strptime.c revision 1dc9e472e19acfe6dc7f41e429236e7eef7ceda1
1/* $OpenBSD: strptime.c,v 1.11 2005/08/08 08:05:38 espie Exp $ */ 2/* $NetBSD: strptime.c,v 1.12 1998/01/20 21:39:40 mycroft Exp $ */ 3 4/*- 5 * Copyright (c) 1997, 1998 The NetBSD Foundation, Inc. 6 * All rights reserved. 7 * 8 * This code was contributed to The NetBSD Foundation by Klaus Klein. 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/localedef.h> 40#include <ctype.h> 41#include <locale.h> 42#include <string.h> 43#include <time.h> 44#include "tzfile.h" 45 46static const struct { 47 const char *abday[7]; 48 const char *day[7]; 49 const char *abmon[12]; 50 const char *mon[12]; 51 const char *am_pm[2]; 52 const char *d_t_fmt; 53 const char *d_fmt; 54 const char *t_fmt; 55 const char *t_fmt_ampm; 56} _DefaultTimeLocale = { 57 { 58 "Sun","Mon","Tue","Wed","Thu","Fri","Sat", 59 }, 60 { 61 "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", 62 "Friday", "Saturday" 63 }, 64 { 65 "Jan", "Feb", "Mar", "Apr", "May", "Jun", 66 "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" 67 }, 68 { 69 "January", "February", "March", "April", "May", "June", "July", 70 "August", "September", "October", "November", "December" 71 }, 72 { 73 "AM", "PM" 74 }, 75 "%a %b %d %H:%M:%S %Y", 76 "%m/%d/%y", 77 "%H:%M:%S", 78 "%I:%M:%S %p" 79}; 80 81#define _ctloc(x) (_DefaultTimeLocale.x) 82 83/* 84 * We do not implement alternate representations. However, we always 85 * check whether a given modifier is allowed for a certain conversion. 86 */ 87#define _ALT_E 0x01 88#define _ALT_O 0x02 89#define _LEGAL_ALT(x) { if (alt_format & ~(x)) return (0); } 90 91 92static int _conv_num(const unsigned char **, int *, int, int); 93static char *_strptime(const char *, const char *, struct tm *, int); 94 95 96char * 97strptime(const char *buf, const char *fmt, struct tm *tm) 98{ 99 return(_strptime(buf, fmt, tm, 1)); 100} 101 102static char * 103_strptime(const char *buf, const char *fmt, struct tm *tm, int initialize) 104{ 105 unsigned char c; 106 const unsigned char *bp; 107 size_t len; 108 int alt_format, i; 109 static int century, relyear; 110 111 if (initialize) { 112 century = TM_YEAR_BASE; 113 relyear = -1; 114 } 115 116 bp = (unsigned char *)buf; 117 while ((c = *fmt) != '\0') { 118 /* Clear `alternate' modifier prior to new conversion. */ 119 alt_format = 0; 120 121 /* Eat up white-space. */ 122 if (isspace(c)) { 123 while (isspace(*bp)) 124 bp++; 125 126 fmt++; 127 continue; 128 } 129 130 if ((c = *fmt++) != '%') 131 goto literal; 132 133 134again: switch (c = *fmt++) { 135 case '%': /* "%%" is converted to "%". */ 136literal: 137 if (c != *bp++) 138 return (NULL); 139 140 break; 141 142 /* 143 * "Alternative" modifiers. Just set the appropriate flag 144 * and start over again. 145 */ 146 case 'E': /* "%E?" alternative conversion modifier. */ 147 _LEGAL_ALT(0); 148 alt_format |= _ALT_E; 149 goto again; 150 151 case 'O': /* "%O?" alternative conversion modifier. */ 152 _LEGAL_ALT(0); 153 alt_format |= _ALT_O; 154 goto again; 155 156 /* 157 * "Complex" conversion rules, implemented through recursion. 