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1.1 root 1: #
2: /*
3: * MAKETIME derive 32-bit time value from TM structure.
4: *
5: * Usage:
6: * long t,maketime();
7: * struct tm *tp; Pointer to TM structure from <time.h>
8: * NOTE: this must be extended version!!!
9: * t = maketime(tp);
10: *
11: * Returns:
12: * 0 if failure; parameter out of range or nonsensical.
13: * else long time-value.
14: * Notes:
15: * This code is quasi-public; it may be used freely in like software.
16: * It is not to be sold, nor used in licensed software without
17: * permission of the author.
18: * For everyone's benefit, please report bugs and improvements!
19: * Copyright 1981 by Ken Harrenstien, SRI International.
20: * (ARPANET: KLH @ SRI)
21: */
22: #ifndef lint
23: static char rcsid[]= "$Id: maketime.c,v 1.8 88/11/08 13:54:53 narten Exp $";
24: #endif
25: /* $Log: maketime.c,v $
26: * Revision 1.8 88/11/08 13:54:53 narten
27: * allow negative timezones (-24h <= x <= 24h)
28: *
29: * Revision 1.7 88/11/08 12:02:24 narten
30: * changes from [email protected] (Paul Eggert)
31: *
32: * Revision 1.7 88/08/28 14:47:52 eggert
33: * Allow cc -R. Remove unportable "#endif XXX"s.
34: *
35: * Revision 1.6 87/12/18 17:05:58 narten
36: * include rcsparam.h
37: *
38: * Revision 1.5 87/12/18 11:35:51 narten
39: * maketime.c: fixed USG code - you have tgo call "tzset" in order to have
40: * "timezone" set. ("localtime" calls it, but it's probably better not to
41: * count on "localtime" having been called.)
42: *
43: * Revision 1.4 87/10/18 10:26:57 narten
44: * Updating version numbers. Changes relative to 1.0 are actually
45: * relative to 1.2
46: *
47: * Revision 1.3 87/09/24 13:58:45 narten
48: * Sources now pass through lint (if you ignore printf/sprintf/fprintf
49: * warnings)
50: *
51: * Revision 1.2 87/03/27 14:21:48 jenkins
52: * Port to suns
53: *
54: * Revision 1.1 84/01/23 14:50:04 kcs
55: * Initial revision
56: *
57: * Revision 1.2 83/12/05 10:12:56 wft
58: * added cond. compilation for USG Unix; long timezone;
59: *
60: * Revision 1.1 82/05/06 11:38:00 wft
61: * Initial revision
62: *
63: */
64:
65:
66: #include "rcsbase.h"
67: #include "time.h"
68:
69: int daytb[] = { /* # days in year thus far, indexed by month (0-12!!) */
70: 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365
71: };
72:
73: struct tm *localtime();
74: long time();
75:
76: long maketime(atm)
77: struct tm *atm;
78: { register struct tm *tp;
79: register int i;
80: int year, yday, mon, day, hour, min, sec, zone, dst, leap;
81: long tres, curtim;
82:
83: VOID time(&curtim);
84: tp = localtime(&curtim); /* Get breakdowns of current time */
85: year = tp->tm_year; /* Use to set up defaults */
86: mon = tp->tm_mon;
87: day = tp->tm_mday;
88:
89:
90: #ifdef DEBUG
91: printf("first YMD: %d %d %d, T=%ld\n",year,mon,day,tres);
92: #endif
93: tp = atm;
94:
95: /* First must find date, using specified year, month, day.
96: * If one of these is unspecified, it defaults either to the
97: * current date (if no more global spec was given) or to the
98: * zero-value for that spec (i.e. a more global spec was seen).
99: * Start with year... note 32 bits can only handle 135 years.
100: */
101: if(tp->tm_year != TMNULL)
102: { if((year = tp->tm_year) >= 1900) /* Allow full yr # */
103: year -= 1900; /* by making kosher */
104: mon = 0; /* Since year was given, default */
105: day = 1; /* for remaining specs is zero */
106: }
107: if(year < 70 || 70+134 < year ) /* Check range */
108: return(0); /* ERR: year out of range */
109: leap = year&03 ? 0 : 1; /* See if leap year */
110: year -= 70; /* UNIX time starts at 1970 */
111:
112: /*
113: * Find day of year.
114: * YDAY is used only if it exists and either the month or day-of-month
115: * is missing.
