Commit | Line | Data |
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b8f253e8 KM |
1 | /* |
2 | * Copyright (c) 1980 Regents of the University of California. | |
3 | * All rights reserved. The Berkeley software License Agreement | |
4 | * specifies the terms and conditions for redistribution. | |
5 | */ | |
6 | ||
455b164d | 7 | #ifndef lint |
3d0f8b49 | 8 | static char sccsid[] = "@(#)ctime.c 5.4 (Berkeley) %G%"; |
b8f253e8 KM |
9 | #endif not lint |
10 | ||
674afc9d BJ |
11 | /* |
12 | * This routine converts time as follows. | |
13 | * The epoch is 0000 Jan 1 1970 GMT. | |
14 | * The argument time is in seconds since then. | |
15 | * The localtime(t) entry returns a pointer to an array | |
16 | * containing | |
17 | * seconds (0-59) | |
18 | * minutes (0-59) | |
19 | * hours (0-23) | |
20 | * day of month (1-31) | |
21 | * month (0-11) | |
22 | * year-1970 | |
23 | * weekday (0-6, Sun is 0) | |
24 | * day of the year | |
25 | * daylight savings flag | |
26 | * | |
27 | * The routine calls the system to determine the local | |
28 | * timezone and whether Daylight Saving Time is permitted locally. | |
7f253f66 | 29 | * (DST is then determined by the current local rules) |
674afc9d BJ |
30 | * |
31 | * The routine does not work | |
32 | * in Saudi Arabia which runs on Solar time. | |
33 | * | |
34 | * asctime(tvec)) | |
35 | * where tvec is produced by localtime | |
36 | * returns a ptr to a character string | |
37 | * that has the ascii time in the form | |
2169a56f RC |
38 | * Thu Jan 01 00:00:00 1970\n\0 |
39 | * 0123456789012345678901234 5 | |
674afc9d BJ |
40 | * 0 1 2 |
41 | * | |
42 | * ctime(t) just calls localtime, then asctime. | |
43 | */ | |
44 | ||
455b164d | 45 | #include <sys/time.h> |
674afc9d BJ |
46 | #include <sys/types.h> |
47 | #include <sys/timeb.h> | |
48 | ||
49 | static char cbuf[26]; | |
50 | static int dmsize[12] = | |
51 | { | |
52 | 31, | |
53 | 28, | |
54 | 31, | |
55 | 30, | |
56 | 31, | |
57 | 30, | |
58 | 31, | |
59 | 31, | |
60 | 30, | |
61 | 31, | |
62 | 30, | |
63 | 31 | |
64 | }; | |
65 | ||
66 | /* | |
67 | * The following table is used for 1974 and 1975 and | |
68 | * gives the day number of the first day after the Sunday of the | |
69 | * change. | |
70 | */ | |
bdea7503 SL |
71 | struct dstab { |
72 | int dayyr; | |
674afc9d BJ |
73 | int daylb; |
74 | int dayle; | |
bdea7503 SL |
75 | }; |
76 | ||
77 | static struct dstab usdaytab[] = { | |
78 | 1974, 5, 333, /* 1974: Jan 6 - last Sun. in Nov */ | |
79 | 1975, 58, 303, /* 1975: Last Sun. in Feb - last Sun in Oct */ | |
80 | 0, 119, 303, /* all other years: end Apr - end Oct */ | |
81 | }; | |
82 | static struct dstab ausdaytab[] = { | |
83 | 1970, 400, 0, /* 1970: no daylight saving at all */ | |
84 | 1971, 303, 0, /* 1971: daylight saving from Oct 31 */ | |
85 | 1972, 303, 58, /* 1972: Jan 1 -> Feb 27 & Oct 31 -> dec 31 */ | |
86 | 0, 303, 65, /* others: -> Mar 7, Oct 31 -> */ | |
87 | }; | |
88 | ||
7f253f66 SL |
89 | /* |
90 | * The European tables ... based on hearsay | |
91 | * Believed correct for: | |
4e884c92 | 92 | * WE: Great Britain, Portugal? |
7f253f66 SL |
93 | * ME: Belgium, Luxembourg, Netherlands, Denmark, Norway, |
94 | * Austria, Poland, Czechoslovakia, Sweden, Switzerland, | |
95 | * DDR, DBR, France, Spain, Hungary, Italy, Jugoslavia | |
4e884c92 | 96 | * Finland (EE timezone, but ME dst rules) |
7f253f66 | 97 | * Eastern European dst is unknown, we'll make it ME until someone speaks up. |
4e884c92 RE |
98 | * EE: Bulgaria, Greece, Rumania, Turkey, Western Russia |
