date.c

   1 /*
   2  * GIT - The information manager from hell
   3  *
   4  * Copyright (C) Linus Torvalds, 2005
   5  */
   6
   7 #include "cache.h"
   8
   9 static time_t my_mktime(struct tm *tm)
  10 {
  11         static const int mdays[] = {
  12             0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334
  13         };
  14         int year = tm->tm_year - 70;
  15         int month = tm->tm_mon;
  16         int day = tm->tm_mday;
  17
  18         if (year < 0 || year > 129) /* algo only works for 1970-2099 */
  19                 return -1;
  20         if (month < 0 || month > 11) /* array bounds */
  21                 return -1;
  22         if (month < 2 || (year + 2) % 4)
  23                 day--;
  24         return (year * 365 + (year + 1) / 4 + mdays[month] + day) * 24*60*60UL +
  25                 tm->tm_hour * 60*60 + tm->tm_min * 60 + tm->tm_sec;
  26 }
  27
  28 static const char *month_names[] = {
  29         "January", "February", "March", "April", "May", "June",
  30         "July", "August", "September", "October", "November", "December"
  31 };
  32
  33 static const char *weekday_names[] = {
  34         "Sundays", "Mondays", "Tuesdays", "Wednesdays", "Thursdays", "Fridays", "Saturdays"
  35 };
  36
  37 static time_t gm_time_t(unsigned long time, int tz)
  38 {
  39         int minutes;
  40
  41         minutes = tz < 0 ? -tz : tz;
  42         minutes = (minutes / 100)*60 + (minutes % 100);
  43         minutes = tz < 0 ? -minutes : minutes;
  44         return time + minutes * 60;
  45 }
  46
  47 /*
  48  * The "tz" thing is passed in as this strange "decimal parse of tz"
  49  * thing, which means that tz -0100 is passed in as the integer -100,
  50  * even though it means "sixty minutes off"
  51  */
  52 static struct tm *time_to_tm(unsigned long time, int tz)
  53 {
  54         time_t t = gm_time_t(time, tz);
  55         return gmtime(&t);
  56 }
  57
  58 const char *show_date(unsigned long time, int tz, int relative)
  59 {
  60         struct tm *tm;
  61         static char timebuf[200];
  62
  63         if (relative) {
  64                 unsigned long diff;
  65                 struct timeval now;
  66                 gettimeofday(&now, NULL);
  67                 if (now.tv_sec < time)
  68                         return "in the future";
  69                 diff = now.tv_sec - time;
  70                 if (diff < 90) {
  71                         snprintf(timebuf, sizeof(timebuf), "%lu seconds ago", diff);
  72                         return timebuf;
  73                 }
  74                 /* Turn it into minutes */
  75                 diff = (diff + 30) / 60;
  76                 if (diff < 90) {
  77                         snprintf(timebuf, sizeof(timebuf), "%lu minutes ago", diff);
  78                         return timebuf;
  79                 }
  80                 /* Turn it into hours */
  81                 diff = (diff + 30) / 60;
  82                 if (diff < 36) {
  83                         snprintf(timebuf, sizeof(timebuf), "%lu hours ago", diff);
  84                         return timebuf;
  85                 }
  86                 /* We deal with number of days from here on */
  87                 diff = (diff + 12) / 24;
  88                 if (diff < 14) {
  89                         snprintf(timebuf, sizeof(timebuf), "%lu days ago", diff);
  90                         return timebuf;
  91                 }
  92                 /* Say weeks for the past 10 weeks or so */
  93                 if (diff < 70) {
  94                         snprintf(timebuf, sizeof(timebuf), "%lu weeks ago", (diff + 3) / 7);
  95                         return timebuf;
  96                 }
  97                 /* Say months for the past 12 months or so */
  98                 if (diff < 360) {
  99                         snprintf(timebuf, sizeof(timebuf), "%lu months ago", (diff + 15) / 30);
 100                         return timebuf;
