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 #pragma ident "%Z%%M% %I% %E% SMI"
31
32 /*
33 * This routine converts time as follows.
34 * The epoch is 0000 Jan 1 1970 GMT.
35 * The argument time is in seconds since then.
36 * The localtime(t) entry returns a pointer to an array
37 * containing
38 * seconds (0-59)
39 * minutes (0-59)
40 * hours (0-23)
41 * day of month (1-31)
42 * month (0-11)
43 * year-1970
44 * weekday (0-6, Sun is 0)
45 * day of the year
46 * daylight savings flag
47 *
48 * The routine corrects for daylight saving
49 * time and will work in any time zone provided
50 * "timezone" is adjusted to the difference between
51 * Greenwich and local standard time (measured in seconds).
52 * In places like Michigan "daylight" must
53 * be initialized to 0 to prevent the conversion
54 * to daylight time.
55 * There is a table which accounts for the peculiarities
56 * undergone by daylight time in 1974-1975.
57 *
58 * The routine does not work
59 * in Saudi Arabia which runs on Solar time.
60 *
61 * asctime(tvec)
62 * where tvec is produced by localtime
63 * returns a ptr to a character string
64 * that has the ascii time in the form
65 * Thu Jan 01 00:00:00 1970\n\0
66 * 01234567890123456789012345
67 * 0 1 2
68 *
69 * ctime(t) just calls localtime, then asctime.
70 *
71 * tzset() looks for an environment variable named
72 * TZ.
73 * If the variable is present, it will set the external
74 * variables "timezone", "altzone", "daylight", and "tzname"
75 * appropriately. It is called by localtime, and
76 * may also be called explicitly by the user.
77 */
78
79 #include "lint.h"
80 #include <time.h>
81 #include <sys/types.h>
82 #include <errno.h>
83 #include <thread.h>
84 #include <synch.h>
85 #include <mtlib.h>
86 #include "libc.h"
87
88
89 /*
90 * POSIX.1c Draft-6 version of the function ctime_r.
91 * It was implemented by Solaris 2.3.
92 */
93 char *
ctime_r(const time_t * t,char * buffer,int buflen)94 ctime_r(const time_t *t, char *buffer, int buflen)
95 {
96 struct tm res;
97
98 if (localtime_r(t, &res) == NULL)
99 return (NULL);
100
101 if (asctime_r(&res, buffer, buflen) == NULL)
102 return (NULL);
103
104 return (buffer);
105 }
106
107 /*
108 * POSIX.1c standard version of the function ctime_r.
109 * User gets it via static ctime_r from the header file.
110 */
111 char *
__posix_ctime_r(const time_t * t,char * buffer)112 __posix_ctime_r(const time_t *t, char *buffer)
113 {
114 struct tm res;
115
116 if (localtime_r(t, &res) == NULL)
117 return (NULL);
118
119 if (__posix_asctime_r(&res, buffer) == NULL)
120 return (NULL);
121
122 return (buffer);
123 }
124