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 <mtlib.h> 81 #include <sys/types.h> 82 #include <time.h> 83 #include <errno.h> 84 #include <thread.h> 85 #include <synch.h> 86 #include "libc.h" 87 #include "tsd.h" 88 89 #define dysize(A) (((A)%4)? 365: 366) 90 #define CBUFSIZ 26 91 92 static char * 93 ct_numb(char *cp, int n) 94 { 95 cp++; 96 if (n >= 10) 97 *cp++ = (n / 10) % 10 + '0'; 98 else 99 *cp++ = ' '; /* Pad with blanks */ 100 *cp++ = n % 10 + '0'; 101 return (cp); 102 } 103 104 /* 105 * POSIX.1c standard version of the function asctime_r. 106 * User gets it via static asctime_r from the header file. 107 */ 108 char * 109 __posix_asctime_r(const struct tm *t, char *cbuf) 110 { 111 char *cp; 112 const char *ncp; 113 const int *tp; 114 const char *Date = "Day Mon 00 00:00:00 1900\n"; 115 const char *Day = "SunMonTueWedThuFriSat"; 116 const char *Month = "JanFebMarAprMayJunJulAugSepOctNovDec"; 117 118 cp = cbuf; 119 for (ncp = Date; *cp++ = *ncp++; /* */) 120 ; 121 ncp = Day + (3 * t->tm_wday); 122 cp = cbuf; 123 *cp++ = *ncp++; 124 *cp++ = *ncp++; 125 *cp++ = *ncp++; 126 cp++; 127 tp = &t->tm_mon; 128 ncp = Month + ((*tp) * 3); 129 *cp++ = *ncp++; 130 *cp++ = *ncp++; 131 *cp++ = *ncp++; 132 cp = ct_numb(cp, *--tp); 133 cp = ct_numb(cp, *--tp + 100); 134 cp = ct_numb(cp, *--tp + 100); 135 --tp; 136 cp = ct_numb(cp, *tp + 100); 137 if (t->tm_year < 100) { 138 /* Common case: "19" already in buffer */ 139 cp += 2; 140 } else if (t->tm_year < 8100) { 141 cp = ct_numb(cp, (1900 + t->tm_year) / 100); 142 cp--; 143 } else { 144 /* Only 4-digit years are supported */ 145 errno = EOVERFLOW; 146 return (NULL); 147 } 148 (void) ct_numb(cp, t->tm_year + 100); 149 return (cbuf); 150 } 151 152 /* 153 * POSIX.1c Draft-6 version of the function asctime_r. 154 * It was implemented by Solaris 2.3. 155 */ 156 char * 157 asctime_r(const struct tm *t, char *cbuf, int buflen) 158 { 159 if (buflen < CBUFSIZ) { 160 errno = ERANGE; 161 return (NULL); 162 } 163 return (__posix_asctime_r(t, cbuf)); 164 } 165 166 char * 167 ctime(const time_t *t) 168 { 169 char *cbuf = tsdalloc(_T_CTIME, CBUFSIZ, NULL); 170 struct tm *p; 171 172 if (cbuf == NULL) 173 return (NULL); 174 p = localtime(t); 175 if (p == NULL) 176 return (NULL); 177 return (__posix_asctime_r(p, cbuf)); 178 } 179 180 char * 181 asctime(const struct tm *t) 182 { 183 char *cbuf = tsdalloc(_T_CTIME, CBUFSIZ, NULL); 184 185 if (cbuf == NULL) 186 return (NULL); 187 return (__posix_asctime_r(t, cbuf)); 188 } 189