* NOEXEC despite rare cases when it can be a "runner" (e.g. cal -n12000 takes you into years 30xx) */
  20. //kbuild:lib-$(CONFIG_CAL) += cal.o
  21. /* BB_AUDIT SUSv3 compliant with -j and -y extensions (from util-linux). */
  22. /* BB_AUDIT BUG: The output of 'cal -j 1752' is incorrect. The upstream
  23. * BB_AUDIT BUG: version in util-linux seems to be broken as well. */
  24. /* http://www.opengroup.org/onlinepubs/007904975/utilities/cal.html */
  25. //usage:#define cal_trivial_usage
  26. //usage: "[-jy] [[MONTH] YEAR]"
  27. //usage:#define cal_full_usage "\n\n"
  28. //usage: "Display a calendar\n"
  29. //usage: "\n -j Use julian dates"
  30. //usage: "\n -y Display the entire year"
  31. #include "libbb.h"
  32. #include "unicode.h"
  33. /* We often use "unsigned" instead of "int", it's easier to div on most CPUs */
  34. #define THURSDAY 4 /* for reformation */
  35. #define SATURDAY 6 /* 1 Jan 1 was a Saturday */
  36. #define FIRST_MISSING_DAY 639787 /* 3 Sep 1752 */
  37. #define NUMBER_MISSING_DAYS 11 /* 11 day correction */
  38. #define MAXDAYS 42 /* max slots in a month array */
  39. #define SPACE -1 /* used in day array */
  40. static const unsigned char days_in_month[] ALIGN1 = {
  41. 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
  42. };
  43. static const unsigned char sep1752[] ALIGN1 = {
  44. 1, 2, 14, 15, 16,
  45. 17, 18, 19, 20, 21, 22, 23,
  46. 24, 25, 26, 27, 28, 29, 30
  47. };
  48. /* Set to 0 or 1 in main */
  49. #define julian ((unsigned)option_mask32)
  50. /* leap year -- account for Gregorian reformation in 1752 */
  51. static int leap_year(unsigned yr)
  52. {
  53. if (yr <= 1752)
  54. return !(yr % 4);
  55. return (!(yr % 4) && (yr % 100)) || !(yr % 400);
  56. }
  57. /* number of centuries since 1700, not inclusive */
  58. #define centuries_since_1700(yr) \
  59. ((yr) > 1700 ? (yr) / 100 - 17 : 0)
  60. /* number of centuries since 1700 whose modulo of 400 is 0 */
  61. #define quad_centuries_since_1700(yr) \
  62. ((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))
  66. static void center(char *, unsigned, unsigned);
  67. static void day_array(unsigned, unsigned, unsigned *);
  68. static void trim_trailing_spaces_and_print(char *);
  69. static void blank_string(char *buf, size_t buflen);
  70. static char *build_row(char *p, unsigned *dp);
  71. #define DAY_LEN 3 /* 3 spaces per day */
  72. #define J_DAY_LEN (DAY_LEN + 1)
  73. #define WEEK_LEN 20 /* 7 * 3 - one space at the end */
  74. #define J_WEEK_LEN (WEEK_LEN + 7)
  75. #define HEAD_SEP 2 /* spaces between day headings */
  76. int cal_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  77. int cal_main(int argc UNUSED_PARAM, char **argv)
  78. {
  79. struct tm zero_tm;
  80. time_t now;
  81. unsigned month, year, flags, i;
  82. char *month_names[12];
  83. /* normal heading: */
  84. /* "Su Mo Tu We Th Fr Sa" */
  85. /* -j heading: */
  86. /* " Su Mo Tu We Th Fr Sa" */
  87. char day_headings[ENABLE_UNICODE_SUPPORT ? 28 * 6 : 28];
  88. IF_UNICODE_SUPPORT(char *hp = day_headings;)
  89. char buf[40];
  90. init_unicode();
  91. flags = getopt32(argv, "jy");
  92. /* This sets julian = flags & 1: */
  93. option_mask32 &= 1;
  94. month = 0;
  95. argv += optind;
  96. if (!argv[0]) {
  97. struct tm *ptm;
  98. time(&now);
  99. ptm = localtime(&now);
  100. year = ptm->tm_year + 1900;
