| /* |
| * Copyright (c) 1997 |
| * The Regents of the University of California. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that: (1) source code distributions |
| * retain the above copyright notice and this paragraph in its entirety, (2) |
| * distributions including binary code include the above copyright notice and |
| * this paragraph in its entirety in the documentation or other materials |
| * provided with the distribution, and (3) all advertising materials mentioning |
| * features or use of this software display the following acknowledgement: |
| * ``This product includes software developed by the University of California, |
| * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of |
| * the University nor the names of its contributors may be used to endorse |
| * or promote products derived from this software without specific prior |
| * written permission. |
| * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED |
| * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF |
| * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. |
| */ |
| |
| #ifndef lint |
| static const char rcsid[] _U_ = |
| "@(#) $Header: /tcpdump/master/tcpdump/gmt2local.c,v 1.9 2003-11-16 09:36:09 guy Exp $ (LBL)"; |
| #endif |
| |
| #ifdef HAVE_CONFIG_H |
| #include "config.h" |
| #endif |
| |
| #include <tcpdump-stdinc.h> |
| |
| #include <stdio.h> |
| |
| #ifdef HAVE_OS_PROTO_H |
| #include "os-proto.h" |
| #endif |
| |
| #include "gmt2local.h" |
| |
| /* |
| * Returns the difference between gmt and local time in seconds. |
| * Use gmtime() and localtime() to keep things simple. |
| */ |
| int32_t |
| gmt2local(time_t t) |
| { |
| register int dt, dir; |
| register struct tm *gmt, *loc; |
| struct tm sgmt; |
| |
| if (t == 0) |
| t = time(NULL); |
| gmt = &sgmt; |
| *gmt = *gmtime(&t); |
| loc = localtime(&t); |
| dt = (loc->tm_hour - gmt->tm_hour) * 60 * 60 + |
| (loc->tm_min - gmt->tm_min) * 60; |
| |
| /* |
| * If the year or julian day is different, we span 00:00 GMT |
| * and must add or subtract a day. Check the year first to |
| * avoid problems when the julian day wraps. |
| */ |
| dir = loc->tm_year - gmt->tm_year; |
| if (dir == 0) |
| dir = loc->tm_yday - gmt->tm_yday; |
| dt += dir * 24 * 60 * 60; |
| |
| return (dt); |
| } |