1 f35a0486 2008-07-09 devnull /*
  2 f35a0486 2008-07-09 devnull  * This routine converts time as follows.
  3 f35a0486 2008-07-09 devnull  * The epoch is 0000 Jan 1 1970 GMT.
  4 f35a0486 2008-07-09 devnull  * The argument time is in seconds since then.
  5 f35a0486 2008-07-09 devnull  * The localtime(t) entry returns a pointer to an array
  6 f35a0486 2008-07-09 devnull  * containing
  7 f35a0486 2008-07-09 devnull  *
  8 f35a0486 2008-07-09 devnull  *	seconds (0-59)
  9 f35a0486 2008-07-09 devnull  *	minutes (0-59)
 10 f35a0486 2008-07-09 devnull  *	hours (0-23)
 11 f35a0486 2008-07-09 devnull  *	day of month (1-31)
 12 f35a0486 2008-07-09 devnull  *	month (0-11)
 13 f35a0486 2008-07-09 devnull  *	year-1970
 14 f35a0486 2008-07-09 devnull  *	weekday (0-6, Sun is 0)
 15 f35a0486 2008-07-09 devnull  *	day of the year
 16 f35a0486 2008-07-09 devnull  *	daylight savings flag
 17 f35a0486 2008-07-09 devnull  *
 18 f35a0486 2008-07-09 devnull  * The routine gets the daylight savings time from the environment.
 19 f35a0486 2008-07-09 devnull  *
 20 f35a0486 2008-07-09 devnull  * asctime(tvec))
 21 f35a0486 2008-07-09 devnull  * where tvec is produced by localtime
 22 f35a0486 2008-07-09 devnull  * returns a ptr to a character string
 23 f35a0486 2008-07-09 devnull  * that has the ascii time in the form
 24 f35a0486 2008-07-09 devnull  *
 25 f35a0486 2008-07-09 devnull  *	                            \\
 26 f35a0486 2008-07-09 devnull  *	Thu Jan 01 00:00:00 GMT 1970n0
 27 f35a0486 2008-07-09 devnull  *	012345678901234567890123456789
 28 f35a0486 2008-07-09 devnull  *	0	  1	    2
 29 f35a0486 2008-07-09 devnull  *
 30 f35a0486 2008-07-09 devnull  * ctime(t) just calls localtime, then asctime.
 31 f35a0486 2008-07-09 devnull  */
 32 f35a0486 2008-07-09 devnull 
 33 fd04aace 2003-11-23 devnull #include <u.h>
 34 fd04aace 2003-11-23 devnull #include <libc.h>
 35 fd04aace 2003-11-23 devnull 
 36 f35a0486 2008-07-09 devnull #include "zoneinfo.h"
 37 f35a0486 2008-07-09 devnull 
 38 f35a0486 2008-07-09 devnull static	char	dmsize[12] =
 39 fd04aace 2003-11-23 devnull {
 40 f35a0486 2008-07-09 devnull 	31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
 41 f35a0486 2008-07-09 devnull };
 42 fd04aace 2003-11-23 devnull 
 43 f35a0486 2008-07-09 devnull #define dysize ctimedysize
 44 f35a0486 2008-07-09 devnull static	int	dysize(int);
 45 f35a0486 2008-07-09 devnull static	void	ct_numb(char*, int);
 46 f35a0486 2008-07-09 devnull 
 47 f35a0486 2008-07-09 devnull char*
 48 f35a0486 2008-07-09 devnull ctime(long t)
 49 f35a0486 2008-07-09 devnull {
 50 f35a0486 2008-07-09 devnull 	return asctime(localtime(t));
 51 fd04aace 2003-11-23 devnull }
 52 fd04aace 2003-11-23 devnull 
 53 f35a0486 2008-07-09 devnull Tm*
 54 f35a0486 2008-07-09 devnull localtime(long tim)
 55 f35a0486 2008-07-09 devnull {
 56 f35a0486 2008-07-09 devnull 	Tinfo ti;
 57 f35a0486 2008-07-09 devnull 	Tm *ct;
 58 f35a0486 2008-07-09 devnull 
