strptime.c revision 1.27
1 /* $NetBSD: strptime.c,v 1.27 2008/04/25 20:51:10 ginsbach 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 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 #if defined(LIBC_SCCS) && !defined(lint) 41 __RCSID("$NetBSD: strptime.c,v 1.27 2008/04/25 20:51:10 ginsbach Exp $"); 42 #endif 43 44 #include "namespace.h" 45 #include <sys/localedef.h> 46 #include <ctype.h> 47 #include <locale.h> 48 #include <string.h> 49 #include <time.h> 50 #include <tzfile.h> 51 52 #ifdef __weak_alias 53 __weak_alias(strptime,_strptime) 54 #endif 55 56 #define _ctloc(x) (_CurrentTimeLocale->x) 57 58 /* 59 * We do not implement alternate representations. However, we always 60 * check whether a given modifier is allowed for a certain conversion. 61 */ 62 #define ALT_E 0x01 63 #define ALT_O 0x02 64 #define LEGAL_ALT(x) { if (alt_format & ~(x)) return NULL; } 65 66 static const char gmt[4] = { "GMT" }; 67 68 static const u_char *conv_num(const unsigned char *, int *, uint, uint); 69 static const u_char *find_string(const u_char *, int *, const char * const *, 70 const char * const *, int); 71 72 73 char * 74 strptime(const char *buf, const char *fmt, struct tm *tm) 75 { 76 unsigned char c; 77 const unsigned char *bp; 78 int alt_format, i, split_year = 0; 79 const char *new_fmt; 80 81 bp = (const u_char *)buf; 82 83 while (bp != NULL && (c = *fmt++) != '\0') { 84 /* Clear `alternate' modifier prior to new conversion. */ 85 alt_format = 0; 86 i = 0; 87 88 /* Eat up white-space. */ 89 if (isspace(c)) { 90 while (isspace(*bp)) 91 bp++; 92 continue; 93 } 94 95 if (c != '%') 96 goto literal; 97 98 99 again: switch (c = *fmt++) { 100 case '%': /* "%%" is converted to "%". */ 101 literal: 102 if (c != *bp++) 103 return NULL; 104 LEGAL_ALT(0); 105 continue; 106 107 /* 108 * "Alternative" modifiers. Just set the appropriate flag 109 * and start over again. 110 */ 111 case 'E': /* "%E?" alternative conversion modifier. */ 112 LEGAL_ALT(0); 113 alt_format |= ALT_E; 114 goto again; 115 116 case 'O': /* "%O?" alternative conversion modifier. */ 117 LEGAL_ALT(0); 118 alt_format |= ALT_O; 119 goto again; 120 121 /* 122 * "Complex" conversion rules, implemented through recursion. 123 */ 124 case 'c': /* Date and time, using the locale's format. */ 125 new_fmt = _ctloc(d_t_fmt); 126 goto recurse; 127 128 case 'D': /* The date as "%m/%d/%y". */ 129 new_fmt = "%m/%d/%y"; 130 LEGAL_ALT(0); 131 goto recurse; 132 133 case 'F': /* The date as "%Y-%m-%d". */ 134 new_fmt = "%Y-%m-%d"; 135 LEGAL_ALT(0); 136 goto recurse; 137 138 case 'R': /* The time as "%H:%M". */ 139 new_fmt = "%H:%M"; 140 LEGAL_ALT(0); 141 goto recurse; 142 143 case 'r': /* The time in 12-hour clock representation. */ 144 new_fmt =_ctloc(t_fmt_ampm); 145 LEGAL_ALT(0); 146 goto recurse; 147 148 case 'T': /* The time as "%H:%M:%S". */ 149 new_fmt = "%H:%M:%S"; 150 LEGAL_ALT(0); 151 goto recurse; 152 153 case 'X': /* The time, using the locale's format. */ 154 new_fmt =_ctloc(t_fmt); 155 goto recurse; 156 157 case 'x': /* The date, using the locale's format. */ 158 new_fmt =_ctloc(d_fmt); 159 recurse: 160 bp = (const u_char *)strptime((const char *)bp, 161 new_fmt, tm); 162 LEGAL_ALT(ALT_E); 163 continue; 164 165 /* 166 * "Elementary" conversion rules. 167 */ 168 case 'A': /* The day of week, using the locale's form. */ 169 case 'a': 170 bp = find_string(bp, &tm->tm_wday, _ctloc(day), 171 _ctloc(abday), 7); 172 LEGAL_ALT(0); 173 continue; 174 175 case 'B': /* The month, using the locale's form. */ 176 case 'b': 177 case 'h': 178 bp = find_string(bp, &tm->tm_mon, _ctloc(mon), 179 _ctloc(abmon), 12); 180 LEGAL_ALT(0); 181 continue; 182 183 case 'C': /* The century number. */ 184 i = 20; 185 bp = conv_num(bp, &i, 0, 99); 186 187 i = i * 100 - TM_YEAR_BASE; 188 if (split_year) 189 i += tm->tm_year % 100; 190 split_year = 1; 191 tm->tm_year = i; 192 LEGAL_ALT(ALT_E); 193 continue; 194 195 case 'd': /* The day of month. */ 196 case 'e': 197 bp = conv_num(bp, &tm->tm_mday, 1, 31); 198 LEGAL_ALT(ALT_O); 199 continue; 200 201 case 'k': /* The hour (24-hour clock representation). */ 202 LEGAL_ALT(0); 203 /* FALLTHROUGH */ 204 case 'H': 