116: */
117: if (tp->tm_yday != TMNULL
118: && (tp->tm_mon == TMNULL || tp->tm_mday == TMNULL))
119: yday = tp->tm_yday;
120: else
121: { if(tp->tm_mon != TMNULL)
122: { mon = tp->tm_mon; /* Month was specified */
123: day = 1; /* so set remaining default */
124: }
125: if(mon < 0 || 11 < mon) return(0); /* ERR: bad month */
126: if(tp->tm_mday != TMNULL) day = tp->tm_mday;
127: if(day < 1
128: || (((daytb[mon+1]-daytb[mon]) < day)
129: && (day!=29 || mon!=1 || !leap) ))
130: return(0); /* ERR: bad day */
131: yday = daytb[mon] /* Add # of days in months so far */
132: + ((leap /* Leap year, and past Feb? If */
133: && mon>1)? 1:0) /* so, add leap day for this year */
134: + day-1; /* And finally add # days this mon */
135:
136: if (tp->tm_yday != TMNULL /* Confirm that YDAY correct */
137: && tp->tm_yday != yday) return(0); /* ERR: conflict */
138: }
139: if(yday < 0 || (leap?366:365) <= yday)
140: return(0); /* ERR: bad YDAY or maketime bug */
141:
142: tres = year*365 /* Get # days of years so far */
143: + ((year+1)>>2) /* plus # of leap days since 1970 */
144: + yday; /* and finally add # days this year */
145:
146: if((i = tp->tm_wday) != TMNULL) /* Check WDAY if present */
147: if(i < 0 || 6 < i /* Ensure within range */
148: || i != (tres+4)%7) /* Matches? Jan 1,1970 was Thu = 4 */
149: return(0); /* ERR: bad WDAY */
150:
151: #ifdef DEBUG
152: printf("YMD: %d %d %d, T=%ld\n",year,mon,day,tres);
153: #endif
154: /*
155: * Now determine time. If not given, default to zeros
156: * (since time is always the least global spec)
157: */
158: tres *= 86400L; /* Get # seconds (24*60*60) */
159: hour = min = sec = 0;
160: if(tp->tm_hour != TMNULL) hour = tp->tm_hour;
161: if(tp->tm_min != TMNULL) min = tp->tm_min;
162: if(tp->tm_sec != TMNULL) sec = tp->tm_sec;
163: if( min < 0 || 60 <= min
164: || sec < 0 || 60 <= sec) return(0); /* ERR: MS out of range */
165: if(hour < 0 || 24 <= hour)
166: if(hour != 24 || (min+sec) !=0) /* Allow 24:00 */
167: return(0); /* ERR: H out of range */
168:
169: /* confirm AM/PM if there */
170: switch(tp->tm_ampm)
171: { case 0: case TMNULL: /* Ignore these values */
172: break;
173: case 1: /* AM */
174: case 2: /* PM */
175: if(hour > 12) return(0); /* ERR: hrs 13-23 bad */
176: if(hour ==12) hour = 0; /* Modulo 12 */
177: if(tp->tm_ampm == 2) /* If PM, then */
178: hour += 12; /* get 24-hour time */
179: break;
180: default: return(0); /* ERR: illegal TM_AMPM value */
181: }
182:
183: tres += sec + 60L*(min + 60L*hour); /* Add in # secs of time */
184:
185: #ifdef DEBUG
186: printf("HMS: %d %d %d T=%ld\n",hour,min,sec,tres);
187: #endif
188: /*
189: * We now have the GMT date/time and must make final
190: * adjustment for the specified time zone. If none is specified,
191: * the local time-zone is assumed.
192: */
193: if((zone = tp->tm_zon) == TMNULL /* If unspecified */
194: || (zone == 1)) /* or local-zone requested */
195: zone = localzone(); /* then set to local zone */
196: if(zone < -24*60 || 24*60 <= zone)
197: return(0); /* ERR: zone out of range */
198:
199: /* See if must apply Daylight Saving Time shift.
200: * Note that if DST is specified, validity is not checked.
201: */
202: if((dst = tp->tm_isdst) == TMNULL) /* Must we figure it out? */
203: { curtim = tres +localzone()*60L; /* Yuck. Get equiv local */
204: dst = localtime(&curtim)->tm_isdst; /* time, and ask. */
205: }
206: tres += zone*60L -(dst?3600:0); /* Add in # seconds of zone adj */
207:
208: return(tres);
209: }
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