 101                 }
 102                 /* Else fall back on absolute format.. */
 103         }
 104
 105         tm = time_to_tm(time, tz);
 106         if (!tm)
 107                 return NULL;
 108         sprintf(timebuf, "%.3s %.3s %d %02d:%02d:%02d %d %+05d",
 109                 weekday_names[tm->tm_wday],
 110                 month_names[tm->tm_mon],
 111                 tm->tm_mday,
 112                 tm->tm_hour, tm->tm_min, tm->tm_sec,
 113                 tm->tm_year + 1900, tz);
 114         return timebuf;
 115 }
 116
 117 const char *show_rfc2822_date(unsigned long time, int tz)
 118 {
 119         struct tm *tm;
 120         static char timebuf[200];
 121
 122         tm = time_to_tm(time, tz);
 123         if (!tm)
 124                 return NULL;
 125         sprintf(timebuf, "%.3s, %d %.3s %d %02d:%02d:%02d %+05d",
 126                 weekday_names[tm->tm_wday], tm->tm_mday,
 127                 month_names[tm->tm_mon], tm->tm_year + 1900,
 128                 tm->tm_hour, tm->tm_min, tm->tm_sec, tz);
 129         return timebuf;
 130 }
 131
 132 /*
 133  * Check these. And note how it doesn't do the summer-time conversion.
 134  *
 135  * In my world, it's always summer, and things are probably a bit off
 136  * in other ways too.
 137  */
 138 static const struct {
 139         const char *name;
 140         int offset;
 141         int dst;
 142 } timezone_names[] = {
 143         { "IDLW", -12, 0, },    /* International Date Line West */
 144         { "NT",   -11, 0, },    /* Nome */
 145         { "CAT",  -10, 0, },    /* Central Alaska */
 146         { "HST",  -10, 0, },    /* Hawaii Standard */
 147         { "HDT",  -10, 1, },    /* Hawaii Daylight */
 148         { "YST",   -9, 0, },    /* Yukon Standard */
 149         { "YDT",   -9, 1, },    /* Yukon Daylight */
 150         { "PST",   -8, 0, },    /* Pacific Standard */
 151         { "PDT",   -8, 1, },    /* Pacific Daylight */
 152         { "MST",   -7, 0, },    /* Mountain Standard */
 153         { "MDT",   -7, 1, },    /* Mountain Daylight */
 154         { "CST",   -6, 0, },    /* Central Standard */
 155         { "CDT",   -6, 1, },    /* Central Daylight */
 156         { "EST",   -5, 0, },    /* Eastern Standard */
 157         { "EDT",   -5, 1, },    /* Eastern Daylight */
 158         { "AST",   -3, 0, },    /* Atlantic Standard */
 159         { "ADT",   -3, 1, },    /* Atlantic Daylight */
 160         { "WAT",   -1, 0, },    /* West Africa */
 161
 162         { "GMT",    0, 0, },    /* Greenwich Mean */
 163         { "UTC",    0, 0, },    /* Universal (Coordinated) */
 164
 165         { "WET",    0, 0, },    /* Western European */
 166         { "BST",    0, 1, },    /* British Summer */
 167         { "CET",   +1, 0, },    /* Central European */
 168         { "MET",   +1, 0, },    /* Middle European */
 169         { "MEWT",  +1, 0, },    /* Middle European Winter */
 170         { "MEST",  +1, 1, },    /* Middle European Summer */
 171         { "CEST",  +1, 1, },    /* Central European Summer */
 172         { "MESZ",  +1, 1, },    /* Middle European Summer */
 173         { "FWT",   +1, 0, },    /* French Winter */
 174         { "FST",   +1, 1, },    /* French Summer */
 175         { "EET",   +2, 0, },    /* Eastern Europe, USSR Zone 1 */
 176         { "EEST",  +2, 1, },    /* Eastern European Daylight */
 177         { "WAST",  +7, 0, },    /* West Australian Standard */
 178         { "WADT",  +7, 1, },    /* West Australian Daylight */
 179         { "CCT",   +8, 0, },    /* China Coast, USSR Zone 7 */
 180         { "JST",   +9, 0, },    /* Japan Standard, USSR Zone 8 */
 181         { "EAST", +10, 0, },    /* Eastern Australian Standard */
 182         { "EADT", +10, 1, },    /* Eastern Australian Daylight */
 183         { "GST",  +10, 0, },    /* Guam Standard, USSR Zone 9 */
 184         { "NZT",  +11, 0, },    /* New Zealand */
 185         { "NZST", +11, 0, },    /* New Zealand Standard */
