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