1 #define NOPLAN9DEFINES
2 #include <u.h>
3 #include <libc.h>
4 #include <stdlib.h> /* setenv etc. */
5 #include <time.h>
6 
7 static int didtz;
8 static int tzdelta;
9 static char tzone[32];
10 
11 static void
12 dotz(void)
13 {
14 	time_t t;
15 	struct tm *gtm;
16 	struct tm tm;
17 
18 	if(didtz)
19 		return;
20 	didtz = 1;
21 	t = time(0);
22 	strftime(tzone, sizeof tzone, "%Z", localtime(&t));
23 	tm = *localtime(&t);	/* set local time zone field */
24 	gtm = gmtime(&t);
25 	tm.tm_sec = gtm->tm_sec;
26 	tm.tm_min = gtm->tm_min;
27 	tm.tm_hour = gtm->tm_hour;
28 	tm.tm_mday = gtm->tm_mday;
29 	tm.tm_mon = gtm->tm_mon;
30 	tm.tm_year = gtm->tm_year;
31 	tm.tm_wday = gtm->tm_wday;
32 	tzdelta = t - mktime(&tm);
33 }
34 
35 static void
36 tm2Tm(struct tm *tm, Tm *bigtm, int gmt)
37 {
38 	memset(bigtm, 0, sizeof *bigtm);
39 	bigtm->sec = tm->tm_sec;
40 	bigtm->min = tm->tm_min;
41 	bigtm->hour = tm->tm_hour;
42 	bigtm->mday = tm->tm_mday;
43 	bigtm->mon = tm->tm_mon;
44 	bigtm->year = tm->tm_year;
45 	bigtm->wday = tm->tm_wday;
46 	if(gmt){
47 		strcpy(bigtm->zone, "GMT");
48 		bigtm->tzoff = 0;
49 	}else{
50 		dotz();
51 		strncpy(bigtm->zone, tzone, 3);
52 		bigtm->zone[3] = 0;
53 		bigtm->tzoff = tzdelta;
54 	}
55 }
56 
57 static void
58 Tm2tm(Tm *bigtm, struct tm *tm)
59 {
60 	/* initialize with current time to get local time zone! (tm_isdst) */
61 	time_t t;
62 	time(&t);
63 	*tm = *localtime(&t);
64 
65 	tm->tm_sec = bigtm->sec;
66 	tm->tm_min = bigtm->min;
67 	tm->tm_hour = bigtm->hour;
68 	tm->tm_mday = bigtm->mday;
69 	tm->tm_mon = bigtm->mon;
70 	tm->tm_year = bigtm->year;
71 	tm->tm_wday = bigtm->wday;
72 }
73 
74 Tm*
75 p9gmtime(long x)
76 {
77 	time_t t;
78 	struct tm tm;
79 	static Tm bigtm;
80 	
81 	t = (time_t)x;
82 	tm = *gmtime(&t);
83 	tm2Tm(&tm, &bigtm, 1);
84 	return &bigtm;
85 }
86 
87 Tm*
88 p9localtime(long x)
89 {
90 	time_t t;
91 	struct tm tm;
92 	static Tm bigtm;
93 
94 	t = (time_t)x;
95 	tm = *localtime(&t);
96 	tm2Tm(&tm, &bigtm, 0);
97 	return &bigtm;
98 }
99 
100 long
101 p9tm2sec(Tm *bigtm)
102 {
103 	time_t t;
104 	struct tm tm;
105 
106 	Tm2tm(bigtm, &tm);
107 	t = mktime(&tm);
108 	if(strcmp(bigtm->zone, "GMT") == 0 || strcmp(bigtm->zone, "UCT") == 0){
109 		dotz();
110 		t += tzdelta;
111 	}
112 	return t;
113 }
114