exp_strf.c

   1 /* exp_strp.c - functions for exp_timestamp */
   2 /*
   3  * strftime.c
   4  *
   5  * Public-domain implementation of ANSI C library routine.
   6  *
   7  * It's written in old-style C for maximal portability.
   8  * However, since I'm used to prototypes, I've included them too.
   9  *
  10  * If you want stuff in the System V ascftime routine, add the SYSV_EXT define.
  11  * For extensions from SunOS, add SUNOS_EXT.
  12  * For stuff needed to implement the P1003.2 date command, add POSIX2_DATE.
  13  * For VMS dates, add VMS_EXT.
  14  * For complete POSIX semantics, add POSIX_SEMANTICS.
  15  *
  16  * The code for %c, %x, and %X now follows the 1003.2 specification for
  17  * the POSIX locale.
  18  * This version ignores LOCALE information.
  19  * It also doesn't worry about multi-byte characters.
  20  * So there.
  21  *
  22  * This file is also shipped with GAWK (GNU Awk), gawk specific bits of
  23  * code are included if GAWK is defined.
  24  *
  25  * Arnold Robbins <arnold@skeeve.atl.ga.us>
  26  * January, February, March, 1991
  27  * Updated March, April 1992
  28  * Updated April, 1993
  29  * Updated February, 1994
  30  * Updated May, 1994
  31  * Updated January 1995
  32  * Updated September 1995
  33  *
  34  * Fixes from ado@elsie.nci.nih.gov
  35  * February 1991, May 1992
  36  * Fixes from Tor Lillqvist tml@tik.vtt.fi
  37  * May, 1993
  38  * Further fixes from ado@elsie.nci.nih.gov
  39  * February 1994
  40  * %z code from chip@chinacat.unicom.com
  41  * Applied September 1995
  42  *
  43  *
  44  * Modified by Don Libes for Expect, 10/93 and 12/95.
  45  * Forced POSIX semantics.
  46  * Replaced inline/min/max stuff with a single range function.
  47  * Removed tzset stuff.
  48  * Commented out tzname stuff.
  49  *
  50  * According to Arnold, the current version of this code can ftp'd from
  51  * ftp.mathcs.emory.edu:/pub/arnold/strftime.shar.gz
  52  *
  53  */
  54
  55 #include "expect_cf.h"
  56 #include "tcl.h"
  57
  58 #include <stdio.h>
  59 #include <ctype.h>
  60 #include "string.h"
  61
  62 /* according to Karl Vogel, time.h is insufficient on Pyramid */
  63 /* following is recommended by autoconf */
  64
  65 #ifdef TIME_WITH_SYS_TIME
  66 # include <sys/time.h>
  67 # include <time.h>
  68 #else
  69 # ifdef HAVE_SYS_TIME_H
  70 #  include <sys/time.h>
  71 # else
  72 #  include <time.h>
  73 # endif
  74 #endif
  75
  76
  77
  78 #include <sys/types.h>
  79
  80 #define SYSV_EXT        1       /* stuff in System V ascftime routine */
  81 #define POSIX2_DATE     1       /* stuff in Posix 1003.2 date command */
  82
  83 #if defined(POSIX2_DATE) && ! defined(SYSV_EXT)
  84 #define SYSV_EXT        1
  85 #endif
  86
  87 #if defined(POSIX2_DATE)
  88 #define adddecl(stuff)  stuff
  89 #else
  90 #define adddecl(stuff)
  91 #endif
  92
  93 #ifndef __STDC__
  94 #define const
  95
  96 extern char *getenv();
  97 static int weeknumber();
  98 adddecl(static int iso8601wknum();)
  99 #else
 100
 101 #ifndef strchr
 102 extern char *strchr(const char *str, int ch);
 103 #endif
 104
 105 extern char *getenv(const char *v);
 106
 107 static int weeknumber(const struct tm *timeptr, int firstweekday);
 108 adddecl(static int iso8601wknum(const struct tm *timeptr);)
 109 #endif
 110
 111 /* attempt to use strftime to compute timezone, else fallback to */
 112 /* less portable ways */
 113 #if !defined(HAVE_STRFTIME)
 114 # if defined(HAVE_SV_TIMEZONE)
 115 extern char *tzname[2];
 116 extern int daylight;
 117 # else
 118 #  if defined(HAVE_TIMEZONE)
 119
 120 char           *
 121 zone_name (tp)
 122 struct tm      *tp;
 123 {
 124         char           *timezone ();
 125         struct timeval  tv;
 126         struct timezone tz;
 127
 128         gettimeofday (&tv, &tz);
 129
