LXR busybox/util-linux/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/* 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
  19//applet:IF_CAL(APPLET_NOEXEC(cal, cal, BB_DIR_USR_BIN, BB_SUID_DROP, cal))
  20/* NOEXEC despite rare cases when it can be a "runner" (e.g. cal -n12000 takes you into years 30xx) */
  21
  22//kbuild:lib-$(CONFIG_CAL) += cal.o
  23
  24/* BB_AUDIT SUSv3 compliant with -j and -y extensions (from util-linux). */
  25/* BB_AUDIT BUG: The output of 'cal -j 1752' is incorrect.  The upstream
  26 * BB_AUDIT BUG: version in util-linux seems to be broken as well. */
  27/* http://www.opengroup.org/onlinepubs/007904975/utilities/cal.html */
  28
  29//usage:#define cal_trivial_usage
  30//usage:       "[-jy] [[MONTH] YEAR]"
  31//usage:#define cal_full_usage "\n\n"
  32//usage:       "Display a calendar\n"
  33//usage:     "\n        -j      Use julian dates"
  34//usage:     "\n        -y      Display the entire year"
  35
  36#include "libbb.h"
  37#include "unicode.h"
  38
  39/* We often use "unsigned" instead of "int", it's easier to div on most CPUs */
  40
  41#define THURSDAY                4               /* for reformation */
  42#define SATURDAY                6               /* 1 Jan 1 was a Saturday */
  43
  44#define FIRST_MISSING_DAY       639787          /* 3 Sep 1752 */
  45#define NUMBER_MISSING_DAYS     11              /* 11 day correction */
  46
  47#define MAXDAYS                 42              /* max slots in a month array */
  48#define SPACE                   -1              /* used in day array */
  49
  50static const unsigned char days_in_month[] ALIGN1 = {
  51        0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
  52};
  53
  54static const unsigned char sep1752[] ALIGN1 = {
  55                1,      2,      14,     15,     16,
  56        17,     18,     19,     20,     21,     22,     23,
  57        24,     25,     26,     27,     28,     29,     30
  58};
  59
  60/* Set to 0 or 1 in main */
  61#define julian ((unsigned)option_mask32)
  62
  63/* leap year -- account for Gregorian reformation in 1752 */
  64static int leap_year(unsigned yr)
  65{
  66        if (yr <= 1752)
  67                return !(yr % 4);
  68        return (!(yr % 4) && (yr % 100)) || !(yr % 400);
  69}
  70
  71/* number of centuries since 1700, not inclusive */
  72#define centuries_since_1700(yr) \
  73        ((yr) > 1700 ? (yr) / 100 - 17 : 0)
  74
  75/* number of centuries since 1700 whose modulo of 400 is 0 */
  76#define quad_centuries_since_1700(yr) \
  77        ((yr) > 1600 ? ((yr) - 1600) / 400 : 0)
  78
  79/* number of leap years between year 1 and this year, not inclusive */
  80#define leap_years_since_year_1(yr) \
  81        ((yr) / 4 - centuries_since_1700(yr) + quad_centuries_since_1700(yr))
  82
  83static void center(char *, unsigned, unsigned);
  84static void day_array(unsigned, unsigned, unsigned *);
  85static void trim_trailing_spaces_and_print(char *);
  86
  87static void blank_string(char *buf, size_t buflen);
  88static char *build_row(char *p, unsigned *dp);
  89
  90#define DAY_LEN         3               /* 3 spaces per day */
  91#define J_DAY_LEN       (DAY_LEN + 1)
  92#define WEEK_LEN        20              /* 7 * 3 - one space at the end */
  93#define J_WEEK_LEN      (WEEK_LEN + 7)
  94#define HEAD_SEP        2               /* spaces between day headings */
  95
  96int cal_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  97int cal_main(int argc UNUSED_PARAM, char **argv)
  98{
  99        struct tm zero_tm;
 100        time_t now;
 101        unsigned month, year, flags, i;
 102        char *month_names[12];
 103        /* normal heading: */
 104        /* "Su Mo Tu We Th Fr Sa" */
 105        /* -j heading: */
 106        /* " Su  Mo  Tu  We  Th  Fr  Sa" */
 107        char day_headings[ENABLE_UNICODE_SUPPORT ? 28 * 6 : 28];
 108        IF_UNICODE_SUPPORT(char *hp = day_headings;)
 109        char buf[40];
 110
 111        init_unicode();
 112
 113        flags = getopt32(argv, "jy");
 114        /* This sets julian = flags & 1: */
 115        option_mask32 &= 1;
 116        month = 0;
 117        argv += optind;
 118
 119        if (!argv[0]) {
 120                struct tm *ptm;
 121
 122                time(&now);
 123                ptm = localtime(&now);
 124                year = ptm->tm_year + 1900;
 125                if (!(flags & 2)) { /* no -y */
 126                        month = ptm->tm_mon + 1;
 127                }
 128        } else {
 129                if (argv[1]) {
 130                        if (argv[2]) {
 131                                bb_show_usage();
 132                        }
 133                        if (!(flags & 2)) { /* no -y */
