1/* $OpenBSD: cal.c,v 1.31 2022/12/04 23:50:47 cheloha Exp $ */ 2/* $NetBSD: cal.c,v 1.6 1995/03/26 03:10:24 glass Exp $ */ 3 4/* 5 * Copyright (c) 1989, 1993, 1994 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * Kim Letkeman. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36#include <sys/types.h> 37 38#include <ctype.h> 39#include <err.h> 40#include <stdio.h> 41#include <stdlib.h> 42#include <string.h> 43#include <time.h> 44#include <unistd.h> 45 46#define THURSDAY 4 /* for reformation */ 47#define SATURDAY 6 /* 1 Jan 1 was a Saturday */ 48 49#define FIRST_MISSING_DAY 639799 /* 3 Sep 1752 */ 50#define NUMBER_MISSING_DAYS 11 /* 11 day correction */ 51 52#define MAXDAYS 42 /* max slots in a month array */ 53#define SPACE -1 /* used in day array */ 54 55static const int days_in_month[2][13] = { 56 {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}, 57 {0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}, 58}; 59 60const int sep1752s[MAXDAYS] = { 61 SPACE, SPACE, 1, 2, 14, 15, 16, 62 17, 18, 19, 20, 21, 22, 23, 63 24, 25, 26, 27, 28, 29, 30, 64 SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, 65 SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, 66 SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, 67}, sep1752m[MAXDAYS] = { 68 SPACE, 1, 2, 14, 15, 16, 17, 69 18, 19, 20, 21, 22, 23, 24, 70 25, 26, 27, 28, 29, 30, SPACE, 71 SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, 72 SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, 73 SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, 74}, sep1752js[MAXDAYS] = { 75 SPACE, SPACE, 245, 246, 258, 259, 260, 76 261, 262, 263, 264, 265, 266, 267, 77 268, 269, 270, 271, 272, 273, 274, 78 SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, 79 SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, 80 SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, 81}, sep1752jm[MAXDAYS] = { 82 SPACE, 245, 246, 258, 259, 260, 261, 83 262, 263, 264, 265, 266, 267, 268, 84 269, 270, 271, 272, 273, 274, SPACE, 85 SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, 86 SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, 87 SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, 88}, empty[MAXDAYS] = { 89 SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, 90 SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, 91 SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, 92 SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, 93 SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, 94 SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, 95}; 96 97const char *month_names[12] = { 98 "January", "February", "March", "April", "May", "June", 99 "July", "August", "September", "October", "November", "December", 100}; 101 102#define DAY_HEADINGS_S "Su Mo Tu We Th Fr Sa" 103#define DAY_HEADINGS_M "Mo Tu We Th Fr Sa Su" 104#define DAY_HEADINGS_JS " Su Mo Tu We Th Fr Sa" 105#define DAY_HEADINGS_JM " Mo Tu We Th Fr Sa Su" 106 107const int *sep1752 = NULL; 108const char *day_headings = NULL; 109 110/* leap year -- account for gregorian reformation in 1752 */ 111#define leap_year(yr) \ 112 ((yr) <= 1752 ? !((yr) % 4) : \ 113 (!((yr) % 4) && ((yr) % 100)) || !