1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 /* Copyright (c) 1988 AT&T */
28 /* All Rights Reserved */
29
30 /*
31 * This routine converts time as follows.
32 * The epoch is 0000 Jan 1 1970 GMT.
33 * The argument time is in seconds since then.
34 * The localtime(t) entry returns a pointer to an array
35 * containing
36 * seconds (0-59)
37 * minutes (0-59)
38 * hours (0-23)
39 * day of month (1-31)
40 * month (0-11)
41 * year-1970
42 * weekday (0-6, Sun is 0)
43 * day of the year
44 * daylight savings flag
45 *
46 * The routine corrects for daylight saving
47 * time and will work in any time zone provided
48 * "timezone" is adjusted to the difference between
49 * Greenwich and local standard time (measured in seconds).
50 * In places like Michigan "daylight" must
51 * be initialized to 0 to prevent the conversion
52 * to daylight time.
53 * There is a table which accounts for the peculiarities
54 * undergone by daylight time in 1974-1975.
55 *
56 * The routine does not work
57 * in Saudi Arabia which runs on Solar time.
58 *
59 * asctime(tvec)
60 * where tvec is produced by localtime
61 * returns a ptr to a character string
62 * that has the ascii time in the form
63 * Thu Jan 01 00:00:00 1970\n\0
64 * 01234567890123456789012345
65 * 0 1 2
66 *
67 * ctime(t) just calls localtime, then asctime.
68 *
69 * tzset() looks for an environment variable named
70 * TZ.
71 * If the variable is present, it will set the external
72 * variables "timezone", "altzone", "daylight", and "tzname"
73 * appropriately. It is called by localtime, and
74 * may also be called explicitly by the user.
75 */
76
77 #include "lint.h"
78 #include <time.h>
79 #include <sys/types.h>
80 #include <errno.h>
81 #include <thread.h>
82 #include <synch.h>
83 #include <mtlib.h>
84 #include "libc.h"
85
86
87 /*
88 * POSIX.1c Draft-6 version of the function ctime_r.
89 * It was implemented by Solaris 2.3.
90 */
91 char *
ctime_r(const time_t * t,char * buffer,int buflen)92 ctime_r(const time_t *t, char *buffer, int buflen)
93 {
94 struct tm res;
95
96 if (localtime_r(t, &res) == NULL)
97 return (NULL);
98
99 if (asctime_r(&res, buffer, buflen) == NULL)
100 return (NULL);
101
102 return (buffer);
103 }
104
105 /*
106 * POSIX.1c standard version of the function ctime_r.
107 * User gets it via static ctime_r from the header file.
108 */
109 char *
__posix_ctime_r(const time_t * t,char * buffer)110 __posix_ctime_r(const time_t *t, char *buffer)
111 {
112 struct tm res;
113
114 if (localtime_r(t, &res) == NULL)
115 return (NULL);
116
117 if (__posix_asctime_r(&res, buffer) == NULL)
118 return (NULL);
119
120 return (buffer);
121 }
122