 186         { "NZDT", +11, 1, },    /* New Zealand Daylight */
 187         { "IDLE", +12, 0, },    /* International Date Line East */
 188 };
 189
 190 static int match_string(const char *date, const char *str)
 191 {
 192         int i = 0;
 193
 194         for (i = 0; *date; date++, str++, i++) {
 195                 if (*date == *str)
 196                         continue;
 197                 if (toupper(*date) == toupper(*str))
 198                         continue;
 199                 if (!isalnum(*date))
 200                         break;
 201                 return 0;
 202         }
 203         return i;
 204 }
 205
 206 static int skip_alpha(const char *date)
 207 {
 208         int i = 0;
 209         do {
 210                 i++;
 211         } while (isalpha(date[i]));
 212         return i;
 213 }
 214
 215 /*
 216 * Parse month, weekday, or timezone name
 217 */
 218 static int match_alpha(const char *date, struct tm *tm, int *offset)
 219 {
 220         int i;
 221
 222         for (i = 0; i < 12; i++) {
 223                 int match = match_string(date, month_names[i]);
 224                 if (match >= 3) {
 225                         tm->tm_mon = i;
 226                         return match;
 227                 }
 228         }
 229
 230         for (i = 0; i < 7; i++) {
 231                 int match = match_string(date, weekday_names[i]);
 232                 if (match >= 3) {
 233                         tm->tm_wday = i;
 234                         return match;
 235                 }
 236         }
 237
 238         for (i = 0; i < ARRAY_SIZE(timezone_names); i++) {
 239                 int match = match_string(date, timezone_names[i].name);
 240                 if (match >= 3) {
 241                         int off = timezone_names[i].offset;
 242
 243                         /* This is bogus, but we like summer */
 244                         off += timezone_names[i].dst;
 245
 246                         /* Only use the tz name offset if we don't have anything better */
 247                         if (*offset == -1)
 248                                 *offset = 60*off;
 249
 250                         return match;
 251                 }
 252         }
 253
 254         if (match_string(date, "PM") == 2) {
 255                 tm->tm_hour = (tm->tm_hour % 12) + 12;
 256                 return 2;
 257         }
 258
 259         if (match_string(date, "AM") == 2) {
 260                 tm->tm_hour = (tm->tm_hour % 12) + 0;
 261                 return 2;
 262         }
 263
 264         /* BAD CRAP */
 265         return skip_alpha(date);
 266 }
 267
 268 static int is_date(int year, int month, int day, struct tm *now_tm, time_t now, struct tm *tm)
 269 {
 270         if (month > 0 && month < 13 && day > 0 && day < 32) {
 271                 struct tm check = *tm;
 272                 struct tm *r = (now_tm ? &check : tm);
 273                 time_t specified;
 274
 275                 r->tm_mon = month - 1;
 276                 r->tm_mday = day;
 277                 if (year == -1) {
 278                         if (!now_tm)
 279                                 return 1;
 280                         r->tm_year = now_tm->tm_year;
 281                 }
 282                 else if (year >= 1970 && year < 2100)
 283                         r->tm_year = year - 1900;
 284                 else if (year > 70 && year < 100)
 285                         r->tm_year = year;
 286                 else if (year < 38)
 287                         r->tm_year = year + 100;
 288                 else
 289                         return 0;
 290                 if (!now_tm)
 291                         return 1;
 292
 293                 specified = my_mktime(r);
 294
 295                 /* Be it commit time or author time, it does not make
 296                  * sense to specify timestamp way into the future.  Make
 297                  * sure it is not later than ten days from now...