 59 f35a0486 2008-07-09 devnull 	if (zonelookuptinfo(&ti, tim)!=-1) {
 60 f35a0486 2008-07-09 devnull 		ct = gmtime(tim+ti.tzoff);
 61 e6ed10f2 2020-01-07 crossd 		strncpy(ct->zone, ti.zone, sizeof ct->zone - 1);
 62 f35a0486 2008-07-09 devnull 		ct->zone[sizeof ct->zone-1] = 0;
 63 f35a0486 2008-07-09 devnull 		ct->tzoff = ti.tzoff;
 64 f35a0486 2008-07-09 devnull 		return ct;
 65 f35a0486 2008-07-09 devnull 	}
 66 f35a0486 2008-07-09 devnull 	return gmtime(tim);
 67 f35a0486 2008-07-09 devnull }
 68 f35a0486 2008-07-09 devnull 
 69 f35a0486 2008-07-09 devnull Tm*
 70 f35a0486 2008-07-09 devnull gmtime(long tim)
 71 f35a0486 2008-07-09 devnull {
 72 f35a0486 2008-07-09 devnull 	int d0, d1;
 73 f35a0486 2008-07-09 devnull 	long hms, day;
 74 f35a0486 2008-07-09 devnull 	static Tm xtime;
 75 f35a0486 2008-07-09 devnull 
 76 f35a0486 2008-07-09 devnull 	/*
 77 f35a0486 2008-07-09 devnull 	 * break initial number into days
 78 f35a0486 2008-07-09 devnull 	 */
 79 f35a0486 2008-07-09 devnull 	hms = tim % 86400L;
 80 f35a0486 2008-07-09 devnull 	day = tim / 86400L;
 81 f35a0486 2008-07-09 devnull 	if(hms < 0) {
 82 f35a0486 2008-07-09 devnull 		hms += 86400L;
 83 f35a0486 2008-07-09 devnull 		day -= 1;
 84 f35a0486 2008-07-09 devnull 	}
 85 f35a0486 2008-07-09 devnull 
 86 f35a0486 2008-07-09 devnull 	/*
 87 f35a0486 2008-07-09 devnull 	 * generate hours:minutes:seconds
 88 f35a0486 2008-07-09 devnull 	 */
 89 f35a0486 2008-07-09 devnull 	xtime.sec = hms % 60;
 90 f35a0486 2008-07-09 devnull 	d1 = hms / 60;
 91 f35a0486 2008-07-09 devnull 	xtime.min = d1 % 60;
 92 f35a0486 2008-07-09 devnull 	d1 /= 60;
 93 f35a0486 2008-07-09 devnull 	xtime.hour = d1;
 94 f35a0486 2008-07-09 devnull 
 95 f35a0486 2008-07-09 devnull 	/*
 96 f35a0486 2008-07-09 devnull 	 * day is the day number.
 97 f35a0486 2008-07-09 devnull 	 * generate day of the week.
 98 f35a0486 2008-07-09 devnull 	 * The addend is 4 mod 7 (1/1/1970 was Thursday)
 99 f35a0486 2008-07-09 devnull 	 */
100 f35a0486 2008-07-09 devnull 
101 f35a0486 2008-07-09 devnull 	xtime.wday = (day + 7340036L) % 7;
102 f35a0486 2008-07-09 devnull 
103 f35a0486 2008-07-09 devnull 	/*
104 f35a0486 2008-07-09 devnull 	 * year number
105 f35a0486 2008-07-09 devnull 	 */
106 f35a0486 2008-07-09 devnull 	if(day >= 0)
107 f35a0486 2008-07-09 devnull 		for(d1 = 1970; day >= dysize(d1); d1++)
108 f35a0486 2008-07-09 devnull 			day -= dysize(d1);
109 f35a0486 2008-07-09 devnull 	else
110 f35a0486 2008-07-09 devnull 		for (d1 = 1970; day < 0; d1--)
111 f35a0486 2008-07-09 devnull 			day += dysize(d1-1);
112 f35a0486 2008-07-09 devnull 	xtime.year = d1-1900;
113 f35a0486 2008-07-09 devnull 	xtime.yday = d0 = day;
114 f35a0486 2008-07-09 devnull 
115 f35a0486 2008-07-09 devnull 	/*
116 f35a0486 2008-07-09 devnull 	 * generate month
117 f35a0486 2008-07-09 devnull 	 */
118 f35a0486 2008-07-09 devnull 
119 f35a0486 2008-07-09 devnull 	if(dysize(d1) == 366)