  101. if (!(flags & 2)) { /* no -y */
  102. month = ptm->tm_mon + 1;
  103. }
  104. } else {
  105. if (argv[1]) {
  106. if (argv[2]) {
  107. bb_show_usage();
  108. }
  109. if (!(flags & 2)) { /* no -y */
  110. month = xatou_range(*argv, 1, 12);
  111. }
  112. argv++;
  113. }
  114. year = xatou_range(*argv, 1, 9999);
  115. }
  116. blank_string(day_headings, sizeof(day_headings) - 7 + 7*julian);
  117. i = 0;
  118. do {
  119. zero_tm.tm_mon = i;
  120. /* full month name according to locale */
  121. strftime(buf, sizeof(buf), "%B", &zero_tm);
  122. month_names[i] = xstrdup(buf);
  123. if (i < 7) {
  124. zero_tm.tm_wday = i;
  125. /* abbreviated weekday name according to locale */
  126. strftime(buf, sizeof(buf), "%a", &zero_tm);
  127. #if ENABLE_UNICODE_SUPPORT
  128. if (julian)
  129. *hp++ = ' ';
  130. {
  131. char *two_wchars = unicode_conv_to_printable_fixedwidth(/*NULL,*/ buf, 2);
  132. strcpy(hp, two_wchars);
  133. free(two_wchars);
  134. }
  135. hp += strlen(hp);
  136. *hp++ = ' ';
  137. #else
  138. strncpy(day_headings + i * (3+julian) + julian, buf, 2);
  139. #endif
  140. }
  141. } while (++i < 12);
  142. IF_UNICODE_SUPPORT(hp[-1] = '\0';)
  143. if (month) {
  144. unsigned row, len, days[MAXDAYS];
  145. unsigned *dp = days;
  146. char lineout[30];
  147. day_array(month, year, dp);
  148. len = sprintf(lineout, "%s %u", month_names[month - 1], year);
  149. printf("%*s%s\n%s\n",
  150. ((7*julian + WEEK_LEN) - len) / 2, "",
  151. lineout, day_headings);
  152. for (row = 0; row < 6; row++) {
  153. build_row(lineout, dp)[0] = '\0';
  154. dp += 7;
  155. trim_trailing_spaces_and_print(lineout);
  156. }
  157. } else {
  158. unsigned row, which_cal, week_len, days[12][MAXDAYS];
  159. unsigned *dp;
  160. char lineout[80];
  161. sprintf(lineout, "%u", year);
  162. center(lineout,
  163. (WEEK_LEN * 3 + HEAD_SEP * 2)
  164. + julian * (J_WEEK_LEN * 2 + HEAD_SEP
  165. - (WEEK_LEN * 3 + HEAD_SEP * 2)),
  166. 0
  167. );
  168. puts("\n"); /* two \n's */
  169. for (i = 0; i < 12; i++) {
  170. day_array(i + 1, year, days[i]);
  171. }
  172. blank_string(lineout, sizeof(lineout));
  173. week_len = WEEK_LEN + julian * (J_WEEK_LEN - WEEK_LEN);
  174. for (month = 0; month < 12; month += 3-julian) {
  175. center(month_names[month], week_len, HEAD_SEP);
  176. if (!julian) {
  177. center(month_names[month + 1], week_len, HEAD_SEP);
  178. }
  179. center(month_names[month + 2 - julian], week_len, 0);
  180. printf("\n%s%*s%s", day_headings, HEAD_SEP, "", day_headings);
  181. if (!julian) {
  182. printf("%*s%s", HEAD_SEP, "", day_headings);
  183. }
  184. bb_putchar('\n');
  185. for (row = 0; row < (6*7); row += 7) {
  186. for (which_cal = 0; which_cal < 3-julian; which_cal++) {
  187. dp = days[month + which_cal] + row;
  188. build_row(lineout + which_cal * (week_len + 2), dp);
  189. }
  190. /* blank_string took care of nul termination. */
  191. trim_trailing_spaces_and_print(lineout);
  192. }
  193. }
  194. }
  195. fflush_stdout_and_exit(EXIT_SUCCESS);
  196. }
  197. /*
  198. * day_array --
  199. * Fill in an array of 42 integers with a calendar. Assume for a moment
  200. * that you took the (maximum) 6 rows in a calendar and stretched them
  201. * out end to end. You would have 42 numbers or spaces. This routine
  202. * builds that array for any month from Jan. 1 through Dec. 9999.