 134                                month = xatou_range(*argv, 1, 12);
 135                        }
 136                        argv++;
 137                }
 138                year = xatou_range(*argv, 1, 9999);
 139        }
 140
 141        blank_string(day_headings, sizeof(day_headings) - 7 + 7*julian);
 142
 143        i = 0;
 144        do {
 145                zero_tm.tm_mon = i;
 146                /* full month name according to locale */
 147                strftime(buf, sizeof(buf), "%B", &zero_tm);
 148                month_names[i] = xstrdup(buf);
 149
 150                if (i < 7) {
 151                        zero_tm.tm_wday = i;
 152                        /* abbreviated weekday name according to locale */
 153                        strftime(buf, sizeof(buf), "%a", &zero_tm);
 154#if ENABLE_UNICODE_SUPPORT
 155                        if (julian)
 156                                *hp++ = ' ';
 157                        {
 158                                char *two_wchars = unicode_conv_to_printable_fixedwidth(/*NULL,*/ buf, 2);
 159                                strcpy(hp, two_wchars);
 160                                free(two_wchars);
 161                        }
 162                        hp += strlen(hp);
 163                        *hp++ = ' ';
 164#else
 165                        strncpy(day_headings + i * (3+julian) + julian, buf, 2);
 166#endif
 167                }
 168        } while (++i < 12);
 169        IF_UNICODE_SUPPORT(hp[-1] = '\0';)
 170
 171        if (month) {
 172                unsigned row, len, days[MAXDAYS];
 173                unsigned *dp = days;
 174                char lineout[30];
 175
 176                day_array(month, year, dp);
 177                len = sprintf(lineout, "%s %u", month_names[month - 1], year);
 178                printf("%*s%s\n%s\n",
 179                                ((7*julian + WEEK_LEN) - len) / 2, "",
 180                                lineout, day_headings);
 181                for (row = 0; row < 6; row++) {
 182                        build_row(lineout, dp)[0] = '\0';
 183                        dp += 7;
 184                        trim_trailing_spaces_and_print(lineout);
 185                }
 186        } else {
 187                unsigned row, which_cal, week_len, days[12][MAXDAYS];
 188                unsigned *dp;
 189                char lineout[80];
 190
 191                sprintf(lineout, "%u", year);
 192                center(lineout,
 193                                (WEEK_LEN * 3 + HEAD_SEP * 2)
 194                                + julian * (J_WEEK_LEN * 2 + HEAD_SEP
 195                                                - (WEEK_LEN * 3 + HEAD_SEP * 2)),
 196                                0
 197                );
 198                puts("\n");             /* two \n's */
 199                for (i = 0; i < 12; i++) {
 200                        day_array(i + 1, year, days[i]);
 201                }
 202                blank_string(lineout, sizeof(lineout));
 203                week_len = WEEK_LEN + julian * (J_WEEK_LEN - WEEK_LEN);
 204                for (month = 0; month < 12; month += 3-julian) {
 205                        center(month_names[month], week_len, HEAD_SEP);
 206                        if (!julian) {
 207                                center(month_names[month + 1], week_len, HEAD_SEP);
 208                        }
 209                        center(month_names[month + 2 - julian], week_len, 0);
 210                        printf("\n%s%*s%s", day_headings, HEAD_SEP, "", day_headings);
 211                        if (!julian) {
 212                                printf("%*s%s", HEAD_SEP, "", day_headings);
 213                        }
 214                        bb_putchar('\n');
 215                        for (row = 0; row < (6*7); row += 7) {
 216                                for (which_cal = 0; which_cal < 3-julian; which_cal++) {
 217                                        dp = days[month + which_cal] + row;
 218                                        build_row(lineout + which_cal * (week_len + 2), dp);
 219                                }
 220                                /* blank_string took care of nul termination. */
 221                                trim_trailing_spaces_and_print(lineout);
 222                        }
 223                }
 224        }
 225
 226        fflush_stdout_and_exit(EXIT_SUCCESS);
 227}
 228
 229/*
 230 * day_array --
 231 *      Fill in an array of 42 integers with a calendar.  Assume for a moment
 232 *      that you took the (maximum) 6 rows in a calendar and stretched them
 233 *      out end to end.  You would have 42 numbers or spaces.  This routine
 234 *      builds that array for any month from Jan. 1 through Dec. 9999.
