chiark / gitweb /
Kill non-re-entrant xgetdate(). We don't use it so we might as well
[disorder] / lib / xgetdate.c
CommitLineData
d436bd52
RK
1/* Derived from getdate.c in glibc 2.3.6. This is pretty much
2 * standard getdate() except that you supply the template in an
3 * argument, rather than messing around with environment variables and
4 * files. */
5
6/* Convert a string representation of time to a time value.
7 Copyright (C) 1997,1998,1999,2000,2001,2003 Free Software Foundation, Inc.
8 This file is part of the GNU C Library.
9 Contributed by Mark Kettenis <kettenis@phys.uva.nl>, 1997.
10
11 The GNU C Library is free software; you can redistribute it and/or
12 modify it under the terms of the GNU Lesser General Public
13 License as published by the Free Software Foundation; either
14 version 2.1 of the License, or (at your option) any later version.
15
16 The GNU C Library is distributed in the hope that it will be useful,
17 but WITHOUT ANY WARRANTY; without even the implied warranty of
18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19 Lesser General Public License for more details.
20
21 You should have received a copy of the GNU Lesser General Public
22 License along with the GNU C Library; if not, write to the Free
23 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
24 02111-1307 USA. */
25
835a5b33 26#define _GNU_SOURCE 1 /* to expose strptime */
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27#include <limits.h>
28#include <stdio.h>
29#include <stdlib.h>
30#include <string.h>
31#include <time.h>
32
33#include "dateparse.h"
34
35#define TM_YEAR_BASE 1900
36
37
38/* Prototypes for local functions. */
39static int first_wday (int year, int mon, int wday);
40static int check_mday (int year, int mon, int mday);
41
42# define isleap(year) \
43 ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))
44
45/* Set to one of the following values to indicate an error.
46 1 the DATEMSK environment variable is null or undefined,
47 2 the template file cannot be opened for reading,
48 3 failed to get file status information,
49 4 the template file is not a regular file,
50 5 an error is encountered while reading the template file,
51 6 memory allication failed (not enough memory available),
52 7 there is no line in the template that matches the input,
53 8 invalid input specification Example: February 31 or a time is
54 specified that can not be represented in a time_t (representing
55 the time in seconds since 00:00:00 UTC, January 1, 1970) */
835a5b33 56/*int xgetdate_err;*/
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57
58
59/* Returns the first weekday WDAY of month MON in the year YEAR. */
60static int
61first_wday (int year, int mon, int wday)
62{
63 struct tm tm;
64
65 if (wday == INT_MIN)
66 return 1;
67
68 memset (&tm, 0, sizeof (struct tm));
69 tm.tm_year = year;
70 tm.tm_mon = mon;
71 tm.tm_mday = 1;
72 mktime (&tm);
73
74 return (1 + (wday - tm.tm_wday + 7) % 7);
75}
76
77
78/* Returns 1 if MDAY is a valid day of the month in month MON of year
79 YEAR, and 0 if it is not. */
80static int
81check_mday (int year, int mon, int mday)
82{
83 switch (mon)
84 {
85 case 0:
86 case 2:
87 case 4:
88 case 6:
89 case 7:
90 case 9:
91 case 11:
92 if (mday >= 1 && mday <= 31)
93 return 1;
94 break;
95 case 3:
96 case 5:
97 case 8:
98 case 10:
99 if (mday >= 1 && mday <= 30)
100 return 1;
101 break;
102 case 1:
103 if (mday >= 1 && mday <= (isleap (year) ? 29 : 28))
104 return 1;
105 break;
106 }
107
108 return 0;
109}
