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1 | /** @file lib/xgetdate.c |
2 | * @brief Date parsing | |
3 | * | |
4 | * Derived from getdate.c in glibc 2.3.6. This is pretty much | |
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5 | * standard getdate() except that you supply the template in an |
6 | * argument, rather than messing around with environment variables and | |
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7 | * files. |
8 | */ | |
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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 | ||
835a5b33 | 30 | #define _GNU_SOURCE 1 /* to expose strptime */ |
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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 | ||
39 | #define TM_YEAR_BASE 1900 | |
40 | ||
41 | ||
42 | /* Prototypes for local functions. */ | |
43 | static int first_wday (int year, int mon, int wday); | |
44 | static int check_mday (int year, int mon, int mday); | |
45 | ||
46 | # define isleap(year) \ | |
47 | ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0)) | |
48 | ||
49 | /* Set to one of the following values to indicate an error. | |
50 | 1 the DATEMSK environment variable is null or undefined, | |
51 | 2 the template file cannot be opened for reading, | |
52 | 3 failed to get file status information, | |
53 | 4 the template file is not a regular file, | |
54 | 5 an error is encountered while reading the template file, | |
55 | 6 memory allication failed (not enough memory available), | |
56 | 7 there is no line in the template that matches the input, | |
57 | 8 invalid input specification Example: February 31 or a time is | |
58 | specified that can not be represented in a time_t (representing | |
59 | the time in seconds since 00:00:00 UTC, January 1, 1970) */ | |
835a5b33 | 60 | /*int xgetdate_err;*/ |
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61 | |
62 | ||
63 | /* Returns the first weekday WDAY of month MON in the year YEAR. */ | |
64 | static int | |
65 | first_wday (int year, int mon, int wday) | |
66 | { | |
67 | struct tm tm; | |
68 | ||
69 | if (wday == INT_MIN) | |
70 | return 1; | |
71 | ||
72 | memset (&tm, 0, sizeof (struct tm)); | |
73 | tm.tm_year = year; | |
74 | tm.tm_mon = mon; | |
75 | tm.tm_mday = 1; | |
76 | mktime (&tm); | |
77 | ||
78 | return (1 + (wday - tm.tm_wday + 7) % 7); | |
79 | } | |
80 | ||
81 | ||
82 | /* Returns 1 if MDAY is a valid day of the month in month MON of year | |
83 | YEAR, and 0 if it is not. */ | |
84 | static int | |
85 | check_mday (int year, int mon, int mday) | |
86 | { | |
87 | switch (mon) | |
88 | { | |
89 | case 0: | |
90 | case 2: | |
91 | case 4: | |
92 | case 6: | |
93 | case 7: | |
94 | case 9: | |
95 | case 11: | |
96 | if (mday >= 1 && mday <= 31) | |
97 | return 1; | |
98 | break; | |
99 | case 3: | |
100 | case 5: | |
101 | case 8: | |
102 | case 10: | |
103 | if (mday >= 1 && mday <= 30) | |
104 | return 1; | |
105 | break; | |
106 | case 1: | |
107 | if (mday >= 1 && mday <= (isleap (year) ? 29 : 28)) | |
108 | return 1; | |
109 | break; | |
110 | } | |
111 | ||
112 | return 0; | |
113 | } | |
114 | ||
115 | ||
116 | int | |
117 | xgetdate_r (const char *string, struct tm *tp, | |
118 | const char *const *template) | |
119 | { | |
120 | const char *line; | |
121 | size_t len; | |
122 | char *result = NULL; | |
123 | time_t timer; | |
124 | struct tm tm; | |
125 | int mday_ok = 0; | |
126 | ||
127 | line = NULL; | |
128 | len = 0; | |
129 | while((line = *template++)) | |
130 | { | |
131 | /* Do the conversion. */ | |
132 | tp->tm_year = tp->tm_mon = tp->tm_mday = tp->tm_wday = INT_MIN; | |