205 bp = conv_num(bp, &tm->tm_hour, 0, 23); 206 LEGAL_ALT(ALT_O); 207 continue; 208 209 case 'l': /* The hour (12-hour clock representation). */ 210 LEGAL_ALT(0); 211 /* FALLTHROUGH */ 212 case 'I': 213 bp = conv_num(bp, &tm->tm_hour, 1, 12); 214 if (tm->tm_hour == 12) 215 tm->tm_hour = 0; 216 LEGAL_ALT(ALT_O); 217 continue; 218 219 case 'j': /* The day of year. */ 220 i = 1; 221 bp = conv_num(bp, &i, 1, 366); 222 tm->tm_yday = i - 1; 223 LEGAL_ALT(0); 224 continue; 225 226 case 'M': /* The minute. */ 227 bp = conv_num(bp, &tm->tm_min, 0, 59); 228 LEGAL_ALT(ALT_O); 229 continue; 230 231 case 'm': /* The month. */ 232 i = 1; 233 bp = conv_num(bp, &i, 1, 12); 234 tm->tm_mon = i - 1; 235 LEGAL_ALT(ALT_O); 236 continue; 237 238 case 'p': /* The locale's equivalent of AM/PM. */ 239 bp = find_string(bp, &i, _ctloc(am_pm), NULL, 2); 240 if (tm->tm_hour > 11) 241 return NULL; 242 tm->tm_hour += i * 12; 243 LEGAL_ALT(0); 244 continue; 245 246 case 'S': /* The seconds. */ 247 bp = conv_num(bp, &tm->tm_sec, 0, 61); 248 LEGAL_ALT(ALT_O); 249 continue; 250 251 case 'U': /* The week of year, beginning on sunday. */ 252 case 'W': /* The week of year, beginning on monday. */ 253 /* 254 * XXX This is bogus, as we can not assume any valid 255 * information present in the tm structure at this 256 * point to calculate a real value, so just check the 257 * range for now. 258 */ 259 bp = conv_num(bp, &i, 0, 53); 260 LEGAL_ALT(ALT_O); 261 continue; 262 263 case 'w': /* The day of week, beginning on sunday. */ 264 bp = conv_num(bp, &tm->tm_wday, 0, 6); 265 LEGAL_ALT(ALT_O); 266 continue; 267 268 case 'Y': /* The year. */ 269 i = TM_YEAR_BASE; /* just for data sanity... */ 270 bp = conv_num(bp, &i, 0, 9999); 271 tm->tm_year = i - TM_YEAR_BASE; 272 LEGAL_ALT(ALT_E); 273 continue; 274 275 case 'y': /* The year within 100 years of the epoch. */ 276 /* LEGAL_ALT(ALT_E | ALT_O); */ 277 bp = conv_num(bp, &i, 0, 99); 278 279 if (split_year) 280 /* preserve century */ 281 i += (tm->tm_year / 100) * 100; 282 else { 283 split_year = 1; 284 if (i <= 68) 285 i = i + 2000 - TM_YEAR_BASE; 286 else 287 i = i + 1900 - TM_YEAR_BASE; 288 } 289 tm->tm_year = i; 290 continue; 291 292 case 'Z': 293 tzset(); 294 if (strncmp((const char *)bp, gmt, 3) == 0) { 295 tm->tm_isdst = 0; 296 #ifdef TM_GMTOFF 297 tm->TM_GMTOFF = 0; 298 #endif 299 #ifdef TM_ZONE 300 tm->TM_ZONE = gmt; 301 #endif 302 bp += 3; 303 } else { 304 const unsigned char *ep; 305 306 ep = find_string(bp, &i, 307 (const char * const *)tzname, 308 NULL, 2); 309 if (ep != NULL) { 310 tm->tm_isdst = i; 311 #ifdef TM_GMTOFF 312 tm->TM_GMTOFF = -(timezone); 313 #endif 314 #ifdef TM_ZONE 315 tm->TM_ZONE = tzname[i]; 316 #endif 317 } 318 bp = ep; 319 } 320 continue; 321 322 /* 323 * Miscellaneous conversions. 324 */ 325 case 'n': /* Any kind of white-space. */ 326 case 't': 327 while (isspace(*bp)) 328 bp++; 329 LEGAL_ALT(0); 330 continue; 331 332 333 default: /* Unknown/unsupported conversion. */ 334 return NULL; 335 } 336 } 337 338 return __UNCONST(bp); 339 } 340 341 342 static const u_char * 343 conv_num(const unsigned char *buf, int *dest, uint llim, uint ulim) 344 { 345 uint result = 0; 346 unsigned char ch; 347 348 /* The limit also determines the number of valid digits. */ 349 uint rulim = ulim; 350 351 ch = *buf; 352 if (ch < '0' || ch > '9') 353 return NULL; 354 355 do { 356 result *= 10; 357 result += ch - '0'; 358 rulim /= 10; 359 ch = *++buf; 360 } while ((result * 10 <= ulim) && rulim && ch >= '0' && ch <= '9'); 361 362 if (result < llim || result > ulim) 363 return NULL; 364 365 *dest = result; 366 return buf; 367 } 368 369 static const u_char * 370 find_string(const u_char *bp, int *tgt, const char * const *n1, 371 const char * const *n2, int c) 372 { 373 int i; 374 unsigned int len; 375 376 /* check full name - then abbreviated ones */ 377 for (; n1 != NULL; n1 = n2, n2 = NULL) { 378 for (i = 0; i < c; i++, n1++) { 379 len = strlen(*n1); 380 if (strncasecmp(*n1, (const char *)bp, len) == 0) { 381 *tgt = i; 382 return bp + len; 383 } 384 } 385 } 386 387 /* Nothing matched */ 388 return NULL; 389 } 390
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