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:       "[-jmy] [[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        -m      Week starts on Monday"
  35//usage:     "\n        -y      Display the entire year"
  36
  37#include "libbb.h"
  38#include "unicode.h"
  39
  40/* We often use "unsigned" instead of "int", it's easier to div on most CPUs */
  41
  42#define SUNDAY                  0
  43#define MONDAY                  1
  44#define THURSDAY                4               /* for reformation */
  45#define SATURDAY                6               /* 1 Jan 1 was a Saturday */
  46
  47#define FIRST_MISSING_DAY       639787          /* 3 Sep 1752 */
  48#define NUMBER_MISSING_DAYS     11              /* 11 day correction */
  49
  50#define MAXDAYS                 42              /* max slots in a month array */
  51#define SPACE                   -1              /* used in day array */
  52
  53static const unsigned char days_in_month[] ALIGN1 = {
  54        0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
  55};
  56
  57static const unsigned char sep1752[] ALIGN1 = {
  58                1,      2,      14,     15,     16,
  59        17,     18,     19,     20,     21,     22,     23,
  60        24,     25,     26,     27,     28,     29,     30
  61};
  62
  63/* Set to 0 or 1 in main */
  64#define julian ((unsigned)option_mask32)
  65
  66/* leap year -- account for Gregorian reformation in 1752 */
  67static int leap_year(unsigned yr)
  68{
  69        if (yr <= 1752)
  70                return !(yr % 4);
  71        return (!(yr % 4) && (yr % 100)) || !(yr % 400);
  72}
  73
  74/* number of centuries since 1700, not inclusive */
  75#define centuries_since_1700(yr) \
  76        ((yr) > 1700 ? (yr) / 100 - 17 : 0)
  77
  78/* number of centuries since 1700 whose modulo of 400 is 0 */
  79#define quad_centuries_since_1700(yr) \
  80        ((yr) > 1600 ? ((yr) - 1600) / 400 : 0)
  81
  82/* number of leap years between year 1 and this year, not inclusive */
  83#define leap_years_since_year_1(yr) \
  84        ((yr) / 4 - centuries_since_1700(yr) + quad_centuries_since_1700(yr))
  85
  86static void center(char *, unsigned, unsigned);
  87static void day_array(unsigned, unsigned, unsigned, unsigned *);
  88static void trim_trailing_spaces_and_print(char *);
  89
  90static void blank_string(char *buf, size_t buflen);
  91static char *build_row(char *p, unsigned *dp);
  92
  93#define DAY_LEN         3               /* 3 spaces per day */
  94#define J_DAY_LEN       (DAY_LEN + 1)
  95#define WEEK_LEN        20              /* 7 * 3 - one space at the end */
  96#define J_WEEK_LEN      (WEEK_LEN + 7)
  97#define HEAD_SEP        2               /* spaces between day headings */
  98
  99enum {
 100        OPT_JULIAN = (1 << 0),
 101        OPT_MONDAY = (1 << 1),
 102        OPT_YEAR   = (1 << 2),
 103};
 104
 105int cal_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 106int cal_main(int argc UNUSED_PARAM, char **argv)
 107{
 108        struct tm zero_tm;
 109        time_t now;
 110        unsigned month, year, flags, i, weekstart;
 111        char *month_names[12];
 112        /* normal heading: */
 113        /* "Su Mo Tu We Th Fr Sa" */
 114        /* -j heading: */
 115        /* " Su  Mo  Tu  We  Th  Fr  Sa" */
 116        char day_headings[ENABLE_UNICODE_SUPPORT ? 28 * 6 : 28];
 117        IF_UNICODE_SUPPORT(char *hp = day_headings;)
 118        char buf[40];
 119
 120        init_unicode();
 121
 122        flags = getopt32(argv, "jmy");
 123        /* This sets julian = flags & OPT_JULIAN: */
 124        option_mask32 &= OPT_JULIAN;
 125        month = 0;
 126        weekstart = (flags & OPT_MONDAY) ? MONDAY : SUNDAY;
 127        argv += optind;
 128
 129        if (!argv[0]) {
 130                struct tm *ptm;
 131
 132                time(&now);
 133                ptm = localtime(&now);
 134                year = ptm->tm_year + 1900;
 135                if (!(flags & OPT_YEAR)) { /* no -y */
 136                        month = ptm->tm_mon + 1;
 137                }
 138        } else {
 139                if (argv[1]) {
 140                        if (argv[2]) {
 141                                bb_show_usage();
 142                        }
 143                        if (!(flags & OPT_YEAR)) { /* no -y */
 144                                month = xatou_range(*argv, 1, 12);
 145                        }
 146                        argv++;
 147                }
 148                year = xatou_range(*argv, 1, 9999);
 149        }
 150
