1 #include "all.h" 2 3 static int sunday(Tm *t, int d); 4 static int dysize(int); 5 static void ct_numb(char*, int); 6 static void klocaltime(long tim, Tm *ct); 7 static void kgmtime(long tim, Tm *ct); 8 9 static char dmsize[12] = 10 { 11 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 12 }; 13 14 /* 15 * The following table is used for 1974 and 1975 and 16 * gives the day number of the first day after the Sunday of the 17 * change. 18 */ 19 static struct 20 { 21 short yrfrom; 22 short yrto; 23 short daylb; 24 short dayle; 25 } daytab[] = 26 { 27 87, 999, 97, 303, 28 76, 86, 119, 303, 29 75, 75, 58, 303, 30 74, 74, 5, 333, 31 0, 73, 119, 303, 32 }; 33 34 static struct 35 { 36 short minuteswest; /* minutes west of Greenwich */ 37 short dsttime; /* dst correction */ 38 } timezone = 39 { 40 5*60, 1 41 }; 42 43 static void 44 klocaltime(long tim, Tm *ct) 45 { 46 int daylbegin, daylend, dayno, i; 47 long copyt; 48 49 copyt = tim - timezone.minuteswest*60L; 50 kgmtime(copyt, ct); 51 dayno = ct->yday; 52 for(i=0;; i++) 53 if(ct->year >= daytab[i].yrfrom && 54 ct->year <= daytab[i].yrto) { 55 daylbegin = sunday(ct, daytab[i].daylb); 56 daylend = sunday(ct, daytab[i].dayle); 57 break; 58 } 59 if(timezone.dsttime && 60 (dayno>daylbegin || (dayno==daylbegin && ct->hour>=2)) && 61 (dayno<daylend || (dayno==daylend && ct->hour<1))) { 62 copyt += 60L*60L; 63 kgmtime(copyt, ct); 64 } 65 } 66 67 /* 68 * The argument is a 0-origin day number. 69 * The value is the day number of the last 70 * Sunday before or after the day. 71 */ 72 static 73 sunday(Tm *t, int d) 74 { 75 if(d >= 58) 76 d += dysize(t->year) - 365; 77 return d - (d - t->yday + t->wday + 700) % 7; 78 } 79 80 static void 81 kgmtime(long tim, Tm *ct) 82 { 83 int d0, d1; 84 long hms, day; 85 86 /* 87 * break initial number into days 88 */ 89 hms = tim % 86400L; 90 day = tim / 86400L; 91 if(hms < 0) { 92 hms += 86400L; 93 day -= 1; 94 } 95 96 /* 97 * generate hours:minutes:seconds 98 */ 99 ct->sec = hms % 60; 100 d1 = hms / 60; 101 ct->min = d1 % 60; 102 d1 /= 60; 103 ct->hour = d1; 104 105 /* 106 * day is the day number. 107 * generate day of the week. 108 * The addend is 4 mod 7 (1/1/1970 was Thursday) 109 */ 110 111 ct->wday = (day + 7340036L) % 7; 112 113 /* 114 * year number 115 */ 116 if(day >= 0) 117 for(d1 = 70; day >= dysize(d1); d1++) 118 day -= dysize(d1); 119 else 120 for (d1 = 70; day < 0; d1--) 121 day += dysize(d1-1); 122 ct->year = d1; 123 ct->yday = d0 = day; 124 125 /* 126 * generate month 127 */ 128 129 if(dysize(d1) == 366) 130 dmsize[1] = 29; 131 for(d1 = 0; d0 >= dmsize[d1]; d1++) 132 d0 -= dmsize[d1]; 133 dmsize[1] = 28; 134 ct->mday = d0 + 1; 135 ct->mon = d1; 136 } 137 138 void 139 datestr(char *s, long t) 140 { 141 Tm tm; 142 143 klocaltime(t, &tm); 144 sprint(s, "%.4d%.2d%.2d", tm.year+1900, tm.mon+1, tm.mday); 145 } 146 147 int 148 Tfmt(Fmt *f1) 149 { 150 char s[30]; 151 char *cp; 152 long t; 153 Tm tm; 154 155 t = va_arg(f1->args, long); 156 if(t == 0) 157 return fmtstrcpy(f1, "The Epoch"); 158 159 klocaltime(t, &tm); 160 strcpy(s, "Day Mon 00 00:00:00 1900"); 161 cp = &"SunMonTueWedThuFriSat"[tm.wday*3]; 162 s[0] = cp[0]; 163 s[1] = cp[1]; 164 s[2] = cp[2]; 165 cp = &"JanFebMarAprMayJunJulAugSepOctNovDec"[tm.mon*3]; 166 s[4] = cp[0]; 167 s[5] = cp[1]; 168 s[6] = cp[2]; 169 ct_numb(s+8, tm.mday); 170 ct_numb(s+11, tm.hour+100); 171 ct_numb(s+14, tm.min+100); 172 ct_numb(s+17, tm.sec+100); 173 if(tm.year >= 100) { 174 s[20] = '2'; 175 s[21] = '0'; 176 } 177 ct_numb(s+22, tm.year+100); 178 179 return fmtstrcpy(f1, s); 180 } 181 182 static 183 dysize(int y) 184 { 185 186 if((y%4) == 0) 187 return 366; 188 return 365; 189 } 190 191 static 192 void 193 ct_numb(char *cp, int n) 194 { 195 196 if(n >= 10) 197 cp[0] = (n/10)%10 + '0'; 198 else 199 cp[0] = ' '; 200 cp[1] = n%10 + '0'; 201 } 202 203 /* 204 * compute the next time after t 205 * that has hour hr and is not on 206 * day in bitpattern -- 207 * for automatic dumps 208 */ 209 long 210 nextime(long t, int hr, int day) 211 { 212 Tm tm; 213 int nhr; 214 215 if(hr < 0 || hr >= 24) 216 hr = 5; 217 if((day&0x7f) == 0x7f) 218 day = 0; 219 220 loop: 221 klocaltime(t, &tm); 222 t -= tm.sec; 223 t -= tm.min*60; 224 nhr = tm.hour; 225 do { 226 t += 60*60; 227 nhr++; 228 } while(nhr%24 != hr); 229 klocaltime(t, &tm); 230 if(tm.hour != hr) { 231 t += 60*60; 232 klocaltime(t, &tm); 233 if(tm.hour != hr) { 234 t -= 60*60; 235 klocaltime(t, &tm); 236 } 237 } 238 if(day & (1<<tm.wday)) { 239 t += 12*60*60; 240 goto loop; 241 } 242 return t; 243 } 244