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 <sys/types.h>
  28 #include <sys/stat.h>
  29 #include <errno.h>
  30
  31 enum {
  32     DATEMSK_NOT_DEFINED = 1,
  33     CANT_OPEN,
  34     CANT_FSTAT,
  35     NOT_FILE,
  36     IO_ERROR,
  37     OUT_OF_MEMORY,
  38     NO_MATCH,
  39     INVALID_DATE
  40 };
  41
  42 #define DATEMSK         "DATEMSK"
  43 #define TM_SEC_SET      0x01
  44 #define TM_MIN_SET      0x02
  45 #define TM_HOUR_SET     0x04
  46 #define TM_MDAY_SET     0x01
  47 #define TM_MON_SET      0x02
  48 #define TM_YEAR_SET     0x04
  49 #define UNDEFINED       -1
  50
  51 static struct tm tmundef = {
  52     UNDEFINED,
  53     UNDEFINED,
  54     UNDEFINED,
  55     UNDEFINED,
  56     UNDEFINED,
  57     UNDEFINED,
  58     UNDEFINED
  59 };
  60
  61 int getdate_err;
  62
  63 /*
  64  * getdate
  65  *
  66  * Call strptime() on each line of the DATEMSK file, and manipulate the
  67  * resulting tm structure.
  68  */
  69 struct tm *
  70 getdate(const char *str)
  71 {
  72     static struct tm tm, *now, *result = NULL;
  73     time_t t;
  74     FILE *fp;
  75     int bufsiz, offset, len, dateset, timeset, saveerrno, wday_set;
  76     char *buf;
  77     struct stat st;
  78     char *file = getenv(DATEMSK);
  79
  80     if(!file || !*file) {
  81         getdate_err = DATEMSK_NOT_DEFINED;
  82         return NULL;
  83     }
  84     saveerrno = errno;
  85     if((fp = fopen(file, "r")) == NULL) {
  86         getdate_err = CANT_OPEN;
  87         errno = saveerrno;
  88         return NULL;
  89     }
  90     do {
  91         if(fstat(fileno(fp), &st) < 0) {
  92             getdate_err = CANT_FSTAT;
  93             break;
  94         }
  95         if((st.st_mode & S_IFMT) != S_IFREG) {
  96             getdate_err = NOT_FILE;
  97             break;
  98         }
  99         if((buf = malloc(bufsiz = BUFSIZ)) == NULL) {
 100             getdate_err = OUT_OF_MEMORY;
 101             break;
 102         }
 103         do {
 104             offset = 0;
 105             for(;;) {
 106                 if(fgets(buf + offset, bufsiz - offset, fp) == NULL) {
 107                     if(ferror(fp)) {
 108                         getdate_err = IO_ERROR;
 109                         break;
 110                     }
 111                     if(offset == 0) {
 112                         getdate_err = NO_MATCH;
 113                         break;
 114                     }
 115                     len = strlen(buf);
 116                 } else if((len = strlen(buf)) == bufsiz - 1
 117                   && buf[len - 1] != '\n') {
 118                     char *newptr = realloc(buf, (bufsiz += BUFSIZ));
 119                     if(newptr == NULL) {
 120                         getdate_err = OUT_OF_MEMORY;
 121                         break;
 122                     }
 123                     buf = newptr;
 124                     offset = len;
 125                     continue;
 126                 }
 127                 if(buf[len - 1] == '\n')
 128                     buf[len - 1] = 0;
 129                 tm = tmundef;
 130                 if(strptime(str, buf, &tm) == NULL) {
 131                     offset = 0;
 132                     continue;
 133                 }
 134                 time(&t);
 135                 now = localtime(&t);
 136                 dateset = timeset = 0;
 137                 if(tm.tm_sec != UNDEFINED)
 138                     timeset |= TM_SEC_SET;
 139                 if(tm.tm_min != UNDEFINED)
 140                     timeset |= TM_MIN_SET;
 141                 if(tm.tm_hour != UNDEFINED)
 142                     timeset |= TM_HOUR_SET;
 143                 if(tm.tm_mday != UNDEFINED)
 144                     dateset |= TM_MDAY_SET;
 145                 if(tm.tm_mon != UNDEFINED)
 146                     dateset |= TM_MON_SET;
 147                 if(tm.tm_year != UNDEFINED)
 148                     dateset |= TM_YEAR_SET;
 149                 wday_set = tm.tm_wday;
 150
 151                 switch(timeset) {
 152                 case 0:
 153                     tm.tm_sec = now->tm_sec;
