stdtime/getdate.c

   1 /*
   2  * Copyright (c) 2004 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24 #include <stdio.h>
  25 #include <time.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28 #include <sys/types.h>
  29 #include <sys/stat.h>
  30 #include <errno.h>
  31
  32 enum {
  33     DATEMSK_NOT_DEFINED = 1,
  34     CANT_OPEN,
  35     CANT_FSTAT,
  36     NOT_FILE,
  37     IO_ERROR,
  38     OUT_OF_MEMORY,
  39     NO_MATCH,
  40     INVALID_DATE
  41 };
  42
  43 #define DATEMSK         "DATEMSK"
  44 #define TM_SEC_SET      0x01
  45 #define TM_MIN_SET      0x02
  46 #define TM_HOUR_SET     0x04
  47 #define TM_MDAY_SET     0x01
  48 #define TM_MON_SET      0x02
  49 #define TM_YEAR_SET     0x04
  50 #define UNDEFINED       -1
  51
  52 static const struct tm tmundef = {
  53     UNDEFINED,
  54     UNDEFINED,
  55     UNDEFINED,
  56     UNDEFINED,
  57     UNDEFINED,
  58     UNDEFINED,
  59     UNDEFINED
  60 };
  61
  62 int getdate_err;
  63
  64 /*
  65  * getdate
  66  *
  67  * Call strptime() on each line of the DATEMSK file, and manipulate the
  68  * resulting tm structure.
  69  */
  70 struct tm *
  71 getdate(const char *str)
  72 {
  73     static struct tm tm;
  74     struct tm *now, *result = NULL;
  75     time_t t;
  76     FILE *fp;
  77     int bufsiz, offset, len, dateset, timeset, saveerrno, wday_set, save_mon;
  78     char *buf;
  79     struct stat st;
  80     char *file = getenv(DATEMSK);
  81
  82     if(!file || !*file) {
  83         getdate_err = DATEMSK_NOT_DEFINED;
  84         return NULL;
  85     }
  86     saveerrno = errno;
  87     if((fp = fopen(file, "r")) == NULL) {
  88         getdate_err = CANT_OPEN;
  89         errno = saveerrno;
  90         return NULL;
  91     }
  92     do {
  93         if(fstat(fileno(fp), &st) < 0) {
  94             getdate_err = CANT_FSTAT;
  95             break;
  96         }
  97         if((st.st_mode & S_IFMT) != S_IFREG) {
  98             getdate_err = NOT_FILE;
  99             break;
 100         }
 101         if((buf = malloc(bufsiz = BUFSIZ)) == NULL) {
 102             getdate_err = OUT_OF_MEMORY;
 103             break;
 104         }
 105         do {
 106             offset = 0;
 107             for(;;) {
 108                 if(fgets(buf + offset, bufsiz - offset, fp) == NULL) {
 109                     if(ferror(fp)) {
 110                         getdate_err = IO_ERROR;
 111                         break;
 112                     }
 113                     if(offset == 0) {
 114                         getdate_err = NO_MATCH;
 115                         break;
 116                     }
 117                     len = strlen(buf);
 118                 } else if((len = strlen(buf)) == bufsiz - 1
 119                   && buf[len - 1] != '\n') {
 120                     char *newptr = realloc(buf, (bufsiz += BUFSIZ));
 121                     if(newptr == NULL) {
 122                         getdate_err = OUT_OF_MEMORY;
 123                         break;
 124                     }
 125                     buf = newptr;
 126                     offset = len;
 127                     continue;
 128                 }
 129                 if(buf[len - 1] == '\n')
 130                     buf[len - 1] = 0;
 131                 tm = tmundef;
 132                 if(strptime(str, buf, &tm) == NULL) {
 133                     offset = 0;
 134                     continue;
 135                 }
 136                 time(&t);
 137                 now = localtime(&t);
 138                 dateset = timeset = 0;
 139                 if(tm.tm_sec != UNDEFINED)
 140                     timeset |= TM_SEC_SET;
 141                 if(tm.tm_min != UNDEFINED)
 142                     timeset |= TM_MIN_SET;
 143                 if(tm.tm_hour != UNDEFINED)
 144                     timeset |= TM_HOUR_SET;
 145                 if(tm.tm_mday != UNDEFINED)
 146                     dateset |= TM_MDAY_SET;
 147                 if(tm.tm_mon != UNDEFINED)
 148                     dateset |= TM_MON_SET;
 149                 if(tm.tm_year != UNDEFINED)
 150                     dateset |= TM_YEAR_SET;
 151                 wday_set = tm.tm_wday;
 152
 153                 switch(timeset) {
 154                 case 0:
 155                     tm.tm_sec = now->tm_sec;
 156                     tm.tm_min = now->tm_min;
 157                     tm.tm_hour = now->tm_hour;
 158                     break;
 159