99 | * | |
100 | * Ireland is unpredictable. (Years when Easter Sunday just happens ...) | |
101 | * Years before 1983 are suspect. | |
7f253f66 SL |
102 | */ |
103 | static struct dstab wedaytab[] = { | |
4e884c92 RE |
104 | 1983, 89, 296, /* 1983: end March - end Oct */ |
105 | 0, 89, 303, /* others: end March - end Oct */ | |
7f253f66 SL |
106 | }; |
107 | ||
108 | static struct dstab medaytab[] = { | |
4e884c92 RE |
109 | 1983, 89, 296, /* 1983: end March - end Oct */ |
110 | 0, 89, 272, /* others: end March - end Sep */ | |
111 | }; | |
112 | ||
113 | /* | |
114 | * Canada, same as the US, except no early 70's fluctuations. | |
115 | * Can this really be right ?? | |
116 | */ | |
117 | static struct dstab candaytab[] = { | |
118 | 0, 119, 303, /* all years: end Apr - end Oct */ | |
7f253f66 SL |
119 | }; |
120 | ||
bdea7503 SL |
121 | static struct dayrules { |
122 | int dst_type; /* number obtained from system */ | |
123 | int dst_hrs; /* hours to add when dst on */ | |
124 | struct dstab * dst_rules; /* one of the above */ | |
125 | enum {STH,NTH} dst_hemi; /* southern, northern hemisphere */ | |
126 | } dayrules [] = { | |
127 | DST_USA, 1, usdaytab, NTH, | |
128 | DST_AUST, 1, ausdaytab, STH, | |
7f253f66 SL |
129 | DST_WET, 1, wedaytab, NTH, |
130 | DST_MET, 1, medaytab, NTH, | |
131 | DST_EET, 1, medaytab, NTH, /* XXX */ | |
4e884c92 | 132 | DST_CAN, 1, candaytab, NTH, |
bdea7503 | 133 | -1, |
674afc9d BJ |
134 | }; |
135 | ||
136 | struct tm *gmtime(); | |
137 | char *ct_numb(); | |
138 | struct tm *localtime(); | |
139 | char *ctime(); | |
140 | char *ct_num(); | |
141 | char *asctime(); | |
142 | ||
143 | char * | |
144 | ctime(t) | |
2169a56f | 145 | time_t *t; |
674afc9d BJ |
146 | { |
147 | return(asctime(localtime(t))); | |
148 | } | |
149 | ||
150 | struct tm * | |
151 | localtime(tim) | |
2169a56f | 152 | time_t *tim; |
674afc9d BJ |
153 | { |
154 | register int dayno; | |
155 | register struct tm *ct; | |
bdea7503 SL |
156 | register dalybeg, daylend; |
157 | register struct dayrules *dr; | |
158 | register struct dstab *ds; | |
159 | int year; | |
2169a56f | 160 | time_t copyt; |
bdea7503 | 161 | struct timeval curtime; |
3d0f8b49 JB |
162 | static struct timezone zone; |
163 | static int init = 0; | |
674afc9d | 164 | |
3d0f8b49 JB |
165 | if (!init) { |
166 | gettimeofday(&curtime, &zone); | |
167 | init++; | |
168 | } | |
2169a56f | 169 | copyt = *tim - (time_t)zone.tz_minuteswest*60; |
674afc9d BJ |
170 | ct = gmtime(©t); |
171 | dayno = ct->tm_yday; | |
bdea7503 SL |
172 | for (dr = dayrules; dr->dst_type >= 0; dr++) |
173 | if (dr->dst_type == zone.tz_dsttime) | |
174 | break; | |
175 | if (dr->dst_type >= 0) { | |
176 | year = ct->tm_year + 1900; | |
177 | for (ds = dr->dst_rules; ds->dayyr; ds++) | |
178 | if (ds->dayyr == year) | |
179 | break; | |
180 | dalybeg = ds->daylb; /* first Sun after dst starts */ | |
181 | daylend = ds->dayle; /* first Sun after dst ends */ | |
182 | dalybeg = sunday(ct, dalybeg); | |
183 | daylend = sunday(ct, daylend); | |
184 | switch (dr->dst_hemi) { | |
185 | case NTH: | |
186 | if (!( | |
187 | (dayno>dalybeg || (dayno==dalybeg && ct->tm_hour>=2)) && | |
188 | (dayno<daylend || (dayno==daylend && ct->tm_hour<1)) | |
189 | )) | |
190 | return(ct); | |
191 | break; | |
192 | case STH: | |
193 | if (!( | |
194 | (dayno>dalybeg || (dayno==dalybeg && ct->tm_hour>=2)) || | |
195 | (dayno<daylend || (dayno==daylend && ct->tm_hour<2)) | |
196 | )) | |
197 | return(ct); | |
198 | break; | |
199 | default: | |