 130         return timezone (tz.tz_minuteswest, tp->tm_isdst);
 131 }
 132
 133 #  endif /* HAVE_TIMEZONE */
 134 # endif /* HAVE_SV_TIMEZONE */
 135 #endif /* HAVE_STRFTIME */
 136
 137 static int
 138 range(low,item,hi)
 139 int low, item, hi;
 140 {
 141         if (item < low) return low;
 142         if (item > hi) return hi;
 143         return item;
 144 }
 145
 146 /* strftime --- produce formatted time */
 147
 148 void
 149 /*size_t*/
 150 #ifndef __STDC__
 151 exp_strftime(/*s,*/ format, timeptr, dstring)
 152 /*char *s;*/
 153 char *format;
 154 const struct tm *timeptr;
 155 Tcl_DString *dstring;
 156 #else
 157 /*exp_strftime(char *s, size_t maxsize, const char *format, const struct tm *timeptr)*/
 158 exp_strftime(char *format, const struct tm *timeptr,Tcl_DString *dstring)
 159 #endif
 160 {
 161         int copied;     /* used to suppress copying when called recursively */
 162
 163 #if 0
 164         char *endp = s + maxsize;
 165         char *start = s;
 166 #endif
 167         char *percentptr;
 168
 169         char tbuf[100];
 170         int i;
 171
 172         /* various tables, useful in North America */
 173         static char *days_a[] = {
 174                 "Sun", "Mon", "Tue", "Wed",
 175                 "Thu", "Fri", "Sat",
 176         };
 177         static char *days_l[] = {
 178                 "Sunday", "Monday", "Tuesday", "Wednesday",
 179                 "Thursday", "Friday", "Saturday",
 180         };
 181         static char *months_a[] = {
 182                 "Jan", "Feb", "Mar", "Apr", "May", "Jun",
 183                 "Jul", "Aug", "Sep", "Oct", "Nov", "Dec",
 184         };
 185         static char *months_l[] = {
 186                 "January", "February", "March", "April",
 187                 "May", "June", "July", "August", "September",
 188                 "October", "November", "December",
 189         };
 190         static char *ampm[] = { "AM", "PM", };
 191
 192 /*      for (; *format && s < endp - 1; format++) {*/
 193         for (; *format ; format++) {
 194                 tbuf[0] = '\0';
 195                 copied = 0;             /* has not been copied yet */
 196                 percentptr = strchr(format,'%');
 197                 if (percentptr == 0) {
 198                         Tcl_DStringAppend(dstring,format,-1);
 199                         goto out;
 200                 } else if (percentptr != format) {
 201                         Tcl_DStringAppend(dstring,format,percentptr - format);
 202                         format = percentptr;
 203                 }
 204 #if 0
 205                 if (*format != '%') {
 206                         *s++ = *format;
 207                         continue;
 208                 }
 209 #endif
 210         again:
 211                 switch (*++format) {
 212                 case '\0':
 213                         Tcl_DStringAppend(dstring,"%",1);
 214 #if 0
 215                         *s++ = '%';
 216 #endif
 217                         goto out;
 218
 219                 case '%':
 220                         Tcl_DStringAppend(dstring,"%",1);
 221                         copied = 1;
 222                         break;
 223 #if 0
 224                         *s++ = '%';
 225                         continue;
 226 #endif
 227
 228                 case 'a':       /* abbreviated weekday name */
 229                         if (timeptr->tm_wday < 0 || timeptr->tm_wday > 6)
 230                                 strcpy(tbuf, "?");
 231                         else
 232                                 strcpy(tbuf, days_a[timeptr->tm_wday]);
 233                         break;
 234
 235                 case 'A':       /* full weekday name */
 236                         if (timeptr->tm_wday < 0 || timeptr->tm_wday > 6)
 237                                 strcpy(tbuf, "?");