110
111
112int
113xgetdate_r (const char *string, struct tm *tp,
114 const char *const *template)
115{
116 const char *line;
117 size_t len;
118 char *result = NULL;
119 time_t timer;
120 struct tm tm;
121 int mday_ok = 0;
122
123 line = NULL;
124 len = 0;
125 while((line = *template++))
126 {
127 /* Do the conversion. */
128 tp->tm_year = tp->tm_mon = tp->tm_mday = tp->tm_wday = INT_MIN;
129 tp->tm_hour = tp->tm_sec = tp->tm_min = INT_MIN;
130 tp->tm_isdst = -1;
131 tp->tm_gmtoff = 0;
132 tp->tm_zone = NULL;
133 result = strptime (string, line, tp);
134 if (result && *result == '\0')
135 break;
136 }
137
138 if (result == NULL || *result != '\0')
139 return 7;
140
141 /* Get current time. */
142 time (&timer);
143 localtime_r (&timer, &tm);
144
145 /* If only the weekday is given, today is assumed if the given day
146 is equal to the current day and next week if it is less. */
147 if (tp->tm_wday >= 0 && tp->tm_wday <= 6 && tp->tm_year == INT_MIN
148 && tp->tm_mon == INT_MIN && tp->tm_mday == INT_MIN)
149 {
150 tp->tm_year = tm.tm_year;
151 tp->tm_mon = tm.tm_mon;
152 tp->tm_mday = tm.tm_mday + (tp->tm_wday - tm.tm_wday + 7) % 7;
153 mday_ok = 1;
154 }
155
156 /* If only the month is given, the current month is assumed if the
157 given month is equal to the current month and next year if it is
158 less and no year is given (the first day of month is assumed if
159 no day is given. */
160 if (tp->tm_mon >= 0 && tp->tm_mon <= 11 && tp->tm_mday == INT_MIN)
161 {
162 if (tp->tm_year == INT_MIN)
163 tp->tm_year = tm.tm_year + (((tp->tm_mon - tm.tm_mon) < 0) ? 1 : 0);
164 tp->tm_mday = first_wday (tp->tm_year, tp->tm_mon, tp->tm_wday);
165 mday_ok = 1;
166 }
167
168 /* If no hour, minute and second are given the current hour, minute
169 and second are assumed. */
170 if (tp->tm_hour == INT_MIN && tp->tm_min == INT_MIN && tp->tm_sec == INT_MIN)
171 {
172 tp->tm_hour = tm.tm_hour;
173 tp->tm_min = tm.tm_min;
174 tp->tm_sec = tm.tm_sec;
175 }
176
177 /* If no date is given, today is assumed if the given hour is
178 greater than the current hour and tomorrow is assumed if
179 it is less. */
180 if (tp->tm_hour >= 0 && tp->tm_hour <= 23
181 && tp->tm_year == INT_MIN && tp->tm_mon == INT_MIN
182 && tp->tm_mday == INT_MIN && tp->tm_wday == INT_MIN)
183 {
184 tp->tm_year = tm.tm_year;
185 tp->tm_mon = tm.tm_mon;
186 tp->tm_mday = tm.tm_mday + ((tp->tm_hour - tm.tm_hour) < 0 ? 1 : 0);
187 mday_ok = 1;
188 }
189
190 /* Fill in the gaps. */
191 if (tp->tm_year == INT_MIN)
192 tp->tm_year = tm.tm_year;
193 if (tp->tm_hour == INT_MIN)
194 tp->tm_hour = 0;
195 if (tp->tm_min == INT_MIN)
196 tp->tm_min = 0;
197 if (tp->tm_sec == INT_MIN)
198 tp->tm_sec = 0;
199
200 /* Check if the day of month is within range, and if the time can be
201 represented in a time_t. We make use of the fact that the mktime
202 call normalizes the struct tm. */
203 if ((!mday_ok && !check_mday (TM_YEAR_BASE + tp->tm_year, tp->tm_mon,
204 tp->tm_mday))
205 || mktime (tp) == (time_t) -1)
206 return 8;
207
208 return 0;
209}
210
211
835a5b33 212#if 0
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213struct tm *
214 xgetdate (const char *string, const char *const *template)
215{
216 /* Buffer returned by getdate. */
217 static struct tm tmbuf;
218 int errval = xgetdate_r (string, &tmbuf, template);
219
220 if (errval != 0)
221 {
835a5b33 222 xgetdate_err = errval;
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223 return NULL;
224 }
225
226 return &tmbuf;
227}
835a5b33 228#endif