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 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 */ 14 15/* Mar 16, 2003 Manuel Novoa III (mjn3@codepoet.org) 16 * 17 * Major size reduction... over 50% (>1.5k) on i386. 18 */ 19 20#include "libbb.h" 21 22/* We often use "unsigned" intead of "int", it's easier to div on most CPUs */ 23 24#define THURSDAY 4 /* for reformation */ 25#define SATURDAY 6 /* 1 Jan 1 was a Saturday */ 26 27#define FIRST_MISSING_DAY 639787 /* 3 Sep 1752 */ 28#define NUMBER_MISSING_DAYS 11 /* 11 day correction */ 29 30#define MAXDAYS 42 /* max slots in a month array */ 31#define SPACE -1 /* used in day array */ 32 33static const unsigned char days_in_month[] ALIGN1 = { 34 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 35}; 36 37static const unsigned char sep1752[] ALIGN1 = { 38 1, 2, 14, 15, 16, 39 17, 18, 19, 20, 21, 22, 23, 40 24, 25, 26, 27, 28, 29, 30 41}; 42 43static unsigned julian; 44 45/* leap year -- account for Gregorian reformation in 1752 */ 46static int leap_year(unsigned yr) 47{ 48 if (yr <= 1752) 49 return !(yr % 4); 50 return (!(yr % 4) && (yr % 100)) || !(yr % 400); 51} 52 53/* number of centuries since 1700, not inclusive */ 54#define centuries_since_1700(yr) \ 55 ((yr) > 1700 ? (yr) / 100 - 17 : 0) 56 57/* number of centuries since 1700 whose modulo of 400 is 0 */ 58#define quad_centuries_since_1700(yr) \ 59 ((yr) > 1600 ? ((yr) - 1600) / 400 : 0) 60 61/* number of leap years between year 1 and this year, not inclusive */ 62#define leap_years_since_year_1(yr) \ 63 ((yr) / 4 - centuries_since_1700(yr) + quad_centuries_since_1700(yr)) 64 65static void center(char *, unsigned, unsigned); 66static void day_array(unsigned, unsigned, unsigned *); 67static void trim_trailing_spaces_and_print(char *); 68 69static void blank_string(char *buf, size_t buflen); 70static char *build_row(char *p, unsigned *dp); 71 72#define DAY_LEN 3 /* 3 spaces per day */ 73#define J_DAY_LEN (DAY_LEN + 1) 74#define WEEK_LEN 20 /* 7 * 3 - one space at the end */ 75#define J_WEEK_LEN (WEEK_LEN + 7) 76#define HEAD_SEP 2 /* spaces between day headings */ 77 78int cal_main(int argc, char **argv); 79int cal_main(int argc, char **argv) 80{ 81 struct tm *local_time; 82 struct tm zero_tm; 83 time_t now; 84 unsigned month, year, flags, i; 85 char *month_names[12]; 86 char day_headings[28]; /* 28 for julian, 21 for nonjulian */ 87 char buf[40]; 88 89 flags = getopt32(argv, "jy"); 90 julian = flags & 1; 91 month = 0; 92 argv += optind; 93 argc -= optind; 94 95 if (argc > 2) { 96 bb_show_usage(); 97 } 98 99 if (!argc) { 100 time(&now); 101 local_time = localtime(&now); 102 year = local_time->tm_year + 1900; 103 if (!(flags & 2)) { 104 month = local_time->tm_mon + 1; 105 } 106 } else { 107 if (argc == 2) { 108 month = xatou_range(*argv++, 1, 12); 109 } 110 year = xatou_range(*argv, 1, 9999); 111 } 112 113 blank_string(day_headings, sizeof(day_headings) - 7 + 7*julian); 114 115 i = 0; 116 do { 117 zero_tm.tm_mon = i; 118 strftime(buf, sizeof(buf), "%B", &zero_tm); 119 month_names[i] = xstrdup(buf); 120 121 if (i < 7) { 122 zero_tm.tm_wday = i; 123 strftime(buf, sizeof(buf), "%a", &zero_tm); 124 strncpy(day_headings + i * (3+julian) + julian, buf, 2); 125 } 126 } while (++i < 12); 127 128 if (month) { 129 unsigned row, len, days[MAXDAYS]; 130 unsigned *dp = days; 131 char lineout[30]; 132 133 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]; 147 148 sprintf(lineout, "%d", year); 149 center(lineout, 150 (WEEK_LEN * 3 + HEAD_SEP * 2) 151 + julian * (J_WEEK_LEN * 2 + HEAD_SEP 152 - (WEEK_LEN * 3 + HEAD_SEP * 2)), 153 0); 154 puts("\n"); /* two \n's */ 155 for (i = 0; i < 12; i++) { 156 day_array(i + 1, year, days[i]); 157 } 158 blank_string(lineout, sizeof(lineout)); 159 week_len = WEEK_LEN + julian * (J_WEEK_LEN - WEEK_LEN); 160 for (month = 0; month < 12; month += 3-julian) { 161 center(month_names[month], week_len, HEAD_SEP); 162 if (!julian) { 163 center(month_names[month + 1], week_len, HEAD_SEP); 164 } 165 center(month_names[month + 2 - julian], week_len, 0); 166 printf("\n%s%*s%s", day_headings, HEAD_SEP, "", day_headings); 167 if (!julian) { 168 printf("%*s%s", HEAD_SEP, "", day_headings); 169 } 170 putchar('\n'); 171 for (row = 0; row < (6*7); row += 7) { 172 for (which_cal = 0; which_cal < 3-julian; which_cal++) { 173 dp = days[month + which_cal] + row; 174 build_row(lineout + which_cal * (week_len + 2), dp); 175 } 176 /* blank_string took care of nul termination. */ 177 trim_trailing_spaces_and_print(lineout); 178 } 179 } 180 } 181 182 fflush_stdout_and_exit(0); 183} 184 185/* 186 * day_array -- 187 * Fill in an array of 42 integers with a calendar. Assume for a moment 188 * that you took the (maximum) 6 rows in a calendar and stretched them 189 * out end to end. You would have 42 numbers or spaces. This routine 190 * builds that array for any month from Jan. 1 through Dec. 9999. 