 298                  */
 299                 if (now + 10*24*3600 < specified)
 300                         return 0;
 301                 tm->tm_mon = r->tm_mon;
 302                 tm->tm_mday = r->tm_mday;
 303                 if (year != -1)
 304                         tm->tm_year = r->tm_year;
 305                 return 1;
 306         }
 307         return 0;
 308 }
 309
 310 static int match_multi_number(unsigned long num, char c, const char *date, char *end, struct tm *tm)
 311 {
 312         time_t now;
 313         struct tm now_tm;
 314         struct tm *refuse_future;
 315         long num2, num3;
 316
 317         num2 = strtol(end+1, &end, 10);
 318         num3 = -1;
 319         if (*end == c && isdigit(end[1]))
 320                 num3 = strtol(end+1, &end, 10);
 321
 322         /* Time? Date? */
 323         switch (c) {
 324         case ':':
 325                 if (num3 < 0)
 326                         num3 = 0;
 327                 if (num < 25 && num2 >= 0 && num2 < 60 && num3 >= 0 && num3 <= 60) {
 328                         tm->tm_hour = num;
 329                         tm->tm_min = num2;
 330                         tm->tm_sec = num3;
 331                         break;
 332                 }
 333                 return 0;
 334
 335         case '-':
 336         case '/':
 337         case '.':
 338                 now = time(NULL);
 339                 refuse_future = NULL;
 340                 if (gmtime_r(&now, &now_tm))
 341                         refuse_future = &now_tm;
 342
 343                 if (num > 70) {
 344                         /* yyyy-mm-dd? */
 345                         if (is_date(num, num2, num3, refuse_future, now, tm))
 346                                 break;
 347                         /* yyyy-dd-mm? */
 348                         if (is_date(num, num3, num2, refuse_future, now, tm))
 349                                 break;
 350                 }
 351                 /* Our eastern European friends say dd.mm.yy[yy]
 352                  * is the norm there, so giving precedence to
 353                  * mm/dd/yy[yy] form only when separator is not '.'
 354                  */
 355                 if (c != '.' &&
 356                     is_date(num3, num, num2, refuse_future, now, tm))
 357                         break;
 358                 /* European dd.mm.yy[yy] or funny US dd/mm/yy[yy] */
 359                 if (is_date(num3, num2, num, refuse_future, now, tm))
 360                         break;
 361                 /* Funny European mm.dd.yy */
 362                 if (c == '.' &&
 363                     is_date(num3, num, num2, refuse_future, now, tm))
 364                         break;
 365                 return 0;
 366         }
 367         return end - date;
 368 }
 369
 370 /*
 371  * We've seen a digit. Time? Year? Date?
 372  */
 373 static int match_digit(const char *date, struct tm *tm, int *offset, int *tm_gmt)
 374 {
 375         int n;
 376         char *end;
 377         unsigned long num;
 378
 379         num = strtoul(date, &end, 10);
 380
 381         /*
 382          * Seconds since 1970? We trigger on that for anything after Jan 1, 2000
 383          */
 384         if (num > 946684800) {
 385                 time_t time = num;
 386                 if (gmtime_r(&time, tm)) {
 387                         *tm_gmt = 1;
 388                         return end - date;
 389                 }
 390         }
 391
 392         /*
 393          * Check for special formats: num[-.:/]num[same]num
 394          */
 395         switch (*end) {
 396         case ':':
 397         case '.':
 398         case '/':
 399         case '-':
 400                 if (isdigit(end[1])) {
 401                         int match = match_multi_number(num, *end, date, end, tm);
 402                         if (match)
 403                                 return match;
 404                 }
 405         }
 406
 407         /*
 408          * None of the special formats? Try to guess what
 409          * the number meant. We use the number of digits
 410          * to make a more educated guess..
