| 1 | /** @file lib/xgetdate.c |
| 2 | * @brief Date parsing |
| 3 | * |
| 4 | * Derived from getdate.c in glibc 2.3.6. This is pretty much |
| 5 | * standard getdate() except that you supply the template in an |
| 6 | * argument, rather than messing around with environment variables and |
| 7 | * files. |
| 8 | */ |
| 9 | |
| 10 | /* Convert a string representation of time to a time value. |
| 11 | Copyright (C) 1997,1998,1999,2000,2001,2003 Free Software Foundation, Inc. |
| 12 | This file is part of the GNU C Library. |
| 13 | Contributed by Mark Kettenis <kettenis@phys.uva.nl>, 1997. |
| 14 | |
| 15 | The GNU C Library is free software; you can redistribute it and/or |
| 16 | modify it under the terms of the GNU Lesser General Public |
| 17 | License as published by the Free Software Foundation; either |
| 18 | version 2.1 of the License, or (at your option) any later version. |
| 19 | |
| 20 | The GNU C Library is distributed in the hope that it will be useful, |
| 21 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 22 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 23 | Lesser General Public License for more details. |
| 24 | |
| 25 | You should have received a copy of the GNU Lesser General Public |
| 26 | License along with the GNU C Library; if not, write to the Free |
| 27 | Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 28 | 02111-1307 USA. */ |
| 29 | |
| 30 | #define _GNU_SOURCE 1 /* to expose strptime */ |
| 31 | #include <limits.h> |
| 32 | #include <stdio.h> |
| 33 | #include <stdlib.h> |
| 34 | #include <string.h> |
| 35 | #include <time.h> |
| 36 | |
| 37 | #include "dateparse.h" |
| 38 | #include "strptime.h" |
| 39 | |
| 40 | #define TM_YEAR_BASE 1900 |
| 41 | |
| 42 | |
| 43 | /* Prototypes for local functions. */ |
| 44 | static int first_wday (int year, int mon, int wday); |
| 45 | static int check_mday (int year, int mon, int mday); |
| 46 | |
| 47 | # define isleap(year) \ |
| 48 | ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0)) |
| 49 | |
| 50 | /* Set to one of the following values to indicate an error. |
| 51 | 1 the DATEMSK environment variable is null or undefined, |
| 52 | 2 the template file cannot be opened for reading, |
| 53 | 3 failed to get file status information, |
| 54 | 4 the template file is not a regular file, |
| 55 | 5 an error is encountered while reading the template file, |
| 56 | 6 memory allication failed (not enough memory available), |
| 57 | 7 there is no line in the template that matches the input, |
| 58 | 8 invalid input specification Example: February 31 or a time is |
| 59 | specified that can not be represented in a time_t (representing |
| 60 | the time in seconds since 00:00:00 UTC, January 1, 1970) */ |
| 61 | /*int xgetdate_err;*/ |
| 62 | |
| 63 | |
| 64 | /* Returns the first weekday WDAY of month MON in the year YEAR. */ |
| 65 | static int |
| 66 | first_wday (int year, int mon, int wday) |
| 67 | { |
| 68 | struct tm tm; |
| 69 | |
| 70 | if (wday == INT_MIN) |
| 71 | return 1; |
| 72 | |
| 73 | memset (&tm, 0, sizeof (struct tm)); |
| 74 | tm.tm_year = year; |
| 75 | tm.tm_mon = mon; |
| 76 | tm.tm_mday = 1; |
| 77 | mktime (&tm); |
| 78 | |
| 79 | return (1 + (wday - tm.tm_wday + 7) % 7); |
| 80 | } |
| 81 | |
| 82 | |
| 83 | /* Returns 1 if MDAY is a valid day of the month in month MON of year |
| 84 | YEAR, and 0 if it is not. */ |
| 85 | static int |
| 86 | check_mday (int year, int mon, int mday) |
| 87 | { |
| 88 | switch (mon) |
| 89 | { |
| 90 | case 0: |
| 91 | case 2: |
| 92 | case 4: |
| 93 | case 6: |
| 94 | case 7: |
| 95 | case 9: |
| 96 | case 11: |
| 97 | if (mday >= 1 && mday <= 31) |
| 98 | return 1; |
| 99 | break; |
| 100 | case 3: |
| 101 | case 5: |
| 102 | case 8: |
| 103 | case 10: |
| 104 | if (mday >= 1 && mday <= 30) |
| 105 | return 1; |
| 106 | break; |
| 107 | case 1: |
| 108 | if (mday >= 1 && mday <= (isleap (year) ? 29 : 28)) |
| 109 | return 1; |
| 110 | break; |
| 111 | } |
| 112 | |
| 113 | return 0; |
| 114 | } |
| 115 | |
| 116 | |
| 117 | int |