 151        blank_string(day_headings, sizeof(day_headings) - 7 + 7*julian);
 152
 153        i = 0;
 154        do {
 155                zero_tm.tm_mon = i;
 156                /* full month name according to locale */
 157                strftime(buf, sizeof(buf), "%B", &zero_tm);
 158                month_names[i] = xstrdup(buf);
 159
 160                if (i < 7) {
 161                        zero_tm.tm_wday = (i + weekstart) % 7;
 162                        /* abbreviated weekday name according to locale */
 163                        strftime(buf, sizeof(buf), "%a", &zero_tm);
 164#if ENABLE_UNICODE_SUPPORT
 165                        if (julian)
 166                                *hp++ = ' ';
 167                        {
 168                                char *two_wchars = unicode_conv_to_printable_fixedwidth(/*NULL,*/ buf, 2);
 169                                strcpy(hp, two_wchars);
 170                                free(two_wchars);
 171                        }
 172                        hp += strlen(hp);
 173                        *hp++ = ' ';
 174#else
 175                        strncpy(day_headings + i * (3+julian) + julian, buf, 2);
 176#endif
 177                }
 178        } while (++i < 12);
 179        IF_UNICODE_SUPPORT(hp[-1] = '\0';)
 180
 181        if (month) {
 182                unsigned row, len, days[MAXDAYS];
 183                unsigned *dp = days;
 184                char lineout[30];
 185
 186                day_array(month, year, weekstart, dp);
 187                len = sprintf(lineout, "%s %u", month_names[month - 1], year);
 188                printf("%*s%s\n%s\n",
 189                                ((7*julian + WEEK_LEN) - len) / 2, "",
 190                                lineout, day_headings);
 191                for (row = 0; row < 6; row++) {
 192                        build_row(lineout, dp)[0] = '\0';
 193                        dp += 7;
 194                        trim_trailing_spaces_and_print(lineout);
 195                }
 196        } else {
 197                unsigned row, which_cal, week_len, days[12][MAXDAYS];
 198                unsigned *dp;
 199                char lineout[80];
 200
 201                sprintf(lineout, "%u", year);
 202                center(lineout,
 203                                (WEEK_LEN * 3 + HEAD_SEP * 2)
 204                                + julian * (J_WEEK_LEN * 2 + HEAD_SEP
 205                                                - (WEEK_LEN * 3 + HEAD_SEP * 2)),
 206                                0
 207                );
 208                puts("\n");             /* two \n's */
 209                for (i = 0; i < 12; i++) {
 210                        day_array(i + 1, year, weekstart, days[i]);
 211                }
 212                blank_string(lineout, sizeof(lineout));
 213                week_len = WEEK_LEN + julian * (J_WEEK_LEN - WEEK_LEN);
 214                for (month = 0; month < 12; month += 3-julian) {
 215                        center(month_names[month], week_len, HEAD_SEP);
 216                        if (!julian) {
 217                                center(month_names[month + 1], week_len, HEAD_SEP);
 218                        }
 219                        center(month_names[month + 2 - julian], week_len, 0);
 220                        printf("\n%s%*s%s", day_headings, HEAD_SEP, "", day_headings);
 221                        if (!julian) {
 222                                printf("%*s%s", HEAD_SEP, "", day_headings);
 223                        }
 224                        bb_putchar('\n');
 225                        for (row = 0; row < (6*7); row += 7) {
 226                                for (which_cal = 0; which_cal < 3-julian; which_cal++) {
 227                                        dp = days[month + which_cal] + row;
 228                                        build_row(lineout + which_cal * (week_len + 2), dp);
 229                                }
 230                                /* blank_string took care of nul termination. */
 231                                trim_trailing_spaces_and_print(lineout);
 232                        }
 233                }
 234        }
 235
 236        fflush_stdout_and_exit(EXIT_SUCCESS);
 237}
 238
 239/*
 240 * day_array --
 241 *      Fill in an array of 42 integers with a calendar.  Assume for a moment
 242 *      that you took the (maximum) 6 rows in a calendar and stretched them
 243 *      out end to end.  You would have 42 numbers or spaces.  This routine
 244 *      builds that array for any month from Jan. 1 through Dec. 9999.
