strptime.c revision 1.28
1 /* $NetBSD: strptime.c,v 1.28 2008/04/28 20:23:01 martin Exp $ */ 2 3 /*- 4 * Copyright (c) 1997, 1998, 2005, 2008 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code was contributed to The NetBSD Foundation by Klaus Klein. 8 * Heavily optimised by David Laight 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 #if defined(LIBC_SCCS) && !defined(lint) 34 __RCSID("$NetBSD: strptime.c,v 1.28 2008/04/28 20:23:01 martin Exp $"); 35 #endif 36 37 #include "namespace.h" 38 #include <sys/localedef.h> 39 #include <ctype.h> 40 #include <locale.h> 41 #include <string.h> 42 #include <time.h> 43 #include <tzfile.h> 44 45 #ifdef __weak_alias 46 __weak_alias(strptime,_strptime) 47 #endif 48 49 #define _ctloc(x) (_CurrentTimeLocale->x) 50 51 /* 52 * We do not implement alternate representations. However, we always 53 * check whether a given modifier is allowed for a certain conversion. 54 */ 55 #define ALT_E 0x01 56 #define ALT_O 0x02 57 #define LEGAL_ALT(x) { if (alt_format & ~(x)) return NULL; } 58 59 static const char gmt[4] = { "GMT" }; 60 61 static const u_char *conv_num(const unsigned char *, int *, uint, uint); 62 static const u_char *find_string(const u_char *, int *, const char * const *, 63 const char * const *, int); 64 65 66 char * 67 strptime(const char *buf, const char *fmt, struct tm *tm) 68 { 69 unsigned char c; 70 const unsigned char *bp; 71 int alt_format, i, split_year = 0; 72 const char *new_fmt; 73 74 bp = (const u_char *)buf; 75 76 while (bp != NULL && (c = *fmt++) != '\0') { 77 /* Clear `alternate' modifier prior to new conversion. */ 78 alt_format = 0; 79 i = 0; 80 81 /* Eat up white-space. */ 82 if (isspace(c)) { 83 while (isspace(*bp)) 84 bp++; 85 continue; 86 } 87 88 if (c != '%') 89 goto literal; 90 91 92 again: switch (c = *fmt++) { 93 case '%': /* "%%" is converted to "%". */ 94 literal: 95 if (c != *bp++) 96 return NULL; 97 LEGAL_ALT(0); 98 continue; 99 100 /* 101 * "Alternative" modifiers. Just set the appropriate flag 102 * and start over again. 103 */ 104 case 'E': /* "%E?" alternative conversion modifier. */ 105 LEGAL_ALT(0); 106 alt_format |= ALT_E; 107 goto again; 108 109 case 'O': /* "%O?" alternative conversion modifier. */ 110 LEGAL_ALT(0); 111 alt_format |= ALT_O; 112 goto again; 113 114 /* 115 * "Complex" conversion rules, implemented through recursion. 116 */ 117 case 'c': /* Date and time, using the locale's format. */ 118 new_fmt = _ctloc(d_t_fmt); 119 goto recurse; 120 121 case 'D': /* The date as "%m/%d/%y". */ 122 new_fmt = "%m/%d/%y"; 123 LEGAL_ALT(0); 124 goto recurse; 125 126 case 'F': /* The date as "%Y-%m-%d". */ 127 new_fmt = "%Y-%m-%d"; 128 LEGAL_ALT(0); 129 goto recurse; 130 131 case 'R': /* The time as "%H:%M". */ 132 new_fmt = "%H:%M"; 133 LEGAL_ALT(0); 134 goto recurse; 135 136 case 'r': /* The time in 12-hour clock representation. */ 137 new_fmt =_ctloc(t_fmt_ampm); 138 LEGAL_ALT(0); 139 goto recurse; 140 141 case 'T': /* The time as "%H:%M:%S". */ 142 new_fmt = "%H:%M:%S"; 143 LEGAL_ALT(0); 144 goto recurse; 145 146 case 'X': /* The time, using the locale's format. */ 147 new_fmt =_ctloc(t_fmt); 148 goto recurse; 149 150 case 'x': /* The date, using the locale's format. */ 151 new_fmt =_ctloc(d_fmt); 152 recurse: 153 bp = (const u_char *)strptime((const char *)bp, 154 new_fmt, tm); 155 LEGAL_ALT(ALT_E); 156 continue; 157 158 /* 159 * "Elementary" conversion rules. 160 */ 161 case 'A': /* The day of week, using the locale's form. */ 162 case 'a': 163 bp = find_string(bp, &tm->tm_wday, _ctloc(day), 164 _ctloc(abday), 7); 165 LEGAL_ALT(0); 166 continue; 167 168 case 'B': /* The month, using the locale's form. */ 169 case 'b': 170 case 'h': 171 bp = find_string(bp, &tm->tm_mon, _ctloc(mon), 172 _ctloc(abmon), 12); 173 LEGAL_ALT(0); 174 continue; 175 176 case 'C': /* The century number. */ 177 i = 20; 178 bp = conv_num(bp, &i, 0, 99); 179 180 i = i * 100 - TM_YEAR_BASE; 181 if (split_year) 182 i += tm->tm_year % 100; 183 split_year = 1; 184 tm->tm_year = i; 185 LEGAL_ALT(ALT_E); 186 continue; 187 188 case 'd': /* The day of month. */ 189 case 'e': 190 bp = conv_num(bp, &tm->tm_mday, 1, 31); 191 LEGAL_ALT(ALT_O); 192 continue; 193 194 case 'k': /* The hour (24-hour clock