 411          */
 412         n = 0;
 413         do {
 414                 n++;
 415         } while (isdigit(date[n]));
 416
 417         /* Four-digit year or a timezone? */
 418         if (n == 4) {
 419                 if (num <= 1400 && *offset == -1) {
 420                         unsigned int minutes = num % 100;
 421                         unsigned int hours = num / 100;
 422                         *offset = hours*60 + minutes;
 423                 } else if (num > 1900 && num < 2100)
 424                         tm->tm_year = num - 1900;
 425                 return n;
 426         }
 427
 428         /*
 429          * NOTE! We will give precedence to day-of-month over month or
 430          * year numbers in the 1-12 range. So 05 is always "mday 5",
 431          * unless we already have a mday..
 432          *
 433          * IOW, 01 Apr 05 parses as "April 1st, 2005".
 434          */
 435         if (num > 0 && num < 32 && tm->tm_mday < 0) {
 436                 tm->tm_mday = num;
 437                 return n;
 438         }
 439
 440         /* Two-digit year? */
 441         if (n == 2 && tm->tm_year < 0) {
 442                 if (num < 10 && tm->tm_mday >= 0) {
 443                         tm->tm_year = num + 100;
 444                         return n;
 445                 }
 446                 if (num >= 70) {
 447                         tm->tm_year = num;
 448                         return n;
 449                 }
 450         }
 451
 452         if (num > 0 && num < 32) {
 453                 tm->tm_mday = num;
 454         } else if (num > 1900) {
 455                 tm->tm_year = num - 1900;
 456         } else if (num > 70) {
 457                 tm->tm_year = num;
 458         } else if (num > 0 && num < 13) {
 459                 tm->tm_mon = num-1;
 460         }
 461
 462         return n;
 463 }
 464
 465 static int match_tz(const char *date, int *offp)
 466 {
 467         char *end;
 468         int offset = strtoul(date+1, &end, 10);
 469         int min, hour;
 470         int n = end - date - 1;
 471
 472         min = offset % 100;
 473         hour = offset / 100;
 474
 475         /*
 476          * Don't accept any random crap.. At least 3 digits, and
 477          * a valid minute. We might want to check that the minutes
 478          * are divisible by 30 or something too.
 479          */
 480         if (min < 60 && n > 2) {
 481                 offset = hour*60+min;
 482                 if (*date == '-')
 483                         offset = -offset;
 484
 485                 *offp = offset;
 486         }
 487         return end - date;
 488 }
 489
 490 static int date_string(unsigned long date, int offset, char *buf, int len)
 491 {
 492         int sign = '+';
 493
 494         if (offset < 0) {
 495                 offset = -offset;
 496                 sign = '-';
 497         }
 498         return snprintf(buf, len, "%lu %c%02d%02d", date, sign, offset / 60, offset % 60);
 499 }
 500
 501 /* Gr. strptime is crap for this; it doesn't have a way to require RFC2822
 502    (i.e. English) day/month names, and it doesn't work correctly with %z. */
 503 int parse_date(const char *date, char *result, int maxlen)
 504 {
 505         struct tm tm;
 506         int offset, tm_gmt;
 507         time_t then;
 508
 509         memset(&tm, 0, sizeof(tm));
 510         tm.tm_year = -1;
 511         tm.tm_mon = -1;
 512         tm.tm_mday = -1;
 513         tm.tm_isdst = -1;
 514         offset = -1;
 515         tm_gmt = 0;
 516
 517         for (;;) {
 518                 int match = 0;
 519                 unsigned char c = *date;
 520
 521                 /* Stop at end of string or newline */
 522                 if (!c || c == '\n')
 523                         break;
 524
 525                 if (isalpha(c))
 526                         match = match_alpha(date, &tm, &offset);
 527                 else if (isdigit(c))
 528                         match = match_digit(date, &tm, &offset, &tm_gmt);
