The Android Open Source Project | 2949f58 | 2009-03-03 19:30:46 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 1997 |
| 3 | * The Regents of the University of California. All rights reserved. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that: (1) source code distributions |
| 7 | * retain the above copyright notice and this paragraph in its entirety, (2) |
| 8 | * distributions including binary code include the above copyright notice and |
| 9 | * this paragraph in its entirety in the documentation or other materials |
| 10 | * provided with the distribution, and (3) all advertising materials mentioning |
| 11 | * features or use of this software display the following acknowledgement: |
| 12 | * ``This product includes software developed by the University of California, |
| 13 | * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of |
| 14 | * the University nor the names of its contributors may be used to endorse |
| 15 | * or promote products derived from this software without specific prior |
| 16 | * written permission. |
| 17 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED |
| 18 | * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF |
| 19 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. |
| 20 | */ |
| 21 | |
| 22 | #ifndef lint |
| 23 | static const char rcsid[] _U_ = |
JP Abgrall | 53f17a9 | 2014-02-12 14:02:41 -0800 | [diff] [blame] | 24 | "@(#) $Header: /tcpdump/master/tcpdump/gmt2local.c,v 1.9 2003-11-16 09:36:09 guy Exp $ (LBL)"; |
The Android Open Source Project | 2949f58 | 2009-03-03 19:30:46 -0800 | [diff] [blame] | 25 | #endif |
| 26 | |
| 27 | #ifdef HAVE_CONFIG_H |
| 28 | #include "config.h" |
| 29 | #endif |
| 30 | |
| 31 | #include <tcpdump-stdinc.h> |
| 32 | |
| 33 | #include <stdio.h> |
| 34 | |
| 35 | #ifdef HAVE_OS_PROTO_H |
| 36 | #include "os-proto.h" |
| 37 | #endif |
| 38 | |
| 39 | #include "gmt2local.h" |
| 40 | |
| 41 | /* |
| 42 | * Returns the difference between gmt and local time in seconds. |
| 43 | * Use gmtime() and localtime() to keep things simple. |
| 44 | */ |
| 45 | int32_t |
| 46 | gmt2local(time_t t) |
| 47 | { |
| 48 | register int dt, dir; |
| 49 | register struct tm *gmt, *loc; |
| 50 | struct tm sgmt; |
| 51 | |
| 52 | if (t == 0) |
| 53 | t = time(NULL); |
| 54 | gmt = &sgmt; |
| 55 | *gmt = *gmtime(&t); |
| 56 | loc = localtime(&t); |
| 57 | dt = (loc->tm_hour - gmt->tm_hour) * 60 * 60 + |
| 58 | (loc->tm_min - gmt->tm_min) * 60; |
| 59 | |
| 60 | /* |
| 61 | * If the year or julian day is different, we span 00:00 GMT |
| 62 | * and must add or subtract a day. Check the year first to |
| 63 | * avoid problems when the julian day wraps. |
| 64 | */ |
| 65 | dir = loc->tm_year - gmt->tm_year; |
| 66 | if (dir == 0) |
| 67 | dir = loc->tm_yday - gmt->tm_yday; |
| 68 | dt += dir * 24 * 60 * 60; |
| 69 | |
| 70 | return (dt); |
| 71 | } |