 245 */
 246static void day_array(unsigned month, unsigned year, unsigned weekstart,
 247                                                unsigned *days)
 248{
 249        unsigned long temp;
 250        unsigned i;
 251        unsigned day, dw, dm;
 252
 253        memset(days, SPACE, MAXDAYS * sizeof(int));
 254
 255        if ((month == 9) && (year == 1752)) {
 256                /* Assumes the Gregorian reformation eliminates
 257                 * 3 Sep. 1752 through 13 Sep. 1752.
 258                 */
 259                unsigned j_offset = julian * 244;
 260                size_t oday = 0;
 261
 262                do {
 263                        days[oday+2-weekstart] = sep1752[oday] + j_offset;
 264                } while (++oday < sizeof(sep1752));
 265
 266                return;
 267        }
 268
 269        /* day_in_year
 270         * return the 1 based day number within the year
 271         */
 272        day = 1;
 273        if ((month > 2) && leap_year(year)) {
 274                ++day;
 275        }
 276
 277        i = month;
 278        while (i) {
 279                day += days_in_month[--i];
 280        }
 281
 282        /* day_in_week
 283         * return the 0 based day number for any date from 1 Jan. 1 to
 284         * 31 Dec. 9999.  Assumes the Gregorian reformation eliminates
 285         * 3 Sep. 1752 through 13 Sep. 1752.  Returns Thursday for all
 286         * missing days.
 287         */
 288        temp = (long)(year - 1) * 365 + leap_years_since_year_1(year - 1) + day;
 289        if (temp < FIRST_MISSING_DAY) {
 290                dw = ((temp - 1 + SATURDAY) % 7);
 291        } else {
 292                dw = (((temp - 1 + SATURDAY) - NUMBER_MISSING_DAYS) % 7);
 293        }
 294        dw = (dw - weekstart + 7) % 7;
 295
 296        if (!julian) {
 297                day = 1;
 298        }
 299
 300        dm = days_in_month[month];
 301        if ((month == 2) && leap_year(year)) {
 302                ++dm;
 303        }
 304
 305        do {
 306                days[dw++] = day++;
 307        } while (--dm);
 308}
 309
 310static void trim_trailing_spaces_and_print(char *s)
 311{
 312        char *p = s;
 313
 314        while (*p) {
 315                ++p;
 316        }
 317        while (p != s) {
 318                --p;
 319                if (!isspace(*p)) {
 320                        p[1] = '\0';
 321                        break;
 322                }
 323        }
 324
 325        puts(s);
 326}
 327
 328static void center(char *str, unsigned len, unsigned separate)
 329{
 330        unsigned n = strlen(str);
 331        len -= n;
 332        printf("%*s%*s", (len/2) + n, str, (len/2) + (len % 2) + separate, "");
 333}
 334
 335static void blank_string(char *buf, size_t buflen)
 336{
 337        memset(buf, ' ', buflen);
 338        buf[buflen-1] = '\0';
 339}
 340
 341static char *build_row(char *p, unsigned *dp)
 342{
 343        unsigned col, val, day;
 344
 345        memset(p, ' ', (julian + DAY_LEN) * 7);
 346
 347        col = 0;
 348        do {
 349                day = *dp++;
 350                if (day != SPACE) {
 351                        if (julian) {
 352                                ++p;
 353                                if (day >= 100) {
 354                                        *p = '0';
 355                                        p[-1] = (day / 100) + '0';
 356                                        day %= 100;
 357                                }
 358                        }
 359                        val = day / 10;
 360                        if (val > 0) {
 361                                *p = val + '0';
 362                        }
 363                        *++p = day % 10 + '0';
 364                        p += 2;
 365                } else {
 366                        p += DAY_LEN + julian;
 367                }
 368        } while (++col < 7);
 369
 370        return p;
 371}
 372
 373/*
 374 * Copyright (c) 1989, 1993, 1994
 375 *      The Regents of the University of California.  All rights reserved.
 376 *
 377 * This code is derived from software contributed to Berkeley by
 378 * Kim Letkeman.
 379 *
 380 * Redistribution and use in source and binary forms, with or without
 381 * modification, are permitted provided that the following conditions
 382 * are met:
 383 * 1. Redistributions of source code must retain the above copyright
 384 *    notice, this list of conditions and the following disclaimer.
 385 * 2. Redistributions in binary form must reproduce the above copyright
 386 *    notice, this list of conditions and the following disclaimer in the
 387 *    documentation and/or other materials provided with the distribution.
 388 * 3. Neither the name of the University nor the names of its contributors
 389 *    may be used to endorse or promote products derived from this software
 390 *    without specific prior written permission.
 391 *
 392 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ''AS IS'' AND
 393 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 394 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 395 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 396 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 397 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 398 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 399 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 400 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 401 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 402 * SUCH DAMAGE.
 403 */
 404