 529                 else if ((c == '-' || c == '+') && isdigit(date[1]))
 530                         match = match_tz(date, &offset);
 531
 532                 if (!match) {
 533                         /* BAD CRAP */
 534                         match = 1;
 535                 }
 536
 537                 date += match;
 538         }
 539
 540         /* mktime uses local timezone */
 541         then = my_mktime(&tm);
 542         if (offset == -1)
 543                 offset = (then - mktime(&tm)) / 60;
 544
 545         if (then == -1)
 546                 return -1;
 547
 548         if (!tm_gmt)
 549                 then -= offset * 60;
 550         return date_string(then, offset, result, maxlen);
 551 }
 552
 553 void datestamp(char *buf, int bufsize)
 554 {
 555         time_t now;
 556         int offset;
 557
 558         time(&now);
 559
 560         offset = my_mktime(localtime(&now)) - now;
 561         offset /= 60;
 562
 563         date_string(now, offset, buf, bufsize);
 564 }
 565
 566 static void update_tm(struct tm *tm, unsigned long sec)
 567 {
 568         time_t n = mktime(tm) - sec;
 569         localtime_r(&n, tm);
 570 }
 571
 572 static void date_yesterday(struct tm *tm, int *num)
 573 {
 574         update_tm(tm, 24*60*60);
 575 }
 576
 577 static void date_time(struct tm *tm, int hour)
 578 {
 579         if (tm->tm_hour < hour)
 580                 date_yesterday(tm, NULL);
 581         tm->tm_hour = hour;
 582         tm->tm_min = 0;
 583         tm->tm_sec = 0;
 584 }
 585
 586 static void date_midnight(struct tm *tm, int *num)
 587 {
 588         date_time(tm, 0);
 589 }
 590
 591 static void date_noon(struct tm *tm, int *num)
 592 {
 593         date_time(tm, 12);
 594 }
 595
 596 static void date_tea(struct tm *tm, int *num)
 597 {
 598         date_time(tm, 17);
 599 }
 600
 601 static void date_pm(struct tm *tm, int *num)
 602 {
 603         int hour, n = *num;
 604         *num = 0;
 605
 606         hour = tm->tm_hour;
 607         if (n) {
 608                 hour = n;
 609                 tm->tm_min = 0;
 610                 tm->tm_sec = 0;
 611         }
 612         tm->tm_hour = (hour % 12) + 12;
 613 }
 614
 615 static void date_am(struct tm *tm, int *num)
 616 {
 617         int hour, n = *num;
 618         *num = 0;
 619
 620         hour = tm->tm_hour;
 621         if (n) {
 622                 hour = n;
 623                 tm->tm_min = 0;
 624                 tm->tm_sec = 0;
 625         }
 626         tm->tm_hour = (hour % 12);
 627 }
 628
 629 static const struct special {
 630         const char *name;
 631         void (*fn)(struct tm *, int *);
 632 } special[] = {
 633         { "yesterday", date_yesterday },
 634         { "noon", date_noon },
 635         { "midnight", date_midnight },
 636         { "tea", date_tea },
 637         { "PM", date_pm },
 638         { "AM", date_am },
 639         { NULL }
 640 };
 641
 642 static const char *number_name[] = {
 643         "zero", "one", "two", "three", "four",
 644         "five", "six", "seven", "eight", "nine", "ten",
 645 };
 646
 647 static const struct typelen {
 648         const char *type;
 649         int length;
 650 } typelen[] = {
 651         { "seconds", 1 },
 652         { "minutes", 60 },
 653         { "hours", 60*60 },
 654         { "days", 24*60*60 },
 655         { "weeks", 7*24*60*60 },
 656         { NULL }
 657 };
 658
 659 static const char *approxidate_alpha(const char *date, struct tm *tm, int *num)
 660 {
 661         const struct typelen *tl;
 662         const struct special *s;
 663         const char *end = date;
 664         int i;
 665
 666         while (isalpha(*++end));
 667                 ;
 668
 669         for (i = 0; i < 12; i++) {
 670                 int match = match_string(date, month_names[i]);
 671                 if (match >= 3) {
 672                         tm->tm_mon = i;
 673                         return end;
 674                 }
 675         }
 676
 677         for (s = special; s->name; s++) {