 238                         else
 239                                 strcpy(tbuf, days_l[timeptr->tm_wday]);
 240                         break;
 241
 242 #ifdef SYSV_EXT
 243                 case 'h':       /* abbreviated month name */
 244 #endif
 245                 case 'b':       /* abbreviated month name */
 246                         if (timeptr->tm_mon < 0 || timeptr->tm_mon > 11)
 247                                 strcpy(tbuf, "?");
 248                         else
 249                                 strcpy(tbuf, months_a[timeptr->tm_mon]);
 250                         break;
 251
 252                 case 'B':       /* full month name */
 253                         if (timeptr->tm_mon < 0 || timeptr->tm_mon > 11)
 254                                 strcpy(tbuf, "?");
 255                         else
 256                                 strcpy(tbuf, months_l[timeptr->tm_mon]);
 257                         break;
 258
 259                 case 'c':       /* appropriate date and time representation */
 260                         sprintf(tbuf, "%s %s %2d %02d:%02d:%02d %d",
 261                                 days_a[range(0, timeptr->tm_wday, 6)],
 262                                 months_a[range(0, timeptr->tm_mon, 11)],
 263                                 range(1, timeptr->tm_mday, 31),
 264                                 range(0, timeptr->tm_hour, 23),
 265                                 range(0, timeptr->tm_min, 59),
 266                                 range(0, timeptr->tm_sec, 61),
 267                                 timeptr->tm_year + 1900);
 268                         break;
 269
 270                 case 'd':       /* day of the month, 01 - 31 */
 271                         i = range(1, timeptr->tm_mday, 31);
 272                         sprintf(tbuf, "%02d", i);
 273                         break;
 274
 275                 case 'H':       /* hour, 24-hour clock, 00 - 23 */
 276                         i = range(0, timeptr->tm_hour, 23);
 277                         sprintf(tbuf, "%02d", i);
 278                         break;
 279
 280                 case 'I':       /* hour, 12-hour clock, 01 - 12 */
 281                         i = range(0, timeptr->tm_hour, 23);
 282                         if (i == 0)
 283                                 i = 12;
 284                         else if (i > 12)
 285                                 i -= 12;
 286                         sprintf(tbuf, "%02d", i);
 287                         break;
 288
 289                 case 'j':       /* day of the year, 001 - 366 */
 290                         sprintf(tbuf, "%03d", timeptr->tm_yday + 1);
 291                         break;
 292
 293                 case 'm':       /* month, 01 - 12 */
 294                         i = range(0, timeptr->tm_mon, 11);
 295                         sprintf(tbuf, "%02d", i + 1);
 296                         break;
 297
 298                 case 'M':       /* minute, 00 - 59 */
 299                         i = range(0, timeptr->tm_min, 59);
 300                         sprintf(tbuf, "%02d", i);
 301                         break;
 302
 303                 case 'p':       /* am or pm based on 12-hour clock */
 304                         i = range(0, timeptr->tm_hour, 23);
 305                         if (i < 12)
 306                                 strcpy(tbuf, ampm[0]);
 307                         else
 308                                 strcpy(tbuf, ampm[1]);
 309                         break;
 310
 311                 case 'S':       /* second, 00 - 61 */
 312                         i = range(0, timeptr->tm_sec, 61);
 313                         sprintf(tbuf, "%02d", i);
 314                         break;
 315
 316                 case 'U':       /* week of year, Sunday is first day of week */