| 118 | xgetdate_r (const char *string, struct tm *tp, |
| 119 | const char *const *template) |
| 120 | { |
| 121 | const char *line; |
| 122 | size_t len; |
| 123 | char *result = NULL; |
| 124 | time_t timer; |
| 125 | struct tm tm; |
| 126 | int mday_ok = 0; |
| 127 | |
| 128 | line = NULL; |
| 129 | len = 0; |
| 130 | while((line = *template++)) |
| 131 | { |
| 132 | /* Do the conversion. */ |
| 133 | tp->tm_year = tp->tm_mon = tp->tm_mday = tp->tm_wday = INT_MIN; |
| 134 | tp->tm_hour = tp->tm_sec = tp->tm_min = INT_MIN; |
| 135 | tp->tm_isdst = -1; |
| 136 | tp->tm_gmtoff = 0; |
| 137 | tp->tm_zone = NULL; |
| 138 | result = my_strptime (string, line, tp); |
| 139 | if (result && *result == '\0') |
| 140 | break; |
| 141 | } |
| 142 | |
| 143 | if (result == NULL || *result != '\0') |
| 144 | return 7; |
| 145 | |
| 146 | /* Get current time. */ |
| 147 | time (&timer); |
| 148 | localtime_r (&timer, &tm); |
| 149 | |
| 150 | /* If only the weekday is given, today is assumed if the given day |
| 151 | is equal to the current day and next week if it is less. */ |
| 152 | if (tp->tm_wday >= 0 && tp->tm_wday <= 6 && tp->tm_year == INT_MIN |
| 153 | && tp->tm_mon == INT_MIN && tp->tm_mday == INT_MIN) |
| 154 | { |
| 155 | tp->tm_year = tm.tm_year; |
| 156 | tp->tm_mon = tm.tm_mon; |
| 157 | tp->tm_mday = tm.tm_mday + (tp->tm_wday - tm.tm_wday + 7) % 7; |
| 158 | mday_ok = 1; |
| 159 | } |
| 160 | |
| 161 | /* If only the month is given, the current month is assumed if the |
| 162 | given month is equal to the current month and next year if it is |
| 163 | less and no year is given (the first day of month is assumed if |
| 164 | no day is given. */ |
| 165 | if (tp->tm_mon >= 0 && tp->tm_mon <= 11 && tp->tm_mday == INT_MIN) |
| 166 | { |
| 167 | if (tp->tm_year == INT_MIN) |
| 168 | tp->tm_year = tm.tm_year + (((tp->tm_mon - tm.tm_mon) < 0) ? 1 : 0); |
| 169 | tp->tm_mday = first_wday (tp->tm_year, tp->tm_mon, tp->tm_wday); |
| 170 | mday_ok = 1; |
| 171 | } |
| 172 | |
| 173 | /* If no hour, minute and second are given the current hour, minute |
| 174 | and second are assumed. */ |
| 175 | if (tp->tm_hour == INT_MIN && tp->tm_min == INT_MIN && tp->tm_sec == INT_MIN) |
| 176 | { |
| 177 | tp->tm_hour = tm.tm_hour; |
| 178 | tp->tm_min = tm.tm_min; |
| 179 | tp->tm_sec = tm.tm_sec; |
| 180 | } |
| 181 | |
| 182 | /* If no date is given, today is assumed if the given hour is |
| 183 | greater than the current hour and tomorrow is assumed if |
| 184 | it is less. */ |
| 185 | if (tp->tm_hour >= 0 && tp->tm_hour <= 23 |
| 186 | && tp->tm_year == INT_MIN && tp->tm_mon == INT_MIN |
| 187 | && tp->tm_mday == INT_MIN && tp->tm_wday == INT_MIN) |
| 188 | { |
| 189 | tp->tm_year = tm.tm_year; |
| 190 | tp->tm_mon = tm.tm_mon; |
| 191 | tp->tm_mday = tm.tm_mday + ((tp->tm_hour - tm.tm_hour) < 0 ? 1 : 0); |
| 192 | mday_ok = 1; |
| 193 | } |
| 194 | |
| 195 | /* Fill in the gaps. */ |
| 196 | if (tp->tm_year == INT_MIN) |
| 197 | tp->tm_year = tm.tm_year; |
| 198 | if (tp->tm_hour == INT_MIN) |
| 199 | tp->tm_hour = 0; |
| 200 | if (tp->tm_min == INT_MIN) |
| 201 | tp->tm_min = 0; |
| 202 | if (tp->tm_sec == INT_MIN) |
| 203 | tp->tm_sec = 0; |
| 204 | |
| 205 | /* Check if the day of month is within range, and if the time can be |
| 206 | represented in a time_t. We make use of the fact that the mktime |
| 207 | call normalizes the struct tm. */ |
| 208 | if ((!mday_ok && !check_mday (TM_YEAR_BASE + tp->tm_year, tp->tm_mon, |
| 209 | tp->tm_mday)) |
| 210 | || mktime (tp) == (time_t) -1) |
| 211 | return 8; |
| 212 | |
| 213 | return 0; |
| 214 | } |
| 215 | |
| 216 | |
| 217 | #if 0 |
| 218 | struct tm * |
| 219 | xgetdate (const char *string, const char *const *template) |
| 220 | { |
| 221 | /* Buffer returned by getdate. */ |
| 222 | static struct tm tmbuf; |
| 223 | int errval = xgetdate_r (string, &tmbuf, template); |
| 224 | |
| 225 | if (errval != 0) |
| 226 | { |
| 227 | xgetdate_err = errval; |
| 228 | return NULL; |
| 229 | } |
| 230 | |
| 231 | return &tmbuf; |
| 232 | } |
| 233 | #endif |