 235 */
 236static void day_array(unsigned month, unsigned year, unsigned *days)
 237{
 238        unsigned long temp;
 239        unsigned i;
 240        unsigned day, dw, dm;
 241
 242        memset(days, SPACE, MAXDAYS * sizeof(int));
 243
 244        if ((month == 9) && (year == 1752)) {
 245                /* Assumes the Gregorian reformation eliminates
 246                 * 3 Sep. 1752 through 13 Sep. 1752.
 247                 */
 248                unsigned j_offset = julian * 244;
 249                size_t oday = 0;
 250
 251                do {
 252                        days[oday+2] = sep1752[oday] + j_offset;
 253                } while (++oday < sizeof(sep1752));
 254
 255                return;
 256        }
 257
 258        /* day_in_year
 259         * return the 1 based day number within the year
 260         */
 261        day = 1;
 262        if ((month > 2) && leap_year(year)) {
 263                ++day;
 264        }
 265
 266        i = month;
 267        while (i) {
 268                day += days_in_month[--i];
 269        }
 270
 271        /* day_in_week
 272         * return the 0 based day number for any date from 1 Jan. 1 to
 273         * 31 Dec. 9999.  Assumes the Gregorian reformation eliminates
 274         * 3 Sep. 1752 through 13 Sep. 1752.  Returns Thursday for all
 275         * missing days.
 276         */
 277        temp = (long)(year - 1) * 365 + leap_years_since_year_1(year - 1) + day;
 278        if (temp < FIRST_MISSING_DAY) {
 279                dw = ((temp - 1 + SATURDAY) % 7);
 280        } else {
 281                dw = (((temp - 1 + SATURDAY) - NUMBER_MISSING_DAYS) % 7);
 282        }
 283
 284        if (!julian) {
 285                day = 1;
 286        }
 287
 288        dm = days_in_month[month];
 289        if ((month == 2) && leap_year(year)) {
 290                ++dm;
 291        }
 292
 293        do {
 294                days[dw++] = day++;
 295        } while (--dm);
 296}
 297
 298static void trim_trailing_spaces_and_print(char *s)
 299{
 300        char *p = s;
 301
 302        while (*p) {
 303                ++p;
 304        }
 305        while (p != s) {
 306                --p;
 307                if (!isspace(*p)) {
 308                        p[1] = '\0';
 309                        break;
 310                }
 311        }
 312
 313        puts(s);
 314}
 315
 316static void center(char *str, unsigned len, unsigned separate)
 317{
 318        unsigned n = strlen(str);
 319        len -= n;
 320        printf("%*s%*s", (len/2) + n, str, (len/2) + (len % 2) + separate, "");
 321}
 322
 323static void blank_string(char *buf, size_t buflen)
 324{
 325        memset(buf, ' ', buflen);
 326        buf[buflen-1] = '\0';
 327}
 328
 329static char *build_row(char *p, unsigned *dp)
 330{
 331        unsigned col, val, day;
 332
 333        memset(p, ' ', (julian + DAY_LEN) * 7);
 334
 335        col = 0;
 336        do {
 337                day = *dp++;
 338                if (day != SPACE) {
 339                        if (julian) {
 340                                ++p;
 341                                if (day >= 100) {
 342                                        *p = '0';
 343                                        p[-1] = (day / 100) + '0';
 344                                        day %= 100;
 345                                }
 346                        }
 347                        val = day / 10;
 348                        if (val > 0) {
 349                                *p = val + '0';
 350                        }
 351                        *++p = day % 10 + '0';
 352                        p += 2;
 353                } else {
 354                        p += DAY_LEN + julian;
 355                }
 356        } while (++col < 7);
 357
 358        return p;
 359}
 360
 361/*
 362 * Copyright (c) 1989, 1993, 1994
 363 *      The Regents of the University of California.  All rights reserved.
 364 *
 365 * This code is derived from software contributed to Berkeley by
 366 * Kim Letkeman.
 367 *
 368 * Redistribution and use in source and binary forms, with or without
 369 * modification, are permitted provided that the following conditions
 370 * are met:
 371 * 1. Redistributions of source code must retain the above copyright
 372 *    notice, this list of conditions and the following disclaimer.
 373 * 2. Redistributions in binary form must reproduce the above copyright
 374 *    notice, this list of conditions and the following disclaimer in the
 375 *    documentation and/or other materials provided with the distribution.
 376 * 3. Neither the name of the University nor the names of its contributors
 377 *    may be used to endorse or promote products derived from this software
 378 *    without specific prior written permission.
 379 *
 380 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ''AS IS'' AND
 381 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 382 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 383 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 384 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 385 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 386 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 387 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 388 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 389 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 390 * SUCH DAMAGE.
 391 */
 392