 317                         sprintf(tbuf, "%02d", weeknumber(timeptr, 0));
 318                         break;
 319
 320                 case 'w':       /* weekday, Sunday == 0, 0 - 6 */
 321                         i = range(0, timeptr->tm_wday, 6);
 322                         sprintf(tbuf, "%d", i);
 323                         break;
 324
 325                 case 'W':       /* week of year, Monday is first day of week */
 326                         sprintf(tbuf, "%02d", weeknumber(timeptr, 1));
 327                         break;
 328
 329                 case 'x':       /* appropriate date representation */
 330                         sprintf(tbuf, "%s %s %2d %d",
 331                                 days_a[range(0, timeptr->tm_wday, 6)],
 332                                 months_a[range(0, timeptr->tm_mon, 11)],
 333                                 range(1, timeptr->tm_mday, 31),
 334                                 timeptr->tm_year + 1900);
 335                         break;
 336
 337                 case 'X':       /* appropriate time representation */
 338                         sprintf(tbuf, "%02d:%02d:%02d",
 339                                 range(0, timeptr->tm_hour, 23),
 340                                 range(0, timeptr->tm_min, 59),
 341                                 range(0, timeptr->tm_sec, 61));
 342                         break;
 343
 344                 case 'y':       /* year without a century, 00 - 99 */
 345                         i = timeptr->tm_year % 100;
 346                         sprintf(tbuf, "%02d", i);
 347                         break;
 348
 349                 case 'Y':       /* year with century */
 350                         sprintf(tbuf, "%d", 1900 + timeptr->tm_year);
 351                         break;
 352
 353                 case 'Z':       /* time zone name or abbrevation */
 354 #if defined(HAVE_STRFTIME)
 355                         strftime(tbuf,sizeof tbuf,"%Z",timeptr);
 356 #else
 357 # if defined(HAVE_SV_TIMEZONE)
 358                         i = 0;
 359                         if (daylight && timeptr->tm_isdst)
 360                                 i = 1;
 361                         strcpy(tbuf, tzname[i]);
 362 # else
 363                         strcpy(tbuf, zone_name (timeptr));
 364 #  if defined(HAVE_TIMEZONE)
 365 #  endif /* HAVE_TIMEZONE */
 366                         /* no timezone available */
 367                         /* feel free to add others here */
 368 # endif /* HAVE_SV_TIMEZONE */
 369 #endif /* HAVE STRFTIME */
 370                         break;
 371
 372 #ifdef SYSV_EXT
 373                 case 'n':       /* same as \n */
 374                         tbuf[0] = '\n';
 375                         tbuf[1] = '\0';
 376                         break;
 377
 378                 case 't':       /* same as \t */
 379                         tbuf[0] = '\t';
 380                         tbuf[1] = '\0';
 381                         break;
 382
 383                 case 'D':       /* date as %m/%d/%y */
 384                         exp_strftime("%m/%d/%y", timeptr, dstring);
 385                         copied = 1;
 386 /*                      exp_strftime(tbuf, sizeof tbuf, "%m/%d/%y", timeptr);*/
 387                         break;
 388
 389                 case 'e':       /* day of month, blank padded */
 390                         sprintf(tbuf, "%2d", range(1, timeptr->tm_mday, 31));
 391                         break;
 392
 393                 case 'r':       /* time as %I:%M:%S %p */
 394                         exp_strftime("%I:%M:%S %p", timeptr, dstring);
 395                         copied = 1;
 396 /*                      exp_strftime(tbuf, sizeof tbuf, "%I:%M:%S %p", timeptr);*/
 397                         break;
 398
 399                 case 'R':       /* time as %H:%M */
