1 /** @file 2 timegm implementation 3 4 Copyright (c) 2011, Intel Corporation. All rights reserved.<BR> 5 This program and the accompanying materials are licensed and made available under 6 the terms and conditions of the BSD License that accompanies this distribution. 7 The full text of the license may be found at 8 http://opensource.org/licenses/bsd-license.php. 9 10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, 11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. 12 13 * Copyright (c) 1987, 1989 Regents of the University of California. 14 * All rights reserved. 15 * 16 * This code is derived from software contributed to Berkeley by 17 * Arthur David Olson of the National Cancer Institute. 18 * 19 * Redistribution and use in source and binary forms, with or without 20 * modification, are permitted provided that the following conditions 21 * are met: 22 * 1. Redistributions of source code must retain the above copyright 23 * notice, this list of conditions and the following disclaimer. 24 * 2. Redistributions in binary form must reproduce the above copyright 25 * notice, this list of conditions and the following disclaimer in the 26 * documentation and/or other materials provided with the distribution. 27 * 3. All advertising materials mentioning features or use of this software 28 * must display the following acknowledgement: 29 * This product includes software developed by the University of 30 * California, Berkeley and its contributors. 31 * 4. Neither the name of the University nor the names of its contributors 32 * may be used to endorse or promote products derived from this software 33 * without specific prior written permission. 34 * 35 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 36 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 37 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 38 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 39 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 40 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 41 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 42 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 43 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 44 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 45 * SUCH DAMAGE. 46 47 static char *sccsid = "from: @(#)ctime.c 5.26 (Berkeley) 2/23/91"; 48 49 50 * This implementation of mktime is lifted straight from the NetBSD (BSD 4.4) 51 * version. I modified it slightly to divorce it from the internals of the 52 * ctime library. Thus this version can't use details of the internal 53 * timezone state file to figure out strange unnormalized struct tm values, 54 * as might result from someone doing date math on the tm struct then passing 55 * it to mktime. 56 * 57 * It just does as well as it can at normalizing the tm input, then does a 58 * binary search of the time space using the system's localtime() function. 59 * 60 * The original binary search was defective in that it didn't consider the 61 * setting of tm_isdst when comparing tm values, causing the search to be 62 * flubbed for times near the dst/standard time changeover. The original 63 * code seems to make up for this by grubbing through the timezone info 64 * whenever the binary search barfed. Since I don't have that luxury in 65 * portable code, I have to take care of tm_isdst in the comparison routine. 66 * This requires knowing how many minutes offset dst is from standard time. 67 * 68 * So, if you live somewhere in the world where dst is not 60 minutes offset, 69 * and your vendor doesn't supply mktime(), you'll have to edit this variable 70 * by hand. Sorry about that. 71 72 $NetBSD: mktime.c,v 1.4 2006/06/11 19:34:10 kardel Exp $ 73 **/ 74 75 #include <LibConfig.h> 76 #include <time.h> 77 78 /* 79 This funciton is in Time.c, which has a different license than timegm. 80 */ 81 time_t 82 time2(struct tm * const tmp, void (* const funcp)(const time_t*, long, struct tm*), 83 const long offset, int * const okayp); 84 85 /* 86 This funciton is in Time.c, which has a different license than timegm. 87 */ 88 void 89 gmtsub( 90 const time_t * const timep, 91 const long offset, 92 struct tm * const tmp 93 ); 94 95 #ifndef WRONG 96 #define WRONG (-1) 97 #endif /* !defined WRONG */ 98 99 /* 100 Convert a tm structure to a GMT based time_t. 101 */ 102 time_t timegm( struct tm * tmp ) 103 { 104 register time_t t; 105 int okay; 106 107 tmp->tm_isdst = 0; 108 t = time2(tmp, gmtsub, 0, &okay); 109 if (okay || tmp->tm_isdst < 0) 110 return t; 111 112 return WRONG; 113 }
