LXR busybox/coreutils/cal.c

   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
  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//usage:#define cal_trivial_usage
  21//usage:       "[-jy] [[MONTH] YEAR]"
  22//usage:#define cal_full_usage "\n\n"
  23//usage:       "Display a calendar\n"
  24//usage:     "\n        -j      Use julian dates"
  25//usage:     "\n        -y      Display the entire year"
  26
  27#include "libbb.h"
  28#include "unicode.h"
  29
  30/* We often use "unsigned" intead of "int", it's easier to div on most CPUs */
  31
  32#define THURSDAY                4               /* for reformation */
  33#define SATURDAY                6               /* 1 Jan 1 was a Saturday */
  34
  35#define FIRST_MISSING_DAY       639787          /* 3 Sep 1752 */
  36#define NUMBER_MISSING_DAYS     11              /* 11 day correction */
  37
  38#define MAXDAYS                 42              /* max slots in a month array */
  39#define SPACE                   -1              /* used in day array */
  40
  41static const unsigned char days_in_month[] ALIGN1 = {
  42        0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
  43};
  44
  45static const unsigned char sep1752[] ALIGN1 = {
  46                1,      2,      14,     15,     16,
  47        17,     18,     19,     20,     21,     22,     23,
  48        24,     25,     26,     27,     28,     29,     30
  49};
  50
  51/* Set to 0 or 1 in main */
  52#define julian ((unsigned)option_mask32)
  53
  54/* leap year -- account for Gregorian reformation in 1752 */
  55static int leap_year(unsigned yr)
  56{
  57        if (yr <= 1752)
  58                return !(yr % 4);
  59        return (!(yr % 4) && (yr % 100)) || !(yr % 400);
  60}
  61
  62/* number of centuries since 1700, not inclusive */
  63#define centuries_since_1700(yr) \
  64        ((yr) > 1700 ? (yr) / 100 - 17 : 0)
  65
  66/* number of centuries since 1700 whose modulo of 400 is 0 */
  67#define quad_centuries_since_1700(yr) \
  68        ((yr) > 1600 ? ((yr) - 1600) / 400 : 0)
  69
  70/* number of leap years between year 1 and this year, not inclusive */
  71#define leap_years_since_year_1(yr) \
  72        ((yr) / 4 - centuries_since_1700(yr) + quad_centuries_since_1700(yr))
  73
  74static void center(char *, unsigned, unsigned);
  75static void day_array(unsigned, unsigned, unsigned *);
  76static void trim_trailing_spaces_and_print(char *);
  77
  78static void blank_string(char *buf, size_t buflen);
  79static char *build_row(char *p, unsigned *dp);
  80
  81#define DAY_LEN         3               /* 3 spaces per day */
  82#define J_DAY_LEN       (DAY_LEN + 1)
  83#define WEEK_LEN        20              /* 7 * 3 - one space at the end */
  84#define J_WEEK_LEN      (WEEK_LEN + 7)
  85#define HEAD_SEP        2               /* spaces between day headings */
  86
  87int cal_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  88int cal_main(int argc UNUSED_PARAM, char **argv)
  89{
  90        struct tm zero_tm;
  91        time_t now;
  92        unsigned month, year, flags, i;
  93        char *month_names[12];
  94        /* normal heading: */
  95        /* "Su Mo Tu We Th Fr Sa" */
  96        /* -j heading: */
  97        /* " Su  Mo  Tu  We  Th  Fr  Sa" */
  98        char day_headings[ENABLE_UNICODE_SUPPORT ? 28 * 6 : 28];
  99        IF_UNICODE_SUPPORT(char *hp = day_headings;)
 100        char buf[40];
 101
 102        init_unicode();
 103
 104        flags = getopt32(argv, "jy");
 105        /* This sets julian = flags & 1: */
 106        option_mask32 &= 1;
 107        month = 0;
 108        argv += optind;
 109
 110        if (!argv[0]) {
 111                struct tm *ptm;
 112
 113                time(&now);
 114                ptm = localtime(&now);
 115                year = ptm->tm_year + 1900;
 116                if (!(flags & 2)) { /* no -y */
 117                        month = ptm->tm_mon + 1;
 118                }
 119        } else {
 120                if (argv[1]) {
 121                        if (argv[2]) {
 122                                bb_show_usage();
 123                        }
 124                        if (!(flags & 2)) { /* no -y */
 125                                month = xatou_range(*argv, 1, 12);
 126                        }
 127                        argv++;
 128                }
 129                year = xatou_range(*argv, 1, 9999);
 130        }
 131
 132        blank_string(day_headings, sizeof(day_headings) - 7 + 7*julian);
 133
 134        i = 0;
 135        do {
 136                zero_tm.tm_mon = i;
 137                /* full month name according to locale */
 138                strftime(buf, sizeof(buf), "%B", &zero_tm);