 400                         exp_strftime("%H:%M", timeptr, dstring);
 401                         copied = 1;
 402 /*                      exp_strftime(tbuf, sizeof tbuf, "%H:%M", timeptr);*/
 403                         break;
 404
 405                 case 'T':       /* time as %H:%M:%S */
 406                         exp_strftime("%H:%M:%S", timeptr, dstring);
 407                         copied = 1;
 408 /*                      exp_strftime(tbuf, sizeof tbuf, "%H:%M:%S", timeptr);*/
 409                         break;
 410 #endif
 411
 412 #ifdef POSIX2_DATE
 413                 case 'C':
 414                         sprintf(tbuf, "%02d", (timeptr->tm_year + 1900) / 100);
 415                         break;
 416
 417
 418                 case 'E':
 419                 case 'O':
 420                         /* POSIX locale extensions, ignored for now */
 421                         goto again;
 422                 case 'V':       /* week of year according ISO 8601 */
 423                         sprintf(tbuf, "%02d", iso8601wknum(timeptr));
 424                         break;
 425
 426                 case 'u':
 427                 /* ISO 8601: Weekday as a decimal number [1 (Monday) - 7] */
 428                         sprintf(tbuf, "%d", timeptr->tm_wday == 0 ? 7 :
 429                                         timeptr->tm_wday);
 430                         break;
 431 #endif  /* POSIX2_DATE */
 432                 default:
 433                         tbuf[0] = '%';
 434                         tbuf[1] = *format;
 435                         tbuf[2] = '\0';
 436                         break;
 437                 }
 438                 if (!copied)
 439                         Tcl_DStringAppend(dstring,tbuf,-1);
 440 #if 0
 441                 i = strlen(tbuf);
 442                 if (i) {
 443                         if (s + i < endp - 1) {
 444                                 strcpy(s, tbuf);
 445                                 s += i;
 446                         } else
 447                                 return 0;
 448 #endif
 449         }
 450 out:;
 451 #if 0
 452         if (s < endp && *format == '\0') {
 453                 *s = '\0';
 454                 return (s - start);
 455         } else
 456                 return 0;
 457 #endif
 458 }
 459
 460 /* isleap --- is a year a leap year? */
 461
 462 #ifndef __STDC__
 463 static int
 464 isleap(year)
 465 int year;
 466 #else
 467 static int
 468 isleap(int year)
 469 #endif
 470 {
 471         return ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0);
 472 }
 473
 474 #ifdef POSIX2_DATE
 475 /* iso8601wknum --- compute week number according to ISO 8601 */
 476
 477 #ifndef __STDC__
 478 static int
 479 iso8601wknum(timeptr)
 480 const struct tm *timeptr;
 481 #else
 482 static int
 483 iso8601wknum(const struct tm *timeptr)
 484 #endif
 485 {
 486         /*
 487          * From 1003.2:
 488          *      If the week (Monday to Sunday) containing January 1
 489          *      has four or more days in the new year, then it is week 1;
 490          *      otherwise it is the highest numbered week of the previous
 491          *      (52 or 53) year, and the next week is week 1.
 492          *
 493          * ADR: This means if Jan 1 was Monday through Thursday,
 494          *      it was week 1, otherwise week 53.
 495          *
 496          * XPG4 erroneously included POSIX.2 rationale text in the
 497          * main body of the standard. Thus it requires week 53.
 498          */
 499
 500         int weeknum, jan1day;
 501
 502         /* get week number, Monday as first day of the week */
 503         weeknum = weeknumber(timeptr, 1);
 504
 505         /*
 506          * With thanks and tip of the hatlo to tml@tik.vtt.fi
 507          *
 508          * What day of the week does January 1 fall on?