((yr) % 400)) 114 115/* number of centuries since 1700, not inclusive */ 116#define centuries_since_1700(yr) \ 117 ((yr) > 1700 ? (yr) / 100 - 17 : 0) 118 119/* number of centuries since 1700 whose modulo of 400 is 0 */ 120#define quad_centuries_since_1700(yr) \ 121 ((yr) > 1600 ? ((yr) - 1600) / 400 : 0) 122 123/* number of leap years between year 1 and this year, not inclusive */ 124#define leap_years_since_year_1(yr) \ 125 ((yr) / 4 - centuries_since_1700(yr) + quad_centuries_since_1700(yr)) 126 127int julian; 128int mflag = 0; 129int wflag = 0; 130 131void ascii_day(char *, int); 132void center(const char *, int, int); 133void day_array(int, int, int *); 134int day_in_week(int, int, int); 135int day_in_year(int, int, int); 136int week(int, int, int); 137int isoweek(int, int, int); 138void j_yearly(int); 139void monthly(int, int); 140void trim_trailing_spaces(char *); 141void usage(void); 142void yearly(int); 143int parsemonth(const char *); 144 145int 146main(int argc, char *argv[]) 147{ 148 struct tm *local_time; 149 time_t now; 150 int ch, month, year, yflag; 151 const char *errstr; 152 153 if (pledge("stdio", NULL) == -1) 154 err(1, "pledge"); 155 156 yflag = year = 0; 157 while ((ch = getopt(argc, argv, "jmwy")) != -1) 158 switch(ch) { 159 case 'j': 160 julian = 1; 161 break; 162 case 'm': 163 mflag = 1; 164 break; 165 case 'w': 166 wflag = 1; 167 break; 168 case 'y': 169 yflag = 1; 170 break; 171 default: 172 usage(); 173 } 174 argc -= optind; 175 argv += optind; 176 177 if (julian && wflag) 178 usage(); 179 180 day_headings = DAY_HEADINGS_S; 181 sep1752 = sep1752s; 182 if (mflag && julian) { 183 sep1752 = sep1752jm; 184 day_headings = DAY_HEADINGS_JM; 185 } else if (mflag) { 186 sep1752 = sep1752m; 187 day_headings = DAY_HEADINGS_M; 188 } else if (julian) { 189 sep1752 = sep1752js; 190 day_headings = DAY_HEADINGS_JS; 191 } 192 193 month = 0; 194 switch(argc) { 195 case 2: 196 month = parsemonth(*argv++); 197 if (!month) 198 errx(1, "Unable to parse month"); 199 /* FALLTHROUGH */ 200 case 1: 201 if (argc == 1 && !isdigit((unsigned char)*argv[0])) { 202 month = parsemonth(*argv); 203 if (!month) 204 errx(1, "illegal year value: use 1-9999"); 205 (void)time(&now); 206 local_time = localtime(&now); 207 year = local_time->tm_year + 1900; 208 } else { 209 year = strtonum(*argv, 1, 9999, &errstr); 210 if (errstr) 211 errx(1, "illegal year value: use 1-9999"); 212 } 213 break; 214 case 0: 215 (void)time(&now); 216 local_time = localtime(&now); 217 year = local_time->tm_year + 1900; 218 if (!yflag) 219 month = local_time->tm_mon + 1; 220 break; 221 default: 222 usage(); 223 } 224 225 if (month) 226 monthly(month, year); 227 else if (julian) 228 j_yearly(year); 229 else 230 yearly(year); 231 exit(0); 232} 233 234#define DAY_LEN 3 /* 3 spaces per day */ 235#define J_DAY_LEN 4 /* 4 spaces per day */ 236#define WEEK_LEN 20 /* 7 * 3 - one space at the end */ 237#define WEEKNUMBER_LEN 5 /* 5 spaces per week number */ 238#define J_WEEK_LEN 27 /* 7 * 4 - one space at the end */ 239#define HEAD_SEP 2 /* spaces between day headings */ 240#define J_HEAD_SEP 2 241 242int 243week(int day, int month, int year) 244{ 245 int yearday; 246 int firstweekday; 247 int weekday; 248 int firstday; 249 int firstsunday; 250 int shift; 251 252 if (mflag) 253 return isoweek(day, month, year); 254 255 yearday = day_in_year(day, month, year); 256 firstweekday = day_in_week(1, 1, year) + 1; 257 weekday = day_in_week(day, month, year) + 1; 258 firstday = day_in_year(1, 1, year); 259 firstsunday = firstday + (8 - firstweekday); 260 261 shift = 1; 262 if (yearday < firstsunday) 263 return (1); 264 if (firstweekday > THURSDAY - 1) 265 shift = 2; 266 return ((((yearday + 1) - (weekday - 1)) / 7) + shift); 267} 268 269int 270isoweek(int day, int month, int year) 271{ 272 /* http://www.tondering.dk/claus/cal/node8.html */ 273 int a, b, c, s, e, f, g, d, n; 274 275 a = month <= 2 ? year - 1 : year; 276 b = a/4 - a/100 + a/400; 277 c = (a-1)/4 - (a-1)/100 + (a-1)/400; 278 s = b - c; 279 if (month <= 2) { 280 e = 0; 281 f = day - 1 + 31 * (month-1); 282 } else { 283 e = s + 1; 284 f = day + ((153 * (month-3) + 2) / 5) + 58 + s; 285 } 286 g = (a + b) % 7; 287 d = (f + g - e) % 7; 288 n = f + 3 - d; 289 290 if (n < 0) 291 return 53 - (g - s) / 5; 292 else if (n > 364 + s) 293 return 1; 294 else 295 return n/7 + 1; 296} 297 298void 299monthly(int month, int year) 300{ 301 int col, row, len, days[MAXDAYS], firstday; 302 char *p, lineout[30]; 303 304 day_array(month, year, days); 305 (void)snprintf(lineout, sizeof(lineout), "%s %d", 306 month_names[month - 1], year); 307 len = strlen(lineout); 308 (void)printf("%*s%s\n%s\n", 309 ((julian ? J_WEEK_LEN : WEEK_LEN) - len) / 2, "", 310 lineout, day_headings); 311 for (row = 0; row < 6; row++) { 312 firstday = SPACE; 313 for (col = 0, p = lineout; col < 7; col++, 314 p += julian ? J_DAY_LEN : DAY_LEN) { 315 if (firstday == SPACE && days[row * 7 + col] != SPACE) 316 firstday = days[row * 7 + col]; 317 ascii_day(p, days[row * 7 + col]); 318 } 319 *p = '\0'; 320 trim_trailing_spaces(lineout); 321 (void)printf("%-20s", lineout); 322 if (wflag && firstday != SPACE) 323 printf(" [%2d]", week(firstday, month, year)); 324 printf("\n"); 325 } 326} 327 328void 329j_yearly(int year) 330{ 331 int col, *dp, i, month, row, which_cal; 332 int days[12][MAXDAYS]; 333 char *p, lineout[80]; 334 335 (void)snprintf(lineout, sizeof(lineout), "%d", year); 336 center(lineout, J_WEEK_LEN * 2 + J_HEAD_SEP, 0); 337 (void)printf("\n\n"); 338 for (i = 0; i < 12; i++) 339 day_array(i + 1, year, days[i]); 340 (void)memset(lineout, ' ', sizeof(lineout) - 1); 341 lineout[sizeof(lineout) - 1] = '\0'; 342 for (month = 0; month < 12; month += 2) { 343 center(month_names[month], J_WEEK_LEN, J_HEAD_SEP); 344 center(month_names[month + 1], J_WEEK_LEN, 0); 345 (void)printf("\n%s%*s%s\n", day_headings, 346 J_HEAD_SEP, "", day_headings); 347 348 for (row = 0; row < 6; row++) { 349 for (which_cal = 0; which_cal < 2; which_cal++) { 350 p = lineout + which_cal * (J_WEEK_LEN + 2); 351 dp = &days[month + which_cal][row * 7]; 352 for (col = 0; col < 7; col++, p += J_DAY_LEN) 353 ascii_day(p, *dp++); 354 } 355 *p = '\0'; 356 trim_trailing_spaces(lineout); 357 (void)printf("%s\n", lineout); 358 } 359 } 360 (void)printf("\n"); 361} 362 363void 364yearly(int year) 365{ 366 int col, *dp, i, month, row, which_cal, week_len, wn, firstday; 367 int days[12][MAXDAYS]; 368 char *p, lineout[81]; 369 370 week_len = WEEK_LEN; 371 if (wflag) 372 week_len += WEEKNUMBER_LEN; 373 (void)snprintf(lineout, sizeof(lineout), "%d", year); 374 center(lineout, week_len * 3 + HEAD_SEP * 2, 0); 375 (void)printf("\n\n"); 376 for (i = 0; i < 12; i++) 377 day_array(i + 1, year, days[i]); 378 (void)memset(lineout, ' ', sizeof(lineout) - 1); 379 lineout[sizeof(lineout) - 1] = '\0'; 380 for (month = 0; month < 12; month += 3) { 381 center(month_names[month], week_len, HEAD_SEP); 382 center(month_names[month + 1], week_len, HEAD_SEP); 383 center(month_names[month + 2], week_len, 0); 384 (void)printf("\n%s%*s%s%*s%s\n", day_headings, 385 HEAD_SEP + (wflag ? WEEKNUMBER_LEN : 0), "", day_headings, 386 HEAD_SEP + (wflag ? WEEKNUMBER_LEN : 0), "", day_headings); 387 388 for (row = 0; row < 6; row++) { 389 for (which_cal = 0; which_cal < 3; which_cal++) { 390 p = lineout + which_cal * (week_len + 2); 391 392 dp = &days[month + which_cal][row * 7]; 393 firstday = SPACE; 394 for (col = 0; col < 7; col++, p += DAY_LEN) { 395 if (firstday == SPACE && *dp != SPACE) 396 firstday = *dp; 397 ascii_day(p, *dp++); 398 } 399 if (wflag && firstday != SPACE) { 400 wn = week(firstday, 401 month + which_cal + 1, year); 402 (void)snprintf(p, 5, "[%2d]", wn); 403 p += strlen(p); 404 *p = ' '; 405 } else 406 memset(p, ' ', 4); 407 } 408 *p = '\0'; 409 trim_trailing_spaces(lineout); 410 (void)printf("%s\n", lineout); 411 } 412 } 413 (void)printf("\n"); 414} 415 416/* 417 * day_array -- 418 * Fill in an array of 42 integers with a calendar. Assume for a moment 419 * that you took the (maximum) 6 rows in a calendar and stretched them 420 * out end to end. You would have 42 numbers or spaces. This routine 421 * builds that array for any month from Jan. 1 through Dec. 9999. 422 */ 423void 424day_array(int month, int year, int *days) 425{ 426 int day, dw, dm; 427 428 if (month == 9 && year == 1752) { 429 memmove(days, sep1752, MAXDAYS * sizeof(int)); 430 return; 431 } 432 memmove(days, empty, MAXDAYS * sizeof(int)); 433 dm = days_in_month[leap_year(year)][month]; 434 dw = day_in_week(mflag?0:1, month, year); 435 day = julian ? day_in_year(1, month, year) : 1; 436 while (dm--) 437 days[dw++] = day++; 438} 439 440/* 441 * day_in_year -- 442 * return the 1 based day number within the year 443 */ 444int 445day_in_year(int day, int month, int year) 446{ 447 int i, leap; 448 449 leap = leap_year(year); 450 for (i = 1; i < month; i++) 451 day += days_in_month[leap][i]; 452 return (day); 453} 454 455/* 456 * day_in_week 457 * return the 0 based day number for any date from 1 Jan. 1 to 458 * 31 Dec. 9999. Assumes the Gregorian reformation eliminates 459 * 3 Sep. 1752 through 13 Sep. 1752. Returns Thursday for all 460 * missing days. 461 */ 462int 463day_in_week(int day, int month, int year) 464{ 465 long temp; 466 467 temp = (long)(year - 1) * 365 + leap_years_since_year_1(year - 1) 468 + day_in_year(day, month, year); 469 if (temp < FIRST_MISSING_DAY) 470 return ((temp - 1 + SATURDAY) % 7); 471 if (temp >= (FIRST_MISSING_DAY + NUMBER_MISSING_DAYS)) 472 return (((temp - 1 + SATURDAY) - NUMBER_MISSING_DAYS) % 7); 473 return (THURSDAY); 474} 475 476void 477ascii_day(char *p, int day) 478{ 479 int display, val; 480 static const char *aday[] = { 481 "", 482 " 1", " 2", " 3", " 4", " 5", " 6", " 7", 483 " 8", " 9", "10", "11", "12", "13", "14", 484 "15", "16", "17", "18", "19", "20", "21", 485 "22", "23", "24", "25", "26", "27", "28", 486 "29", "30", "31", 487 }; 488 489 if (day == SPACE) { 490 memset(p, ' ', julian ? J_DAY_LEN : DAY_LEN); 491 return; 492 } 493 if (julian) { 494 val = day / 100; 495 if (val) { 496 day %= 100; 497 *p++ = val + '0'; 498 display = 1; 499 } else { 500 *p++ = ' '; 501 display = 0; 502 } 503 val = day / 10; 504 if (val || display) 505 *p++ = val + '0'; 506 else 507 *p++ = ' '; 508 *p++ = day % 10 + '0'; 509 } else { 510 *p++ = aday[day][0]; 511 *p++ = aday[day][1]; 512 } 513 *p = ' '; 514} 515 516void 517trim_trailing_spaces(char *s) 518{ 519 char *p; 520 521 for (p = s; *p; ++p) 522 continue; 523 while (p > s && isspace((unsigned char)*--p)) 524 continue; 525 if (p > s) 526 ++p; 527 *p = '\0'; 528} 529 530void 531center(const char *str, int len, int separate) 532{ 533 534 len -= strlen(str); 535 (void)printf("%*s%s%*s", len / 2, "", str, 536 len / 2 + len % 2 + separate, ""); 537} 538 539void 540usage(void) 541{ 542 543 (void)fprintf(stderr, "usage: cal [-jmwy] [month] [year]\n"); 544 exit(1); 545} 546 547int 548parsemonth(const char *s) 549{ 550 struct tm tm; 551 char *cp; 552 int v; 553 554 v = (int)strtol(s, &cp, 10); 555 if (*cp != '\0') { /* s wasn't purely numeric */ 556 v = 0; 557 if ((cp = strptime(s, "%b", &tm)) != NULL && *cp == '\0') 558 v = tm.tm_mon + 1; 559 } 560 if (v <= 0 || v > 12) 561 errx(1, "invalid month: use 1-12 or a name"); 562 return (v); 563} 564