 678                 int len = strlen(s->name);
 679                 if (match_string(date, s->name) == len) {
 680                         s->fn(tm, num);
 681                         return end;
 682                 }
 683         }
 684
 685         if (!*num) {
 686                 for (i = 1; i < 11; i++) {
 687                         int len = strlen(number_name[i]);
 688                         if (match_string(date, number_name[i]) == len) {
 689                                 *num = i;
 690                                 return end;
 691                         }
 692                 }
 693                 if (match_string(date, "last") == 4)
 694                         *num = 1;
 695                 return end;
 696         }
 697
 698         tl = typelen;
 699         while (tl->type) {
 700                 int len = strlen(tl->type);
 701                 if (match_string(date, tl->type) >= len-1) {
 702                         update_tm(tm, tl->length * *num);
 703                         *num = 0;
 704                         return end;
 705                 }
 706                 tl++;
 707         }
 708
 709         for (i = 0; i < 7; i++) {
 710                 int match = match_string(date, weekday_names[i]);
 711                 if (match >= 3) {
 712                         int diff, n = *num -1;
 713                         *num = 0;
 714
 715                         diff = tm->tm_wday - i;
 716                         if (diff <= 0)
 717                                 n++;
 718                         diff += 7*n;
 719
 720                         update_tm(tm, diff * 24 * 60 * 60);
 721                         return end;
 722                 }
 723         }
 724
 725         if (match_string(date, "months") >= 5) {
 726                 int n = tm->tm_mon - *num;
 727                 *num = 0;
 728                 while (n < 0) {
 729                         n += 12;
 730                         tm->tm_year--;
 731                 }
 732                 tm->tm_mon = n;
 733                 return end;
 734         }
 735
 736         if (match_string(date, "years") >= 4) {
 737                 tm->tm_year -= *num;
 738                 *num = 0;
 739                 return end;
 740         }
 741
 742         return end;
 743 }
 744
 745 static const char *approxidate_digit(const char *date, struct tm *tm, int *num)
 746 {
 747         char *end;
 748         unsigned long number = strtoul(date, &end, 10);
 749
 750         switch (*end) {
 751         case ':':
 752         case '.':
 753         case '/':
 754         case '-':
 755                 if (isdigit(end[1])) {
 756                         int match = match_multi_number(number, *end, date, end, tm);
 757                         if (match)
 758                                 return date + match;
 759                 }
 760         }
 761
 762         *num = number;
 763         return end;
 764 }
 765
 766 unsigned long approxidate(const char *date)
 767 {
 768         int number = 0;
 769         struct tm tm, now;
 770         struct timeval tv;
 771         char buffer[50];
 772
 773         if (parse_date(date, buffer, sizeof(buffer)) > 0)
 774                 return strtoul(buffer, NULL, 10);
 775
 776         gettimeofday(&tv, NULL);
 777         localtime_r(&tv.tv_sec, &tm);
 778         now = tm;
 779         for (;;) {
 780                 unsigned char c = *date;
 781                 if (!c)
 782                         break;
 783                 date++;
 784                 if (isdigit(c)) {
 785                         date = approxidate_digit(date-1, &tm, &number);
 786                         continue;
 787                 }
 788                 if (isalpha(c))
 789                         date = approxidate_alpha(date-1, &tm, &number);
 790         }
 791         if (number > 0 && number < 32)
 792                 tm.tm_mday = number;
 793         if (tm.tm_mon > now.tm_mon && tm.tm_year == now.tm_year)
 794                 tm.tm_year--;
 795         return mktime(&tm);
 796 }