191 */ 192static void day_array(unsigned month, unsigned year, unsigned *days) 193{ 194 unsigned long temp; 195 unsigned i; 196 unsigned day, dw, dm; 197 198 memset(days, SPACE, MAXDAYS * sizeof(int)); 199 200 if ((month == 9) && (year == 1752)) { 201 /* Assumes the Gregorian reformation eliminates 202 * 3 Sep. 1752 through 13 Sep. 1752. 203 */ 204 unsigned j_offset = julian * 244; 205 size_t oday = 0; 206 207 do { 208 days[oday+2] = sep1752[oday] + j_offset; 209 } while (++oday < sizeof(sep1752)); 210 211 return; 212 } 213 214 /* day_in_year 215 * return the 1 based day number within the year 216 */ 217 day = 1; 218 if ((month > 2) && leap_year(year)) { 219 ++day; 220 } 221 222 i = month; 223 while (i) { 224 day += days_in_month[--i]; 225 } 226 227 /* day_in_week 228 * return the 0 based day number for any date from 1 Jan. 1 to 229 * 31 Dec. 9999. Assumes the Gregorian reformation eliminates 230 * 3 Sep. 1752 through 13 Sep. 1752. Returns Thursday for all 231 * missing days. 232 */ 233 temp = (long)(year - 1) * 365 + leap_years_since_year_1(year - 1) + day; 234 if (temp < FIRST_MISSING_DAY) { 235 dw = ((temp - 1 + SATURDAY) % 7); 236 } else { 237 dw = (((temp - 1 + SATURDAY) - NUMBER_MISSING_DAYS) % 7); 238 } 239 240 if (!julian) { 241 day = 1; 242 } 243 244 dm = days_in_month[month]; 245 if ((month == 2) && leap_year(year)) { 246 ++dm; 247 } 248 249 do { 250 days[dw++] = day++; 251 } while (--dm); 252} 253 254static void trim_trailing_spaces_and_print(char *s) 255{ 256 char *p = s; 257 258 while (*p) { 259 ++p; 260 } 261 while (p != s) { 262 --p; 263 if (!(isspace)(*p)) { /* We want the function... not the inline. */ 264 p[1] = '\0'; 265 break; 266 } 267 } 268 269 puts(s); 270} 271 272static void center(char *str, unsigned len, unsigned separate) 273{ 274 unsigned n = strlen(str); 275 len -= n; 276 printf("%*s%*s", (len/2) + n, str, (len/2) + (len % 2) + separate, ""); 277} 278 279static void blank_string(char *buf, size_t buflen) 280{ 281 memset(buf, ' ', buflen); 282 buf[buflen-1] = '\0'; 283} 284 285static char *build_row(char *p, unsigned *dp) 286{ 287 unsigned col, val, day; 288 289 memset(p, ' ', (julian + DAY_LEN) * 7); 290 291 col = 0; 292 do { 293 day = *dp++; 294 if (day != SPACE) { 295 if (julian) { 296 ++p; 297 if (day >= 100) { 298 *p = '0'; 299 p[-1] = (day / 100) + '0'; 300 day %= 100; 301 } 302 } 303 val = day / 10; 304 if (val > 0) { 305 *p = val + '0'; 306 } 307 *++p = day % 10 + '0'; 308 p += 2; 309 } else { 310 p += DAY_LEN + julian; 311 } 312 } while (++col < 7); 313 314 return p; 315} 316 317/* 318 * Copyright (c) 1989, 1993, 1994 319 * The Regents of the University of California. All rights reserved. 320 * 321 * This code is derived from software contributed to Berkeley by 322 * Kim Letkeman. 323 * 324 * Redistribution and use in source and binary forms, with or without 325 * modification, are permitted provided that the following conditions 326 * are met: 327 * 1. Redistributions of source code must retain the above copyright 328 * notice, this list of conditions and the following disclaimer. 329 * 2. Redistributions in binary form must reproduce the above copyright 330 * notice, this list of conditions and the following disclaimer in the 331 * documentation and/or other materials provided with the distribution. 332 * 3. Neither the name of the University nor the names of its contributors 333 * may be used to endorse or promote products derived from this software 334 * without specific prior written permission. 335 * 336 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 337 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 338 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 339 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 340 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 341 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 342 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 343 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 344 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 345 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 346 * SUCH DAMAGE. 347 */ 348