 509          * We know that
 510          *      (timeptr->tm_yday - jan1.tm_yday) MOD 7 ==
 511          *              (timeptr->tm_wday - jan1.tm_wday) MOD 7
 512          * and that
 513          *      jan1.tm_yday == 0
 514          * and that
 515          *      timeptr->tm_wday MOD 7 == timeptr->tm_wday
 516          * from which it follows that. . .
 517          */
 518         jan1day = timeptr->tm_wday - (timeptr->tm_yday % 7);
 519         if (jan1day < 0)
 520                 jan1day += 7;
 521
 522         /*
 523          * If Jan 1 was a Monday through Thursday, it was in
 524          * week 1.  Otherwise it was last year's highest week, which is
 525          * this year's week 0.
 526          *
 527          * What does that mean?
 528          * If Jan 1 was Monday, the week number is exactly right, it can
 529          *      never be 0.
 530          * If it was Tuesday through Thursday, the weeknumber is one
 531          *      less than it should be, so we add one.
 532          * Otherwise, Friday, Saturday or Sunday, the week number is
 533          * OK, but if it is 0, it needs to be 52 or 53.
 534          */
 535         switch (jan1day) {
 536         case 1:         /* Monday */
 537                 break;
 538         case 2:         /* Tuesday */
 539         case 3:         /* Wednesday */
 540         case 4:         /* Thursday */
 541                 weeknum++;
 542                 break;
 543         case 5:         /* Friday */
 544         case 6:         /* Saturday */
 545         case 0:         /* Sunday */
 546                 if (weeknum == 0) {
 547 #ifdef USE_BROKEN_XPG4
 548                         /* XPG4 (as of March 1994) says 53 unconditionally */
 549                         weeknum = 53;
 550 #else
 551                         /* get week number of last week of last year */
 552                         struct tm dec31ly;      /* 12/31 last year */
 553                         dec31ly = *timeptr;
 554                         dec31ly.tm_year--;
 555                         dec31ly.tm_mon = 11;
 556                         dec31ly.tm_mday = 31;
 557                         dec31ly.tm_wday = (jan1day == 0) ? 6 : jan1day - 1;
 558                         dec31ly.tm_yday = 364 + isleap(dec31ly.tm_year + 1900);
 559                         weeknum = iso8601wknum(& dec31ly);
 560 #endif
 561                 }
 562                 break;
 563         }
 564
 565         if (timeptr->tm_mon == 11) {
 566                 /*
 567                  * The last week of the year
 568                  * can be in week 1 of next year.
 569                  * Sigh.
 570                  *
 571                  * This can only happen if
 572                  *      M   T  W
 573                  *      29  30 31
 574                  *      30  31
 575                  *      31
 576                  */
 577                 int wday, mday;
 578
 579                 wday = timeptr->tm_wday;
 580                 mday = timeptr->tm_mday;
 581                 if (   (wday == 1 && (mday >= 29 && mday <= 31))
 582                     || (wday == 2 && (mday == 30 || mday == 31))
 583                     || (wday == 3 &&  mday == 31))
 584                         weeknum = 1;
 585         }
 586
 587         return weeknum;
 588 }
 589 #endif
 590
 591 /* weeknumber --- figure how many weeks into the year */
 592
 593 /* With thanks and tip of the hatlo to ado@elsie.nci.nih.gov */
 594
 595 #ifndef __STDC__
 596 static int
 597 weeknumber(timeptr, firstweekday)
 598 const struct tm *timeptr;
 599 int firstweekday;
 600 #else
 601 static int
 602 weeknumber(const struct tm *timeptr, int firstweekday)
 603 #endif
 604 {
 605         int wday = timeptr->tm_wday;
 606         int ret;
 607
 608         if (firstweekday == 1) {
 609                 if (wday == 0)  /* sunday */
 610                         wday = 6;
 611                 else
 612                         wday--;
 613         }
 614         ret = ((timeptr->tm_yday + 7 - wday) / 7);
 615         if (ret < 0)
 616                 ret = 0;
 617         return ret;
 618 }