200 | return(ct); | |
201 | } | |
202 | copyt += dr->dst_hrs*60*60; | |
674afc9d BJ |
203 | ct = gmtime(©t); |
204 | ct->tm_isdst++; | |
205 | } | |
206 | return(ct); | |
207 | } | |
208 | ||
209 | /* | |
210 | * The argument is a 0-origin day number. | |
83b7f1ba | 211 | * The value is the day number of the last |
4e884c92 | 212 | * Sunday on or before the day. |
674afc9d BJ |
213 | */ |
214 | static | |
215 | sunday(t, d) | |
216 | register struct tm *t; | |
217 | register int d; | |
218 | { | |
219 | if (d >= 58) | |
220 | d += dysize(t->tm_year) - 365; | |
221 | return(d - (d - t->tm_yday + t->tm_wday + 700) % 7); | |
222 | } | |
223 | ||
224 | struct tm * | |
225 | gmtime(tim) | |
2169a56f | 226 | time_t *tim; |
674afc9d BJ |
227 | { |
228 | register int d0, d1; | |
2b5f753c | 229 | long hms, day; |
674afc9d BJ |
230 | register int *tp; |
231 | static struct tm xtime; | |
232 | ||
233 | /* | |
234 | * break initial number into days | |
235 | */ | |
236 | hms = *tim % 86400; | |
237 | day = *tim / 86400; | |
238 | if (hms<0) { | |
239 | hms += 86400; | |
240 | day -= 1; | |
241 | } | |
242 | tp = (int *)&xtime; | |
243 | ||
244 | /* | |
245 | * generate hours:minutes:seconds | |
246 | */ | |
247 | *tp++ = hms%60; | |
248 | d1 = hms/60; | |
249 | *tp++ = d1%60; | |
250 | d1 /= 60; | |
251 | *tp++ = d1; | |
252 | ||
253 | /* | |
254 | * day is the day number. | |
255 | * generate day of the week. | |
256 | * The addend is 4 mod 7 (1/1/1970 was Thursday) | |
257 | */ | |
258 | ||
259 | xtime.tm_wday = (day+7340036)%7; | |
260 | ||
261 | /* | |
262 | * year number | |
263 | */ | |
264 | if (day>=0) for(d1=70; day >= dysize(d1); d1++) | |
265 | day -= dysize(d1); | |
266 | else for (d1=70; day<0; d1--) | |
267 | day += dysize(d1-1); | |
268 | xtime.tm_year = d1; | |
269 | xtime.tm_yday = d0 = day; | |
270 | ||
271 | /* | |
272 | * generate month | |
273 | */ | |
274 | ||
275 | if (dysize(d1)==366) | |
276 | dmsize[1] = 29; | |
277 | for(d1=0; d0 >= dmsize[d1]; d1++) | |
278 | d0 -= dmsize[d1]; | |
279 | dmsize[1] = 28; | |
280 | *tp++ = d0+1; | |
281 | *tp++ = d1; | |
282 | xtime.tm_isdst = 0; | |
283 | return(&xtime); | |
284 | } | |
285 | ||
286 | char * | |
287 | asctime(t) | |
288 | struct tm *t; | |
289 | { | |
290 | register char *cp, *ncp; | |
291 | register int *tp; | |
292 | ||
293 | cp = cbuf; | |
294 | for (ncp = "Day Mon 00 00:00:00 1900\n"; *cp++ = *ncp++;); | |
295 | ncp = &"SunMonTueWedThuFriSat"[3*t->tm_wday]; | |
296 | cp = cbuf; | |
297 | *cp++ = *ncp++; | |
298 | *cp++ = *ncp++; | |
299 | *cp++ = *ncp++; | |
300 | cp++; | |
301 | tp = &t->tm_mon; | |
302 | ncp = &"JanFebMarAprMayJunJulAugSepOctNovDec"[(*tp)*3]; | |
303 | *cp++ = *ncp++; | |
304 | *cp++ = *ncp++; | |
305 | *cp++ = *ncp++; | |
306 | cp = ct_numb(cp, *--tp); | |
307 | cp = ct_numb(cp, *--tp+100); | |
308 | cp = ct_numb(cp, *--tp+100); | |
309 | cp = ct_numb(cp, *--tp+100); | |
310 | if (t->tm_year>=100) { | |
311 | cp[1] = '2'; | |
2169a56f | 312 | cp[2] = '0' + (t->tm_year-100) / 100; |
674afc9d BJ |
313 | } |
314 | cp += 2; | |
315 | cp = ct_numb(cp, t->tm_year+100); | |
316 | return(cbuf); | |
317 | } | |
318 | ||
319 | dysize(y) | |
320 | { | |
321 | if((y%4) == 0) | |
322 | return(366); | |
323 | return(365); | |
324 | } | |
325 | ||
326 | static char * | |
327 | ct_numb(cp, n) | |
328 | register char *cp; | |
329 | { | |
330 | cp++; | |
331 | if (n>=10) | |
332 | *cp++ = (n/10)%10 + '0'; | |
333 | else | |
334 | *cp++ = ' '; | |
335 | *cp++ = n%10 + '0'; | |
336 | return(cp); | |
337 | } |