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More clang-inspired fixes
[disorder] / lib / xgetdate.c
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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"
477f956c 38#include "strptime.h"
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39
40#define TM_YEAR_BASE 1900
41
42
43/* Prototypes for local functions. */
44static int first_wday (int year, int mon, int wday);
45static 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) */
835a5b33 61/*int xgetdate_err;*/
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62
63
64/* Returns the first weekday WDAY of month MON in the year YEAR. */
65static int
66first_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. */
85static int
86check_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
117int
118xgetdate_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;
477f956c 138 result = my_strptime (string, line, tp);
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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
835a5b33 217#if 0
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218struct 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 {
835a5b33 227 xgetdate_err = errval;
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228 return NULL;
229 }
230
231 return &tmbuf;
232}
835a5b33 233#endif