xapian-applications/omega/datetime.cc

   1 /** @file
   2  * @brief Parse date/time strings
   3  */
   4 /* Copyright (c) 2013,2014,2015 Olly Betts
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to
   8  * deal in the Software without restriction, including without limitation the
   9  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
  10  * sell copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  19  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  21  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  22  * IN THE SOFTWARE.
  23  */
  24
  25 #include <config.h>
  26
  27 #include "datetime.h"
  28
  29 #include "timegm.h"
  30
  31 #include <cstdlib>
  32
  33 using namespace std;
  34
  35 time_t
  36 parse_datetime(const string & s)
  37 {
  38     struct tm t;
  39     const char * p = s.c_str();
  40     char * q;
  41     if (s.find('T') != string::npos || s.find('-') != string::npos) {
  42         // E.g. "2013-01-17T09:10:55Z"
  43         t.tm_year = strtoul(p, &q, 10) - 1900;
  44         p = q;
  45         if (*p == '-') {
  46             t.tm_mon = strtoul(p + 1, &q, 10) - 1;
  47             p = q;
  48         } else {
  49             t.tm_mon = 0;
  50         }
  51         if (*p == '-') {
  52             t.tm_mday = strtoul(p + 1, &q, 10);
  53             p = q;
  54         } else {
  55             t.tm_mday = 1;
  56         }
  57         if (*p == 'T') {
  58             t.tm_hour = strtoul(p + 1, &q, 10);
  59             p = q;
  60             if (*p == ':') {
  61                 t.tm_min = strtoul(p + 1, &q, 10);
  62                 p = q;
  63             } else {
  64                 t.tm_min = 0;
  65             }
  66             if (*p == ':') {
  67                 t.tm_sec = strtoul(p + 1, &q, 10);
  68                 p = q;
  69             } else {
  70                 t.tm_sec = 0;
  71             }
  72         } else {
  73             t.tm_hour = t.tm_min = t.tm_sec = 0;
  74         }
  75         if (*p == 'Z') {
  76             // FIXME: always assume UTC for now...
  77         }
  78     } else {
  79         // As produced by LibreOffice HTML export.
  80         // E.g.
  81         // "20130117;09105500" == 2013-01-17T09:10:55
  82         // "20070903;200000000000" == 2007-09-03T00:02:00
  83         // "20070831;5100000000000" == 2007-08-31T00:51:00
  84         unsigned long v = strtoul(p, &q, 10);
  85         if (v == 0) {
  86             // LibreOffice sometimes exports "0;0".  A date of "0" is
  87             // clearly invalid.
  88             return time_t(-1);
  89         }
  90         p = q;
  91         t.tm_mday = v % 100;
  92         v /= 100;
  93         t.tm_mon = v % 100 - 1;
  94         t.tm_year = v / 100 - 1900;
  95         if (*p == ';') {
  96             ++p;
  97             v = strtoul(p, &q, 10);
  98             v /= (q - p > 10) ? 1000000000 : 100;
  99             t.tm_sec = v % 100;
 100             v /= 100;
 101             t.tm_min = v % 100;
 102             t.tm_hour = v / 100;
 103         } else {
 104             t.tm_hour = t.tm_min = t.tm_sec = 0;
 105         }
 106     }
 107     t.tm_isdst = -1;
 108
 109     return timegm(&t);
 110 }