 139                month_names[i] = xstrdup(buf);
 140
 141                if (i < 7) {
 142                        zero_tm.tm_wday = i;
 143                        /* abbreviated weekday name according to locale */
 144                        strftime(buf, sizeof(buf), "%a", &zero_tm);
 145#if ENABLE_UNICODE_SUPPORT
 146                        if (julian)
 147                                *hp++ = ' ';
 148                        {
 149                                char *two_wchars = unicode_conv_to_printable_fixedwidth(/*NULL,*/ buf, 2);
 150                                strcpy(hp, two_wchars);
 151                                free(two_wchars);
 152                        }
 153                        hp += strlen(hp);
 154                        *hp++ = ' ';
 155#else
 156                        strncpy(day_headings + i * (3+julian) + julian, buf, 2);
 157#endif
 158                }
 159        } while (++i < 12);
 160        IF_UNICODE_SUPPORT(hp[-1] = '\0';)
 161
 162        if (month) {
 163                unsigned row, len, days[MAXDAYS];
 164                unsigned *dp = days;
 165                char lineout[30];
 166
 167                day_array(month, year, dp);
 168                len = sprintf(lineout, "%s %u", month_names[month - 1], year);
 169                printf("%*s%s\n%s\n",
 170                                ((7*julian + WEEK_LEN) - len) / 2, "",
 171                                lineout, day_headings);
 172                for (row = 0; row < 6; row++) {
 173                        build_row(lineout, dp)[0] = '\0';
 174                        dp += 7;
 175                        trim_trailing_spaces_and_print(lineout);
 176                }
 177        } else {
 178                unsigned row, which_cal, week_len, days[12][MAXDAYS];
 179                unsigned *dp;
 180                char lineout[80];
 181
 182                sprintf(lineout, "%u", year);
 183                center(lineout,
 184                                (WEEK_LEN * 3 + HEAD_SEP * 2)
 185                                + julian * (J_WEEK_LEN * 2 + HEAD_SEP
 186                                                - (WEEK_LEN * 3 + HEAD_SEP * 2)),
 187                                0
 188                );
 189                puts("\n");             /* two \n's */
 190                for (i = 0; i < 12; i++) {
 191                        day_array(i + 1, year, days[i]);
 192                }
 193                blank_string(lineout, sizeof(lineout));
 194                week_len = WEEK_LEN + julian * (J_WEEK_LEN - WEEK_LEN);
 195                for (month = 0; month < 12; month += 3-julian) {
 196                        center(month_names[month], week_len, HEAD_SEP);
 197                        if (!julian) {
 198                                center(month_names[month + 1], week_len, HEAD_SEP);
 199                        }
 200                        center(month_names[month + 2 - julian], week_len, 0);
 201                        printf("\n%s%*s%s", day_headings, HEAD_SEP, "", day_headings);
 202                        if (!julian) {
 203                                printf("%*s%s", HEAD_SEP, "", day_headings);
 204                        }
 205                        bb_putchar('\n');
 206                        for (row = 0; row < (6*7); row += 7) {
 207                                for (which_cal = 0; which_cal < 3-julian; which_cal++) {
 208                                        dp = days[month + which_cal] + row;
 209                                        build_row(lineout + which_cal * (week_len + 2), dp);
 210                                }
 211                                /* blank_string took care of nul termination. */
 212                                trim_trailing_spaces_and_print(lineout);
 213                        }
 214                }
 215        }
 216
 217        fflush_stdout_and_exit(EXIT_SUCCESS);
 218}
 219
 220/*
 221 * day_array --
 222 *      Fill in an array of 42 integers with a calendar.  Assume for a moment
 223 *      that you took the (maximum) 6 rows in a calendar and stretched them
 224 *      out end to end.  You would have 42 numbers or spaces.  This routine
 225 *      builds that array for any month from Jan. 1 through Dec. 9999.
 226 */
 227static void day_array(unsigned month, unsigned year, unsigned *days)
 228{
 229        unsigned long temp;
 230        unsigned i;
 231        unsigned day, dw, dm;
 232
 233        memset(days, SPACE, MAXDAYS * sizeof(int));
 234
 235        if ((month == 9) && (year == 1752)) {
 236                /* Assumes the Gregorian reformation eliminates
 237                 * 3 Sep. 1752 through 13 Sep. 1752.
