1 #include <u.h>
2 #include <stdlib.h> /* setenv etc. */
3 #define NOPLAN9DEFINES
4 #include <libc.h>
5 #include <time.h>
6 
7 #define _HAVETIMEGM 1
8 #define _HAVETMZONE 1
9 #define _HAVETMTZOFF 1
10 
11 #if defined(__linux__)
12 #	undef _HAVETMZONE
13 #	undef _HAVETMTZOFF
14 
15 #elif defined(__sun__)
16 #	undef _HAVETIMEGM
17 #	undef _HAVETMZONE
18 #	undef _HAVETMTZOFF
19 
20 #endif
21 
22 static Tm bigtm;
23 
24 static void
25 tm2Tm(struct tm *tm, Tm *bigtm)
26 {
27 	char *s;
28 
29 	memset(bigtm, 0, sizeof *bigtm);
30 	bigtm->sec = tm->tm_sec;
31 	bigtm->min = tm->tm_min;
32 	bigtm->hour = tm->tm_hour;
33 	bigtm->mday = tm->tm_mday;
34 	bigtm->mon = tm->tm_mon;
35 	bigtm->year = tm->tm_year;
36 	bigtm->wday = tm->tm_wday;
37 #ifdef _HAVETMZONE
38 	strecpy(bigtm->zone, bigtm->zone+4, tm->tm_zone);
39 #endif
40 #ifdef _HAVETZOFF
41 	bigtm->tzoff = tm->tm_gmtoff;
42 #endif
43 	if(bigtm->zone[0] == 0){
44 		s = getenv("TIMEZONE");
45 		if(s){
46 			strecpy(bigtm->zone, bigtm->zone+4, s);
47 			free(s);
48 		}
49 	}
50 }
51 
52 static void
53 Tm2tm(Tm *bigtm, struct tm *tm)
54 {
55 	memset(tm, 0, sizeof *tm);
56 	tm->tm_sec = bigtm->sec;
57 	tm->tm_min = bigtm->min;
58 	tm->tm_hour = bigtm->hour;
59 	tm->tm_mday = bigtm->mday;
60 	tm->tm_mon = bigtm->mon;
61 	tm->tm_year = bigtm->year;
62 	tm->tm_wday = bigtm->wday;
63 #ifdef _HAVETMZONE
64 	tm->tm_zone = bigtm->zone;
65 #endif
66 #ifdef _HAVETZOFF
67 	tm->tm_gmtoff = bigtm->tzoff;
68 #endif
69 }
70 
71 Tm*
72 p9gmtime(long t)
73 {
74 	struct tm tm;
75 
76 	tm = *gmtime(&t);
77 	tm2Tm(&tm, &bigtm);
78 	return &bigtm;
79 }
80 
81 Tm*
82 p9localtime(long t)
83 {
84 	struct tm tm;
85 
86 	tm = *localtime(&t);
87 	tm2Tm(&tm, &bigtm);
88 	return &bigtm;
89 }
90 
91 #if !defined(_HAVETIMEGM)
92 static time_t
93 timegm(struct tm *tm)
94 {
95 	time_t ret;
96 	char *tz;
97 	char *s;
98 
99 	tz = getenv("TZ");
100 	putenv("TZ=");
101 	tzset();
102 	ret = mktime(tm);
103 	if(tz){
104 		s = smprint("TZ=%s", tz);
105 		if(s)
106 			putenv(s);
107 	}
108 	return ret;
109 }
110 #endif
111 
112 long
113 p9tm2sec(Tm *bigtm)
114 {
115 	struct tm tm;
116 
117 	Tm2tm(bigtm, &tm);
118 	if(strcmp(bigtm->zone, "GMT") == 0 || strcmp(bigtm->zone, "UCT") == 0)
119 		return timegm(&tm);
120 	return mktime(&tm);	/* local time zone */
121 }
122