toolchain/gcc/newlib/libc/time/strptime.c

   1 /*
   2  * Copyright (c) 1999 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of KTH nor the names of its contributors may be
  18  *    used to endorse or promote products derived from this software without
  19  *    specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY KTH AND ITS CONTRIBUTORS ``AS IS'' AND ANY
  22  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  24  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL KTH OR ITS CONTRIBUTORS BE
  25  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  26  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  27  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  28  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  29  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  30  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  31  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */
  32
  33 #include <stddef.h>
  34 #include <stdio.h>
  35 #include <time.h>
  36
  37 static const char *abb_weekdays[] = {
  38     "Sun",
  39     "Mon",
  40     "Tue",
  41     "Wed",
  42     "Thu",
  43     "Fri",
  44     "Sat",
  45     NULL
  46 };
  47
  48 static const char *full_weekdays[] = {
  49     "Sunday",
  50     "Monday",
  51     "Tuesday",
  52     "Wednesday",
  53     "Thursday",
  54     "Friday",
  55     "Saturday",
  56     NULL
  57 };
  58
  59 static const char *abb_month[] = {
  60     "Jan",
  61     "Feb",
  62     "Mar",
  63     "Apr",
  64     "May",
  65     "Jun",
  66     "Jul",
  67     "Aug",
  68     "Sep",
  69     "Oct",
  70     "Nov",
  71     "Dec",
  72     NULL
  73 };
  74
  75 static const char *full_month[] = {
  76     "January",
  77     "February",
  78     "Mars",
  79     "April",
  80     "May",
  81     "June",
  82     "July",
  83     "August",
  84     "September",
  85     "October",
  86     "November",
  87     "December",
  88     NULL,
  89 };
  90
  91 static const char *ampm[] = {
  92     "am",
  93     "pm",
  94     NULL
  95 };
  96
  97 /*
  98  * tm_year is relative this year
  99  */
 100 const int tm_year_base = 1900;
 101
 102 /*
 103  * Return TRUE iff `year' was a leap year.
 104  * Needed for strptime.
 105  */
 106 static int
 107 is_leap_year (int year)
 108 {
 109     return (year % 4) == 0 && ((year % 100) != 0 || (year % 400) == 0);
 110 }
 111
 112 /* Needed for strptime. */
 113 static int
 114 match_string (const char **buf, const char **strs)
 115 {
 116     int i = 0;
 117
 118     for (i = 0; strs[i] != NULL; ++i) {
 119         int len = strlen (strs[i]);
 120
 121         if (strncasecmp (*buf, strs[i], len) == 0) {
 122             *buf += len;
 123             return i;
 124         }
 125     }
 126     return -1;
 127 }
 128
 129 /* Needed for strptime. */
 130 static int
 131 first_day (int year)
 132 {
 133     int ret = 4;
 134
 135     for (; year > 1970; --year)
 136         ret = (ret + 365 + is_leap_year (year) ? 1 : 0) % 7;
 137     return ret;
 138 }
 139
 140 /*
 141  * Set `timeptr' given `wnum' (week number [0, 53])
 142  * Needed for strptime
 143  */
 144
 145 static void
 146 set_week_number_sun (struct tm *timeptr, int wnum)
 147 {
 148     int fday = first_day (timeptr->tm_year + tm_year_base);
 149
 150     timeptr->tm_yday = wnum * 7 + timeptr->tm_wday - fday;
 151     if (timeptr->tm_yday < 0) {
 152         timeptr->tm_wday = fday;
 153         timeptr->tm_yday = 0;
 154     }
 155 }
 156
 157 /*
 158  * Set `timeptr' given `wnum' (week number [0, 53])
 159  * Needed for strptime
 160  */
 161
 162 static void
 163 set_week_number_mon (struct tm *timeptr, int wnum)
 164 {
 165     int fday = (first_day (timeptr->tm_year + tm_year_base) + 6) % 7;
 166
 167     timeptr->tm_yday = wnum * 7 + (timeptr->tm_wday + 6) % 7 - fday;
 168     if (timeptr->tm_yday < 0) {
 169         timeptr->tm_wday = (fday + 1) % 7;
 170         timeptr->tm_yday = 0;
 171     }
 172 }
 173
 174 /*
 175  * Set `timeptr' given `wnum' (week number [0, 53])
 176  * Needed for strptime
 177  */
 178 static void
 179 set_week_number_mon4 (struct tm *timeptr, int wnum)
 180 {
 181     int fday = (first_day (timeptr->tm_year + tm_year_base) + 6) % 7;
 182     int offset = 0;
 183
 184     if (fday < 4)
 185         offset += 7;
 186
 187     timeptr->tm_yday = offset + (wnum - 1) * 7 + timeptr->tm_wday - fday;
 188     if (timeptr->tm_yday < 0) {