120 f35a0486 2008-07-09 devnull 		dmsize[1] = 29;
121 f35a0486 2008-07-09 devnull 	for(d1 = 0; d0 >= dmsize[d1]; d1++)
122 f35a0486 2008-07-09 devnull 		d0 -= dmsize[d1];
123 f35a0486 2008-07-09 devnull 	dmsize[1] = 28;
124 f35a0486 2008-07-09 devnull 	xtime.mday = d0 + 1;
125 f35a0486 2008-07-09 devnull 	xtime.mon = d1;
126 f35a0486 2008-07-09 devnull 	strcpy(xtime.zone, "GMT");
127 f35a0486 2008-07-09 devnull 	return &xtime;
128 f35a0486 2008-07-09 devnull }
129 f35a0486 2008-07-09 devnull 
130 fd04aace 2003-11-23 devnull char*
131 fd04aace 2003-11-23 devnull asctime(Tm *t)
132 fd04aace 2003-11-23 devnull {
133 fc567f47 2011-08-02 rsc 	const char *ncp;
134 fd04aace 2003-11-23 devnull 	static char cbuf[30];
135 fd04aace 2003-11-23 devnull 
136 fd04aace 2003-11-23 devnull 	strcpy(cbuf, "Thu Jan 01 00:00:00 GMT 1970\n");
137 fd04aace 2003-11-23 devnull 	ncp = &"SunMonTueWedThuFriSat"[t->wday*3];
138 fd04aace 2003-11-23 devnull 	cbuf[0] = *ncp++;
139 fd04aace 2003-11-23 devnull 	cbuf[1] = *ncp++;
140 fd04aace 2003-11-23 devnull 	cbuf[2] = *ncp;
141 fd04aace 2003-11-23 devnull 	ncp = &"JanFebMarAprMayJunJulAugSepOctNovDec"[t->mon*3];
142 fd04aace 2003-11-23 devnull 	cbuf[4] = *ncp++;
143 fd04aace 2003-11-23 devnull 	cbuf[5] = *ncp++;
144 fd04aace 2003-11-23 devnull 	cbuf[6] = *ncp;
145 fd04aace 2003-11-23 devnull 	ct_numb(cbuf+8, t->mday);
146 fd04aace 2003-11-23 devnull 	ct_numb(cbuf+11, t->hour+100);
147 fd04aace 2003-11-23 devnull 	ct_numb(cbuf+14, t->min+100);
148 fd04aace 2003-11-23 devnull 	ct_numb(cbuf+17, t->sec+100);
149 fd04aace 2003-11-23 devnull 	ncp = t->zone;
150 fd04aace 2003-11-23 devnull 	cbuf[20] = *ncp++;
151 fd04aace 2003-11-23 devnull 	cbuf[21] = *ncp++;
152 fd04aace 2003-11-23 devnull 	cbuf[22] = *ncp;
153 fd04aace 2003-11-23 devnull 	if(t->year >= 100) {
154 fd04aace 2003-11-23 devnull 		cbuf[24] = '2';
155 fd04aace 2003-11-23 devnull 		cbuf[25] = '0';
156 fd04aace 2003-11-23 devnull 	}
157 fd04aace 2003-11-23 devnull 	ct_numb(cbuf+26, t->year+100);
158 fd04aace 2003-11-23 devnull 	return cbuf;
159 fd04aace 2003-11-23 devnull }
160 fd04aace 2003-11-23 devnull 
161 f35a0486 2008-07-09 devnull static
162 f35a0486 2008-07-09 devnull int
163 f35a0486 2008-07-09 devnull dysize(int y)
164 fd04aace 2003-11-23 devnull {
165 f35a0486 2008-07-09 devnull 
166 f35a0486 2008-07-09 devnull 	if(y%4 == 0 && (y%100 != 0 || y%400 == 0))
167 f35a0486 2008-07-09 devnull 		return 366;
168 f35a0486 2008-07-09 devnull 	return 365;
169 fd04aace 2003-11-23 devnull }
170 fd04aace 2003-11-23 devnull 
171 f35a0486 2008-07-09 devnull static
172 f35a0486 2008-07-09 devnull void
173 f35a0486 2008-07-09 devnull ct_numb(char *cp, int n)
174 f35a0486 2008-07-09 devnull {
175 f35a0486 2008-07-09 devnull 
176 f35a0486 2008-07-09 devnull 	cp[0] = ' ';
177 f35a0486 2008-07-09 devnull 	if(n >= 10)
178 f35a0486 2008-07-09 devnull 		cp[0] = (n/10)%10 + '0';
179 f35a0486 2008-07-09 devnull 	cp[1] = n%10 + '0';
180 f35a0486 2008-07-09 devnull }