133 | tp->tm_hour = tp->tm_sec = tp->tm_min = INT_MIN; | |
134 | tp->tm_isdst = -1; | |
135 | tp->tm_gmtoff = 0; | |
136 | tp->tm_zone = NULL; | |
137 | result = strptime (string, line, tp); | |
138 | if (result && *result == '\0') | |
139 | break; | |
140 | } | |
141 | ||
142 | if (result == NULL || *result != '\0') | |
143 | return 7; | |
144 | ||
145 | /* Get current time. */ | |
146 | time (&timer); | |
147 | localtime_r (&timer, &tm); | |
148 | ||
149 | /* If only the weekday is given, today is assumed if the given day | |
150 | is equal to the current day and next week if it is less. */ | |
151 | if (tp->tm_wday >= 0 && tp->tm_wday <= 6 && tp->tm_year == INT_MIN | |
152 | && tp->tm_mon == INT_MIN && tp->tm_mday == INT_MIN) | |
153 | { | |
154 | tp->tm_year = tm.tm_year; | |
155 | tp->tm_mon = tm.tm_mon; | |
156 | tp->tm_mday = tm.tm_mday + (tp->tm_wday - tm.tm_wday + 7) % 7; | |
157 | mday_ok = 1; | |
158 | } | |
159 | ||
160 | /* If only the month is given, the current month is assumed if the | |
161 | given month is equal to the current month and next year if it is | |
162 | less and no year is given (the first day of month is assumed if | |
163 | no day is given. */ | |
164 | if (tp->tm_mon >= 0 && tp->tm_mon <= 11 && tp->tm_mday == INT_MIN) | |
165 | { | |
166 | if (tp->tm_year == INT_MIN) | |
167 | tp->tm_year = tm.tm_year + (((tp->tm_mon - tm.tm_mon) < 0) ? 1 : 0); | |
168 | tp->tm_mday = first_wday (tp->tm_year, tp->tm_mon, tp->tm_wday); | |
169 | mday_ok = 1; | |
170 | } | |
171 | ||
172 | /* If no hour, minute and second are given the current hour, minute | |
173 | and second are assumed. */ | |
174 | if (tp->tm_hour == INT_MIN && tp->tm_min == INT_MIN && tp->tm_sec == INT_MIN) | |
175 | { | |
176 | tp->tm_hour = tm.tm_hour; | |
177 | tp->tm_min = tm.tm_min; | |
178 | tp->tm_sec = tm.tm_sec; | |
179 | } | |
180 | ||
181 | /* If no date is given, today is assumed if the given hour is | |
182 | greater than the current hour and tomorrow is assumed if | |
183 | it is less. */ | |
184 | if (tp->tm_hour >= 0 && tp->tm_hour <= 23 | |
185 | && tp->tm_year == INT_MIN && tp->tm_mon == INT_MIN | |
186 | && tp->tm_mday == INT_MIN && tp->tm_wday == INT_MIN) | |
187 | { | |
188 | tp->tm_year = tm.tm_year; | |
189 | tp->tm_mon = tm.tm_mon; | |
190 | tp->tm_mday = tm.tm_mday + ((tp->tm_hour - tm.tm_hour) < 0 ? 1 : 0); | |
191 | mday_ok = 1; | |
192 | } | |
193 | ||
194 | /* Fill in the gaps. */ | |
195 | if (tp->tm_year == INT_MIN) | |
196 | tp->tm_year = tm.tm_year; | |
197 | if (tp->tm_hour == INT_MIN) | |
198 | tp->tm_hour = 0; | |
199 | if (tp->tm_min == INT_MIN) | |
200 | tp->tm_min = 0; | |
201 | if (tp->tm_sec == INT_MIN) | |
202 | tp->tm_sec = 0; | |
203 | ||
204 | /* Check if the day of month is within range, and if the time can be | |
205 | represented in a time_t. We make use of the fact that the mktime | |
206 | call normalizes the struct tm. */ | |
207 | if ((!mday_ok && !check_mday (TM_YEAR_BASE + tp->tm_year, tp->tm_mon, | |
208 | tp->tm_mday)) | |
209 | || mktime (tp) == (time_t) -1) | |
210 | return 8; | |
211 | ||
212 | return 0; | |
213 | } | |
214 | ||
215 | ||
835a5b33 | 216 | #if 0 |
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217 | struct tm * |
218 | xgetdate (const char *string, const char *const *template) | |
219 | { | |
220 | /* Buffer returned by getdate. */ | |
221 | static struct tm tmbuf; | |
222 | int errval = xgetdate_r (string, &tmbuf, template); | |
223 | ||
224 | if (errval != 0) | |
225 | { | |
835a5b33 | 226 | xgetdate_err = errval; |
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227 | return NULL; |
228 | } | |
229 | ||
230 | return &tmbuf; | |
231 | } | |
835a5b33 | 232 | #endif |