  203. */
  204. static void day_array(unsigned month, unsigned year, unsigned *days)
  205. {
  206. unsigned long temp;
  207. unsigned i;
  208. unsigned day, dw, dm;
  209. memset(days, SPACE, MAXDAYS * sizeof(int));
  210. if ((month == 9) && (year == 1752)) {
  211. /* Assumes the Gregorian reformation eliminates
  212. * 3 Sep. 1752 through 13 Sep. 1752.
  213. */
  214. unsigned j_offset = julian * 244;
  215. size_t oday = 0;
  216. do {
  217. days[oday+2] = sep1752[oday] + j_offset;
  218. } while (++oday < sizeof(sep1752));
  219. return;
  220. }
  221. /* day_in_year
  222. * return the 1 based day number within the year
  223. */
  224. day = 1;
  225. if ((month > 2) && leap_year(year)) {
  226. ++day;
  227. }
  228. i = month;
  229. while (i) {
  230. day += days_in_month[--i];
  231. }
  232. /* day_in_week
  233. * return the 0 based day number for any date from 1 Jan. 1 to
  234. * 31 Dec. 9999. Assumes the Gregorian reformation eliminates
  235. * 3 Sep. 1752 through 13 Sep. 1752. Returns Thursday for all
  236. * missing days.
  237. */
  238. temp = (long)(year - 1) * 365 + leap_years_since_year_1(year - 1) + day;
  239. if (temp < FIRST_MISSING_DAY) {
  240. dw = ((temp - 1 + SATURDAY) % 7);
  241. } else {
  242. dw = (((temp - 1 + SATURDAY) - NUMBER_MISSING_DAYS) % 7);
  243. }
  244. if (!julian) {
  245. day = 1;
  246. }
  247. dm = days_in_month[month];
  248. if ((month == 2) && leap_year(year)) {
  249. ++dm;
  250. }
  251. do {
  252. days[dw++] = day++;
  253. } while (--dm);
  254. }
  255. static void trim_trailing_spaces_and_print(char *s)
  256. {
  257. char *p = s;
  258. while (*p) {
  259. ++p;
  260. }
  261. while (p != s) {
  262. --p;
  263. if (!isspace(*p)) {
  264. p[1] = '\0';
  265. break;
  266. }
  267. }
  268. puts(s);
  269. }
  270. static void center(char *str, unsigned len, unsigned separate)
  271. {
  272. unsigned n = strlen(str);
  273. len -= n;
  274. printf("%*s%*s", (len/2) + n, str, (len/2) + (len % 2) + separate, "");
  275. }
  276. static void blank_string(char *buf, size_t buflen)
  277. {
  278. memset(buf, ' ', buflen);
  279. buf[buflen-1] = '\0';
  280. }
  281. static char *build_row(char *p, unsigned *dp)
  282. {
  283. unsigned col, val, day;
  284. memset(p, ' ', (julian + DAY_LEN) * 7);
  285. col = 0;
  286. do {
  287. day = *dp++;
  288. if (day != SPACE) {
  289. if (julian) {
  290. ++p;
  291. if (day >= 100) {
  292. *p = '0';
  293. p[-1] = (day / 100) + '0';
  294. day %= 100;
  295. }
  296. }
  297. val = day / 10;
  298. if (val > 0) {
  299. *p = val + '0';
  300. }
  301. *++p = day % 10 + '0';
  302. p += 2;
  303. } else {
  304. p += DAY_LEN + julian;
  305. }
  306. } while (++col < 7);
  307. return p;
  308. }
  309. /*
  310. * Copyright (c) 1989, 1993, 1994
  311. * The Regents of the University of California. All rights reserved.
  312. *
  313. * This code is derived from software contributed to Berkeley by
  314. * Kim Letkeman.
  315. *
  316. * Redistribution and use in source and binary forms, with or without
  317. * modification, are permitted provided that the following conditions
  318. * are met:
  319. * 1. Redistributions of source code must retain the above copyright
  320. * notice, this list of conditions and the following disclaimer.
  321. * 2. Redistributions in binary form must reproduce the above copyright
  322. * notice, this list of conditions and the following disclaimer in the
  323. * documentation and/or other materials provided with the distribution.
  324. * 3. Neither the name of the University nor the names of its contributors
  325. * may be used to endorse or promote products derived from this software
  326. * without specific prior written permission.
  327. *
  328. * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ''AS IS'' AND
  329. * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  330. * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  331. * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  332. * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  333. * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  334. * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  335. * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  336. * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  337. * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  338. * SUCH DAMAGE.
  339. */