 160                 case TM_SEC_SET:
 161                     tm.tm_hour = now->tm_hour;
 162                     tm.tm_min = now->tm_min;
 163                     if(tm.tm_sec < now->tm_sec)
 164                         tm.tm_min++;
 165                     break;
 166
 167                 case TM_MIN_SET:
 168                     tm.tm_hour = now->tm_hour;
 169                     if(tm.tm_min < now->tm_min)
 170                         tm.tm_hour++;
 171                     tm.tm_sec = 0;
 172                     break;
 173
 174                 case TM_MIN_SET | TM_SEC_SET:
 175                     tm.tm_hour = now->tm_hour;
 176                     if((60 * tm.tm_min + tm.tm_sec)
 177                       < (60 * now->tm_min + now->tm_sec))
 178                         tm.tm_hour++;
 179                     break;
 180
 181                 case TM_HOUR_SET:
 182                     tm.tm_min = 0;
 183                     tm.tm_sec = 0;
 184                     break;
 185
 186                 case TM_HOUR_SET | TM_SEC_SET:
 187                     tm.tm_min = 0;
 188                     break;
 189
 190                 case TM_HOUR_SET | TM_MIN_SET:
 191                     tm.tm_sec = 0;
 192                     break;
 193                 }
 194
 195                 switch(dateset) {
 196                 case 0:
 197                     tm.tm_mday = now->tm_mday;
 198                     if(tm.tm_hour < now->tm_hour)
 199                         tm.tm_mday++;
 200                     tm.tm_mon = now->tm_mon;
 201                     tm.tm_year = now->tm_year;
 202                     break;
 203
 204                 case TM_MDAY_SET:
 205                     tm.tm_year = now->tm_year;
 206                     tm.tm_mon = now->tm_mon;
 207                     if(tm.tm_mday < now->tm_mday)
 208                         tm.tm_mon++;
 209                     break;
 210
 211                 case TM_MON_SET:
 212                 case TM_MON_SET | TM_MDAY_SET:
 213                     tm.tm_year = now->tm_year;
 214                     if(tm.tm_mon < now->tm_mon)
 215                         tm.tm_year++;
 216                     if(!(dateset & TM_MDAY_SET))
 217                         tm.tm_mday = 1;
 218                     break;
 219
 220                 case TM_YEAR_SET:
 221                 case TM_YEAR_SET | TM_MON_SET:
 222                     if(!(dateset & TM_MON_SET))
 223                         tm.tm_mon = 0;
 224                     tm.tm_mday = 1;
 225                     break;
 226
 227                 case TM_YEAR_SET | TM_MDAY_SET:
 228                     tm.tm_mon = now->tm_mon;
 229                     if(tm.tm_mday < now->tm_mday)
 230                         tm.tm_mon++;
 231                     break;
 232                 }
 233
 234                 tm.tm_wday = now->tm_wday;
 235                 tm.tm_gmtoff = now->tm_gmtoff;  /* XXX: can't grok timezones */
 236                 tm.tm_isdst = -1;
 237                 save_mon = tm.tm_mon;
 238                 if(mktime(&tm) == (time_t)-1) {
 239                     getdate_err = INVALID_DATE;
 240                     break;
 241                 } else if ((dateset & TM_MON_SET) && (tm.tm_mon != save_mon)) { /* Did mktime fixup an overflow date? */
 242                         getdate_err = INVALID_DATE;
 243                         break;
 244                 }
 245                 if(wday_set != UNDEFINED &&
 246                         (dateset != (TM_YEAR_SET | TM_MON_SET | TM_MDAY_SET))) {
 247                     /*
 248                      * We got back a week day, but not enough information to resolve it
 249                      * to a specific day, so we need to push forward the time to the
 250                      * correct wday.  <rdar://problem/27439823>
 251                      */
 252                     int delta = wday_set - tm.tm_wday;
 253                     if(delta < 0) {
 254                         delta += 7;
 255                     }
 256                     tm.tm_mday += delta;
 257                     if(mktime(&tm) == (time_t)-1) {
 258                         getdate_err = INVALID_DATE;
 259                         break;
 260                     }
 261                 }
 262                 result = &tm;
 263                 break;
 264             }
 265         } while(0);
 266
 267         free(buf);
 268     } while(0);
 269
 270     fclose(fp);
 271     errno = saveerrno;
 272     return result;
 273 }