 189         timeptr->tm_wday = fday;
 190         timeptr->tm_yday = 0;
 191     }
 192 }
 193
 194 /* strptime: roken */
 195 //extern "C"
 196 char *
 197 //strptime (const char *buf, const char *format, struct tm *timeptr)
 198 _DEFUN (strptime, (buf, format, timeptr),
 199         _CONST char *buf _AND
 200         _CONST char *format _AND
 201         struct tm *timeptr)
 202 {
 203     char c;
 204
 205     for (; (c = *format) != '\0'; ++format) {
 206         char *s;
 207         int ret;
 208
 209         if (isspace (c)) {
 210             while (isspace (*buf))
 211                 ++buf;
 212         } else if (c == '%' && format[1] != '\0') {
 213             c = *++format;
 214             if (c == 'E' || c == 'O')
 215                 c = *++format;
 216             switch (c) {
 217             case 'A' :
 218                 ret = match_string (&buf, full_weekdays);
 219                 if (ret < 0)
 220                     return NULL;
 221                 timeptr->tm_wday = ret;
 222                 break;
 223             case 'a' :
 224                 ret = match_string (&buf, abb_weekdays);
 225                 if (ret < 0)
 226                     return NULL;
 227                 timeptr->tm_wday = ret;
 228                 break;
 229             case 'B' :
 230                 ret = match_string (&buf, full_month);
 231                 if (ret < 0)
 232                     return NULL;
 233                 timeptr->tm_mon = ret;
 234                 break;
 235             case 'b' :
 236             case 'h' :
 237                 ret = match_string (&buf, abb_month);
 238                 if (ret < 0)
 239                     return NULL;
 240                 timeptr->tm_mon = ret;
 241                 break;
 242             case 'C' :
 243                 ret = strtol (buf, &s, 10);
 244                 if (s == buf)
 245                     return NULL;
 246                 timeptr->tm_year = (ret * 100) - tm_year_base;
 247                 buf = s;
 248                 break;
 249             case 'c' :
 250                 abort ();
 251             case 'D' :          /* %m/%d/%y */
 252                 s = strptime (buf, "%m/%d/%y", timeptr);
 253                 if (s == NULL)
 254                     return NULL;
 255                 buf = s;
 256                 break;
 257             case 'd' :
 258             case 'e' :
 259                 ret = strtol (buf, &s, 10);
 260                 if (s == buf)
 261                     return NULL;
 262                 timeptr->tm_mday = ret;
 263                 buf = s;
 264                 break;
 265             case 'H' :
 266             case 'k' :
 267                 ret = strtol (buf, &s, 10);
 268                 if (s == buf)
 269                     return NULL;
 270                 timeptr->tm_hour = ret;
 271                 buf = s;
 272                 break;
 273             case 'I' :
 274             case 'l' :
 275                 ret = strtol (buf, &s, 10);
 276                 if (s == buf)
 277                     return NULL;
 278                 if (ret == 12)
 279                     timeptr->tm_hour = 0;
 280                 else
 281                     timeptr->tm_hour = ret;
 282                 buf = s;
 283                 break;
 284             case 'j' :
 285                 ret = strtol (buf, &s, 10);
 286                 if (s == buf)
 287                     return NULL;
 288                 timeptr->tm_yday = ret - 1;
 289                 buf = s;
 290                 break;
 291             case 'm' :
 292                 ret = strtol (buf, &s, 10);
 293                 if (s == buf)
 294                     return NULL;
 295                 timeptr->tm_mon = ret - 1;
 296                 buf = s;
 297                 break;
 298             case 'M' :
 299                 ret = strtol (buf, &s, 10);
 300                 if (s == buf)
 301                     return NULL;
 302                 timeptr->tm_min = ret;
 303                 buf = s;
 304                 break;
 305             case 'n' :
 306                 if (*buf == '\n')
 307                     ++buf;
 308                 else
 309                     return NULL;
 310                 break;
 311             case 'p' :
 312                 ret = match_string (&buf, ampm);
 313                 if (ret < 0)
 314                     return NULL;
