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
7 #ifndef lint
8 static char sccsid[] = "@(#)unctime.c 5.1 (Berkeley) 06/05/85";
9 #endif not lint
10
11 #include "include.4.1/sys/types.h"
12 #include "include.4.1/time.h"
13 /*
14 * Convert a ctime(3) format string into a system format date.
15 * Return the date thus calculated.
16 *
17 * Return -1 if the string is not in ctime format.
18 */
19
20 /*
21 * Offsets into the ctime string to various parts.
22 */
23
24 #define E_MONTH 4
25 #define E_DAY 8
26 #define E_HOUR 11
27 #define E_MINUTE 14
28 #define E_SECOND 17
29 #define E_YEAR 20
30
unctime(str)31 time_t unctime(str)
32 char *str;
33 {
34 struct tm then;
35 char dbuf[30];
36 time_t emitl();
37
38 if (strlen(str) != 25)
39 str[25] = 0;
40 strcpy(dbuf, str);
41 dbuf[E_MONTH+3] = 0;
42 if ( (then.tm_mon = lookup(&dbuf[E_MONTH])) < 0)
43 return(-1);;
44 then.tm_mday = atoi(&dbuf[E_DAY]);
45 then.tm_hour = atoi(&dbuf[E_HOUR]);
46 then.tm_min = atoi(&dbuf[E_MINUTE]);
47 then.tm_sec = atoi(&dbuf[E_SECOND]);
48 then.tm_year = atoi(&dbuf[E_YEAR]) - 1900;
49 return(emitl(&then));
50 }
51
52 static char months[] =
53 "JanFebMarAprMayJunJulAugSepOctNovDec";
54
55 static
lookup(str)56 lookup(str)
57 char *str;
58 {
59 register char *cp, *cp2;
60
61 for (cp = months, cp2 = str; *cp != 0; cp += 3)
62 if (strncmp(cp, cp2, 3) == 0)
63 return((cp-months) / 3);
64 return(-1);
65 }
66 /*
67 * Routine to convert a localtime(3) format date back into
68 * a system format date.
69 *
70 * Use a binary search.
71 */
72
73 struct tm *localtime();
74
emitl(dp)75 time_t emitl(dp)
76 struct tm *dp;
77 {
78 time_t conv;
79 register int i, bit;
80 struct tm dcopy;
81
82 dcopy = *dp;
83 dp = &dcopy;
84 conv = 0;
85 for (i = 31; i >= 0; i--) {
86 bit = 1 << i;
87 conv |= bit;
88 if (dcmp(localtime(&conv), dp) > 0)
89 conv &= ~bit;
90 }
91 return(conv);
92 }
93
94 /*
95 * Compare two localtime dates, return result.
96 */
97
98 #define DECIDE(a) \
99 if (dp->a > dp2->a) \
100 return(1); \
101 if (dp->a < dp2->a) \
102 return(-1)
103
104 static
dcmp(dp,dp2)105 dcmp(dp, dp2)
106 register struct tm *dp, *dp2;
107 {
108
109 DECIDE(tm_year);
110 DECIDE(tm_mon);
111 DECIDE(tm_mday);
112 DECIDE(tm_hour);
113 DECIDE(tm_min);
114 DECIDE(tm_sec);
115 return(0);
116 }
117