158 */ 159 case 'c': /* Date and time, using the locale's format. */ 160 _LEGAL_ALT(_ALT_E); 161 if (!(bp = _strptime(bp, _ctloc(d_t_fmt), tm, 0))) 162 return (NULL); 163 break; 164 165 case 'D': /* The date as "%m/%d/%y". */ 166 _LEGAL_ALT(0); 167 if (!(bp = _strptime(bp, "%m/%d/%y", tm, 0))) 168 return (NULL); 169 break; 170 171 case 'R': /* The time as "%H:%M". */ 172 _LEGAL_ALT(0); 173 if (!(bp = _strptime(bp, "%H:%M", tm, 0))) 174 return (NULL); 175 break; 176 177 case 'r': /* The time as "%I:%M:%S %p". */ 178 _LEGAL_ALT(0); 179 if (!(bp = _strptime(bp, "%I:%M:%S %p", tm, 0))) 180 return (NULL); 181 break; 182 183 case 'T': /* The time as "%H:%M:%S". */ 184 _LEGAL_ALT(0); 185 if (!(bp = _strptime(bp, "%H:%M:%S", tm, 0))) 186 return (NULL); 187 break; 188 189 case 'X': /* The time, using the locale's format. */ 190 _LEGAL_ALT(_ALT_E); 191 if (!(bp = _strptime(bp, _ctloc(t_fmt), tm, 0))) 192 return (NULL); 193 break; 194 195 case 'x': /* The date, using the locale's format. */ 196 _LEGAL_ALT(_ALT_E); 197 if (!(bp = _strptime(bp, _ctloc(d_fmt), tm, 0))) 198 return (NULL); 199 break; 200 201 /* 202 * "Elementary" conversion rules. 203 */ 204 case 'A': /* The day of week, using the locale's form. */ 205 case 'a': 206 _LEGAL_ALT(0); 207 for (i = 0; i < 7; i++) { 208 /* Full name. */ 209 len = strlen(_ctloc(day[i])); 210 if (strncasecmp(_ctloc(day[i]), bp, len) == 0) 211 break; 212 213 /* Abbreviated name. */ 214 len = strlen(_ctloc(abday[i])); 215 if (strncasecmp(_ctloc(abday[i]), bp, len) == 0) 216 break; 217 } 218 219 /* Nothing matched. */ 220 if (i == 7) 221 return (NULL); 222 223 tm->tm_wday = i; 224 bp += len; 225 break; 226 227 case 'B': /* The month, using the locale's form. */ 228 case 'b': 229 case 'h': 230 _LEGAL_ALT(0); 231 for (i = 0; i < 12; i++) { 232 /* Full name. */ 233 len = strlen(_ctloc(mon[i])); 234 if (strncasecmp(_ctloc(mon[i]), bp, len) == 0) 235 break; 236 237 /* Abbreviated name. */ 238 len = strlen(_ctloc(abmon[i])); 239 if (strncasecmp(_ctloc(abmon[i]), bp, len) == 0) 240 break; 241 } 242 243 /* Nothing matched. */ 244 if (i == 12) 245 return (NULL); 246 247 tm->tm_mon = i; 248 bp += len; 249 break; 250 251 case 'C': /* The century number. */ 252 _LEGAL_ALT(_ALT_E); 253 if (!(_conv_num(&bp, &i, 0, 99))) 254 return (NULL); 255 256 century = i * 100; 257 break; 258 259 case 'd': /* The day of month. */ 260 case 'e': 261 _LEGAL_ALT(_ALT_O); 262 if (!(_conv_num(&bp, &tm->tm_mday, 1, 31))) 263 return (NULL); 264 break; 265 266 case 'k': /* The hour (24-hour clock representation). */ 267 _LEGAL_ALT(0); 268 /* FALLTHROUGH */ 269 case 'H': 270 _LEGAL_ALT(_ALT_O); 271 if (!(_conv_num(&bp, &tm->tm_hour, 0, 23))) 272 return (NULL); 273 break; 274 275 case 'l': /* The hour (12-hour clock representation). */ 276 _LEGAL_ALT(0); 277 /* FALLTHROUGH */ 278 case 'I': 279 _LEGAL_ALT(_ALT_O); 280 if (!(_conv_num(&bp, &tm->tm_hour, 1, 12))) 281 return (NULL); 282 break; 283 284 case 'j': /* The day of year. */ 285 _LEGAL_ALT(0); 286 if (!(_conv_num(&bp, &tm->tm_yday, 1, 366))) 287 return (NULL); 288 tm->tm_yday--; 289 break; 290 291 case 'M': /* The minute. */ 292 _LEGAL_ALT(_ALT_O); 293 if (!