1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
|
/*
* Copyright (C) 1996-8 Michael R. Elkins <me@cs.hmc.edu>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "mutt.h"
/* returns the seconds west of UTC given `g' and its corresponding gmtime()
representation */
static time_t mutt_compute_tz (time_t g, struct tm *utc)
{
struct tm *lt = localtime (&g);
time_t t;
t = (((utc->tm_hour - lt->tm_hour) * 60) + (utc->tm_min - lt->tm_min)) * 60;
switch (utc->tm_yday - lt->tm_yday)
{
case 0:
break;
case 1:
case -364:
case -365:
t += 24 * 60 * 60;
break;
case -1:
case 364:
case 365:
t -= 24 * 60 * 60;
break;
default:
mutt_error ("Please report this program error in the function mutt_mktime.");
}
return t;
}
time_t mutt_local_tz (void)
{
struct tm *ptm;
struct tm utc;
time_t now;
now = time (NULL);
ptm = gmtime (&now);
/* need to make a copy because gmtime/localtime return a pointer to
static memory (grr!) */
memcpy (&utc, ptm, sizeof (utc));
return (mutt_compute_tz (now, &utc));
}
/* converts struct tm to time_t, but does not take the local timezone into
account unless ``local'' is nonzero */
time_t mutt_mktime (struct tm *t, int local)
{
time_t g;
static int AccumDaysPerMonth[12] = {
0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334
};
/* Compute the number of days since January 1 in the same year */
g = AccumDaysPerMonth [t->tm_mon % 12];
/* The leap years are 1972 and every 4. year until 2096,
* but this algoritm will fail after year 2099 */
g += t->tm_mday;
if ((t->tm_year % 4) || t->tm_mon < 2)
g--;
t->tm_yday = g;
/* Compute the number of days since January 1, 1970 */
g += (t->tm_year - 70) * 365;
g += (t->tm_year - 69) / 4;
/* Compute the number of hours */
g *= 24;
g += t->tm_hour;
/* Compute the number of minutes */
g *= 60;
g += t->tm_min;
/* Compute the number of seconds */
g *= 60;
g += t->tm_sec;
if (local)
g += mutt_compute_tz (g, t);
return (g);
}
void mutt_normalize_time (struct tm *tm)
{
static char DaysPerMonth[12] = {
31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
};
while (tm->tm_sec < 0)
{
tm->tm_sec += 60;
tm->tm_min--;
}
while (tm->tm_min < 0)
{
tm->tm_min += 60;
tm->tm_hour--;
}
while (tm->tm_hour < 0)
{
tm->tm_hour += 24;
tm->tm_mday--;
}
while (tm->tm_mon < 0)
{
tm->tm_mon += 12;
tm->tm_year--;
}
while (tm->tm_mday < 0)
{
if (tm->tm_mon)
tm->tm_mon--;
else
{
tm->tm_mon = 11;
tm->tm_year--;
}
tm->tm_mday += DaysPerMonth[tm->tm_mon];
}
}
|