 315                 if (timeptr->tm_hour == 0) {
 316                     if (ret == 1)
 317                         timeptr->tm_hour = 12;
 318                 } else
 319                     timeptr->tm_hour += 12;
 320                 break;
 321             case 'r' :          /* %I:%M:%S %p */
 322                 s = strptime (buf, "%I:%M:%S %p", timeptr);
 323                 if (s == NULL)
 324                     return NULL;
 325                 buf = s;
 326                 break;
 327             case 'R' :          /* %H:%M */
 328                 s = strptime (buf, "%H:%M", timeptr);
 329                 if (s == NULL)
 330                     return NULL;
 331                 buf = s;
 332                 break;
 333             case 'S' :
 334                 ret = strtol (buf, &s, 10);
 335                 if (s == buf)
 336                     return NULL;
 337                 timeptr->tm_sec = ret;
 338                 buf = s;
 339                 break;
 340             case 't' :
 341                 if (*buf == '\t')
 342                     ++buf;
 343                 else
 344                     return NULL;
 345                 break;
 346             case 'T' :          /* %H:%M:%S */
 347             case 'X' :
 348                 s = strptime (buf, "%H:%M:%S", timeptr);
 349                 if (s == NULL)
 350                     return NULL;
 351                 buf = s;
 352                 break;
 353             case 'u' :
 354                 ret = strtol (buf, &s, 10);
 355                 if (s == buf)
 356                     return NULL;
 357                 timeptr->tm_wday = ret - 1;
 358                 buf = s;
 359                 break;
 360             case 'w' :
 361                 ret = strtol (buf, &s, 10);
 362                 if (s == buf)
 363                     return NULL;
 364                 timeptr->tm_wday = ret;
 365                 buf = s;
 366                 break;
 367             case 'U' :
 368                 ret = strtol (buf, &s, 10);
 369                 if (s == buf)
 370                     return NULL;
 371                 set_week_number_sun (timeptr, ret);
 372                 buf = s;
 373                 break;
 374             case 'V' :
 375                 ret = strtol (buf, &s, 10);
 376                 if (s == buf)
 377                     return NULL;
 378                 set_week_number_mon4 (timeptr, ret);
 379                 buf = s;
 380                 break;
 381             case 'W' :
 382                 ret = strtol (buf, &s, 10);
 383                 if (s == buf)
 384                     return NULL;
 385                 set_week_number_mon (timeptr, ret);
 386                 buf = s;
 387                 break;
 388             case 'x' :
 389                 s = strptime (buf, "%Y:%m:%d", timeptr);
 390                 if (s == NULL)
 391                     return NULL;
 392                 buf = s;
 393                 break;
 394             case 'y' :
 395                 ret = strtol (buf, &s, 10);
 396                 if (s == buf)
 397                     return NULL;
 398                 if (ret < 70)
 399                     timeptr->tm_year = 100 + ret;
 400                 else
 401                     timeptr->tm_year = ret;
 402                 buf = s;
 403                 break;
 404             case 'Y' :
 405                 ret = strtol (buf, &s, 10);
 406                 if (s == buf)
 407                     return NULL;
 408                 timeptr->tm_year = ret - tm_year_base;
 409                 buf = s;
 410                 break;
 411             case 'Z' :
 412                 abort ();
 413             case '\0' :
 414                 --format;
 415                 /* FALLTHROUGH */
 416             case '%' :
 417                 if (*buf == '%')
 418                     ++buf;
 419                 else
 420                     return NULL;
 421                 break;
 422             default :
 423                 if (*buf == '%' || *++buf == c)
 424                     ++buf;
 425                 else
 426                     return NULL;
 427                 break;
 428             }
 429         } else {
 430             if (*buf == c)
 431                 ++buf;
 432             else
 433                 return NULL;
 434         }
 435     }
 436     return (char *)buf;
 437 }
 438