(_conv_num(&bp, &tm->tm_min, 0, 59))) 294 return (NULL); 295 break; 296 297 case 'm': /* The month. */ 298 _LEGAL_ALT(_ALT_O); 299 if (!(_conv_num(&bp, &tm->tm_mon, 1, 12))) 300 return (NULL); 301 tm->tm_mon--; 302 break; 303 304 case 'p': /* The locale's equivalent of AM/PM. */ 305 _LEGAL_ALT(0); 306 /* AM? */ 307 len = strlen(_ctloc(am_pm[0])); 308 if (strncasecmp(_ctloc(am_pm[0]), bp, len) == 0) { 309 if (tm->tm_hour > 12) /* i.e., 13:00 AM ?! */ 310 return (NULL); 311 else if (tm->tm_hour == 12) 312 tm->tm_hour = 0; 313 314 bp += len; 315 break; 316 } 317 /* PM? */ 318 len = strlen(_ctloc(am_pm[1])); 319 if (strncasecmp(_ctloc(am_pm[1]), bp, len) == 0) { 320 if (tm->tm_hour > 12) /* i.e., 13:00 PM ?! */ 321 return (NULL); 322 else if (tm->tm_hour < 12) 323 tm->tm_hour += 12; 324 325 bp += len; 326 break; 327 } 328 329 /* Nothing matched. */ 330 return (NULL); 331 332 case 'S': /* The seconds. */ 333 _LEGAL_ALT(_ALT_O); 334 if (!(_conv_num(&bp, &tm->tm_sec, 0, 61))) 335 return (NULL); 336 break; 337 338 case 'U': /* The week of year, beginning on sunday. */ 339 case 'W': /* The week of year, beginning on monday. */ 340 _LEGAL_ALT(_ALT_O); 341 /* 342 * XXX This is bogus, as we can not assume any valid 343 * information present in the tm structure at this 344 * point to calculate a real value, so just check the 345 * range for now. 346 */ 347 if (!(_conv_num(&bp, &i, 0, 53))) 348 return (NULL); 349 break; 350 351 case 'w': /* The day of week, beginning on sunday. */ 352 _LEGAL_ALT(_ALT_O); 353 if (!(_conv_num(&bp, &tm->tm_wday, 0, 6))) 354 return (NULL); 355 break; 356 357 case 'Y': /* The year. */ 358 _LEGAL_ALT(_ALT_E); 359 if (!(_conv_num(&bp, &i, 0, 9999))) 360 return (NULL); 361 362 relyear = -1; 363 tm->tm_year = i - TM_YEAR_BASE; 364 break; 365 366 case 'y': /* The year within the century (2 digits). */ 367 _LEGAL_ALT(_ALT_E | _ALT_O); 368 if (!(_conv_num(&bp, &relyear, 0, 99))) 369 return (NULL); 370 break; 371 372 /* 373 * Miscellaneous conversions. 374 */ 375 case 'n': /* Any kind of white-space. */ 376 case 't': 377 _LEGAL_ALT(0); 378 while (isspace(*bp)) 379 bp++; 380 break; 381 382 383 default: /* Unknown/unsupported conversion. */ 384 return (NULL); 385 } 386 387 388 } 389 390 /* 391 * We need to evaluate the two digit year spec (%y) 392 * last as we can get a century spec (%C) at any time. 393 */ 394 if (relyear != -1) { 395 if (century == TM_YEAR_BASE) { 396 if (relyear <= 68) 397 tm->tm_year = relyear + 2000 - TM_YEAR_BASE; 398 else 399 tm->tm_year = relyear + 1900 - TM_YEAR_BASE; 400 } else { 401 tm->tm_year = relyear + century - TM_YEAR_BASE; 402 } 403 } 404 405 return ((char *)bp); 406} 407 408 409static int 410_conv_num(const unsigned char **buf, int *dest, int llim, int ulim) 411{ 412 int result = 0; 413 int rulim = ulim; 414 415 if (**buf < '0' || **buf > '9') 416 return (0); 417 418 /* we use rulim to break out of the loop when we run out of digits */ 419 do { 420 result *= 10; 421 result += *(*buf)++ - '0'; 422 rulim /= 10; 423 } while ((result * 10 <= ulim) && rulim && **buf >= '0' && **buf <= '9'); 424 425 if (result < llim || result > ulim) 426 return (0); 427 428 *dest = result; 429 return (1); 430} 431