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[4];
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 		strcpy(bigtm->zone, tzone);
52 		bigtm->tzoff = tzdelta;
53 	}
54 }
55 
56 static void
57 Tm2tm(Tm *bigtm, struct tm *tm)
58 {
59 	/* initialize with current time to get local time zone! (tm_isdst) */
60 	time_t t;
61 	time(&t);
62 	*tm = *localtime(&t);
63 
64 	tm->tm_sec = bigtm->sec;
65 	tm->tm_min = bigtm->min;
66 	tm->tm_hour = bigtm->hour;
67 	tm->tm_mday = bigtm->mday;
68 	tm->tm_mon = bigtm->mon;
69 	tm->tm_year = bigtm->year;
70 	tm->tm_wday = bigtm->wday;
71 }
72 
73 Tm*
74 p9gmtime(long x)
75 {
76 	time_t t;
77 	struct tm tm;
78 	static Tm bigtm;
79 	
80 	t = (time_t)x;
81 	tm = *gmtime(&t);
82 	tm2Tm(&tm, &bigtm, 1);
83 	return &bigtm;
84 }
85 
86 Tm*
87 p9localtime(long x)
88 {
89 	time_t t;
90 	struct tm tm;
91 	static Tm bigtm;
92 
93 	t = (time_t)x;
94 	tm = *localtime(&t);
95 	tm2Tm(&tm, &bigtm, 0);
96 	return &bigtm;
97 }
98 
99 long
100 p9tm2sec(Tm *bigtm)
101 {
102 	time_t t;
103 	struct tm tm;
104 
105 	Tm2tm(bigtm, &tm);
106 	t = mktime(&tm);
107 	if(strcmp(bigtm->zone, "GMT") == 0 || strcmp(bigtm->zone, "UCT") == 0){
108 		dotz();
109 		t += tzdelta;
110 	}
111 	return t;
112 }
113