representation). */ 195 LEGAL_ALT(0); 196 /* FALLTHROUGH */ 197 case 'H': 198 bp = conv_num(bp, &tm->tm_hour, 0, 23); 199 LEGAL_ALT(ALT_O); 200 continue; 201 202 case 'l': /* The hour (12-hour clock representation). */ 203 LEGAL_ALT(0); 204 /* FALLTHROUGH */ 205 case 'I': 206 bp = conv_num(bp, &tm->tm_hour, 1, 12); 207 if (tm->tm_hour == 12) 208 tm->tm_hour = 0; 209 LEGAL_ALT(ALT_O); 210 continue; 211 212 case 'j': /* The day of year. */ 213 i = 1; 214 bp = conv_num(bp, &i, 1, 366); 215 tm->tm_yday = i - 1; 216 LEGAL_ALT(0); 217 continue; 218 219 case 'M': /* The minute. */ 220 bp = conv_num(bp, &tm->tm_min, 0, 59); 221 LEGAL_ALT(ALT_O); 222 continue; 223 224 case 'm': /* The month. */ 225 i = 1; 226 bp = conv_num(bp, &i, 1, 12); 227 tm->tm_mon = i - 1; 228 LEGAL_ALT(ALT_O); 229 continue; 230 231 case 'p': /* The locale's equivalent of AM/PM. */ 232 bp = find_string(bp, &i, _ctloc(am_pm), NULL, 2); 233 if (tm->tm_hour > 11) 234 return NULL; 235 tm->tm_hour += i * 12; 236 LEGAL_ALT(0); 237 continue; 238 239 case 'S': /* The seconds. */ 240 bp = conv_num(bp, &tm->tm_sec, 0, 61); 241 LEGAL_ALT(ALT_O); 242 continue; 243 244 case 'U': /* The week of year, beginning on sunday. */ 245 case 'W': /* The week of year, beginning on monday. */ 246 /* 247 * XXX This is bogus, as we can not assume any valid 248 * information present in the tm structure at this 249 * point to calculate a real value, so just check the 250 * range for now. 251 */ 252 bp = conv_num(bp, &i, 0, 53); 253 LEGAL_ALT(ALT_O); 254 continue; 255 256 case 'w': /* The day of week, beginning on sunday. */ 257 bp = conv_num(bp, &tm->tm_wday, 0, 6); 258 LEGAL_ALT(ALT_O); 259 continue; 260 261 case 'Y': /* The year. */ 262 i = TM_YEAR_BASE; /* just for data sanity... */ 263 bp = conv_num(bp, &i, 0, 9999); 264 tm->tm_year = i - TM_YEAR_BASE; 265 LEGAL_ALT(ALT_E); 266 continue; 267 268 case 'y': /* The year within 100 years of the epoch. */ 269 /* LEGAL_ALT(ALT_E | ALT_O); */ 270 bp = conv_num(bp, &i, 0, 99); 271 272 if (split_year) 273 /* preserve century */ 274 i += (tm->tm_year / 100) * 100; 275 else { 276 split_year = 1; 277 if (i <= 68) 278 i = i + 2000 - TM_YEAR_BASE; 279 else 280 i = i + 1900 - TM_YEAR_BASE; 281 } 282 tm->tm_year = i; 283 continue; 284 285 case 'Z': 286 tzset(); 287 if (strncmp((const char *)bp, gmt, 3) == 0) { 288 tm->tm_isdst = 0; 289 #ifdef TM_GMTOFF 290 tm->TM_GMTOFF = 0; 291 #endif 292 #ifdef TM_ZONE 293 tm->TM_ZONE = gmt; 294 #endif 295 bp += 3; 296 } else { 297 const unsigned char *ep; 298 299 ep = find_string(bp, &i, 300 (const char * const *)tzname, 301 NULL, 2); 302 if (ep != NULL) { 303 tm->tm_isdst = i; 304 #ifdef TM_GMTOFF 305 tm->TM_GMTOFF = -(timezone); 306 #endif 307 #ifdef TM_ZONE 308 tm->TM_ZONE = tzname[i]; 309 #endif 310 } 311 bp = ep; 312 } 313 continue; 314 315 /* 316 * Miscellaneous conversions. 317 */ 318 case 'n': /* Any kind of white-space. */ 319 case 't': 320 while (isspace(*bp)) 321 bp++; 322 LEGAL_ALT(0); 323 continue; 324 325 326 default: /* Unknown/unsupported conversion. */ 327 return NULL; 328 } 329 } 330 331 return __UNCONST(bp); 332 } 333 334 335 static const u_char * 336 conv_num(const unsigned char *buf, int *dest, uint llim, uint ulim) 337 { 338 uint result = 0; 339 unsigned char ch; 340 341 /* The limit also determines the number of valid digits. */ 342 uint rulim = ulim; 343 344 ch = *buf; 345 if (ch < '0' || ch > '9') 346 return NULL; 347 348 do { 349 result *= 10; 350 result += ch - '0'; 351 rulim /= 10; 352 ch = *++buf; 353 } while ((result * 10 <= ulim) && rulim && ch >= '0' && ch <= '9'); 354 355 if (result < llim || result > ulim) 356 return NULL; 357 358 *dest = result; 359 return buf; 360 } 361 362 static const u_char * 363 find_string(const u_char *bp, int *tgt, const char * const *n1, 364 const char * const *n2, int c) 365 { 366 int i; 367 unsigned int len; 368 369 /* check full name - then abbreviated ones */ 370 for (; n1 != NULL; n1 = n2, n2 = NULL) { 371 for (i = 0; i < c; i++, n1++) { 372 len = strlen(*n1); 373 if (strncasecmp(*n1, (const char *)bp, len) == 0) { 374 *tgt = i; 375 return bp + len; 376 } 377 } 378 } 379 380 /* Nothing matched */ 381 return NULL; 382 } 383
Indexes created Fri Oct 03 02:09:57 GMT 2025