 154                     tm.tm_min = now->tm_min;
 155                     tm.tm_hour = now->tm_hour;
 156                     break;
 157
 158                 case TM_SEC_SET:
 159                     tm.tm_hour = now->tm_hour;
 160                     tm.tm_min = now->tm_min;
 161                     if(tm.tm_sec < now->tm_sec)
 162                         tm.tm_min++;
 163                     break;
 164
 165                 case TM_MIN_SET:
 166                     tm.tm_hour = now->tm_hour;
 167                     if(tm.tm_min < now->tm_min)
 168                         tm.tm_hour++;
 169                     tm.tm_sec = 0;
 170                     break;
 171
 172                 case TM_MIN_SET | TM_SEC_SET:
 173                     tm.tm_hour = now->tm_hour;
 174                     if((60 * tm.tm_min + tm.tm_sec)
 175                       < (60 * now->tm_min + now->tm_sec))
 176                         tm.tm_hour++;
 177                     break;
 178
 179                 case TM_HOUR_SET:
 180                     tm.tm_min = 0;
 181                     tm.tm_sec = 0;
 182                     break;
 183
 184                 case TM_HOUR_SET | TM_SEC_SET:
 185                     tm.tm_min = 0;
 186                     break;
 187
 188                 case TM_HOUR_SET | TM_MIN_SET:
 189                     tm.tm_sec = 0;
 190                     break;
 191                 }
 192
 193                 switch(dateset) {
 194                 case 0:
 195                     tm.tm_mday = now->tm_mday;
 196                     if(tm.tm_hour < now->tm_hour)
 197                         tm.tm_mday++;
 198                     tm.tm_mon = now->tm_mon;
 199                     tm.tm_year = now->tm_year;
 200                     break;
 201
 202                 case TM_MDAY_SET:
 203                     tm.tm_year = now->tm_year;
 204                     tm.tm_mon = now->tm_mon;
 205                     if(tm.tm_mday < now->tm_mday)
 206                         tm.tm_mon++;
 207                     break;
 208
 209                 case TM_MON_SET:
 210                 case TM_MON_SET | TM_MDAY_SET:
 211                     tm.tm_year = now->tm_year;
 212                     if(tm.tm_mon < now->tm_mon)
 213                         tm.tm_year++;
 214                     if(!(dateset & TM_MDAY_SET))
 215                         tm.tm_mday = 1;
 216                     break;
 217
 218                 case TM_YEAR_SET:
 219                 case TM_YEAR_SET | TM_MON_SET:
 220                     if(!(dateset & TM_MON_SET))
 221                         tm.tm_mon = 1;
 222                     tm.tm_mday = 1;
 223                     break;
 224
 225                 case TM_YEAR_SET | TM_MDAY_SET:
 226                     tm.tm_mon = now->tm_mon;
 227                     if(tm.tm_mday < now->tm_mday)
 228                         tm.tm_mon++;
 229                     break;
 230                 }
 231
 232                 tm.tm_wday = now->tm_wday;
 233                 tm.tm_gmtoff = now->tm_gmtoff;  /* XXX: can't grok timezones */
 234                 tm.tm_isdst = -1;
 235
 236                 if(mktime(&tm) == (time_t)-1) {
 237                     getdate_err = INVALID_DATE;
 238                     break;
 239                 }
 240                 if(wday_set != UNDEFINED) {
 241                     int delta = wday_set - tm.tm_wday;
 242                     if(delta && (dateset & TM_MDAY_SET)) {
 243                         getdate_err = INVALID_DATE;
 244                         break;
 245                     }
 246                     if(delta < 0)
 247                         delta += 7;
 248                     tm.tm_mday += delta;
 249                     if(mktime(&tm) == (time_t)-1) {
 250                         getdate_err = INVALID_DATE;
 251                         break;
 252                     }
 253                 }
 254                 result = &tm;
 255             }
 256         } while(0);
 257
 258         free(buf);
 259     } while(0);
 260
 261     fclose(fp);
 262     errno = saveerrno;
 263     return result;
 264 }