 238                 */
 239                unsigned j_offset = julian * 244;
 240                size_t oday = 0;
 241
 242                do {
 243                        days[oday+2] = sep1752[oday] + j_offset;
 244                } while (++oday < sizeof(sep1752));
 245
 246                return;
 247        }
 248
 249        /* day_in_year
 250         * return the 1 based day number within the year
 251         */
 252        day = 1;
 253        if ((month > 2) && leap_year(year)) {
 254                ++day;
 255        }
 256
 257        i = month;
 258        while (i) {
 259                day += days_in_month[--i];
 260        }
 261
 262        /* day_in_week
 263         * return the 0 based day number for any date from 1 Jan. 1 to
 264         * 31 Dec. 9999.  Assumes the Gregorian reformation eliminates
 265         * 3 Sep. 1752 through 13 Sep. 1752.  Returns Thursday for all
 266         * missing days.
 267         */
 268        temp = (long)(year - 1) * 365 + leap_years_since_year_1(year - 1) + day;
 269        if (temp < FIRST_MISSING_DAY) {
 270                dw = ((temp - 1 + SATURDAY) % 7);
 271        } else {
 272                dw = (((temp - 1 + SATURDAY) - NUMBER_MISSING_DAYS) % 7);
 273        }
 274
 275        if (!julian) {
 276                day = 1;
 277        }
 278
 279        dm = days_in_month[month];
 280        if ((month == 2) && leap_year(year)) {
 281                ++dm;
 282        }
 283
 284        do {
 285                days[dw++] = day++;
 286        } while (--dm);
 287}
 288
 289static void trim_trailing_spaces_and_print(char *s)
 290{
 291        char *p = s;
 292
 293        while (*p) {
 294                ++p;
 295        }
 296        while (p != s) {
 297                --p;
 298                if (!isspace(*p)) {
 299                        p[1] = '\0';
 300                        break;
 301                }
 302        }
 303
 304        puts(s);
 305}
 306
 307static void center(char *str, unsigned len, unsigned separate)
 308{
 309        unsigned n = strlen(str);
 310        len -= n;
 311        printf("%*s%*s", (len/2) + n, str, (len/2) + (len % 2) + separate, "");
 312}
 313
 314static void blank_string(char *buf, size_t buflen)
 315{
 316        memset(buf, ' ', buflen);
 317        buf[buflen-1] = '\0';
 318}
 319
 320static char *build_row(char *p, unsigned *dp)
 321{
 322        unsigned col, val, day;
 323
 324        memset(p, ' ', (julian + DAY_LEN) * 7);
 325
 326        col = 0;
 327        do {
 328                day = *dp++;
 329                if (day != SPACE) {
 330                        if (julian) {
 331                                ++p;
 332                                if (day >= 100) {
 333                                        *p = '0';
 334                                        p[-1] = (day / 100) + '0';
 335                                        day %= 100;
 336                                }
 337                        }
 338                        val = day / 10;
 339                        if (val > 0) {
 340                                *p = val + '0';
 341                        }
 342                        *++p = day % 10 + '0';
 343                        p += 2;
 344                } else {
 345                        p += DAY_LEN + julian;
 346                }
 347        } while (++col < 7);
 348
 349        return p;
 350}
 351
 352/*
 353 * Copyright (c) 1989, 1993, 1994
 354 *      The Regents of the University of California.  All rights reserved.
 355 *
 356 * This code is derived from software contributed to Berkeley by
 357 * Kim Letkeman.
 358 *
 359 * Redistribution and use in source and binary forms, with or without
 360 * modification, are permitted provided that the following conditions
 361 * are met:
 362 * 1. Redistributions of source code must retain the above copyright
 363 *    notice, this list of conditions and the following disclaimer.
 364 * 2. Redistributions in binary form must reproduce the above copyright
 365 *    notice, this list of conditions and the following disclaimer in the
 366 *    documentation and/or other materials provided with the distribution.
 367 * 3. Neither the name of the University nor the names of its contributors
 368 *    may be used to endorse or promote products derived from this software
 369 *    without specific prior written permission.
 370 *
 371 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 372 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 373 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 374 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 375 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 376 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 377 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 378 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 379 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 380 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 381 * SUCH DAMAGE.
 382 */
 383